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, 2020 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, 2020 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, 2019 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, 2019 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 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@*
72 Copyright @copyright{} 2020 Leo Prikler@*
73 Copyright @copyright{} 2019 Simon Tournier@*
75 Permission is granted to copy, distribute and/or modify this document
76 under the terms of the GNU Free Documentation License, Version 1.3 or
77 any later version published by the Free Software Foundation; with no
78 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
79 copy of the license is included in the section entitled ``GNU Free
80 Documentation License''.
83 @dircategory System administration
85 * Guix: (guix). Manage installed software and system configuration.
86 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
87 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
88 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
89 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
90 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
93 @dircategory Software development
95 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
96 * guix build: (guix)Invoking guix build. Building packages.
97 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
101 @title GNU Guix Reference Manual
102 @subtitle Using the GNU Guix Functional Package Manager
103 @author The GNU Guix Developers
106 @vskip 0pt plus 1filll
107 Edition @value{EDITION} @*
115 @c *********************************************************************
119 This document describes GNU Guix version @value{VERSION}, a functional
120 package management tool written for the GNU system.
122 @c TRANSLATORS: You can replace the following paragraph with information on
123 @c how to join your own translation team and how to report issues with the
125 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
126 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
127 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
128 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
129 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
130 would like to translate it in your native language, consider joining the
131 @uref{https://translationproject.org/domain/guix-manual.html, Translation
135 * Introduction:: What is Guix about?
136 * Installation:: Installing Guix.
137 * System Installation:: Installing the whole operating system.
138 * Package Management:: Package installation, upgrade, etc.
139 * Development:: Guix-aided software development.
140 * Programming Interface:: Using Guix in Scheme.
141 * Utilities:: Package management commands.
142 * System Configuration:: Configuring the operating system.
143 * Documentation:: Browsing software user manuals.
144 * Installing Debugging Files:: Feeding the debugger.
145 * Security Updates:: Deploying security fixes quickly.
146 * Bootstrapping:: GNU/Linux built from scratch.
147 * Porting:: Targeting another platform or kernel.
148 * Contributing:: Your help needed!
150 * Acknowledgments:: Thanks!
151 * GNU Free Documentation License:: The license of this manual.
152 * Concept Index:: Concepts.
153 * Programming Index:: Data types, functions, and variables.
156 --- The Detailed Node Listing ---
160 * Managing Software the Guix Way:: What's special.
161 * GNU Distribution:: The packages and tools.
165 * Binary Installation:: Getting Guix running in no time!
166 * Requirements:: Software needed to build and run Guix.
167 * Running the Test Suite:: Testing Guix.
168 * Setting Up the Daemon:: Preparing the build daemon's environment.
169 * Invoking guix-daemon:: Running the build daemon.
170 * Application Setup:: Application-specific setup.
172 Setting Up the Daemon
174 * Build Environment Setup:: Preparing the isolated build environment.
175 * Daemon Offload Setup:: Offloading builds to remote machines.
176 * SELinux Support:: Using an SELinux policy for the daemon.
180 * Limitations:: What you can expect.
181 * Hardware Considerations:: Supported hardware.
182 * USB Stick and DVD Installation:: Preparing the installation medium.
183 * Preparing for Installation:: Networking, partitioning, etc.
184 * Guided Graphical Installation:: Easy graphical installation.
185 * Manual Installation:: Manual installation for wizards.
186 * After System Installation:: When installation succeeded.
187 * Installing Guix in a VM:: Guix System playground.
188 * Building the Installation Image:: How this comes to be.
192 * Keyboard Layout and Networking and Partitioning:: Initial setup.
193 * Proceeding with the Installation:: Installing.
197 * Features:: How Guix will make your life brighter.
198 * Invoking guix package:: Package installation, removal, etc.
199 * Substitutes:: Downloading pre-built binaries.
200 * Packages with Multiple Outputs:: Single source package, multiple outputs.
201 * Invoking guix gc:: Running the garbage collector.
202 * Invoking guix pull:: Fetching the latest Guix and distribution.
203 * Channels:: Customizing the package collection.
204 * Invoking guix time-machine:: Running an older revision of Guix.
205 * Inferiors:: Interacting with another revision of Guix.
206 * Invoking guix describe:: Display information about your Guix revision.
207 * Invoking guix archive:: Exporting and importing store files.
211 * Official Substitute Server:: One particular source of substitutes.
212 * Substitute Server Authorization:: How to enable or disable substitutes.
213 * Substitute Authentication:: How Guix verifies substitutes.
214 * Proxy Settings:: How to get substitutes via proxy.
215 * Substitution Failure:: What happens when substitution fails.
216 * On Trusting Binaries:: How can you trust that binary blob?
220 * Invoking guix environment:: Setting up development environments.
221 * Invoking guix pack:: Creating software bundles.
223 Programming Interface
225 * Package Modules:: Packages from the programmer's viewpoint.
226 * Defining Packages:: Defining new packages.
227 * Build Systems:: Specifying how packages are built.
228 * The Store:: Manipulating the package store.
229 * Derivations:: Low-level interface to package derivations.
230 * The Store Monad:: Purely functional interface to the store.
231 * G-Expressions:: Manipulating build expressions.
232 * Invoking guix repl:: Fiddling with Guix interactively.
236 * package Reference:: The package data type.
237 * origin Reference:: The origin data type.
241 * Invoking guix build:: Building packages from the command line.
242 * Invoking guix edit:: Editing package definitions.
243 * Invoking guix download:: Downloading a file and printing its hash.
244 * Invoking guix hash:: Computing the cryptographic hash of a file.
245 * Invoking guix import:: Importing package definitions.
246 * Invoking guix refresh:: Updating package definitions.
247 * Invoking guix lint:: Finding errors in package definitions.
248 * Invoking guix size:: Profiling disk usage.
249 * Invoking guix graph:: Visualizing the graph of packages.
250 * Invoking guix publish:: Sharing substitutes.
251 * Invoking guix challenge:: Challenging substitute servers.
252 * Invoking guix copy:: Copying to and from a remote store.
253 * Invoking guix container:: Process isolation.
254 * Invoking guix weather:: Assessing substitute availability.
255 * Invoking guix processes:: Listing client processes.
257 Invoking @command{guix build}
259 * Common Build Options:: Build options for most commands.
260 * Package Transformation Options:: Creating variants of packages.
261 * Additional Build Options:: Options specific to 'guix build'.
262 * Debugging Build Failures:: Real life packaging experience.
266 * Using the Configuration System:: Customizing your GNU system.
267 * operating-system Reference:: Detail of operating-system declarations.
268 * File Systems:: Configuring file system mounts.
269 * Mapped Devices:: Block device extra processing.
270 * User Accounts:: Specifying user accounts.
271 * Keyboard Layout:: How the system interprets key strokes.
272 * Locales:: Language and cultural convention settings.
273 * Services:: Specifying system services.
274 * Setuid Programs:: Programs running with root privileges.
275 * X.509 Certificates:: Authenticating HTTPS servers.
276 * Name Service Switch:: Configuring libc's name service switch.
277 * Initial RAM Disk:: Linux-Libre bootstrapping.
278 * Bootloader Configuration:: Configuring the boot loader.
279 * Invoking guix system:: Instantiating a system configuration.
280 * Invoking guix deploy:: Deploying a system configuration to a remote host.
281 * Running Guix in a VM:: How to run Guix System in a virtual machine.
282 * Defining Services:: Adding new service definitions.
286 * Base Services:: Essential system services.
287 * Scheduled Job Execution:: The mcron service.
288 * Log Rotation:: The rottlog service.
289 * Networking Services:: Network setup, SSH daemon, etc.
290 * X Window:: Graphical display.
291 * Printing Services:: Local and remote printer support.
292 * Desktop Services:: D-Bus and desktop services.
293 * Sound Services:: ALSA and Pulseaudio services.
294 * Database Services:: SQL databases, key-value stores, etc.
295 * Mail Services:: IMAP, POP3, SMTP, and all that.
296 * Messaging Services:: Messaging services.
297 * Telephony Services:: Telephony services.
298 * Monitoring Services:: Monitoring services.
299 * Kerberos Services:: Kerberos services.
300 * Web Services:: Web servers.
301 * Certificate Services:: TLS certificates via Let's Encrypt.
302 * DNS Services:: DNS daemons.
303 * VPN Services:: VPN daemons.
304 * Network File System:: NFS related services.
305 * Continuous Integration:: The Cuirass service.
306 * Power Management Services:: Extending battery life.
307 * Audio Services:: The MPD.
308 * Virtualization Services:: Virtualization services.
309 * Version Control Services:: Providing remote access to Git repositories.
310 * Game Services:: Game servers.
311 * PAM Mount Service:: Service to mount volumes when logging in.
312 * Miscellaneous Services:: Other services.
316 * Service Composition:: The model for composing services.
317 * Service Types and Services:: Types and services.
318 * Service Reference:: API reference.
319 * Shepherd Services:: A particular type of service.
324 @c *********************************************************************
326 @chapter Introduction
329 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
330 using the international phonetic alphabet (IPA).} is a package
331 management tool for and distribution of the GNU system.
332 Guix makes it easy for unprivileged
333 users to install, upgrade, or remove software packages, to roll back to a
334 previous package set, to build packages from source, and generally
335 assists with the creation and maintenance of software environments.
338 @cindex GuixSD, now Guix System
339 @cindex Guix System Distribution, now Guix System
340 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
341 complements the available tools without interference (@pxref{Installation}),
342 or you can use it as a standalone operating system distribution,
343 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
344 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
345 group everything under the ``Guix'' banner since, after all, Guix System is
346 readily available through the @command{guix system} command, even if you're
347 using a different distro underneath!}. @xref{GNU Distribution}.
350 * Managing Software the Guix Way:: What's special.
351 * GNU Distribution:: The packages and tools.
354 @node Managing Software the Guix Way
355 @section Managing Software the Guix Way
357 @cindex user interfaces
358 Guix provides a command-line package management interface
359 (@pxref{Package Management}), tools to help with software development
360 (@pxref{Development}), command-line utilities for more advanced usage,
361 (@pxref{Utilities}), as well as Scheme programming interfaces
362 (@pxref{Programming Interface}).
364 Its @dfn{build daemon} is responsible for building packages on behalf of
365 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
366 binaries from authorized sources (@pxref{Substitutes}).
368 @cindex extensibility of the distribution
369 @cindex customization, of packages
370 Guix includes package definitions for many GNU and non-GNU packages, all
371 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
372 user's computing freedom}. It is @emph{extensible}: users can write
373 their own package definitions (@pxref{Defining Packages}) and make them
374 available as independent package modules (@pxref{Package Modules}). It
375 is also @emph{customizable}: users can @emph{derive} specialized package
376 definitions from existing ones, including from the command line
377 (@pxref{Package Transformation Options}).
379 @cindex functional package management
381 Under the hood, Guix implements the @dfn{functional package management}
382 discipline pioneered by Nix (@pxref{Acknowledgments}).
383 In Guix, the package build and installation process is seen
384 as a @emph{function}, in the mathematical sense. That function takes inputs,
385 such as build scripts, a compiler, and libraries, and
386 returns an installed package. As a pure function, its result depends
387 solely on its inputs---for instance, it cannot refer to software or
388 scripts that were not explicitly passed as inputs. A build function
389 always produces the same result when passed a given set of inputs. It
390 cannot alter the environment of the running system in
391 any way; for instance, it cannot create, modify, or delete files outside
392 of its build and installation directories. This is achieved by running
393 build processes in isolated environments (or @dfn{containers}), where only their
394 explicit inputs are visible.
397 The result of package build functions is @dfn{cached} in the file
398 system, in a special directory called @dfn{the store} (@pxref{The
399 Store}). Each package is installed in a directory of its own in the
400 store---by default under @file{/gnu/store}. The directory name contains
401 a hash of all the inputs used to build that package; thus, changing an
402 input yields a different directory name.
404 This approach is the foundation for the salient features of Guix: support
405 for transactional package upgrade and rollback, per-user installation, and
406 garbage collection of packages (@pxref{Features}).
409 @node GNU Distribution
410 @section GNU Distribution
413 Guix comes with a distribution of the GNU system consisting entirely of
414 free software@footnote{The term ``free'' here refers to the
415 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
416 users of that software}.}. The
417 distribution can be installed on its own (@pxref{System Installation}),
418 but it is also possible to install Guix as a package manager on top of
419 an installed GNU/Linux system (@pxref{Installation}). When we need to
420 distinguish between the two, we refer to the standalone distribution as
423 The distribution provides core GNU packages such as GNU libc, GCC, and
424 Binutils, as well as many GNU and non-GNU applications. The complete
425 list of available packages can be browsed
426 @url{https://www.gnu.org/software/guix/packages,on-line} or by
427 running @command{guix package} (@pxref{Invoking guix package}):
430 guix package --list-available
433 Our goal is to provide a practical 100% free software distribution of
434 Linux-based and other variants of GNU, with a focus on the promotion and
435 tight integration of GNU components, and an emphasis on programs and
436 tools that help users exert that freedom.
438 Packages are currently available on the following platforms:
443 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
446 Intel 32-bit architecture (IA32), Linux-Libre kernel;
449 ARMv7-A architecture with hard float, Thumb-2 and NEON,
450 using the EABI hard-float application binary interface (ABI),
451 and Linux-Libre kernel.
454 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
457 little-endian 64-bit MIPS processors, specifically the Loongson series,
458 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
459 supported; in particular, the project's build farms no longer provide
460 substitutes for this architecture.
464 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
465 configuration and Guix takes care of instantiating the configuration in a
466 transactional, reproducible, and stateless fashion (@pxref{System
467 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
468 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
469 Manual}), the well-known GNU utilities and tool chain, as well as the
470 graphical environment or system services of your choice.
472 Guix System is available on all the above platforms except
473 @code{mips64el-linux}.
476 For information on porting to other architectures or kernels,
479 Building this distribution is a cooperative effort, and you are invited
480 to join! @xref{Contributing}, for information about how you can help.
483 @c *********************************************************************
485 @chapter Installation
487 @cindex installing Guix
490 We recommend the use of this
491 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
492 shell installer script} to install Guix on top of a running GNU/Linux system,
493 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
494 with the installation of the package manager, which can be done on top of a
495 running GNU/Linux system. If, instead, you want to install the complete GNU
496 operating system, @pxref{System Installation}.} The script automates the
497 download, installation, and initial configuration of Guix. It should be run
501 @cindex foreign distro
502 @cindex directories related to foreign distro
503 When installed on a foreign distro, GNU@tie{}Guix complements the available
504 tools without interference. Its data lives exclusively in two directories,
505 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
506 such as @file{/etc}, are left untouched.
508 Once installed, Guix can be updated by running @command{guix pull}
509 (@pxref{Invoking guix pull}).
511 If you prefer to perform the installation steps manually or want to tweak
512 them, you may find the following subsections useful. They describe the
513 software requirements of Guix, as well as how to install it manually and get
517 * Binary Installation:: Getting Guix running in no time!
518 * Requirements:: Software needed to build and run Guix.
519 * Running the Test Suite:: Testing Guix.
520 * Setting Up the Daemon:: Preparing the build daemon's environment.
521 * Invoking guix-daemon:: Running the build daemon.
522 * Application Setup:: Application-specific setup.
523 * Upgrading Guix:: Upgrading Guix and its build daemon.
526 @node Binary Installation
527 @section Binary Installation
529 @cindex installing Guix from binaries
530 @cindex installer script
531 This section describes how to install Guix on an arbitrary system from a
532 self-contained tarball providing binaries for Guix and for all its
533 dependencies. This is often quicker than installing from source, which
534 is described in the next sections. The only requirement is to have
537 @c Note duplicated from the ``Installation'' node.
539 We recommend the use of this
540 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
541 shell installer script}. The script automates the download, installation, and
542 initial configuration steps described below. It should be run as the root
546 Installing goes along these lines:
550 @cindex downloading Guix binary
551 Download the binary tarball from
552 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
553 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
554 already running the kernel Linux, and so on.
556 @c The following is somewhat duplicated in ``System Installation''.
557 Make sure to download the associated @file{.sig} file and to verify the
558 authenticity of the tarball against it, along these lines:
561 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
562 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
565 If that command fails because you do not have the required public key,
566 then run this command to import it:
569 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
570 -qO - | gpg --import -
574 and rerun the @code{gpg --verify} command.
576 Take note that a warning like ``This key is not certified with a trusted
577 signature!'' is normal.
579 @c end authentication part
582 Now, you need to become the @code{root} user. Depending on your distribution,
583 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
587 # tar --warning=no-timestamp -xf \
588 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
589 # mv var/guix /var/ && mv gnu /
592 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
593 The latter contains a ready-to-use profile for @code{root} (see next
596 Do @emph{not} unpack the tarball on a working Guix system since that
597 would overwrite its own essential files.
599 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
600 not emit warnings about ``implausibly old time stamps'' (such
601 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
603 They stem from the fact that all the
604 files in the archive have their modification time set to zero (which
605 means January 1st, 1970.) This is done on purpose to make sure the
606 archive content is independent of its creation time, thus making it
610 Make the profile available under @file{~root/.config/guix/current}, which is
611 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
614 # mkdir -p ~root/.config/guix
615 # ln -sf /var/guix/profiles/per-user/root/current-guix \
616 ~root/.config/guix/current
619 Source @file{etc/profile} to augment @code{PATH} and other relevant
620 environment variables:
623 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
624 source $GUIX_PROFILE/etc/profile
628 Create the group and user accounts for build users as explained below
629 (@pxref{Build Environment Setup}).
632 Run the daemon, and set it to automatically start on boot.
634 If your host distro uses the systemd init system, this can be achieved
637 @c Versions of systemd that supported symlinked service files are not
638 @c yet widely deployed, so we should suggest that users copy the service
641 @c See this thread for more information:
642 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
645 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
647 # systemctl start guix-daemon && systemctl enable guix-daemon
650 If your host distro uses the Upstart init system:
653 # initctl reload-configuration
654 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
659 Otherwise, you can still start the daemon manually with:
662 # ~root/.config/guix/current/bin/guix-daemon \
663 --build-users-group=guixbuild
667 Make the @command{guix} command available to other users on the machine,
671 # mkdir -p /usr/local/bin
673 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
676 It is also a good idea to make the Info version of this manual available
680 # mkdir -p /usr/local/share/info
681 # cd /usr/local/share/info
682 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
686 That way, assuming @file{/usr/local/share/info} is in the search path,
687 running @command{info guix} will open this manual (@pxref{Other Info
688 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
692 @cindex substitutes, authorization thereof
693 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
694 (@pxref{Substitutes}), authorize them:
697 # guix archive --authorize < \
698 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
702 Each user may need to perform a few additional steps to make their Guix
703 environment ready for use, @pxref{Application Setup}.
706 Voilà, the installation is complete!
708 You can confirm that Guix is working by installing a sample package into
715 The binary installation tarball can be (re)produced and verified simply
716 by running the following command in the Guix source tree:
719 make guix-binary.@var{system}.tar.xz
723 ...@: which, in turn, runs:
726 guix pack -s @var{system} --localstatedir \
727 --profile-name=current-guix guix
730 @xref{Invoking guix pack}, for more info on this handy tool.
733 @section Requirements
735 This section lists requirements when building Guix from source. The
736 build procedure for Guix is the same as for other GNU software, and is
737 not covered here. Please see the files @file{README} and @file{INSTALL}
738 in the Guix source tree for additional details.
740 @cindex official website
741 GNU Guix is available for download from its website at
742 @url{https://www.gnu.org/software/guix/}.
744 GNU Guix depends on the following packages:
747 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
748 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
751 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
752 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
753 Guile,, gnutls-guile, GnuTLS-Guile});
755 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
758 @c FIXME: Specify a version number once a release has been made.
759 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
761 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
762 @item @url{https://zlib.net, zlib};
763 @item @url{https://www.gnu.org/software/make/, GNU Make}.
766 The following dependencies are optional:
770 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
771 Support for build offloading (@pxref{Daemon Offload Setup}) and
772 @command{guix copy} (@pxref{Invoking guix copy}) depends on
773 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
774 version 0.10.2 or later.
777 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
778 substitutes can be used and @command{guix publish} can compress substitutes
782 When @url{http://www.bzip.org, libbz2} is available,
783 @command{guix-daemon} can use it to compress build logs.
786 Unless @code{--disable-daemon} was passed to @command{configure}, the
787 following packages are also needed:
790 @item @url{https://gnupg.org/, GNU libgcrypt};
791 @item @url{https://sqlite.org, SQLite 3};
792 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
796 @cindex state directory
797 When configuring Guix on a system that already has a Guix installation,
798 be sure to specify the same state directory as the existing installation
799 using the @code{--localstatedir} option of the @command{configure}
800 script (@pxref{Directory Variables, @code{localstatedir},, standards,
801 GNU Coding Standards}). Usually, this @var{localstatedir} option is
802 set to the value @file{/var}. The @command{configure} script protects
803 against unintended misconfiguration of @var{localstatedir} so you do not
804 inadvertently corrupt your store (@pxref{The Store}).
806 @node Running the Test Suite
807 @section Running the Test Suite
810 After a successful @command{configure} and @code{make} run, it is a good
811 idea to run the test suite. It can help catch issues with the setup or
812 environment, or bugs in Guix itself---and really, reporting test
813 failures is a good way to help improve the software. To run the test
820 Test cases can run in parallel: you can use the @code{-j} option of
821 GNU@tie{}make to speed things up. The first run may take a few minutes
822 on a recent machine; subsequent runs will be faster because the store
823 that is created for test purposes will already have various things in
826 It is also possible to run a subset of the tests by defining the
827 @code{TESTS} makefile variable as in this example:
830 make check TESTS="tests/store.scm tests/cpio.scm"
833 By default, tests results are displayed at a file level. In order to
834 see the details of every individual test cases, it is possible to define
835 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
838 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
841 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
842 @file{test-suite.log} file. Please specify the Guix version being used
843 as well as version numbers of the dependencies (@pxref{Requirements}) in
846 Guix also comes with a whole-system test suite that tests complete
847 Guix System instances. It can only run on systems where
848 Guix is already installed, using:
855 or, again, by defining @code{TESTS} to select a subset of tests to run:
858 make check-system TESTS="basic mcron"
861 These system tests are defined in the @code{(gnu tests @dots{})}
862 modules. They work by running the operating systems under test with
863 lightweight instrumentation in a virtual machine (VM). They can be
864 computationally intensive or rather cheap, depending on whether
865 substitutes are available for their dependencies (@pxref{Substitutes}).
866 Some of them require a lot of storage space to hold VM images.
868 Again in case of test failures, please send @email{bug-guix@@gnu.org}
871 @node Setting Up the Daemon
872 @section Setting Up the Daemon
875 Operations such as building a package or running the garbage collector
876 are all performed by a specialized process, the @dfn{build daemon}, on
877 behalf of clients. Only the daemon may access the store and its
878 associated database. Thus, any operation that manipulates the store
879 goes through the daemon. For instance, command-line tools such as
880 @command{guix package} and @command{guix build} communicate with the
881 daemon (@i{via} remote procedure calls) to instruct it what to do.
883 The following sections explain how to prepare the build daemon's
884 environment. See also @ref{Substitutes}, for information on how to allow
885 the daemon to download pre-built binaries.
888 * Build Environment Setup:: Preparing the isolated build environment.
889 * Daemon Offload Setup:: Offloading builds to remote machines.
890 * SELinux Support:: Using an SELinux policy for the daemon.
893 @node Build Environment Setup
894 @subsection Build Environment Setup
896 @cindex build environment
897 In a standard multi-user setup, Guix and its daemon---the
898 @command{guix-daemon} program---are installed by the system
899 administrator; @file{/gnu/store} is owned by @code{root} and
900 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
901 Guix tools to build packages or otherwise access the store, and the
902 daemon will do it on their behalf, ensuring that the store is kept in a
903 consistent state, and allowing built packages to be shared among users.
906 When @command{guix-daemon} runs as @code{root}, you may not want package
907 build processes themselves to run as @code{root} too, for obvious
908 security reasons. To avoid that, a special pool of @dfn{build users}
909 should be created for use by build processes started by the daemon.
910 These build users need not have a shell and a home directory: they will
911 just be used when the daemon drops @code{root} privileges in build
912 processes. Having several such users allows the daemon to launch
913 distinct build processes under separate UIDs, which guarantees that they
914 do not interfere with each other---an essential feature since builds are
915 regarded as pure functions (@pxref{Introduction}).
917 On a GNU/Linux system, a build user pool may be created like this (using
918 Bash syntax and the @code{shadow} commands):
920 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
921 @c for why `-G' is needed.
923 # groupadd --system guixbuild
924 # for i in `seq -w 1 10`;
926 useradd -g guixbuild -G guixbuild \
927 -d /var/empty -s `which nologin` \
928 -c "Guix build user $i" --system \
934 The number of build users determines how many build jobs may run in
935 parallel, as specified by the @option{--max-jobs} option
936 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
937 @command{guix system vm} and related commands, you may need to add the
938 build users to the @code{kvm} group so they can access @file{/dev/kvm},
939 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
940 (@pxref{Invoking guix system}).
942 The @code{guix-daemon} program may then be run as @code{root} with the
943 following command@footnote{If your machine uses the systemd init system,
944 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
945 file in @file{/etc/systemd/system} will ensure that
946 @command{guix-daemon} is automatically started. Similarly, if your
947 machine uses the Upstart init system, drop the
948 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
949 file in @file{/etc/init}.}:
952 # guix-daemon --build-users-group=guixbuild
957 This way, the daemon starts build processes in a chroot, under one of
958 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
959 environment contains nothing but:
961 @c Keep this list in sync with libstore/build.cc! -----------------------
964 a minimal @code{/dev} directory, created mostly independently from the
965 host @code{/dev}@footnote{``Mostly'', because while the set of files
966 that appear in the chroot's @code{/dev} is fixed, most of these files
967 can only be created if the host has them.};
970 the @code{/proc} directory; it only shows the processes of the container
971 since a separate PID name space is used;
974 @file{/etc/passwd} with an entry for the current user and an entry for
978 @file{/etc/group} with an entry for the user's group;
981 @file{/etc/hosts} with an entry that maps @code{localhost} to
985 a writable @file{/tmp} directory.
988 You can influence the directory where the daemon stores build trees
989 @i{via} the @code{TMPDIR} environment variable. However, the build tree
990 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
991 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
992 This way, the value of @code{TMPDIR} does not leak inside build
993 environments, which avoids discrepancies in cases where build processes
994 capture the name of their build tree.
997 The daemon also honors the @code{http_proxy} environment variable for
998 HTTP downloads it performs, be it for fixed-output derivations
999 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1001 If you are installing Guix as an unprivileged user, it is still possible
1002 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1003 However, build processes will not be isolated from one another, and not
1004 from the rest of the system. Thus, build processes may interfere with
1005 each other, and may access programs, libraries, and other files
1006 available on the system---making it much harder to view them as
1007 @emph{pure} functions.
1010 @node Daemon Offload Setup
1011 @subsection Using the Offload Facility
1015 When desired, the build daemon can @dfn{offload} derivation builds to
1016 other machines running Guix, using the @code{offload} @dfn{build
1017 hook}@footnote{This feature is available only when
1018 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1019 present.}. When that
1020 feature is enabled, a list of user-specified build machines is read from
1021 @file{/etc/guix/machines.scm}; every time a build is requested, for
1022 instance via @code{guix build}, the daemon attempts to offload it to one
1023 of the machines that satisfy the constraints of the derivation, in
1024 particular its system type---e.g., @file{x86_64-linux}. Missing
1025 prerequisites for the build are copied over SSH to the target machine,
1026 which then proceeds with the build; upon success the output(s) of the
1027 build are copied back to the initial machine.
1029 The @file{/etc/guix/machines.scm} file typically looks like this:
1032 (list (build-machine
1033 (name "eightysix.example.org")
1034 (system "x86_64-linux")
1035 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1037 (speed 2.)) ;incredibly fast!
1040 (name "meeps.example.org")
1041 (system "mips64el-linux")
1042 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1045 (string-append (getenv "HOME")
1046 "/.ssh/identity-for-guix"))))
1050 In the example above we specify a list of two build machines, one for
1051 the @code{x86_64} architecture and one for the @code{mips64el}
1054 In fact, this file is---not surprisingly!---a Scheme file that is
1055 evaluated when the @code{offload} hook is started. Its return value
1056 must be a list of @code{build-machine} objects. While this example
1057 shows a fixed list of build machines, one could imagine, say, using
1058 DNS-SD to return a list of potential build machines discovered in the
1059 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1060 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1063 @deftp {Data Type} build-machine
1064 This data type represents build machines to which the daemon may offload
1065 builds. The important fields are:
1070 The host name of the remote machine.
1073 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1076 The user account to use when connecting to the remote machine over SSH.
1077 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1078 allow non-interactive logins.
1081 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1082 This is used to authenticate the machine when we connect to it. It is a
1083 long string that looks like this:
1086 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1089 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1090 key can be found in a file such as
1091 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1093 If the machine is running the SSH daemon of GNU@tie{}lsh,
1094 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1095 similar file. It can be converted to the OpenSSH format using
1096 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1099 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1100 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1105 A number of optional fields may be specified:
1109 @item @code{port} (default: @code{22})
1110 Port number of SSH server on the machine.
1112 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1113 The SSH private key file to use when connecting to the machine, in
1114 OpenSSH format. This key must not be protected with a passphrase.
1116 Note that the default value is the private key @emph{of the root
1117 account}. Make sure it exists if you use the default.
1119 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1120 @itemx @code{compression-level} (default: @code{3})
1121 The SSH-level compression methods and compression level requested.
1123 Note that offloading relies on SSH compression to reduce bandwidth usage
1124 when transferring files to and from build machines.
1126 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1127 File name of the Unix-domain socket @command{guix-daemon} is listening
1130 @item @code{parallel-builds} (default: @code{1})
1131 The number of builds that may run in parallel on the machine.
1133 @item @code{speed} (default: @code{1.0})
1134 A ``relative speed factor''. The offload scheduler will tend to prefer
1135 machines with a higher speed factor.
1137 @item @code{features} (default: @code{'()})
1138 A list of strings denoting specific features supported by the machine.
1139 An example is @code{"kvm"} for machines that have the KVM Linux modules
1140 and corresponding hardware support. Derivations can request features by
1141 name, and they will be scheduled on matching build machines.
1146 The @command{guix} command must be in the search path on the build
1147 machines. You can check whether this is the case by running:
1150 ssh build-machine guix repl --version
1153 There is one last thing to do once @file{machines.scm} is in place. As
1154 explained above, when offloading, files are transferred back and forth
1155 between the machine stores. For this to work, you first need to
1156 generate a key pair on each machine to allow the daemon to export signed
1157 archives of files from the store (@pxref{Invoking guix archive}):
1160 # guix archive --generate-key
1164 Each build machine must authorize the key of the master machine so that
1165 it accepts store items it receives from the master:
1168 # guix archive --authorize < master-public-key.txt
1172 Likewise, the master machine must authorize the key of each build machine.
1174 All the fuss with keys is here to express pairwise mutual trust
1175 relations between the master and the build machines. Concretely, when
1176 the master receives files from a build machine (and @i{vice versa}), its
1177 build daemon can make sure they are genuine, have not been tampered
1178 with, and that they are signed by an authorized key.
1180 @cindex offload test
1181 To test whether your setup is operational, run this command on the
1188 This will attempt to connect to each of the build machines specified in
1189 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1190 available on each machine, attempt to export to the machine and import
1191 from it, and report any error in the process.
1193 If you want to test a different machine file, just specify it on the
1197 # guix offload test machines-qualif.scm
1200 Last, you can test the subset of the machines whose name matches a
1201 regular expression like this:
1204 # guix offload test machines.scm '\.gnu\.org$'
1207 @cindex offload status
1208 To display the current load of all build hosts, run this command on the
1212 # guix offload status
1216 @node SELinux Support
1217 @subsection SELinux Support
1219 @cindex SELinux, daemon policy
1220 @cindex mandatory access control, SELinux
1221 @cindex security, guix-daemon
1222 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1223 can be installed on a system where SELinux is enabled, in order to label
1224 Guix files and to specify the expected behavior of the daemon. Since
1225 Guix System does not provide an SELinux base policy, the daemon policy cannot
1226 be used on Guix System.
1228 @subsubsection Installing the SELinux policy
1229 @cindex SELinux, policy installation
1230 To install the policy run this command as root:
1233 semodule -i etc/guix-daemon.cil
1236 Then relabel the file system with @code{restorecon} or by a different
1237 mechanism provided by your system.
1239 Once the policy is installed, the file system has been relabeled, and
1240 the daemon has been restarted, it should be running in the
1241 @code{guix_daemon_t} context. You can confirm this with the following
1245 ps -Zax | grep guix-daemon
1248 Monitor the SELinux log files as you run a command like @code{guix build
1249 hello} to convince yourself that SELinux permits all necessary
1252 @subsubsection Limitations
1253 @cindex SELinux, limitations
1255 This policy is not perfect. Here is a list of limitations or quirks
1256 that should be considered when deploying the provided SELinux policy for
1261 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1262 operations involve contexts that have anything to do with
1263 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1264 but it would be preferrable to define socket rules for only this label.
1267 @code{guix gc} cannot access arbitrary links to profiles. By design,
1268 the file label of the destination of a symlink is independent of the
1269 file label of the link itself. Although all profiles under
1270 $localstatedir are labelled, the links to these profiles inherit the
1271 label of the directory they are in. For links in the user’s home
1272 directory this will be @code{user_home_t}. But for links from the root
1273 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1274 directory, etc, this won’t work. @code{guix gc} would be prevented from
1275 reading and following these links.
1278 The daemon’s feature to listen for TCP connections might no longer work.
1279 This might require extra rules, because SELinux treats network sockets
1280 differently from files.
1283 Currently all files with a name matching the regular expression
1284 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1285 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1286 that name in any profile would be permitted to run in the
1287 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1288 build a package that provides this executable and convince a user to
1289 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1290 At that point SELinux could not prevent it from accessing files that are
1291 allowed for processes in that domain.
1293 We could generate a much more restrictive policy at installation time,
1294 so that only the @emph{exact} file name of the currently installed
1295 @code{guix-daemon} executable would be labelled with
1296 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1297 The downside is that root would have to install or upgrade the policy at
1298 installation time whenever the Guix package that provides the
1299 effectively running @code{guix-daemon} executable is upgraded.
1302 @node Invoking guix-daemon
1303 @section Invoking @command{guix-daemon}
1305 The @command{guix-daemon} program implements all the functionality to
1306 access the store. This includes launching build processes, running the
1307 garbage collector, querying the availability of a build result, etc. It
1308 is normally run as @code{root} like this:
1311 # guix-daemon --build-users-group=guixbuild
1315 For details on how to set it up, @pxref{Setting Up the Daemon}.
1318 @cindex container, build environment
1319 @cindex build environment
1320 @cindex reproducible builds
1321 By default, @command{guix-daemon} launches build processes under
1322 different UIDs, taken from the build group specified with
1323 @code{--build-users-group}. In addition, each build process is run in a
1324 chroot environment that only contains the subset of the store that the
1325 build process depends on, as specified by its derivation
1326 (@pxref{Programming Interface, derivation}), plus a set of specific
1327 system directories. By default, the latter contains @file{/dev} and
1328 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1329 @dfn{container}: in addition to having its own file system tree, it has
1330 a separate mount name space, its own PID name space, network name space,
1331 etc. This helps achieve reproducible builds (@pxref{Features}).
1333 When the daemon performs a build on behalf of the user, it creates a
1334 build directory under @file{/tmp} or under the directory specified by
1335 its @code{TMPDIR} environment variable. This directory is shared with
1336 the container for the duration of the build, though within the container,
1337 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1339 The build directory is automatically deleted upon completion, unless the
1340 build failed and the client specified @option{--keep-failed}
1341 (@pxref{Invoking guix build, @option{--keep-failed}}).
1343 The daemon listens for connections and spawns one sub-process for each session
1344 started by a client (one of the @command{guix} sub-commands.) The
1345 @command{guix processes} command allows you to get an overview of the activity
1346 on your system by viewing each of the active sessions and clients.
1347 @xref{Invoking guix processes}, for more information.
1349 The following command-line options are supported:
1352 @item --build-users-group=@var{group}
1353 Take users from @var{group} to run build processes (@pxref{Setting Up
1354 the Daemon, build users}).
1356 @item --no-substitutes
1358 Do not use substitutes for build products. That is, always build things
1359 locally instead of allowing downloads of pre-built binaries
1360 (@pxref{Substitutes}).
1362 When the daemon runs with @code{--no-substitutes}, clients can still
1363 explicitly enable substitution @i{via} the @code{set-build-options}
1364 remote procedure call (@pxref{The Store}).
1366 @item --substitute-urls=@var{urls}
1367 @anchor{daemon-substitute-urls}
1368 Consider @var{urls} the default whitespace-separated list of substitute
1369 source URLs. When this option is omitted,
1370 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1372 This means that substitutes may be downloaded from @var{urls}, as long
1373 as they are signed by a trusted signature (@pxref{Substitutes}).
1377 Do not use offload builds to other machines (@pxref{Daemon Offload
1378 Setup}). That is, always build things locally instead of offloading
1379 builds to remote machines.
1381 @item --cache-failures
1382 Cache build failures. By default, only successful builds are cached.
1384 When this option is used, @command{guix gc --list-failures} can be used
1385 to query the set of store items marked as failed; @command{guix gc
1386 --clear-failures} removes store items from the set of cached failures.
1387 @xref{Invoking guix gc}.
1389 @item --cores=@var{n}
1391 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1394 The default value is @code{0}, but it may be overridden by clients, such
1395 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1398 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1399 in the build process, which can then use it to exploit internal
1400 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1402 @item --max-jobs=@var{n}
1404 Allow at most @var{n} build jobs in parallel. The default value is
1405 @code{1}. Setting it to @code{0} means that no builds will be performed
1406 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1407 Setup}), or simply fail.
1409 @item --max-silent-time=@var{seconds}
1410 When the build or substitution process remains silent for more than
1411 @var{seconds}, terminate it and report a build failure.
1413 The default value is @code{0}, which disables the timeout.
1415 The value specified here can be overridden by clients (@pxref{Common
1416 Build Options, @code{--max-silent-time}}).
1418 @item --timeout=@var{seconds}
1419 Likewise, when the build or substitution process lasts for more than
1420 @var{seconds}, terminate it and report a build failure.
1422 The default value is @code{0}, which disables the timeout.
1424 The value specified here can be overridden by clients (@pxref{Common
1425 Build Options, @code{--timeout}}).
1427 @item --rounds=@var{N}
1428 Build each derivation @var{n} times in a row, and raise an error if
1429 consecutive build results are not bit-for-bit identical. Note that this
1430 setting can be overridden by clients such as @command{guix build}
1431 (@pxref{Invoking guix build}).
1433 When used in conjunction with @option{--keep-failed}, the differing
1434 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1435 This makes it easy to look for differences between the two results.
1438 Produce debugging output.
1440 This is useful to debug daemon start-up issues, but then it may be
1441 overridden by clients, for example the @code{--verbosity} option of
1442 @command{guix build} (@pxref{Invoking guix build}).
1444 @item --chroot-directory=@var{dir}
1445 Add @var{dir} to the build chroot.
1447 Doing this may change the result of build processes---for instance if
1448 they use optional dependencies found in @var{dir} when it is available,
1449 and not otherwise. For that reason, it is not recommended to do so.
1450 Instead, make sure that each derivation declares all the inputs that it
1453 @item --disable-chroot
1454 Disable chroot builds.
1456 Using this option is not recommended since, again, it would allow build
1457 processes to gain access to undeclared dependencies. It is necessary,
1458 though, when @command{guix-daemon} is running under an unprivileged user
1461 @item --log-compression=@var{type}
1462 Compress build logs according to @var{type}, one of @code{gzip},
1463 @code{bzip2}, or @code{none}.
1465 Unless @code{--lose-logs} is used, all the build logs are kept in the
1466 @var{localstatedir}. To save space, the daemon automatically compresses
1467 them with bzip2 by default.
1469 @item --disable-deduplication
1470 @cindex deduplication
1471 Disable automatic file ``deduplication'' in the store.
1473 By default, files added to the store are automatically ``deduplicated'':
1474 if a newly added file is identical to another one found in the store,
1475 the daemon makes the new file a hard link to the other file. This can
1476 noticeably reduce disk usage, at the expense of slightly increased
1477 input/output load at the end of a build process. This option disables
1480 @item --gc-keep-outputs[=yes|no]
1481 Tell whether the garbage collector (GC) must keep outputs of live
1485 @cindex garbage collector roots
1486 When set to ``yes'', the GC will keep the outputs of any live derivation
1487 available in the store---the @code{.drv} files. The default is ``no'',
1488 meaning that derivation outputs are kept only if they are reachable from a GC
1489 root. @xref{Invoking guix gc}, for more on GC roots.
1491 @item --gc-keep-derivations[=yes|no]
1492 Tell whether the garbage collector (GC) must keep derivations
1493 corresponding to live outputs.
1495 When set to ``yes'', as is the case by default, the GC keeps
1496 derivations---i.e., @code{.drv} files---as long as at least one of their
1497 outputs is live. This allows users to keep track of the origins of
1498 items in their store. Setting it to ``no'' saves a bit of disk space.
1500 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1501 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1502 ``yes'' causes liveness to flow from derivations to outputs. When both are
1503 set to ``yes'', the effect is to keep all the build prerequisites (the
1504 sources, compiler, libraries, and other build-time tools) of live objects in
1505 the store, regardless of whether these prerequisites are reachable from a GC
1506 root. This is convenient for developers since it saves rebuilds or downloads.
1508 @item --impersonate-linux-2.6
1509 On Linux-based systems, impersonate Linux 2.6. This means that the
1510 kernel's @code{uname} system call will report 2.6 as the release number.
1512 This might be helpful to build programs that (usually wrongfully) depend
1513 on the kernel version number.
1516 Do not keep build logs. By default they are kept under
1517 @code{@var{localstatedir}/guix/log}.
1519 @item --system=@var{system}
1520 Assume @var{system} as the current system type. By default it is the
1521 architecture/kernel pair found at configure time, such as
1522 @code{x86_64-linux}.
1524 @item --listen=@var{endpoint}
1525 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1526 as the file name of a Unix-domain socket if it starts with
1527 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1528 host name or host name and port to listen to. Here are a few examples:
1531 @item --listen=/gnu/var/daemon
1532 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1533 creating it if needed.
1535 @item --listen=localhost
1536 @cindex daemon, remote access
1537 @cindex remote access to the daemon
1538 @cindex daemon, cluster setup
1539 @cindex clusters, daemon setup
1540 Listen for TCP connections on the network interface corresponding to
1541 @code{localhost}, on port 44146.
1543 @item --listen=128.0.0.42:1234
1544 Listen for TCP connections on the network interface corresponding to
1545 @code{128.0.0.42}, on port 1234.
1548 This option can be repeated multiple times, in which case
1549 @command{guix-daemon} accepts connections on all the specified
1550 endpoints. Users can tell client commands what endpoint to connect to
1551 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1552 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1555 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1556 @code{--listen=@var{host}} is suitable on local networks, such as
1557 clusters, where only trusted nodes may connect to the build daemon. In
1558 other cases where remote access to the daemon is needed, we recommend
1559 using Unix-domain sockets along with SSH.
1562 When @code{--listen} is omitted, @command{guix-daemon} listens for
1563 connections on the Unix-domain socket located at
1564 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1568 @node Application Setup
1569 @section Application Setup
1571 @cindex foreign distro
1572 When using Guix on top of GNU/Linux distribution other than Guix System---a
1573 so-called @dfn{foreign distro}---a few additional steps are needed to
1574 get everything in place. Here are some of them.
1578 @anchor{locales-and-locpath}
1579 @cindex locales, when not on Guix System
1581 @vindex GUIX_LOCPATH
1582 Packages installed @i{via} Guix will not use the locale data of the
1583 host system. Instead, you must first install one of the locale packages
1584 available with Guix and then define the @code{GUIX_LOCPATH} environment
1588 $ guix install glibc-locales
1589 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1592 Note that the @code{glibc-locales} package contains data for all the
1593 locales supported by the GNU@tie{}libc and weighs in at around
1594 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1595 limited to a few UTF-8 locales.
1597 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1598 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1599 Manual}). There are two important differences though:
1603 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1604 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1605 to make sure the programs of the foreign distro will not end up loading
1606 incompatible locale data.
1609 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1610 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1611 should your Guix profile contain a mixture of programs linked against
1612 different libc version, each libc version will only try to load locale
1613 data in the right format.
1616 This is important because the locale data format used by different libc
1617 versions may be incompatible.
1619 @subsection Name Service Switch
1621 @cindex name service switch, glibc
1622 @cindex NSS (name service switch), glibc
1623 @cindex nscd (name service caching daemon)
1624 @cindex name service caching daemon (nscd)
1625 When using Guix on a foreign distro, we @emph{strongly recommend} that
1626 the system run the GNU C library's @dfn{name service cache daemon},
1627 @command{nscd}, which should be listening on the
1628 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1629 installed with Guix may fail to look up host names or user accounts, or
1630 may even crash. The next paragraphs explain why.
1632 @cindex @file{nsswitch.conf}
1633 The GNU C library implements a @dfn{name service switch} (NSS), which is
1634 an extensible mechanism for ``name lookups'' in general: host name
1635 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1636 The GNU C Library Reference Manual}).
1638 @cindex Network information service (NIS)
1639 @cindex NIS (Network information service)
1640 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1641 lookup implementations: for example, the @code{nss-mdns} plugin allow
1642 resolution of @code{.local} host names, the @code{nis} plugin allows
1643 user account lookup using the Network information service (NIS), and so
1644 on. These extra ``lookup services'' are configured system-wide in
1645 @file{/etc/nsswitch.conf}, and all the programs running on the system
1646 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1649 When they perform a name lookup---for instance by calling the
1650 @code{getaddrinfo} function in C---applications first try to connect to
1651 the nscd; on success, nscd performs name lookups on their behalf. If
1652 the nscd is not running, then they perform the name lookup by
1653 themselves, by loading the name lookup services into their own address
1654 space and running it. These name lookup services---the
1655 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1656 the host system's C library, rather than from the C library the
1657 application is linked against (the C library coming from Guix).
1659 And this is where the problem is: if your application is linked against
1660 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1661 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1662 likely crash or have its name lookups fail unexpectedly.
1664 Running @command{nscd} on the system, among other advantages, eliminates
1665 this binary incompatibility problem because those @code{libnss_*.so}
1666 files are loaded in the @command{nscd} process, not in applications
1669 @subsection X11 Fonts
1672 The majority of graphical applications use Fontconfig to locate and
1673 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1674 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1675 by default. Thus, to allow graphical applications installed with Guix
1676 to display fonts, you have to install fonts with Guix as well.
1677 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1678 @code{font-gnu-freefont-ttf}.
1680 To display text written in Chinese languages, Japanese, or Korean in
1681 graphical applications, consider installing
1682 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1683 has multiple outputs, one per language family (@pxref{Packages with
1684 Multiple Outputs}). For instance, the following command installs fonts
1685 for Chinese languages:
1688 guix install font-adobe-source-han-sans:cn
1691 @cindex @code{xterm}
1692 Older programs such as @command{xterm} do not use Fontconfig and instead
1693 rely on server-side font rendering. Such programs require to specify a
1694 full name of a font using XLFD (X Logical Font Description), like this:
1697 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1700 To be able to use such full names for the TrueType fonts installed in
1701 your Guix profile, you need to extend the font path of the X server:
1703 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1704 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1706 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1709 @cindex @code{xlsfonts}
1710 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1711 to make sure your TrueType fonts are listed there.
1713 @cindex @code{fc-cache}
1715 After installing fonts you may have to refresh the font cache to use
1716 them in applications. The same applies when applications installed via
1717 Guix do not seem to find fonts. To force rebuilding of the font cache
1718 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1719 the @code{fontconfig} package.
1721 @subsection X.509 Certificates
1723 @cindex @code{nss-certs}
1724 The @code{nss-certs} package provides X.509 certificates, which allow
1725 programs to authenticate Web servers accessed over HTTPS.
1727 When using Guix on a foreign distro, you can install this package and
1728 define the relevant environment variables so that packages know where to
1729 look for certificates. @xref{X.509 Certificates}, for detailed
1732 @subsection Emacs Packages
1734 @cindex @code{emacs}
1735 When you install Emacs packages with Guix, the elisp files may be placed
1736 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1738 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1739 directory exists because potentially there may exist thousands of Emacs
1740 packages and storing all their files in a single directory may not be
1741 reliable (because of name conflicts). So we think using a separate
1742 directory for each package is a good idea. It is very similar to how
1743 the Emacs package system organizes the file structure (@pxref{Package
1744 Files,,, emacs, The GNU Emacs Manual}).
1746 By default, Emacs (installed with Guix) ``knows'' where these packages
1747 are placed, so you do not need to perform any configuration. If, for
1748 some reason, you want to avoid auto-loading Emacs packages installed
1749 with Guix, you can do so by running Emacs with @code{--no-site-file}
1750 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1752 @subsection The GCC toolchain
1757 Guix offers individual compiler packages such as @code{gcc} but if you
1758 are in need of a complete toolchain for compiling and linking source
1759 code what you really want is the @code{gcc-toolchain} package. This
1760 package provides a complete GCC toolchain for C/C++ development,
1761 including GCC itself, the GNU C Library (headers and binaries, plus
1762 debugging symbols in the @code{debug} output), Binutils, and a linker
1765 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1766 passed to the linker, add corresponding @code{-rpath} arguments, and
1767 invoke the actual linker with this new set of arguments. You can instruct the
1768 wrapper to refuse to link against libraries not in the store by setting the
1769 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1771 @node Upgrading Guix
1772 @section Upgrading Guix
1774 @cindex Upgrading Guix, on a foreign distro
1776 To upgrade Guix, run:
1782 @xref{Invoking guix pull}, for more information.
1784 @cindex upgrading Guix for the root user, on a foreign distro
1785 @cindex upgrading the Guix daemon, on a foreign distro
1786 @cindex @command{guix pull} for the root user, on a foreign distro
1788 On a foreign distro, you can upgrade the build daemon by running:
1795 followed by (assuming your distro uses the systemd service management
1799 systemctl restart guix-daemon.service
1802 On Guix System, upgrading the daemon is achieved by reconfiguring the
1803 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1807 @c *********************************************************************
1808 @node System Installation
1809 @chapter System Installation
1811 @cindex installing Guix System
1812 @cindex Guix System, installation
1813 This section explains how to install Guix System
1814 on a machine. Guix, as a package manager, can
1815 also be installed on top of a running GNU/Linux system,
1816 @pxref{Installation}.
1820 @c This paragraph is for people reading this from tty2 of the
1821 @c installation image.
1822 You are reading this documentation with an Info reader. For details on
1823 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1824 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1825 Info}. Hit @kbd{l} afterwards to come back here.
1827 Alternately, run @command{info info} in another tty to keep the manual
1833 * Limitations:: What you can expect.
1834 * Hardware Considerations:: Supported hardware.
1835 * USB Stick and DVD Installation:: Preparing the installation medium.
1836 * Preparing for Installation:: Networking, partitioning, etc.
1837 * Guided Graphical Installation:: Easy graphical installation.
1838 * Manual Installation:: Manual installation for wizards.
1839 * After System Installation:: When installation succeeded.
1840 * Installing Guix in a VM:: Guix System playground.
1841 * Building the Installation Image:: How this comes to be.
1845 @section Limitations
1847 We consider Guix System to be ready for a wide range of ``desktop'' and server
1848 use cases. The reliability guarantees it provides---transactional upgrades
1849 and rollbacks, reproducibility---make it a solid foundation.
1851 Nevertheless, before you proceed with the installation, be aware of the
1852 following noteworthy limitations applicable to version @value{VERSION}:
1856 Support for the Logical Volume Manager (LVM) is missing.
1859 More and more system services are provided (@pxref{Services}), but some
1863 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1864 as well as a number of X11 window managers. However, KDE is currently
1868 More than a disclaimer, this is an invitation to report issues (and success
1869 stories!), and to join us in improving it. @xref{Contributing}, for more
1873 @node Hardware Considerations
1874 @section Hardware Considerations
1876 @cindex hardware support on Guix System
1877 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1878 builds around the kernel Linux-libre, which means that only hardware for
1879 which free software drivers and firmware exist is supported. Nowadays,
1880 a wide range of off-the-shelf hardware is supported on
1881 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1882 Ethernet controllers. Unfortunately, there are still areas where
1883 hardware vendors deny users control over their own computing, and such
1884 hardware is not supported on Guix System.
1886 @cindex WiFi, hardware support
1887 One of the main areas where free drivers or firmware are lacking is WiFi
1888 devices. WiFi devices known to work include those using Atheros chips
1889 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1890 driver, and those using Broadcom/AirForce chips (BCM43xx with
1891 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1892 Linux-libre driver. Free firmware exists for both and is available
1893 out-of-the-box on Guix System, as part of @code{%base-firmware}
1894 (@pxref{operating-system Reference, @code{firmware}}).
1896 @cindex RYF, Respects Your Freedom
1897 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1898 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1899 certification program for hardware products that respect your freedom
1900 and your privacy and ensure that you have control over your device. We
1901 encourage you to check the list of RYF-certified devices.
1903 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1904 web site. It contains a catalog of hardware devices with information
1905 about their support in GNU/Linux.
1908 @node USB Stick and DVD Installation
1909 @section USB Stick and DVD Installation
1911 An ISO-9660 installation image that can be written to a USB stick or
1912 burnt to a DVD can be downloaded from
1913 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1914 where @var{system} is one of:
1918 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1921 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1924 @c start duplication of authentication part from ``Binary Installation''
1925 Make sure to download the associated @file{.sig} file and to verify the
1926 authenticity of the image against it, along these lines:
1929 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1930 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1933 If that command fails because you do not have the required public key,
1934 then run this command to import it:
1937 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1938 -qO - | gpg --import -
1942 and rerun the @code{gpg --verify} command.
1944 Take note that a warning like ``This key is not certified with a trusted
1945 signature!'' is normal.
1949 This image contains the tools necessary for an installation.
1950 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1952 @unnumberedsubsec Copying to a USB Stick
1954 To copy the image to a USB stick, follow these steps:
1958 Decompress the image using the @command{xz} command:
1961 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1965 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1966 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1967 copy the image with:
1970 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1974 Access to @file{/dev/sdX} usually requires root privileges.
1977 @unnumberedsubsec Burning on a DVD
1979 To copy the image to a DVD, follow these steps:
1983 Decompress the image using the @command{xz} command:
1986 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1990 Insert a blank DVD into your machine, and determine
1991 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1992 copy the image with:
1995 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1998 Access to @file{/dev/srX} usually requires root privileges.
2001 @unnumberedsubsec Booting
2003 Once this is done, you should be able to reboot the system and boot from
2004 the USB stick or DVD. The latter usually requires you to get in the
2005 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2007 @xref{Installing Guix in a VM}, if, instead, you would like to install
2008 Guix System in a virtual machine (VM).
2011 @node Preparing for Installation
2012 @section Preparing for Installation
2014 Once you have booted, you can use the guided graphical installer, which makes
2015 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2016 if you are already familiar with GNU/Linux and if you want more control than
2017 what the graphical installer provides, you can choose the ``manual''
2018 installation process (@pxref{Manual Installation}).
2020 The graphical installer is available on TTY1. You can obtain root shells on
2021 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2022 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2023 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2024 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2025 which allows you to select text with the left mouse button and to paste it
2026 with the middle button.
2029 Installation requires access to the Internet so that any missing
2030 dependencies of your system configuration can be downloaded. See the
2031 ``Networking'' section below.
2034 @node Guided Graphical Installation
2035 @section Guided Graphical Installation
2037 The graphical installer is a text-based user interface. It will guide you,
2038 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2040 The first dialog boxes allow you to set up the system as you use it during the
2041 installation: you can choose the language, keyboard layout, and set up
2042 networking, which will be used during the installation. The image below shows
2043 the networking dialog.
2045 @image{images/installer-network,5in,, networking setup with the graphical installer}
2047 Later steps allow you to partition your hard disk, as shown in the image
2048 below, to choose whether or not to use encrypted file systems, to enter the
2049 host name and root password, and to create an additional account, among other
2052 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2054 Note that, at any time, the installer allows you to exit the current
2055 installation step and resume at a previous step, as show in the image below.
2057 @image{images/installer-resume,5in,, resuming the installation process}
2059 Once you're done, the installer produces an operating system configuration and
2060 displays it (@pxref{Using the Configuration System}). At that point you can
2061 hit ``OK'' and installation will proceed. On success, you can reboot into the
2062 new system and enjoy. @xref{After System Installation}, for what's next!
2065 @node Manual Installation
2066 @section Manual Installation
2068 This section describes how you would ``manually'' install GNU@tie{}Guix System
2069 on your machine. This option requires familiarity with GNU/Linux, with the
2070 shell, and with common administration tools. If you think this is not for
2071 you, consider using the guided graphical installer (@pxref{Guided Graphical
2074 The installation system provides root shells on TTYs 3 to 6; press
2075 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2076 many common tools needed to install the system. But it is also a full-blown
2077 Guix System, which means that you can install additional packages, should you
2078 need it, using @command{guix package} (@pxref{Invoking guix package}).
2081 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2082 * Proceeding with the Installation:: Installing.
2085 @node Keyboard Layout and Networking and Partitioning
2086 @subsection Keyboard Layout, Networking, and Partitioning
2088 Before you can install the system, you may want to adjust the keyboard layout,
2089 set up networking, and partition your target hard disk. This section will
2090 guide you through this.
2092 @subsubsection Keyboard Layout
2094 @cindex keyboard layout
2095 The installation image uses the US qwerty keyboard layout. If you want
2096 to change it, you can use the @command{loadkeys} command. For example,
2097 the following command selects the Dvorak keyboard layout:
2103 See the files under @file{/run/current-system/profile/share/keymaps} for
2104 a list of available keyboard layouts. Run @command{man loadkeys} for
2107 @subsubsection Networking
2109 Run the following command to see what your network interfaces are called:
2116 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2122 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2123 Wired interfaces have a name starting with @samp{e}; for example, the
2124 interface corresponding to the first on-board Ethernet controller is
2125 called @samp{eno1}. Wireless interfaces have a name starting with
2126 @samp{w}, like @samp{w1p2s0}.
2129 @item Wired connection
2130 To configure a wired network run the following command, substituting
2131 @var{interface} with the name of the wired interface you want to use.
2134 ifconfig @var{interface} up
2138 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2141 ip link set @var{interface} up
2144 @item Wireless connection
2147 To configure wireless networking, you can create a configuration file
2148 for the @command{wpa_supplicant} configuration tool (its location is not
2149 important) using one of the available text editors such as
2153 nano wpa_supplicant.conf
2156 As an example, the following stanza can go to this file and will work
2157 for many wireless networks, provided you give the actual SSID and
2158 passphrase for the network you are connecting to:
2162 ssid="@var{my-ssid}"
2164 psk="the network's secret passphrase"
2168 Start the wireless service and run it in the background with the
2169 following command (substitute @var{interface} with the name of the
2170 network interface you want to use):
2173 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2176 Run @command{man wpa_supplicant} for more information.
2180 At this point, you need to acquire an IP address. On a network where IP
2181 addresses are automatically assigned @i{via} DHCP, you can run:
2184 dhclient -v @var{interface}
2187 Try to ping a server to see if networking is up and running:
2193 Setting up network access is almost always a requirement because the
2194 image does not contain all the software and tools that may be needed.
2196 @cindex installing over SSH
2197 If you want to, you can continue the installation remotely by starting
2201 herd start ssh-daemon
2204 Make sure to either set a password with @command{passwd}, or configure
2205 OpenSSH public key authentication before logging in.
2207 @subsubsection Disk Partitioning
2209 Unless this has already been done, the next step is to partition, and
2210 then format the target partition(s).
2212 The installation image includes several partitioning tools, including
2213 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2214 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2215 the partition layout you want:
2221 If your disk uses the GUID Partition Table (GPT) format and you plan to
2222 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2223 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2226 @cindex EFI, installation
2227 @cindex UEFI, installation
2228 @cindex ESP, EFI system partition
2229 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2230 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2231 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2234 parted /dev/sda set 1 esp on
2238 @vindex grub-bootloader
2239 @vindex grub-efi-bootloader
2240 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2241 @file{/sys/firmware/efi} exists in the installation image, then you should
2242 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2243 Otherwise you should use the BIOS-based GRUB, known as
2244 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2248 Once you are done partitioning the target hard disk drive, you have to
2249 create a file system on the relevant partition(s)@footnote{Currently
2250 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2251 code that reads file system UUIDs and labels only works for these file system
2252 types.}. For the ESP, if you have one and assuming it is
2253 @file{/dev/sda1}, run:
2256 mkfs.fat -F32 /dev/sda1
2259 Preferably, assign file systems a label so that you can easily and
2260 reliably refer to them in @code{file-system} declarations (@pxref{File
2261 Systems}). This is typically done using the @code{-L} option of
2262 @command{mkfs.ext4} and related commands. So, assuming the target root
2263 partition lives at @file{/dev/sda2}, a file system with the label
2264 @code{my-root} can be created with:
2267 mkfs.ext4 -L my-root /dev/sda2
2270 @cindex encrypted disk
2271 If you are instead planning to encrypt the root partition, you can use
2272 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2273 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2274 @code{man cryptsetup}} for more information.) Assuming you want to
2275 store the root partition on @file{/dev/sda2}, the command sequence would
2276 be along these lines:
2279 cryptsetup luksFormat /dev/sda2
2280 cryptsetup open --type luks /dev/sda2 my-partition
2281 mkfs.ext4 -L my-root /dev/mapper/my-partition
2284 Once that is done, mount the target file system under @file{/mnt}
2285 with a command like (again, assuming @code{my-root} is the label of the
2289 mount LABEL=my-root /mnt
2292 Also mount any other file systems you would like to use on the target
2293 system relative to this path. If you have opted for @file{/boot/efi} as an
2294 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2295 found by @code{guix system init} afterwards.
2297 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2298 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2299 sure to initialize them with @command{mkswap}. Assuming you have one
2300 swap partition on @file{/dev/sda3}, you would run:
2307 Alternatively, you may use a swap file. For example, assuming that in
2308 the new system you want to use the file @file{/swapfile} as a swap file,
2309 you would run@footnote{This example will work for many types of file
2310 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2311 btrfs), the required steps may be different. For details, see the
2312 manual pages for @command{mkswap} and @command{swapon}.}:
2315 # This is 10 GiB of swap space. Adjust "count" to change the size.
2316 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2317 # For security, make the file readable and writable only by root.
2318 chmod 600 /mnt/swapfile
2319 mkswap /mnt/swapfile
2320 swapon /mnt/swapfile
2323 Note that if you have encrypted the root partition and created a swap
2324 file in its file system as described above, then the encryption also
2325 protects the swap file, just like any other file in that file system.
2327 @node Proceeding with the Installation
2328 @subsection Proceeding with the Installation
2330 With the target partitions ready and the target root mounted on
2331 @file{/mnt}, we're ready to go. First, run:
2334 herd start cow-store /mnt
2337 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2338 during the installation phase are written to the target disk on @file{/mnt}
2339 rather than kept in memory. This is necessary because the first phase of
2340 the @command{guix system init} command (see below) entails downloads or
2341 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2343 Next, you have to edit a file and
2344 provide the declaration of the operating system to be installed. To
2345 that end, the installation system comes with three text editors. We
2346 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2347 supports syntax highlighting and parentheses matching; other editors
2348 include GNU Zile (an Emacs clone), and
2349 nvi (a clone of the original BSD @command{vi} editor).
2350 We strongly recommend storing that file on the target root file system, say,
2351 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2352 configuration file once you have rebooted into the newly-installed system.
2354 @xref{Using the Configuration System}, for an overview of the
2355 configuration file. The example configurations discussed in that
2356 section are available under @file{/etc/configuration} in the
2357 installation image. Thus, to get started with a system configuration
2358 providing a graphical display server (a ``desktop'' system), you can run
2359 something along these lines:
2363 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2364 # nano /mnt/etc/config.scm
2367 You should pay attention to what your configuration file contains, and
2372 Make sure the @code{bootloader-configuration} form refers to the target
2373 you want to install GRUB on. It should mention @code{grub-bootloader} if
2374 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2375 for newer UEFI systems. For legacy systems, the @code{target} field
2376 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2377 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2378 currently mounted and a @code{file-system} entry is specified in your
2382 Be sure that your file system labels match the value of their respective
2383 @code{device} fields in your @code{file-system} configuration, assuming
2384 your @code{file-system} configuration uses the @code{file-system-label}
2385 procedure in its @code{device} field.
2388 If there are encrypted or RAID partitions, make sure to add a
2389 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2392 Once you are done preparing the configuration file, the new system must
2393 be initialized (remember that the target root file system is mounted
2397 guix system init /mnt/etc/config.scm /mnt
2401 This copies all the necessary files and installs GRUB on
2402 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2403 more information, @pxref{Invoking guix system}. This command may trigger
2404 downloads or builds of missing packages, which can take some time.
2406 Once that command has completed---and hopefully succeeded!---you can run
2407 @command{reboot} and boot into the new system. The @code{root} password
2408 in the new system is initially empty; other users' passwords need to be
2409 initialized by running the @command{passwd} command as @code{root},
2410 unless your configuration specifies otherwise
2411 (@pxref{user-account-password, user account passwords}).
2412 @xref{After System Installation}, for what's next!
2415 @node After System Installation
2416 @section After System Installation
2418 Success, you've now booted into Guix System! From then on, you can update the
2419 system whenever you want by running, say:
2423 sudo guix system reconfigure /etc/config.scm
2427 This builds a new system generation with the latest packages and services
2428 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2429 your system includes the latest security updates (@pxref{Security Updates}).
2431 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2433 @cindex sudo vs. @command{guix pull}
2434 Note that @command{sudo guix} runs your user's @command{guix} command and
2435 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2436 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2439 Join us on @code{#guix} on the Freenode IRC network or on
2440 @email{guix-devel@@gnu.org} to share your experience!
2443 @node Installing Guix in a VM
2444 @section Installing Guix in a Virtual Machine
2446 @cindex virtual machine, Guix System installation
2447 @cindex virtual private server (VPS)
2448 @cindex VPS (virtual private server)
2449 If you'd like to install Guix System in a virtual machine (VM) or on a
2450 virtual private server (VPS) rather than on your beloved machine, this
2453 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2454 disk image, follow these steps:
2458 First, retrieve and decompress the Guix system installation image as
2459 described previously (@pxref{USB Stick and DVD Installation}).
2462 Create a disk image that will hold the installed system. To make a
2463 qcow2-formatted disk image, use the @command{qemu-img} command:
2466 qemu-img create -f qcow2 guix-system.img 50G
2469 The resulting file will be much smaller than 50 GB (typically less than
2470 1 MB), but it will grow as the virtualized storage device is filled up.
2473 Boot the USB installation image in an VM:
2476 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2477 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2478 -drive file=guix-system.img \
2479 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2482 @code{-enable-kvm} is optional, but significantly improves performance,
2483 @pxref{Running Guix in a VM}.
2486 You're now root in the VM, proceed with the installation process.
2487 @xref{Preparing for Installation}, and follow the instructions.
2490 Once installation is complete, you can boot the system that's on your
2491 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2494 @node Building the Installation Image
2495 @section Building the Installation Image
2497 @cindex installation image
2498 The installation image described above was built using the @command{guix
2499 system} command, specifically:
2502 guix system disk-image --file-system-type=iso9660 \
2503 gnu/system/install.scm
2506 Have a look at @file{gnu/system/install.scm} in the source tree,
2507 and see also @ref{Invoking guix system} for more information
2508 about the installation image.
2510 @section Building the Installation Image for ARM Boards
2512 Many ARM boards require a specific variant of the
2513 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2515 If you build a disk image and the bootloader is not available otherwise
2516 (on another boot drive etc), it's advisable to build an image that
2517 includes the bootloader, specifically:
2520 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2523 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2524 board, a list of possible boards will be printed.
2526 @c *********************************************************************
2527 @node Package Management
2528 @chapter Package Management
2531 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2532 remove software packages, without having to know about their build
2533 procedures or dependencies. Guix also goes beyond this obvious set of
2536 This chapter describes the main features of Guix, as well as the
2537 package management tools it provides. Along with the command-line
2538 interface described below (@pxref{Invoking guix package, @code{guix
2539 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2540 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2541 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2545 guix install emacs-guix
2549 * Features:: How Guix will make your life brighter.
2550 * Invoking guix package:: Package installation, removal, etc.
2551 * Substitutes:: Downloading pre-built binaries.
2552 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2553 * Invoking guix gc:: Running the garbage collector.
2554 * Invoking guix pull:: Fetching the latest Guix and distribution.
2555 * Channels:: Customizing the package collection.
2556 * Invoking guix time-machine:: Running an older revision of Guix.
2557 * Inferiors:: Interacting with another revision of Guix.
2558 * Invoking guix describe:: Display information about your Guix revision.
2559 * Invoking guix archive:: Exporting and importing store files.
2565 When using Guix, each package ends up in the @dfn{package store}, in its
2566 own directory---something that resembles
2567 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2569 Instead of referring to these directories, users have their own
2570 @dfn{profile}, which points to the packages that they actually want to
2571 use. These profiles are stored within each user's home directory, at
2572 @code{$HOME/.guix-profile}.
2574 For example, @code{alice} installs GCC 4.7.2. As a result,
2575 @file{/home/alice/.guix-profile/bin/gcc} points to
2576 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2577 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2578 simply continues to point to
2579 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2580 coexist on the same system without any interference.
2582 The @command{guix package} command is the central tool to manage
2583 packages (@pxref{Invoking guix package}). It operates on the per-user
2584 profiles, and can be used @emph{with normal user privileges}.
2586 @cindex transactions
2587 The command provides the obvious install, remove, and upgrade
2588 operations. Each invocation is actually a @emph{transaction}: either
2589 the specified operation succeeds, or nothing happens. Thus, if the
2590 @command{guix package} process is terminated during the transaction,
2591 or if a power outage occurs during the transaction, then the user's
2592 profile remains in its previous state, and remains usable.
2594 In addition, any package transaction may be @emph{rolled back}. So, if,
2595 for example, an upgrade installs a new version of a package that turns
2596 out to have a serious bug, users may roll back to the previous instance
2597 of their profile, which was known to work well. Similarly, the global
2598 system configuration on Guix is subject to
2599 transactional upgrades and roll-back
2600 (@pxref{Using the Configuration System}).
2602 All packages in the package store may be @emph{garbage-collected}.
2603 Guix can determine which packages are still referenced by user
2604 profiles, and remove those that are provably no longer referenced
2605 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2606 generations of their profile so that the packages they refer to can be
2609 @cindex reproducibility
2610 @cindex reproducible builds
2611 Guix takes a @dfn{purely functional} approach to package
2612 management, as described in the introduction (@pxref{Introduction}).
2613 Each @file{/gnu/store} package directory name contains a hash of all the
2614 inputs that were used to build that package---compiler, libraries, build
2615 scripts, etc. This direct correspondence allows users to make sure a
2616 given package installation matches the current state of their
2617 distribution. It also helps maximize @dfn{build reproducibility}:
2618 thanks to the isolated build environments that are used, a given build
2619 is likely to yield bit-identical files when performed on different
2620 machines (@pxref{Invoking guix-daemon, container}).
2623 This foundation allows Guix to support @dfn{transparent binary/source
2624 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2625 available from an external source---a @dfn{substitute}, Guix just
2626 downloads it and unpacks it;
2627 otherwise, it builds the package from source, locally
2628 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2629 reproducible, users do not have to trust servers that provide
2630 substitutes: they can force a local build and @emph{challenge} providers
2631 (@pxref{Invoking guix challenge}).
2633 Control over the build environment is a feature that is also useful for
2634 developers. The @command{guix environment} command allows developers of
2635 a package to quickly set up the right development environment for their
2636 package, without having to manually install the dependencies of the
2637 package into their profile (@pxref{Invoking guix environment}).
2639 @cindex replication, of software environments
2640 @cindex provenance tracking, of software artifacts
2641 All of Guix and its package definitions is version-controlled, and
2642 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2643 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2644 Guix instance on a different machine or at a later point in time, which in
2645 turn allows you to @emph{replicate complete software environments}, while
2646 retaining precise @dfn{provenance tracking} of the software.
2648 @node Invoking guix package
2649 @section Invoking @command{guix package}
2651 @cindex installing packages
2652 @cindex removing packages
2653 @cindex package installation
2654 @cindex package removal
2655 The @command{guix package} command is the tool that allows users to
2656 install, upgrade, and remove packages, as well as rolling back to
2657 previous configurations. It operates only on the user's own profile,
2658 and works with normal user privileges (@pxref{Features}). Its syntax
2662 guix package @var{options}
2665 @cindex transactions
2666 Primarily, @var{options} specifies the operations to be performed during
2667 the transaction. Upon completion, a new profile is created, but
2668 previous @dfn{generations} of the profile remain available, should the user
2671 For example, to remove @code{lua} and install @code{guile} and
2672 @code{guile-cairo} in a single transaction:
2675 guix package -r lua -i guile guile-cairo
2678 @cindex aliases, for @command{guix package}
2679 For your convenience, we also provide the following aliases:
2683 @command{guix search} is an alias for @command{guix package -s},
2685 @command{guix install} is an alias for @command{guix package -i},
2687 @command{guix remove} is an alias for @command{guix package -r},
2689 @command{guix upgrade} is an alias for @command{guix package -u},
2691 and @command{guix show} is an alias for @command{guix package --show=}.
2694 These aliases are less expressive than @command{guix package} and provide
2695 fewer options, so in some cases you'll probably want to use @command{guix
2698 @command{guix package} also supports a @dfn{declarative approach}
2699 whereby the user specifies the exact set of packages to be available and
2700 passes it @i{via} the @option{--manifest} option
2701 (@pxref{profile-manifest, @option{--manifest}}).
2704 For each user, a symlink to the user's default profile is automatically
2705 created in @file{$HOME/.guix-profile}. This symlink always points to the
2706 current generation of the user's default profile. Thus, users can add
2707 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2708 variable, and so on.
2709 @cindex search paths
2710 If you are not using Guix System, consider adding the
2711 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2712 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2713 shells get all the right environment variable definitions:
2716 GUIX_PROFILE="$HOME/.guix-profile" ; \
2717 source "$HOME/.guix-profile/etc/profile"
2720 In a multi-user setup, user profiles are stored in a place registered as
2721 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2722 to (@pxref{Invoking guix gc}). That directory is normally
2723 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2724 @var{localstatedir} is the value passed to @code{configure} as
2725 @code{--localstatedir}, and @var{user} is the user name. The
2726 @file{per-user} directory is created when @command{guix-daemon} is
2727 started, and the @var{user} sub-directory is created by @command{guix
2730 The @var{options} can be among the following:
2734 @item --install=@var{package} @dots{}
2735 @itemx -i @var{package} @dots{}
2736 Install the specified @var{package}s.
2738 Each @var{package} may specify either a simple package name, such as
2739 @code{guile}, or a package name followed by an at-sign and version number,
2740 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2741 case, the newest version prefixed by @code{1.8} is selected.)
2743 If no version number is specified, the
2744 newest available version will be selected. In addition, @var{package}
2745 may contain a colon, followed by the name of one of the outputs of the
2746 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2747 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2748 name (and optionally version) are searched for among the GNU
2749 distribution modules (@pxref{Package Modules}).
2751 @cindex propagated inputs
2752 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2753 that automatically get installed along with the required package
2754 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2755 @code{package} objects}, for information about propagated inputs in
2756 package definitions).
2758 @anchor{package-cmd-propagated-inputs}
2759 An example is the GNU MPC library: its C header files refer to those of
2760 the GNU MPFR library, which in turn refer to those of the GMP library.
2761 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2762 in the profile; removing MPC also removes MPFR and GMP---unless they had
2763 also been explicitly installed by the user.
2765 Besides, packages sometimes rely on the definition of environment
2766 variables for their search paths (see explanation of
2767 @code{--search-paths} below). Any missing or possibly incorrect
2768 environment variable definitions are reported here.
2770 @item --install-from-expression=@var{exp}
2772 Install the package @var{exp} evaluates to.
2774 @var{exp} must be a Scheme expression that evaluates to a
2775 @code{<package>} object. This option is notably useful to disambiguate
2776 between same-named variants of a package, with expressions such as
2777 @code{(@@ (gnu packages base) guile-final)}.
2779 Note that this option installs the first output of the specified
2780 package, which may be insufficient when needing a specific output of a
2781 multiple-output package.
2783 @item --install-from-file=@var{file}
2784 @itemx -f @var{file}
2785 Install the package that the code within @var{file} evaluates to.
2787 As an example, @var{file} might contain a definition like this
2788 (@pxref{Defining Packages}):
2791 @include package-hello.scm
2794 Developers may find it useful to include such a @file{guix.scm} file
2795 in the root of their project source tree that can be used to test
2796 development snapshots and create reproducible development environments
2797 (@pxref{Invoking guix environment}).
2799 @item --remove=@var{package} @dots{}
2800 @itemx -r @var{package} @dots{}
2801 Remove the specified @var{package}s.
2803 As for @code{--install}, each @var{package} may specify a version number
2804 and/or output name in addition to the package name. For instance,
2805 @code{-r glibc:debug} would remove the @code{debug} output of
2808 @item --upgrade[=@var{regexp} @dots{}]
2809 @itemx -u [@var{regexp} @dots{}]
2810 @cindex upgrading packages
2811 Upgrade all the installed packages. If one or more @var{regexp}s are
2812 specified, upgrade only installed packages whose name matches a
2813 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2815 Note that this upgrades package to the latest version of packages found
2816 in the distribution currently installed. To update your distribution,
2817 you should regularly run @command{guix pull} (@pxref{Invoking guix
2820 @item --do-not-upgrade[=@var{regexp} @dots{}]
2821 When used together with the @code{--upgrade} option, do @emph{not}
2822 upgrade any packages whose name matches a @var{regexp}. For example, to
2823 upgrade all packages in the current profile except those containing the
2824 substring ``emacs'':
2827 $ guix package --upgrade . --do-not-upgrade emacs
2830 @item @anchor{profile-manifest}--manifest=@var{file}
2831 @itemx -m @var{file}
2832 @cindex profile declaration
2833 @cindex profile manifest
2834 Create a new generation of the profile from the manifest object
2835 returned by the Scheme code in @var{file}. This option can be repeated
2836 several times, in which case the manifests are concatenated.
2838 This allows you to @emph{declare} the profile's contents rather than
2839 constructing it through a sequence of @code{--install} and similar
2840 commands. The advantage is that @var{file} can be put under version
2841 control, copied to different machines to reproduce the same profile, and
2844 @c FIXME: Add reference to (guix profile) documentation when available.
2845 @var{file} must return a @dfn{manifest} object, which is roughly a list
2848 @findex packages->manifest
2850 (use-package-modules guile emacs)
2855 ;; Use a specific package output.
2856 (list guile-2.0 "debug")))
2859 @findex specifications->manifest
2860 In this example we have to know which modules define the @code{emacs}
2861 and @code{guile-2.0} variables to provide the right
2862 @code{use-package-modules} line, which can be cumbersome. We can
2863 instead provide regular package specifications and let
2864 @code{specifications->manifest} look up the corresponding package
2868 (specifications->manifest
2869 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2873 @cindex rolling back
2874 @cindex undoing transactions
2875 @cindex transactions, undoing
2876 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2877 the last transaction.
2879 When combined with options such as @code{--install}, roll back occurs
2880 before any other actions.
2882 When rolling back from the first generation that actually contains
2883 installed packages, the profile is made to point to the @dfn{zeroth
2884 generation}, which contains no files apart from its own metadata.
2886 After having rolled back, installing, removing, or upgrading packages
2887 overwrites previous future generations. Thus, the history of the
2888 generations in a profile is always linear.
2890 @item --switch-generation=@var{pattern}
2891 @itemx -S @var{pattern}
2893 Switch to a particular generation defined by @var{pattern}.
2895 @var{pattern} may be either a generation number or a number prefixed
2896 with ``+'' or ``-''. The latter means: move forward/backward by a
2897 specified number of generations. For example, if you want to return to
2898 the latest generation after @code{--roll-back}, use
2899 @code{--switch-generation=+1}.
2901 The difference between @code{--roll-back} and
2902 @code{--switch-generation=-1} is that @code{--switch-generation} will
2903 not make a zeroth generation, so if a specified generation does not
2904 exist, the current generation will not be changed.
2906 @item --search-paths[=@var{kind}]
2907 @cindex search paths
2908 Report environment variable definitions, in Bash syntax, that may be
2909 needed in order to use the set of installed packages. These environment
2910 variables are used to specify @dfn{search paths} for files used by some
2911 of the installed packages.
2913 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2914 environment variables to be defined so it can look for headers and
2915 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2916 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2917 library are installed in the profile, then @code{--search-paths} will
2918 suggest setting these variables to @code{@var{profile}/include} and
2919 @code{@var{profile}/lib}, respectively.
2921 The typical use case is to define these environment variables in the
2925 $ eval `guix package --search-paths`
2928 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2929 meaning that the returned environment variable definitions will either
2930 be exact settings, or prefixes or suffixes of the current value of these
2931 variables. When omitted, @var{kind} defaults to @code{exact}.
2933 This option can also be used to compute the @emph{combined} search paths
2934 of several profiles. Consider this example:
2937 $ guix package -p foo -i guile
2938 $ guix package -p bar -i guile-json
2939 $ guix package -p foo -p bar --search-paths
2942 The last command above reports about the @code{GUILE_LOAD_PATH}
2943 variable, even though, taken individually, neither @file{foo} nor
2944 @file{bar} would lead to that recommendation.
2947 @item --profile=@var{profile}
2948 @itemx -p @var{profile}
2949 Use @var{profile} instead of the user's default profile.
2951 @var{profile} must be the name of a file that will be created upon
2952 completion. Concretely, @var{profile} will be a mere symbolic link
2953 (``symlink'') pointing to the actual profile where packages are
2957 $ guix install hello -p ~/code/my-profile
2959 $ ~/code/my-profile/bin/hello
2963 All it takes to get rid of the profile is to remove this symlink and its
2964 siblings that point to specific generations:
2967 $ rm ~/code/my-profile ~/code/my-profile-*-link
2970 @item --list-profiles
2971 List all the user's profiles:
2974 $ guix package --list-profiles
2975 /home/charlie/.guix-profile
2976 /home/charlie/code/my-profile
2977 /home/charlie/code/devel-profile
2978 /home/charlie/tmp/test
2981 When running as root, list all the profiles of all the users.
2983 @cindex collisions, in a profile
2984 @cindex colliding packages in profiles
2985 @cindex profile collisions
2986 @item --allow-collisions
2987 Allow colliding packages in the new profile. Use at your own risk!
2989 By default, @command{guix package} reports as an error @dfn{collisions}
2990 in the profile. Collisions happen when two or more different versions
2991 or variants of a given package end up in the profile.
2994 Use the bootstrap Guile to build the profile. This option is only
2995 useful to distribution developers.
2999 In addition to these actions, @command{guix package} supports the
3000 following options to query the current state of a profile, or the
3001 availability of packages:
3005 @item --search=@var{regexp}
3006 @itemx -s @var{regexp}
3007 @cindex searching for packages
3008 List the available packages whose name, synopsis, or description matches
3009 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3010 Print all the metadata of matching packages in
3011 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3012 GNU recutils manual}).
3014 This allows specific fields to be extracted using the @command{recsel}
3015 command, for instance:
3018 $ guix package -s malloc | recsel -p name,version,relevance
3032 Similarly, to show the name of all the packages available under the
3033 terms of the GNU@tie{}LGPL version 3:
3036 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3043 It is also possible to refine search results using several @code{-s} flags to
3044 @command{guix package}, or several arguments to @command{guix search}. For
3045 example, the following command returns a list of board games (this time using
3046 the @command{guix search} alias):
3049 $ guix search '\<board\>' game | recsel -p name
3054 If we were to omit @code{-s game}, we would also get software packages
3055 that deal with printed circuit boards; removing the angle brackets
3056 around @code{board} would further add packages that have to do with
3059 And now for a more elaborate example. The following command searches
3060 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3061 libraries, and prints the name and synopsis of the matching packages:
3064 $ guix search crypto library | \
3065 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3069 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3070 information on @dfn{selection expressions} for @code{recsel -e}.
3072 @item --show=@var{package}
3073 Show details about @var{package}, taken from the list of available packages, in
3074 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3078 $ guix package --show=python | recsel -p name,version
3086 You may also specify the full name of a package to only get details about a
3087 specific version of it (this time using the @command{guix show} alias):
3089 $ guix show python@@3.4 | recsel -p name,version
3096 @item --list-installed[=@var{regexp}]
3097 @itemx -I [@var{regexp}]
3098 List the currently installed packages in the specified profile, with the
3099 most recently installed packages shown last. When @var{regexp} is
3100 specified, list only installed packages whose name matches @var{regexp}.
3102 For each installed package, print the following items, separated by
3103 tabs: the package name, its version string, the part of the package that
3104 is installed (for instance, @code{out} for the default output,
3105 @code{include} for its headers, etc.), and the path of this package in
3108 @item --list-available[=@var{regexp}]
3109 @itemx -A [@var{regexp}]
3110 List packages currently available in the distribution for this system
3111 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3112 installed packages whose name matches @var{regexp}.
3114 For each package, print the following items separated by tabs: its name,
3115 its version string, the parts of the package (@pxref{Packages with
3116 Multiple Outputs}), and the source location of its definition.
3118 @item --list-generations[=@var{pattern}]
3119 @itemx -l [@var{pattern}]
3121 Return a list of generations along with their creation dates; for each
3122 generation, show the installed packages, with the most recently
3123 installed packages shown last. Note that the zeroth generation is never
3126 For each installed package, print the following items, separated by
3127 tabs: the name of a package, its version string, the part of the package
3128 that is installed (@pxref{Packages with Multiple Outputs}), and the
3129 location of this package in the store.
3131 When @var{pattern} is used, the command returns only matching
3132 generations. Valid patterns include:
3135 @item @emph{Integers and comma-separated integers}. Both patterns denote
3136 generation numbers. For instance, @code{--list-generations=1} returns
3139 And @code{--list-generations=1,8,2} outputs three generations in the
3140 specified order. Neither spaces nor trailing commas are allowed.
3142 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3143 specified generations and everything in between. Note that the start of
3144 a range must be smaller than its end.
3146 It is also possible to omit the endpoint. For example,
3147 @code{--list-generations=2..}, returns all generations starting from the
3150 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3151 or months by passing an integer along with the first letter of the
3152 duration. For example, @code{--list-generations=20d} lists generations
3153 that are up to 20 days old.
3156 @item --delete-generations[=@var{pattern}]
3157 @itemx -d [@var{pattern}]
3158 When @var{pattern} is omitted, delete all generations except the current
3161 This command accepts the same patterns as @option{--list-generations}.
3162 When @var{pattern} is specified, delete the matching generations. When
3163 @var{pattern} specifies a duration, generations @emph{older} than the
3164 specified duration match. For instance, @code{--delete-generations=1m}
3165 deletes generations that are more than one month old.
3167 If the current generation matches, it is @emph{not} deleted. Also, the
3168 zeroth generation is never deleted.
3170 Note that deleting generations prevents rolling back to them.
3171 Consequently, this command must be used with care.
3175 Finally, since @command{guix package} may actually start build
3176 processes, it supports all the common build options (@pxref{Common Build
3177 Options}). It also supports package transformation options, such as
3178 @option{--with-source} (@pxref{Package Transformation Options}).
3179 However, note that package transformations are lost when upgrading; to
3180 preserve transformations across upgrades, you should define your own
3181 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3182 (@pxref{Defining Packages}).
3185 @section Substitutes
3188 @cindex pre-built binaries
3189 Guix supports transparent source/binary deployment, which means that it
3190 can either build things locally, or download pre-built items from a
3191 server, or both. We call these pre-built items @dfn{substitutes}---they
3192 are substitutes for local build results. In many cases, downloading a
3193 substitute is much faster than building things locally.
3195 Substitutes can be anything resulting from a derivation build
3196 (@pxref{Derivations}). Of course, in the common case, they are
3197 pre-built package binaries, but source tarballs, for instance, which
3198 also result from derivation builds, can be available as substitutes.
3201 * Official Substitute Server:: One particular source of substitutes.
3202 * Substitute Server Authorization:: How to enable or disable substitutes.
3203 * Substitute Authentication:: How Guix verifies substitutes.
3204 * Proxy Settings:: How to get substitutes via proxy.
3205 * Substitution Failure:: What happens when substitution fails.
3206 * On Trusting Binaries:: How can you trust that binary blob?
3209 @node Official Substitute Server
3210 @subsection Official Substitute Server
3213 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3214 that builds packages from Guix continuously for some
3215 architectures, and makes them available as substitutes. This is the
3216 default source of substitutes; it can be overridden by passing the
3217 @option{--substitute-urls} option either to @command{guix-daemon}
3218 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3219 or to client tools such as @command{guix package}
3220 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3223 Substitute URLs can be either HTTP or HTTPS.
3224 HTTPS is recommended because communications are encrypted; conversely,
3225 using HTTP makes all communications visible to an eavesdropper, who
3226 could use the information gathered to determine, for instance, whether
3227 your system has unpatched security vulnerabilities.
3229 Substitutes from the official build farm are enabled by default when
3230 using Guix System (@pxref{GNU Distribution}). However,
3231 they are disabled by default when using Guix on a foreign distribution,
3232 unless you have explicitly enabled them via one of the recommended
3233 installation steps (@pxref{Installation}). The following paragraphs
3234 describe how to enable or disable substitutes for the official build
3235 farm; the same procedure can also be used to enable substitutes for any
3236 other substitute server.
3238 @node Substitute Server Authorization
3239 @subsection Substitute Server Authorization
3242 @cindex substitutes, authorization thereof
3243 @cindex access control list (ACL), for substitutes
3244 @cindex ACL (access control list), for substitutes
3245 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3247 must add its public key to the access control list (ACL) of archive
3248 imports, using the @command{guix archive} command (@pxref{Invoking guix
3249 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3250 be compromised and to serve genuine substitutes.
3252 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3253 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3254 the installation prefix of Guix. If you installed Guix from source,
3255 make sure you checked the GPG signature of
3256 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3257 Then, you can run something like this:
3260 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3263 Once this is in place, the output of a command like @code{guix build}
3264 should change from something like:
3267 $ guix build emacs --dry-run
3268 The following derivations would be built:
3269 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3270 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3271 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3272 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3280 $ guix build emacs --dry-run
3281 112.3 MB would be downloaded:
3282 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3283 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3284 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3285 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3290 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3291 will be downloaded, when possible, for future builds.
3293 @cindex substitutes, how to disable
3294 The substitute mechanism can be disabled globally by running
3295 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3296 guix-daemon}). It can also be disabled temporarily by passing the
3297 @code{--no-substitutes} option to @command{guix package}, @command{guix
3298 build}, and other command-line tools.
3300 @node Substitute Authentication
3301 @subsection Substitute Authentication
3303 @cindex digital signatures
3304 Guix detects and raises an error when attempting to use a substitute
3305 that has been tampered with. Likewise, it ignores substitutes that are
3306 not signed, or that are not signed by one of the keys listed in the ACL.
3308 There is one exception though: if an unauthorized server provides
3309 substitutes that are @emph{bit-for-bit identical} to those provided by
3310 an authorized server, then the unauthorized server becomes eligible for
3311 downloads. For example, assume we have chosen two substitute servers
3315 --substitute-urls="https://a.example.org https://b.example.org"
3319 @cindex reproducible builds
3320 If the ACL contains only the key for @code{b.example.org}, and if
3321 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3322 then Guix will download substitutes from @code{a.example.org} because it
3323 comes first in the list and can be considered a mirror of
3324 @code{b.example.org}. In practice, independent build machines usually
3325 produce the same binaries, thanks to bit-reproducible builds (see
3328 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3329 (in other words, the server is not authenticated), contrary to what
3330 HTTPS clients such as Web browsers usually do. This is because Guix
3331 authenticates substitute information itself, as explained above, which
3332 is what we care about (whereas X.509 certificates are about
3333 authenticating bindings between domain names and public keys.)
3335 @node Proxy Settings
3336 @subsection Proxy Settings
3339 Substitutes are downloaded over HTTP or HTTPS.
3340 The @code{http_proxy} environment
3341 variable can be set in the environment of @command{guix-daemon} and is
3342 honored for downloads of substitutes. Note that the value of
3343 @code{http_proxy} in the environment where @command{guix build},
3344 @command{guix package}, and other client commands are run has
3345 @emph{absolutely no effect}.
3347 @node Substitution Failure
3348 @subsection Substitution Failure
3350 Even when a substitute for a derivation is available, sometimes the
3351 substitution attempt will fail. This can happen for a variety of
3352 reasons: the substitute server might be offline, the substitute may
3353 recently have been deleted, the connection might have been interrupted,
3356 When substitutes are enabled and a substitute for a derivation is
3357 available, but the substitution attempt fails, Guix will attempt to
3358 build the derivation locally depending on whether or not
3359 @code{--fallback} was given (@pxref{fallback-option,, common build
3360 option @code{--fallback}}). Specifically, if @code{--fallback} was
3361 omitted, then no local build will be performed, and the derivation is
3362 considered to have failed. However, if @code{--fallback} was given,
3363 then Guix will attempt to build the derivation locally, and the success
3364 or failure of the derivation depends on the success or failure of the
3365 local build. Note that when substitutes are disabled or no substitute
3366 is available for the derivation in question, a local build will
3367 @emph{always} be performed, regardless of whether or not
3368 @code{--fallback} was given.
3370 To get an idea of how many substitutes are available right now, you can
3371 try running the @command{guix weather} command (@pxref{Invoking guix
3372 weather}). This command provides statistics on the substitutes provided
3375 @node On Trusting Binaries
3376 @subsection On Trusting Binaries
3378 @cindex trust, of pre-built binaries
3379 Today, each individual's control over their own computing is at the
3380 mercy of institutions, corporations, and groups with enough power and
3381 determination to subvert the computing infrastructure and exploit its
3382 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3383 convenient, we encourage users to also build on their own, or even run
3384 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3385 interesting target. One way to help is by publishing the software you
3386 build using @command{guix publish} so that others have one more choice
3387 of server to download substitutes from (@pxref{Invoking guix publish}).
3389 Guix has the foundations to maximize build reproducibility
3390 (@pxref{Features}). In most cases, independent builds of a given
3391 package or derivation should yield bit-identical results. Thus, through
3392 a diverse set of independent package builds, we can strengthen the
3393 integrity of our systems. The @command{guix challenge} command aims to
3394 help users assess substitute servers, and to assist developers in
3395 finding out about non-deterministic package builds (@pxref{Invoking guix
3396 challenge}). Similarly, the @option{--check} option of @command{guix
3397 build} allows users to check whether previously-installed substitutes
3398 are genuine by rebuilding them locally (@pxref{build-check,
3399 @command{guix build --check}}).
3401 In the future, we want Guix to have support to publish and retrieve
3402 binaries to/from other users, in a peer-to-peer fashion. If you would
3403 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3405 @node Packages with Multiple Outputs
3406 @section Packages with Multiple Outputs
3408 @cindex multiple-output packages
3409 @cindex package outputs
3412 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3413 source package leads to exactly one directory in the store. When running
3414 @command{guix install glibc}, one installs the default output of the
3415 GNU libc package; the default output is called @code{out}, but its name
3416 can be omitted as shown in this command. In this particular case, the
3417 default output of @code{glibc} contains all the C header files, shared
3418 libraries, static libraries, Info documentation, and other supporting
3421 Sometimes it is more appropriate to separate the various types of files
3422 produced from a single source package into separate outputs. For
3423 instance, the GLib C library (used by GTK+ and related packages)
3424 installs more than 20 MiB of reference documentation as HTML pages.
3425 To save space for users who do not need it, the documentation goes to a
3426 separate output, called @code{doc}. To install the main GLib output,
3427 which contains everything but the documentation, one would run:
3433 @cindex documentation
3434 The command to install its documentation is:
3437 guix install glib:doc
3440 Some packages install programs with different ``dependency footprints''.
3441 For instance, the WordNet package installs both command-line tools and
3442 graphical user interfaces (GUIs). The former depend solely on the C
3443 library, whereas the latter depend on Tcl/Tk and the underlying X
3444 libraries. In this case, we leave the command-line tools in the default
3445 output, whereas the GUIs are in a separate output. This allows users
3446 who do not need the GUIs to save space. The @command{guix size} command
3447 can help find out about such situations (@pxref{Invoking guix size}).
3448 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3450 There are several such multiple-output packages in the GNU distribution.
3451 Other conventional output names include @code{lib} for libraries and
3452 possibly header files, @code{bin} for stand-alone programs, and
3453 @code{debug} for debugging information (@pxref{Installing Debugging
3454 Files}). The outputs of a packages are listed in the third column of
3455 the output of @command{guix package --list-available} (@pxref{Invoking
3459 @node Invoking guix gc
3460 @section Invoking @command{guix gc}
3462 @cindex garbage collector
3464 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3465 The @command{guix gc} command allows users to explicitly run the garbage
3466 collector to reclaim space from the @file{/gnu/store} directory. It is
3467 the @emph{only} way to remove files from @file{/gnu/store}---removing
3468 files or directories manually may break it beyond repair!
3471 @cindex garbage collector roots
3472 The garbage collector has a set of known @dfn{roots}: any file under
3473 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3474 cannot be deleted; any other file is considered @dfn{dead} and may be
3475 deleted. The set of garbage collector roots (``GC roots'' for short)
3476 includes default user profiles; by default, the symlinks under
3477 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3478 added with @command{guix build --root}, for example (@pxref{Invoking
3479 guix build}). The @command{guix gc --list-roots} command lists them.
3481 Prior to running @code{guix gc --collect-garbage} to make space, it is
3482 often useful to remove old generations from user profiles; that way, old
3483 package builds referenced by those generations can be reclaimed. This
3484 is achieved by running @code{guix package --delete-generations}
3485 (@pxref{Invoking guix package}).
3487 Our recommendation is to run a garbage collection periodically, or when
3488 you are short on disk space. For instance, to guarantee that at least
3489 5@tie{}GB are available on your disk, simply run:
3495 It is perfectly safe to run as a non-interactive periodic job
3496 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3497 Running @command{guix gc} with no arguments will collect as
3498 much garbage as it can, but that is often inconvenient: you may find
3499 yourself having to rebuild or re-download software that is ``dead'' from
3500 the GC viewpoint but that is necessary to build other pieces of
3501 software---e.g., the compiler tool chain.
3503 The @command{guix gc} command has three modes of operation: it can be
3504 used to garbage-collect any dead files (the default), to delete specific
3505 files (the @code{--delete} option), to print garbage-collector
3506 information, or for more advanced queries. The garbage collection
3507 options are as follows:
3510 @item --collect-garbage[=@var{min}]
3511 @itemx -C [@var{min}]
3512 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3513 sub-directories. This is the default operation when no option is
3516 When @var{min} is given, stop once @var{min} bytes have been collected.
3517 @var{min} may be a number of bytes, or it may include a unit as a
3518 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3519 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3521 When @var{min} is omitted, collect all the garbage.
3523 @item --free-space=@var{free}
3524 @itemx -F @var{free}
3525 Collect garbage until @var{free} space is available under
3526 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3527 as @code{500MiB}, as described above.
3529 When @var{free} or more is already available in @file{/gnu/store}, do
3530 nothing and exit immediately.
3532 @item --delete-generations[=@var{duration}]
3533 @itemx -d [@var{duration}]
3534 Before starting the garbage collection process, delete all the generations
3535 older than @var{duration}, for all the user profiles; when run as root, this
3536 applies to all the profiles @emph{of all the users}.
3538 For example, this command deletes all the generations of all your profiles
3539 that are older than 2 months (except generations that are current), and then
3540 proceeds to free space until at least 10 GiB are available:
3543 guix gc -d 2m -F 10G
3548 Attempt to delete all the store files and directories specified as
3549 arguments. This fails if some of the files are not in the store, or if
3550 they are still live.
3552 @item --list-failures
3553 List store items corresponding to cached build failures.
3555 This prints nothing unless the daemon was started with
3556 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3557 @option{--cache-failures}}).
3560 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3564 List store items in use by currently running processes. These store
3565 items are effectively considered GC roots: they cannot be deleted.
3567 @item --clear-failures
3568 Remove the specified store items from the failed-build cache.
3570 Again, this option only makes sense when the daemon is started with
3571 @option{--cache-failures}. Otherwise, it does nothing.
3574 Show the list of dead files and directories still present in the
3575 store---i.e., files and directories no longer reachable from any root.
3578 Show the list of live store files and directories.
3582 In addition, the references among existing store files can be queried:
3588 @cindex package dependencies
3589 List the references (respectively, the referrers) of store files given
3595 List the requisites of the store files passed as arguments. Requisites
3596 include the store files themselves, their references, and the references
3597 of these, recursively. In other words, the returned list is the
3598 @dfn{transitive closure} of the store files.
3600 @xref{Invoking guix size}, for a tool to profile the size of the closure
3601 of an element. @xref{Invoking guix graph}, for a tool to visualize
3602 the graph of references.
3606 Return the derivation(s) leading to the given store items
3607 (@pxref{Derivations}).
3609 For example, this command:
3612 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3616 returns the @file{.drv} file(s) leading to the @code{emacs} package
3617 installed in your profile.
3619 Note that there may be zero matching @file{.drv} files, for instance
3620 because these files have been garbage-collected. There can also be more
3621 than one matching @file{.drv} due to fixed-output derivations.
3624 Lastly, the following options allow you to check the integrity of the
3625 store and to control disk usage.
3629 @item --verify[=@var{options}]
3630 @cindex integrity, of the store
3631 @cindex integrity checking
3632 Verify the integrity of the store.
3634 By default, make sure that all the store items marked as valid in the
3635 database of the daemon actually exist in @file{/gnu/store}.
3637 When provided, @var{options} must be a comma-separated list containing one
3638 or more of @code{contents} and @code{repair}.
3640 When passing @option{--verify=contents}, the daemon computes the
3641 content hash of each store item and compares it against its hash in the
3642 database. Hash mismatches are reported as data corruptions. Because it
3643 traverses @emph{all the files in the store}, this command can take a
3644 long time, especially on systems with a slow disk drive.
3646 @cindex repairing the store
3647 @cindex corruption, recovering from
3648 Using @option{--verify=repair} or @option{--verify=contents,repair}
3649 causes the daemon to try to repair corrupt store items by fetching
3650 substitutes for them (@pxref{Substitutes}). Because repairing is not
3651 atomic, and thus potentially dangerous, it is available only to the
3652 system administrator. A lightweight alternative, when you know exactly
3653 which items in the store are corrupt, is @command{guix build --repair}
3654 (@pxref{Invoking guix build}).
3657 @cindex deduplication
3658 Optimize the store by hard-linking identical files---this is
3659 @dfn{deduplication}.
3661 The daemon performs deduplication after each successful build or archive
3662 import, unless it was started with @code{--disable-deduplication}
3663 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3664 this option is primarily useful when the daemon was running with
3665 @code{--disable-deduplication}.
3669 @node Invoking guix pull
3670 @section Invoking @command{guix pull}
3672 @cindex upgrading Guix
3673 @cindex updating Guix
3674 @cindex @command{guix pull}
3676 Packages are installed or upgraded to the latest version available in
3677 the distribution currently available on your local machine. To update
3678 that distribution, along with the Guix tools, you must run @command{guix
3679 pull}: the command downloads the latest Guix source code and package
3680 descriptions, and deploys it. Source code is downloaded from a
3681 @uref{https://git-scm.com, Git} repository, by default the official
3682 GNU@tie{}Guix repository, though this can be customized.
3684 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3685 (@pxref{Channels}) specified by one of the followings, in this order:
3689 the @option{--channels} option;
3691 the user's @file{~/.config/guix/channels.scm} file;
3693 the system-wide @file{/etc/guix/channels.scm} file;
3695 the built-in default channels specified in the @code{%default-channels}
3699 On completion, @command{guix package} will use packages and package
3700 versions from this just-retrieved copy of Guix. Not only that, but all
3701 the Guix commands and Scheme modules will also be taken from that latest
3702 version. New @command{guix} sub-commands added by the update also
3705 Any user can update their Guix copy using @command{guix pull}, and the
3706 effect is limited to the user who ran @command{guix pull}. For
3707 instance, when user @code{root} runs @command{guix pull}, this has no
3708 effect on the version of Guix that user @code{alice} sees, and vice
3711 The result of running @command{guix pull} is a @dfn{profile} available
3712 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3713 make sure to add it to the beginning of your search path so that you use
3714 the latest version, and similarly for the Info manual
3715 (@pxref{Documentation}):
3718 export PATH="$HOME/.config/guix/current/bin:$PATH"
3719 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3722 The @code{--list-generations} or @code{-l} option lists past generations
3723 produced by @command{guix pull}, along with details about their provenance:
3727 Generation 1 Jun 10 2018 00:18:18
3729 repository URL: https://git.savannah.gnu.org/git/guix.git
3730 branch: origin/master
3731 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3733 Generation 2 Jun 11 2018 11:02:49
3735 repository URL: https://git.savannah.gnu.org/git/guix.git
3736 branch: origin/master
3737 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3738 2 new packages: keepalived, libnfnetlink
3739 6 packages upgraded: emacs-nix-mode@@2.0.4,
3740 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3741 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3743 Generation 3 Jun 13 2018 23:31:07 (current)
3745 repository URL: https://git.savannah.gnu.org/git/guix.git
3746 branch: origin/master
3747 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3748 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3749 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3752 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3753 describe the current status of Guix.
3755 This @code{~/.config/guix/current} profile works exactly like the profiles
3756 created by @command{guix package} (@pxref{Invoking guix package}). That
3757 is, you can list generations, roll back to the previous
3758 generation---i.e., the previous Guix---and so on:
3761 $ guix pull --roll-back
3762 switched from generation 3 to 2
3763 $ guix pull --delete-generations=1
3764 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3767 You can also use @command{guix package} (@pxref{Invoking guix package})
3768 to manage the profile by naming it explicitly:
3770 $ guix package -p ~/.config/guix/current --roll-back
3771 switched from generation 3 to 2
3772 $ guix package -p ~/.config/guix/current --delete-generations=1
3773 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3776 The @command{guix pull} command is usually invoked with no arguments,
3777 but it supports the following options:
3780 @item --url=@var{url}
3781 @itemx --commit=@var{commit}
3782 @itemx --branch=@var{branch}
3783 Download code for the @code{guix} channel from the specified @var{url}, at the
3784 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3785 string), or @var{branch}.
3787 @cindex @file{channels.scm}, configuration file
3788 @cindex configuration file for channels
3789 These options are provided for convenience, but you can also specify your
3790 configuration in the @file{~/.config/guix/channels.scm} file or using the
3791 @option{--channels} option (see below).
3793 @item --channels=@var{file}
3794 @itemx -C @var{file}
3795 Read the list of channels from @var{file} instead of
3796 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3797 @var{file} must contain Scheme code that
3798 evaluates to a list of channel objects. @xref{Channels}, for more
3801 @cindex channel news
3804 Display the list of packages added or upgraded since the previous
3805 generation, as well as, occasionally, news written by channel authors
3806 for their users (@pxref{Channels, Writing Channel News}).
3808 The package information is the same as displayed upon @command{guix
3809 pull} completion, but without ellipses; it is also similar to the output
3810 of @command{guix pull -l} for the last generation (see below).
3812 @item --list-generations[=@var{pattern}]
3813 @itemx -l [@var{pattern}]
3814 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3815 is provided, the subset of generations that match @var{pattern}.
3816 The syntax of @var{pattern} is the same as with @code{guix package
3817 --list-generations} (@pxref{Invoking guix package}).
3820 @cindex rolling back
3821 @cindex undoing transactions
3822 @cindex transactions, undoing
3823 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3824 undo the last transaction.
3826 @item --switch-generation=@var{pattern}
3827 @itemx -S @var{pattern}
3829 Switch to a particular generation defined by @var{pattern}.
3831 @var{pattern} may be either a generation number or a number prefixed
3832 with ``+'' or ``-''. The latter means: move forward/backward by a
3833 specified number of generations. For example, if you want to return to
3834 the latest generation after @code{--roll-back}, use
3835 @code{--switch-generation=+1}.
3837 @item --delete-generations[=@var{pattern}]
3838 @itemx -d [@var{pattern}]
3839 When @var{pattern} is omitted, delete all generations except the current
3842 This command accepts the same patterns as @option{--list-generations}.
3843 When @var{pattern} is specified, delete the matching generations. When
3844 @var{pattern} specifies a duration, generations @emph{older} than the
3845 specified duration match. For instance, @code{--delete-generations=1m}
3846 deletes generations that are more than one month old.
3848 If the current generation matches, it is @emph{not} deleted.
3850 Note that deleting generations prevents rolling back to them.
3851 Consequently, this command must be used with care.
3853 @xref{Invoking guix describe}, for a way to display information about the
3854 current generation only.
3856 @item --profile=@var{profile}
3857 @itemx -p @var{profile}
3858 Use @var{profile} instead of @file{~/.config/guix/current}.
3862 Show which channel commit(s) would be used and what would be built or
3863 substituted but do not actually do it.
3865 @item --system=@var{system}
3866 @itemx -s @var{system}
3867 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3868 the system type of the build host.
3871 Produce verbose output, writing build logs to the standard error output.
3874 Use the bootstrap Guile to build the latest Guix. This option is only
3875 useful to Guix developers.
3878 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3879 repository and branch to pull from, as well as @emph{additional} repositories
3880 containing package modules that should be deployed. @xref{Channels}, for more
3883 In addition, @command{guix pull} supports all the common build options
3884 (@pxref{Common Build Options}).
3890 @cindex @file{channels.scm}, configuration file
3891 @cindex configuration file for channels
3892 @cindex @command{guix pull}, configuration file
3893 @cindex configuration of @command{guix pull}
3894 Guix and its package collection are updated by running @command{guix pull}
3895 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3896 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3897 customized by defining @dfn{channels} in the
3898 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3899 of a Git repository to be deployed, and @command{guix pull} can be instructed
3900 to pull from one or more channels. In other words, channels can be used to
3901 @emph{customize} and to @emph{extend} Guix, as we will see below.
3903 @subsection Using a Custom Guix Channel
3905 The channel called @code{guix} specifies where Guix itself---its command-line
3906 tools as well as its package collection---should be downloaded. For instance,
3907 suppose you want to update from your own copy of the Guix repository at
3908 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3909 write in @code{~/.config/guix/channels.scm} this specification:
3912 ;; Tell 'guix pull' to use my own repo.
3915 (url "https://example.org/my-guix.git")
3916 (branch "super-hacks")))
3920 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3921 branch of the repository at @code{example.org}.
3923 @subsection Specifying Additional Channels
3925 @cindex extending the package collection (channels)
3926 @cindex personal packages (channels)
3927 @cindex channels, for personal packages
3928 You can also specify @emph{additional channels} to pull from. Let's say you
3929 have a bunch of custom package variants or personal packages that you think
3930 would make little sense to contribute to the Guix project, but would like to
3931 have these packages transparently available to you at the command line. You
3932 would first write modules containing those package definitions (@pxref{Package
3933 Modules}), maintain them in a Git repository, and then you and anyone else can
3934 use it as an additional channel to get packages from. Neat, no?
3936 @c What follows stems from discussions at
3937 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3938 @c earlier discussions on guix-devel@gnu.org.
3940 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3941 publish your personal channel to the world, we would like to share a few words
3946 Before publishing a channel, please consider contributing your package
3947 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3948 to free software of all sorts, and packages in Guix proper are readily
3949 available to all Guix users and benefit from the project's quality assurance
3953 When you maintain package definitions outside Guix, we, Guix developers,
3954 consider that @emph{the compatibility burden is on you}. Remember that
3955 package modules and package definitions are just Scheme code that uses various
3956 programming interfaces (APIs). We want to remain free to change these APIs to
3957 keep improving Guix, possibly in ways that break your channel. We never
3958 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3962 Corollary: if you're using an external channel and that channel breaks, please
3963 @emph{report the issue to the channel authors}, not to the Guix project.
3966 You've been warned! Having said this, we believe external channels are a
3967 practical way to exert your freedom to augment Guix' package collection and to
3968 share your improvements, which are basic tenets of
3969 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3970 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3973 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3974 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3977 @vindex %default-channels
3979 ;; Add my personal packages to those Guix provides.
3981 (name 'my-personal-packages)
3982 (url "https://example.org/personal-packages.git"))
3987 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3988 add a channel the list of channels that the variable @code{%default-channels}
3989 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3990 Manual}). With this file in place, @command{guix pull} builds not only Guix
3991 but also the package modules from your own repository. The result in
3992 @file{~/.config/guix/current} is the union of Guix with your own package
3996 $ guix pull --list-generations
3998 Generation 19 Aug 27 2018 16:20:48
4000 repository URL: https://git.savannah.gnu.org/git/guix.git
4002 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4003 my-personal-packages dd3df5e
4004 repository URL: https://example.org/personal-packages.git
4006 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4007 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4008 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4012 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4013 both Guix and packages from the @code{my-personal-packages} channel. Among
4014 the new and upgraded packages that are listed, some like @code{my-gimp} and
4015 @code{my-emacs-with-cool-features} might come from
4016 @code{my-personal-packages}, while others come from the Guix default channel.
4018 To create a channel, create a Git repository containing your own package
4019 modules and make it available. The repository can contain anything, but a
4020 useful channel will contain Guile modules that export packages. Once you
4021 start using a channel, Guix will behave as if the root directory of that
4022 channel's Git repository has been added to the Guile load path (@pxref{Load
4023 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4024 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4025 module, then the module will be available under the name @code{(my-packages
4026 my-tools)}, and you will be able to use it like any other module
4027 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4029 @cindex dependencies, channels
4030 @cindex meta-data, channels
4031 @subsection Declaring Channel Dependencies
4033 Channel authors may decide to augment a package collection provided by other
4034 channels. They can declare their channel to be dependent on other channels in
4035 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4036 the channel repository.
4038 The meta-data file should contain a simple S-expression like this:
4045 (name some-collection)
4046 (url "https://example.org/first-collection.git"))
4048 (name some-other-collection)
4049 (url "https://example.org/second-collection.git")
4050 (branch "testing"))))
4053 In the above example this channel is declared to depend on two other channels,
4054 which will both be fetched automatically. The modules provided by the channel
4055 will be compiled in an environment where the modules of all these declared
4056 channels are available.
4058 For the sake of reliability and maintainability, you should avoid dependencies
4059 on channels that you don't control, and you should aim to keep the number of
4060 dependencies to a minimum.
4062 @cindex subdirectory, channels
4063 @subsection Package Modules in a Sub-directory
4065 As a channel author, you may want to keep your channel modules in a
4066 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4067 add a meta-data file @file{.guix-channel} that contains:
4075 @cindex news, for channels
4076 @subsection Writing Channel News
4078 Channel authors may occasionally want to communicate to their users
4079 information about important changes in the channel. You'd send them all
4080 an email, but that's not convenient.
4082 Instead, channels can provide a @dfn{news file}; when the channel users
4083 run @command{guix pull}, that news file is automatically read and
4084 @command{guix pull --news} can display the announcements that correspond
4085 to the new commits that have been pulled, if any.
4087 To do that, channel authors must first declare the name of the news file
4088 in their @file{.guix-channel} file:
4093 (news-file "etc/news.txt"))
4096 The news file itself, @file{etc/news.txt} in this example, must look
4097 something like this:
4102 (entry (tag "the-bug-fix")
4103 (title (en "Fixed terrible bug")
4105 (body (en "@@emph@{Good news@}! It's fixed!")
4106 (eo "Certe ĝi pli bone funkcias nun!")))
4107 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4108 (title (en "Added a great package")
4109 (ca "Què vol dir guix?"))
4110 (body (en "Don't miss the @@code@{hello@} package!"))))
4113 The file consists of a list of @dfn{news entries}. Each entry is
4114 associated with a commit or tag: it describes changes made in this
4115 commit, possibly in preceding commits as well. Users see entries only
4116 the first time they obtain the commit the entry refers to.
4118 The @code{title} field should be a one-line summary while @code{body}
4119 can be arbitrarily long, and both can contain Texinfo markup
4120 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4121 a list of language tag/message tuples, which allows @command{guix pull}
4122 to display news in the language that corresponds to the user's locale.
4124 If you want to translate news using a gettext-based workflow, you can
4125 extract translatable strings with @command{xgettext} (@pxref{xgettext
4126 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4127 you write news entries in English first, the command below creates a PO
4128 file containing the strings to translate:
4131 xgettext -o news.po -l scheme -ken etc/news.scm
4134 To sum up, yes, you could use your channel as a blog. But beware, this
4135 is @emph{not quite} what your users might expect.
4137 @subsection Replicating Guix
4139 @cindex pinning, channels
4140 @cindex replicating Guix
4141 @cindex reproducibility, of Guix
4142 The @command{guix pull --list-generations} output above shows precisely which
4143 commits were used to build this instance of Guix. We can thus replicate it,
4144 say, on another machine, by providing a channel specification in
4145 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4148 ;; Deploy specific commits of my channels of interest.
4151 (url "https://git.savannah.gnu.org/git/guix.git")
4152 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4154 (name 'my-personal-packages)
4155 (url "https://example.org/personal-packages.git")
4156 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4159 The @command{guix describe --format=channels} command can even generate this
4160 list of channels directly (@pxref{Invoking guix describe}). The resulting
4161 file can be used with the -C options of @command{guix pull}
4162 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4163 (@pxref{Invoking guix time-machine}).
4165 At this point the two machines run the @emph{exact same Guix}, with access to
4166 the @emph{exact same packages}. The output of @command{guix build gimp} on
4167 one machine will be exactly the same, bit for bit, as the output of the same
4168 command on the other machine. It also means both machines have access to all
4169 the source code of Guix and, transitively, to all the source code of every
4172 This gives you super powers, allowing you to track the provenance of binary
4173 artifacts with very fine grain, and to reproduce software environments at
4174 will---some sort of ``meta reproducibility'' capabilities, if you will.
4175 @xref{Inferiors}, for another way to take advantage of these super powers.
4177 @node Invoking guix time-machine
4178 @section Invoking @command{guix time-machine}
4180 @cindex @command{guix time-machine}
4181 @cindex pinning, channels
4182 @cindex replicating Guix
4183 @cindex reproducibility, of Guix
4185 The @command{guix time-machine} command provides access to other
4186 revisions of Guix, for example to install older versions of packages,
4187 or to reproduce a computation in an identical environment. The revision
4188 of Guix to be used is defined by a commit or by a channel
4189 description file created by @command{guix describe}
4190 (@pxref{Invoking guix describe}).
4192 The general syntax is:
4195 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4198 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4199 @command{guix} command if the specified revision. The @var{options} that define
4200 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4203 @item --url=@var{url}
4204 @itemx --commit=@var{commit}
4205 @itemx --branch=@var{branch}
4206 Use the @code{guix} channel from the specified @var{url}, at the
4207 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4208 string), or @var{branch}.
4210 @item --channels=@var{file}
4211 @itemx -C @var{file}
4212 Read the list of channels from @var{file}. @var{file} must contain
4213 Scheme code that evaluates to a list of channel objects.
4214 @xref{Channels} for more information.
4217 As for @command{guix pull}, the absence of any options means that the
4218 the latest commit on the master branch will be used. The command
4221 guix time-machine -- build hello
4224 will thus build the package @code{hello} as defined in the master branch,
4225 which is in general a newer revison of Guix than you have installed.
4226 Time travel works in both directions!
4228 Note that @command{guix time-machine} can trigger builds of channels and
4229 their dependencies, and these are controlled by the standard build
4230 options (@pxref{Common Build Options}).
4235 @c TODO: Remove this once we're more confident about API stability.
4237 The functionality described here is a ``technology preview'' as of version
4238 @value{VERSION}. As such, the interface is subject to change.
4242 @cindex composition of Guix revisions
4243 Sometimes you might need to mix packages from the revision of Guix you're
4244 currently running with packages available in a different revision of Guix.
4245 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4246 revisions in arbitrary ways.
4248 @cindex inferior packages
4249 Technically, an ``inferior'' is essentially a separate Guix process connected
4250 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4251 @code{(guix inferior)} module allows you to create inferiors and to
4252 communicate with them. It also provides a high-level interface to browse and
4253 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4255 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4256 to interact with a separate revision of Guix. For example, let's assume you
4257 want to install in your profile the current @code{guile} package, along with
4258 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4259 because the newer @code{guile-json} has an incompatible API and you want to
4260 run your code against the old API@. To do that, you could write a manifest for
4261 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4262 manifest, you would create an inferior for that old Guix revision you care
4263 about, and you would look up the @code{guile-json} package in the inferior:
4266 (use-modules (guix inferior) (guix channels)
4267 (srfi srfi-1)) ;for 'first'
4270 ;; This is the old revision from which we want to
4271 ;; extract guile-json.
4274 (url "https://git.savannah.gnu.org/git/guix.git")
4276 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4279 ;; An inferior representing the above revision.
4280 (inferior-for-channels channels))
4282 ;; Now create a manifest with the current "guile" package
4283 ;; and the old "guile-json" package.
4285 (list (first (lookup-inferior-packages inferior "guile-json"))
4286 (specification->package "guile")))
4289 On its first run, @command{guix package --manifest} might have to build the
4290 channel you specified before it can create the inferior; subsequent runs will
4291 be much faster because the Guix revision will be cached.
4293 The @code{(guix inferior)} module provides the following procedures to open an
4296 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4297 [#:cache-directory] [#:ttl]
4298 Return an inferior for @var{channels}, a list of channels. Use the cache at
4299 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4300 This procedure opens a new connection to the build daemon.
4302 As a side effect, this procedure may build or substitute binaries for
4303 @var{channels}, which can take time.
4306 @deffn {Scheme Procedure} open-inferior @var{directory} @
4307 [#:command "bin/guix"]
4308 Open the inferior Guix in @var{directory}, running
4309 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4310 the inferior could not be launched.
4313 @cindex inferior packages
4314 The procedures listed below allow you to obtain and manipulate inferior
4317 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4318 Return the list of packages known to @var{inferior}.
4321 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4323 Return the sorted list of inferior packages matching @var{name} in
4324 @var{inferior}, with highest version numbers first. If @var{version} is true,
4325 return only packages with a version number prefixed by @var{version}.
4328 @deffn {Scheme Procedure} inferior-package? @var{obj}
4329 Return true if @var{obj} is an inferior package.
4332 @deffn {Scheme Procedure} inferior-package-name @var{package}
4333 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4334 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4335 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4336 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4337 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4338 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4339 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4340 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4341 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4342 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4343 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4344 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4345 These procedures are the counterpart of package record accessors
4346 (@pxref{package Reference}). Most of them work by querying the inferior
4347 @var{package} comes from, so the inferior must still be live when you call
4351 Inferior packages can be used transparently like any other package or
4352 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4353 transparently handled by the @code{packages->manifest} procedure, which is
4354 commonly use in manifests (@pxref{Invoking guix package, the
4355 @option{--manifest} option of @command{guix package}}). Thus you can insert
4356 an inferior package pretty much anywhere you would insert a regular package:
4357 in manifests, in the @code{packages} field of your @code{operating-system}
4358 declaration, and so on.
4360 @node Invoking guix describe
4361 @section Invoking @command{guix describe}
4363 @cindex reproducibility
4364 @cindex replicating Guix
4365 Often you may want to answer questions like: ``Which revision of Guix am I
4366 using?'' or ``Which channels am I using?'' This is useful information in many
4367 situations: if you want to @emph{replicate} an environment on a different
4368 machine or user account, if you want to report a bug or to determine what
4369 change in the channels you are using caused it, or if you want to record your
4370 system state for reproducibility purposes. The @command{guix describe}
4371 command answers these questions.
4373 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4374 displays the channel(s) that it was built from, including their repository URL
4375 and commit IDs (@pxref{Channels}):
4379 Generation 10 Sep 03 2018 17:32:44 (current)
4381 repository URL: https://git.savannah.gnu.org/git/guix.git
4383 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4386 If you're familiar with the Git version control system, this is similar in
4387 spirit to @command{git describe}; the output is also similar to that of
4388 @command{guix pull --list-generations}, but limited to the current generation
4389 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4390 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4391 information is all it takes to describe the revision of Guix you're using, and
4392 also to replicate it.
4394 To make it easier to replicate Guix, @command{guix describe} can also be asked
4395 to return a list of channels instead of the human-readable description above:
4398 $ guix describe -f channels
4401 (url "https://git.savannah.gnu.org/git/guix.git")
4403 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4407 You can save this to a file and feed it to @command{guix pull -C} on some
4408 other machine or at a later point in time, which will instantiate @emph{this
4409 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4410 From there on, since you're able to deploy the same revision of Guix, you can
4411 just as well @emph{replicate a complete software environment}. We humbly
4412 think that this is @emph{awesome}, and we hope you'll like it too!
4414 The details of the options supported by @command{guix describe} are as
4418 @item --format=@var{format}
4419 @itemx -f @var{format}
4420 Produce output in the specified @var{format}, one of:
4424 produce human-readable output;
4426 produce a list of channel specifications that can be passed to @command{guix
4427 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4431 produce a list of channel specifications in JSON format;
4433 produce a list of channel specifications in Recutils format.
4436 @item --profile=@var{profile}
4437 @itemx -p @var{profile}
4438 Display information about @var{profile}.
4441 @node Invoking guix archive
4442 @section Invoking @command{guix archive}
4444 @cindex @command{guix archive}
4446 The @command{guix archive} command allows users to @dfn{export} files
4447 from the store into a single archive, and to later @dfn{import} them on
4448 a machine that runs Guix.
4449 In particular, it allows store files to be transferred from one machine
4450 to the store on another machine.
4453 If you're looking for a way to produce archives in a format suitable for
4454 tools other than Guix, @pxref{Invoking guix pack}.
4457 @cindex exporting store items
4458 To export store files as an archive to standard output, run:
4461 guix archive --export @var{options} @var{specifications}...
4464 @var{specifications} may be either store file names or package
4465 specifications, as for @command{guix package} (@pxref{Invoking guix
4466 package}). For instance, the following command creates an archive
4467 containing the @code{gui} output of the @code{git} package and the main
4468 output of @code{emacs}:
4471 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4474 If the specified packages are not built yet, @command{guix archive}
4475 automatically builds them. The build process may be controlled with the
4476 common build options (@pxref{Common Build Options}).
4478 To transfer the @code{emacs} package to a machine connected over SSH,
4482 guix archive --export -r emacs | ssh the-machine guix archive --import
4486 Similarly, a complete user profile may be transferred from one machine
4487 to another like this:
4490 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4491 ssh the-machine guix archive --import
4495 However, note that, in both examples, all of @code{emacs} and the
4496 profile as well as all of their dependencies are transferred (due to
4497 @code{-r}), regardless of what is already available in the store on the
4498 target machine. The @code{--missing} option can help figure out which
4499 items are missing from the target store. The @command{guix copy}
4500 command simplifies and optimizes this whole process, so this is probably
4501 what you should use in this case (@pxref{Invoking guix copy}).
4503 @cindex nar, archive format
4504 @cindex normalized archive (nar)
4505 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4506 comparable in spirit to `tar', but with differences
4507 that make it more appropriate for our purposes. First, rather than
4508 recording all Unix metadata for each file, the nar format only mentions
4509 the file type (regular, directory, or symbolic link); Unix permissions
4510 and owner/group are dismissed. Second, the order in which directory
4511 entries are stored always follows the order of file names according to
4512 the C locale collation order. This makes archive production fully
4515 When exporting, the daemon digitally signs the contents of the archive,
4516 and that digital signature is appended. When importing, the daemon
4517 verifies the signature and rejects the import in case of an invalid
4518 signature or if the signing key is not authorized.
4519 @c FIXME: Add xref to daemon doc about signatures.
4521 The main options are:
4525 Export the specified store files or packages (see below.) Write the
4526 resulting archive to the standard output.
4528 Dependencies are @emph{not} included in the output, unless
4529 @code{--recursive} is passed.
4533 When combined with @code{--export}, this instructs @command{guix
4534 archive} to include dependencies of the given items in the archive.
4535 Thus, the resulting archive is self-contained: it contains the closure
4536 of the exported store items.
4539 Read an archive from the standard input, and import the files listed
4540 therein into the store. Abort if the archive has an invalid digital
4541 signature, or if it is signed by a public key not among the authorized
4542 keys (see @code{--authorize} below.)
4545 Read a list of store file names from the standard input, one per line,
4546 and write on the standard output the subset of these files missing from
4549 @item --generate-key[=@var{parameters}]
4550 @cindex signing, archives
4551 Generate a new key pair for the daemon. This is a prerequisite before
4552 archives can be exported with @code{--export}. Note that this operation
4553 usually takes time, because it needs to gather enough entropy to
4554 generate the key pair.
4556 The generated key pair is typically stored under @file{/etc/guix}, in
4557 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4558 key, which must be kept secret.) When @var{parameters} is omitted,
4559 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4560 versions before 1.6.0, it is a 4096-bit RSA key.
4561 Alternatively, @var{parameters} can specify
4562 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4563 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4564 Libgcrypt Reference Manual}).
4567 @cindex authorizing, archives
4568 Authorize imports signed by the public key passed on standard input.
4569 The public key must be in ``s-expression advanced format''---i.e., the
4570 same format as the @file{signing-key.pub} file.
4572 The list of authorized keys is kept in the human-editable file
4573 @file{/etc/guix/acl}. The file contains
4574 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4575 s-expressions''} and is structured as an access-control list in the
4576 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4579 @item --extract=@var{directory}
4580 @itemx -x @var{directory}
4581 Read a single-item archive as served by substitute servers
4582 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4583 low-level operation needed in only very narrow use cases; see below.
4585 For example, the following command extracts the substitute for Emacs
4586 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4590 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4591 | bunzip2 | guix archive -x /tmp/emacs
4594 Single-item archives are different from multiple-item archives produced
4595 by @command{guix archive --export}; they contain a single store item,
4596 and they do @emph{not} embed a signature. Thus this operation does
4597 @emph{no} signature verification and its output should be considered
4600 The primary purpose of this operation is to facilitate inspection of
4601 archive contents coming from possibly untrusted substitute servers.
4605 Read a single-item archive as served by substitute servers
4606 (@pxref{Substitutes}) and print the list of files it contains, as in
4611 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4612 | lzip -d | guix archive -t
4618 @c *********************************************************************
4620 @chapter Development
4622 @cindex software development
4623 If you are a software developer, Guix provides tools that you should find
4624 helpful---independently of the language you're developing in. This is what
4625 this chapter is about.
4627 The @command{guix environment} command provides a convenient way to set up
4628 @dfn{development environments} containing all the dependencies and tools
4629 necessary to work on the software package of your choice. The @command{guix
4630 pack} command allows you to create @dfn{application bundles} that can be
4631 easily distributed to users who do not run Guix.
4634 * Invoking guix environment:: Setting up development environments.
4635 * Invoking guix pack:: Creating software bundles.
4638 @node Invoking guix environment
4639 @section Invoking @command{guix environment}
4641 @cindex reproducible build environments
4642 @cindex development environments
4643 @cindex @command{guix environment}
4644 @cindex environment, package build environment
4645 The purpose of @command{guix environment} is to assist hackers in
4646 creating reproducible development environments without polluting their
4647 package profile. The @command{guix environment} tool takes one or more
4648 packages, builds all of their inputs, and creates a shell
4649 environment to use them.
4651 The general syntax is:
4654 guix environment @var{options} @var{package}@dots{}
4657 The following example spawns a new shell set up for the development of
4661 guix environment guile
4664 If the needed dependencies are not built yet, @command{guix environment}
4665 automatically builds them. The environment of the new shell is an augmented
4666 version of the environment that @command{guix environment} was run in.
4667 It contains the necessary search paths for building the given package
4668 added to the existing environment variables. To create a ``pure''
4669 environment, in which the original environment variables have been unset,
4670 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4671 environment variables such as @code{PATH} in their @file{~/.bashrc}
4672 file. As a consequence, when @code{guix environment} launches it, Bash
4673 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4674 environment variables. It is an error to define such environment
4675 variables in @file{.bashrc}; instead, they should be defined in
4676 @file{.bash_profile}, which is sourced only by log-in shells.
4677 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4678 details on Bash start-up files.}.
4680 @vindex GUIX_ENVIRONMENT
4681 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4682 variable in the shell it spawns; its value is the file name of the
4683 profile of this environment. This allows users to, say, define a
4684 specific prompt for development environments in their @file{.bashrc}
4685 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4688 if [ -n "$GUIX_ENVIRONMENT" ]
4690 export PS1="\u@@\h \w [dev]\$ "
4695 ...@: or to browse the profile:
4698 $ ls "$GUIX_ENVIRONMENT/bin"
4701 Additionally, more than one package may be specified, in which case the
4702 union of the inputs for the given packages are used. For example, the
4703 command below spawns a shell where all of the dependencies of both Guile
4704 and Emacs are available:
4707 guix environment guile emacs
4710 Sometimes an interactive shell session is not desired. An arbitrary
4711 command may be invoked by placing the @code{--} token to separate the
4712 command from the rest of the arguments:
4715 guix environment guile -- make -j4
4718 In other situations, it is more convenient to specify the list of
4719 packages needed in the environment. For example, the following command
4720 runs @command{python} from an environment containing Python@tie{}2.7 and
4724 guix environment --ad-hoc python2-numpy python-2.7 -- python
4727 Furthermore, one might want the dependencies of a package and also some
4728 additional packages that are not build-time or runtime dependencies, but
4729 are useful when developing nonetheless. Because of this, the
4730 @code{--ad-hoc} flag is positional. Packages appearing before
4731 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4732 added to the environment. Packages appearing after are interpreted as
4733 packages that will be added to the environment directly. For example,
4734 the following command creates a Guix development environment that
4735 additionally includes Git and strace:
4738 guix environment guix --ad-hoc git strace
4741 Sometimes it is desirable to isolate the environment as much as
4742 possible, for maximal purity and reproducibility. In particular, when
4743 using Guix on a host distro that is not Guix System, it is desirable to
4744 prevent access to @file{/usr/bin} and other system-wide resources from
4745 the development environment. For example, the following command spawns
4746 a Guile REPL in a ``container'' where only the store and the current
4747 working directory are mounted:
4750 guix environment --ad-hoc --container guile -- guile
4754 The @code{--container} option requires Linux-libre 3.19 or newer.
4757 The available options are summarized below.
4760 @item --root=@var{file}
4761 @itemx -r @var{file}
4762 @cindex persistent environment
4763 @cindex garbage collector root, for environments
4764 Make @var{file} a symlink to the profile for this environment, and
4765 register it as a garbage collector root.
4767 This is useful if you want to protect your environment from garbage
4768 collection, to make it ``persistent''.
4770 When this option is omitted, the environment is protected from garbage
4771 collection only for the duration of the @command{guix environment}
4772 session. This means that next time you recreate the same environment,
4773 you could have to rebuild or re-download packages. @xref{Invoking guix
4774 gc}, for more on GC roots.
4776 @item --expression=@var{expr}
4777 @itemx -e @var{expr}
4778 Create an environment for the package or list of packages that
4779 @var{expr} evaluates to.
4781 For example, running:
4784 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4787 starts a shell with the environment for this specific variant of the
4793 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4796 starts a shell with all the base system packages available.
4798 The above commands only use the default output of the given packages.
4799 To select other outputs, two element tuples can be specified:
4802 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4805 @item --load=@var{file}
4806 @itemx -l @var{file}
4807 Create an environment for the package or list of packages that the code
4808 within @var{file} evaluates to.
4810 As an example, @var{file} might contain a definition like this
4811 (@pxref{Defining Packages}):
4814 @verbatiminclude environment-gdb.scm
4817 @item --manifest=@var{file}
4818 @itemx -m @var{file}
4819 Create an environment for the packages contained in the manifest object
4820 returned by the Scheme code in @var{file}. This option can be repeated
4821 several times, in which case the manifests are concatenated.
4823 This is similar to the same-named option in @command{guix package}
4824 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4828 Include all specified packages in the resulting environment, as if an
4829 @i{ad hoc} package were defined with them as inputs. This option is
4830 useful for quickly creating an environment without having to write a
4831 package expression to contain the desired inputs.
4833 For instance, the command:
4836 guix environment --ad-hoc guile guile-sdl -- guile
4839 runs @command{guile} in an environment where Guile and Guile-SDL are
4842 Note that this example implicitly asks for the default output of
4843 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4844 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4845 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4847 This option may be composed with the default behavior of @command{guix
4848 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4849 as packages whose dependencies will be added to the environment, the
4850 default behavior. Packages appearing after are interpreted as packages
4851 that will be added to the environment directly.
4854 Unset existing environment variables when building the new environment, except
4855 those specified with @option{--preserve} (see below.) This has the effect of
4856 creating an environment in which search paths only contain package inputs.
4858 @item --preserve=@var{regexp}
4859 @itemx -E @var{regexp}
4860 When used alongside @option{--pure}, preserve the environment variables
4861 matching @var{regexp}---in other words, put them on a ``white list'' of
4862 environment variables that must be preserved. This option can be repeated
4866 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4870 This example runs @command{mpirun} in a context where the only environment
4871 variables defined are @code{PATH}, environment variables whose name starts
4872 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4875 @item --search-paths
4876 Display the environment variable definitions that make up the
4879 @item --system=@var{system}
4880 @itemx -s @var{system}
4881 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4886 Run @var{command} within an isolated container. The current working
4887 directory outside the container is mapped inside the container.
4888 Additionally, unless overridden with @code{--user}, a dummy home
4889 directory is created that matches the current user's home directory, and
4890 @file{/etc/passwd} is configured accordingly.
4892 The spawned process runs as the current user outside the container. Inside
4893 the container, it has the same UID and GID as the current user, unless
4894 @option{--user} is passed (see below.)
4898 For containers, share the network namespace with the host system.
4899 Containers created without this flag only have access to the loopback
4902 @item --link-profile
4904 For containers, link the environment profile to
4905 @file{~/.guix-profile} within the container. This is equivalent to
4906 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4907 within the container. Linking will fail and abort the environment if
4908 the directory already exists, which will certainly be the case if
4909 @command{guix environment} was invoked in the user's home directory.
4911 Certain packages are configured to look in
4912 @code{~/.guix-profile} for configuration files and data;@footnote{For
4913 example, the @code{fontconfig} package inspects
4914 @file{~/.guix-profile/share/fonts} for additional fonts.}
4915 @code{--link-profile} allows these programs to behave as expected within
4918 @item --user=@var{user}
4919 @itemx -u @var{user}
4920 For containers, use the username @var{user} in place of the current
4921 user. The generated @file{/etc/passwd} entry within the container will
4922 contain the name @var{user}, the home directory will be
4923 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4924 the UID and GID inside the container are 1000. @var{user}
4925 need not exist on the system.
4927 Additionally, any shared or exposed path (see @code{--share} and
4928 @code{--expose} respectively) whose target is within the current user's
4929 home directory will be remapped relative to @file{/home/USER}; this
4930 includes the automatic mapping of the current working directory.
4933 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4935 guix environment --container --user=foo \
4936 --expose=$HOME/test \
4937 --expose=/tmp/target=$HOME/target
4940 While this will limit the leaking of user identity through home paths
4941 and each of the user fields, this is only one useful component of a
4942 broader privacy/anonymity solution---not one in and of itself.
4945 For containers, the default behavior is to share the current working
4946 directory with the isolated container and immediately change to that
4947 directory within the container. If this is undesirable, @code{--no-cwd}
4948 will cause the current working directory to @emph{not} be automatically
4949 shared and will change to the user's home directory within the container
4950 instead. See also @code{--user}.
4952 @item --expose=@var{source}[=@var{target}]
4953 For containers, expose the file system @var{source} from the host system
4954 as the read-only file system @var{target} within the container. If
4955 @var{target} is not specified, @var{source} is used as the target mount
4956 point in the container.
4958 The example below spawns a Guile REPL in a container in which the user's
4959 home directory is accessible read-only via the @file{/exchange}
4963 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4966 @item --share=@var{source}[=@var{target}]
4967 For containers, share the file system @var{source} from the host system
4968 as the writable file system @var{target} within the container. If
4969 @var{target} is not specified, @var{source} is used as the target mount
4970 point in the container.
4972 The example below spawns a Guile REPL in a container in which the user's
4973 home directory is accessible for both reading and writing via the
4974 @file{/exchange} directory:
4977 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4981 @command{guix environment}
4982 also supports all of the common build options that @command{guix
4983 build} supports (@pxref{Common Build Options}) as well as package
4984 transformation options (@pxref{Package Transformation Options}).
4986 @node Invoking guix pack
4987 @section Invoking @command{guix pack}
4989 Occasionally you want to pass software to people who are not (yet!)
4990 lucky enough to be using Guix. You'd tell them to run @command{guix
4991 package -i @var{something}}, but that's not possible in this case. This
4992 is where @command{guix pack} comes in.
4995 If you are looking for ways to exchange binaries among machines that
4996 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4997 publish}, and @ref{Invoking guix archive}.
5002 @cindex application bundle
5003 @cindex software bundle
5004 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5005 @dfn{software bundle}: it creates a tarball or some other archive
5006 containing the binaries of the software you're interested in, and all
5007 its dependencies. The resulting archive can be used on any machine that
5008 does not have Guix, and people can run the exact same binaries as those
5009 you have with Guix. The pack itself is created in a bit-reproducible
5010 fashion, so anyone can verify that it really contains the build results
5011 that you pretend to be shipping.
5013 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5014 their dependencies, you can run:
5017 $ guix pack guile emacs geiser
5019 /gnu/store/@dots{}-pack.tar.gz
5022 The result here is a tarball containing a @file{/gnu/store} directory
5023 with all the relevant packages. The resulting tarball contains a
5024 @dfn{profile} with the three packages of interest; the profile is the
5025 same as would be created by @command{guix package -i}. It is this
5026 mechanism that is used to create Guix's own standalone binary tarball
5027 (@pxref{Binary Installation}).
5029 Users of this pack would have to run
5030 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5031 find inconvenient. To work around it, you can create, say, a
5032 @file{/opt/gnu/bin} symlink to the profile:
5035 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5039 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5041 @cindex relocatable binaries, with @command{guix pack}
5042 What if the recipient of your pack does not have root privileges on
5043 their machine, and thus cannot unpack it in the root file system? In
5044 that case, you will want to use the @code{--relocatable} option (see
5045 below). This option produces @dfn{relocatable binaries}, meaning they
5046 they can be placed anywhere in the file system hierarchy: in the example
5047 above, users can unpack your tarball in their home directory and
5048 directly run @file{./opt/gnu/bin/guile}.
5050 @cindex Docker, build an image with guix pack
5051 Alternatively, you can produce a pack in the Docker image format using
5052 the following command:
5055 guix pack -f docker guile emacs geiser
5059 The result is a tarball that can be passed to the @command{docker load}
5061 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5062 documentation} for more information.
5064 @cindex Singularity, build an image with guix pack
5065 @cindex SquashFS, build an image with guix pack
5066 Yet another option is to produce a SquashFS image with the following
5070 guix pack -f squashfs bash guile emacs geiser
5074 The result is a SquashFS file system image that can either be mounted or
5075 directly be used as a file system container image with the
5076 @uref{https://singularity.lbl.gov, Singularity container execution
5077 environment}, using commands like @command{singularity shell} or
5078 @command{singularity exec}.
5080 Several command-line options allow you to customize your pack:
5083 @item --format=@var{format}
5084 @itemx -f @var{format}
5085 Produce a pack in the given @var{format}.
5087 The available formats are:
5091 This is the default format. It produces a tarball containing all the
5092 specified binaries and symlinks.
5095 This produces a tarball that follows the
5096 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5097 Docker Image Specification}. The ``repository name'' as it appears in
5098 the output of the @command{docker images} command is computed from
5099 package names passed on the command line or in the manifest file.
5102 This produces a SquashFS image containing all the specified binaries and
5103 symlinks, as well as empty mount points for virtual file systems like
5107 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5108 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5109 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5110 with something like:
5113 guix pack -f squashfs bash @dots{}
5116 If you forget the @code{bash} (or similar) package, @command{singularity
5117 run} and @command{singularity exec} will fail with an unhelpful ``no
5118 such file or directory'' message.
5122 @cindex relocatable binaries
5125 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5126 anywhere in the file system hierarchy and run from there.
5128 When this option is passed once, the resulting binaries require support for
5129 @dfn{user namespaces} in the kernel Linux; when passed
5130 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5131 PRoot support, can be thought of as the abbreviation of ``Really
5132 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5133 if user namespaces are unavailable, and essentially work anywhere---see below
5134 for the implications.
5136 For example, if you create a pack containing Bash with:
5139 guix pack -RR -S /mybin=bin bash
5143 ...@: you can copy that pack to a machine that lacks Guix, and from your
5144 home directory as a normal user, run:
5152 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5153 @file{/gnu/store} shows up and contains all the dependencies of
5154 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5155 altogether! That is probably the simplest way to deploy Guix-built
5156 software on a non-Guix machine.
5159 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5160 the kernel Linux, which allows unprivileged users to mount or change root.
5161 Old versions of Linux did not support it, and some GNU/Linux distributions
5164 To produce relocatable binaries that work even in the absence of user
5165 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5166 case, binaries will try user namespace support and fall back to PRoot if user
5167 namespaces are not supported.
5169 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5170 support for file system virtualization. It achieves that by using the
5171 @code{ptrace} system call on the running program. This approach has the
5172 advantage to work without requiring special kernel support, but it incurs
5173 run-time overhead every time a system call is made.
5176 @cindex entry point, for Docker images
5177 @item --entry-point=@var{command}
5178 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5179 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5180 support it. @var{command} must be relative to the profile contained in the
5183 The entry point specifies the command that tools like @code{docker run} or
5184 @code{singularity run} automatically start by default. For example, you can
5188 guix pack -f docker --entry-point=bin/guile guile
5191 The resulting pack can easily be loaded and @code{docker run} with no extra
5192 arguments will spawn @code{bin/guile}:
5195 docker load -i pack.tar.gz
5196 docker run @var{image-id}
5199 @item --expression=@var{expr}
5200 @itemx -e @var{expr}
5201 Consider the package @var{expr} evaluates to.
5203 This has the same purpose as the same-named option in @command{guix
5204 build} (@pxref{Additional Build Options, @code{--expression} in
5205 @command{guix build}}).
5207 @item --manifest=@var{file}
5208 @itemx -m @var{file}
5209 Use the packages contained in the manifest object returned by the Scheme
5210 code in @var{file}. This option can be repeated several times, in which
5211 case the manifests are concatenated.
5213 This has a similar purpose as the same-named option in @command{guix
5214 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5215 same manifest files. It allows you to define a collection of packages
5216 once and use it both for creating profiles and for creating archives
5217 for use on machines that do not have Guix installed. Note that you can
5218 specify @emph{either} a manifest file @emph{or} a list of packages,
5221 @item --system=@var{system}
5222 @itemx -s @var{system}
5223 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5224 the system type of the build host.
5226 @item --target=@var{triplet}
5227 @cindex cross-compilation
5228 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5229 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5230 configuration triplets,, autoconf, Autoconf}).
5232 @item --compression=@var{tool}
5233 @itemx -C @var{tool}
5234 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5235 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5237 @item --symlink=@var{spec}
5238 @itemx -S @var{spec}
5239 Add the symlinks specified by @var{spec} to the pack. This option can
5240 appear several times.
5242 @var{spec} has the form @code{@var{source}=@var{target}}, where
5243 @var{source} is the symlink that will be created and @var{target} is the
5246 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5247 symlink pointing to the @file{bin} sub-directory of the profile.
5249 @item --save-provenance
5250 Save provenance information for the packages passed on the command line.
5251 Provenance information includes the URL and commit of the channels in use
5254 Provenance information is saved in the
5255 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5256 usual package metadata---the name and version of each package, their
5257 propagated inputs, and so on. It is useful information to the recipient of
5258 the pack, who then knows how the pack was (supposedly) obtained.
5260 This option is not enabled by default because, like timestamps, provenance
5261 information contributes nothing to the build process. In other words, there
5262 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5263 Recording such ``silent'' metadata in the output thus potentially breaks the
5264 source-to-binary bitwise reproducibility property.
5266 @item --root=@var{file}
5267 @itemx -r @var{file}
5268 @cindex garbage collector root, for packs
5269 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5272 @item --localstatedir
5273 @itemx --profile-name=@var{name}
5274 Include the ``local state directory'', @file{/var/guix}, in the resulting
5275 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5276 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5277 @file{~root/.guix-profile}.
5279 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5280 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5281 the pack means that the store is ``complete'' and manageable by Guix;
5282 not providing it pack means that the store is ``dead'': items cannot be
5283 added to it or removed from it after extraction of the pack.
5285 One use case for this is the Guix self-contained binary tarball
5286 (@pxref{Binary Installation}).
5290 Print the name of the derivation that builds the pack.
5293 Use the bootstrap binaries to build the pack. This option is only
5294 useful to Guix developers.
5297 In addition, @command{guix pack} supports all the common build options
5298 (@pxref{Common Build Options}) and all the package transformation
5299 options (@pxref{Package Transformation Options}).
5302 @c *********************************************************************
5303 @node Programming Interface
5304 @chapter Programming Interface
5306 GNU Guix provides several Scheme programming interfaces (APIs) to
5307 define, build, and query packages. The first interface allows users to
5308 write high-level package definitions. These definitions refer to
5309 familiar packaging concepts, such as the name and version of a package,
5310 its build system, and its dependencies. These definitions can then be
5311 turned into concrete build actions.
5313 Build actions are performed by the Guix daemon, on behalf of users. In a
5314 standard setup, the daemon has write access to the store---the
5315 @file{/gnu/store} directory---whereas users do not. The recommended
5316 setup also has the daemon perform builds in chroots, under a specific
5317 build users, to minimize interference with the rest of the system.
5320 Lower-level APIs are available to interact with the daemon and the
5321 store. To instruct the daemon to perform a build action, users actually
5322 provide it with a @dfn{derivation}. A derivation is a low-level
5323 representation of the build actions to be taken, and the environment in
5324 which they should occur---derivations are to package definitions what
5325 assembly is to C programs. The term ``derivation'' comes from the fact
5326 that build results @emph{derive} from them.
5328 This chapter describes all these APIs in turn, starting from high-level
5329 package definitions.
5332 * Package Modules:: Packages from the programmer's viewpoint.
5333 * Defining Packages:: Defining new packages.
5334 * Build Systems:: Specifying how packages are built.
5335 * The Store:: Manipulating the package store.
5336 * Derivations:: Low-level interface to package derivations.
5337 * The Store Monad:: Purely functional interface to the store.
5338 * G-Expressions:: Manipulating build expressions.
5339 * Invoking guix repl:: Fiddling with Guix interactively.
5342 @node Package Modules
5343 @section Package Modules
5345 From a programming viewpoint, the package definitions of the
5346 GNU distribution are provided by Guile modules in the @code{(gnu packages
5347 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5348 packages @dots{})} module name space are not necessarily ``GNU
5349 packages''. This module naming scheme follows the usual Guile module
5350 naming convention: @code{gnu} means that these modules are distributed
5351 as part of the GNU system, and @code{packages} identifies modules that
5352 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5353 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5354 module exports a variable named @code{emacs}, which is bound to a
5355 @code{<package>} object (@pxref{Defining Packages}).
5357 The @code{(gnu packages @dots{})} module name space is
5358 automatically scanned for packages by the command-line tools. For
5359 instance, when running @code{guix install emacs}, all the @code{(gnu
5360 packages @dots{})} modules are scanned until one that exports a package
5361 object whose name is @code{emacs} is found. This package search
5362 facility is implemented in the @code{(gnu packages)} module.
5364 @cindex customization, of packages
5365 @cindex package module search path
5366 Users can store package definitions in modules with different
5367 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5368 name and module name must match. For instance, the @code{(my-packages
5369 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5370 relative to the load path specified with @option{--load-path} or
5371 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5372 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5373 these package definitions visible to the user interfaces:
5377 By adding the directory containing your package modules to the search path
5378 with the @code{-L} flag of @command{guix package} and other commands
5379 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5380 environment variable described below.
5383 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5384 pulls from it. A channel is essentially a Git repository containing package
5385 modules. @xref{Channels}, for more information on how to define and use
5389 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5391 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5392 This is a colon-separated list of directories to search for additional
5393 package modules. Directories listed in this variable take precedence
5394 over the own modules of the distribution.
5397 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5398 each package is built based solely on other packages in the
5399 distribution. The root of this dependency graph is a small set of
5400 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5401 bootstrap)} module. For more information on bootstrapping,
5402 @pxref{Bootstrapping}.
5404 @node Defining Packages
5405 @section Defining Packages
5407 The high-level interface to package definitions is implemented in the
5408 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5409 example, the package definition, or @dfn{recipe}, for the GNU Hello
5410 package looks like this:
5413 (define-module (gnu packages hello)
5414 #:use-module (guix packages)
5415 #:use-module (guix download)
5416 #:use-module (guix build-system gnu)
5417 #:use-module (guix licenses)
5418 #:use-module (gnu packages gawk))
5420 (define-public hello
5426 (uri (string-append "mirror://gnu/hello/hello-" version
5430 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5431 (build-system gnu-build-system)
5432 (arguments '(#:configure-flags '("--enable-silent-rules")))
5433 (inputs `(("gawk" ,gawk)))
5434 (synopsis "Hello, GNU world: An example GNU package")
5435 (description "Guess what GNU Hello prints!")
5436 (home-page "https://www.gnu.org/software/hello/")
5441 Without being a Scheme expert, the reader may have guessed the meaning
5442 of the various fields here. This expression binds the variable
5443 @code{hello} to a @code{<package>} object, which is essentially a record
5444 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5445 This package object can be inspected using procedures found in the
5446 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5447 returns---surprise!---@code{"hello"}.
5449 With luck, you may be able to import part or all of the definition of
5450 the package you are interested in from another repository, using the
5451 @code{guix import} command (@pxref{Invoking guix import}).
5453 In the example above, @var{hello} is defined in a module of its own,
5454 @code{(gnu packages hello)}. Technically, this is not strictly
5455 necessary, but it is convenient to do so: all the packages defined in
5456 modules under @code{(gnu packages @dots{})} are automatically known to
5457 the command-line tools (@pxref{Package Modules}).
5459 There are a few points worth noting in the above package definition:
5463 The @code{source} field of the package is an @code{<origin>} object
5464 (@pxref{origin Reference}, for the complete reference).
5465 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5466 meaning that the source is a file to be downloaded over FTP or HTTP.
5468 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5469 the GNU mirrors defined in @code{(guix download)}.
5471 The @code{sha256} field specifies the expected SHA256 hash of the file
5472 being downloaded. It is mandatory, and allows Guix to check the
5473 integrity of the file. The @code{(base32 @dots{})} form introduces the
5474 base32 representation of the hash. You can obtain this information with
5475 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5476 hash} (@pxref{Invoking guix hash}).
5479 When needed, the @code{origin} form can also have a @code{patches} field
5480 listing patches to be applied, and a @code{snippet} field giving a
5481 Scheme expression to modify the source code.
5484 @cindex GNU Build System
5485 The @code{build-system} field specifies the procedure to build the
5486 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5487 represents the familiar GNU Build System, where packages may be
5488 configured, built, and installed with the usual @code{./configure &&
5489 make && make check && make install} command sequence.
5492 The @code{arguments} field specifies options for the build system
5493 (@pxref{Build Systems}). Here it is interpreted by
5494 @var{gnu-build-system} as a request run @file{configure} with the
5495 @code{--enable-silent-rules} flag.
5501 What about these quote (@code{'}) characters? They are Scheme syntax to
5502 introduce a literal list; @code{'} is synonymous with @code{quote}.
5503 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5504 for details. Here the value of the @code{arguments} field is a list of
5505 arguments passed to the build system down the road, as with @code{apply}
5506 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5509 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5510 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5511 @code{#:configure-flags} is a keyword used to pass a keyword argument
5512 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5516 The @code{inputs} field specifies inputs to the build process---i.e.,
5517 build-time or run-time dependencies of the package. Here, we define an
5518 input called @code{"gawk"} whose value is that of the @var{gawk}
5519 variable; @var{gawk} is itself bound to a @code{<package>} object.
5521 @cindex backquote (quasiquote)
5524 @cindex comma (unquote)
5528 @findex unquote-splicing
5529 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5530 us to introduce a literal list in the @code{inputs} field, while
5531 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5532 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5535 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5536 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5537 of ensuring that they are present (@pxref{Build Systems}).
5539 However, any other dependencies need to be specified in the
5540 @code{inputs} field. Any dependency not specified here will simply be
5541 unavailable to the build process, possibly leading to a build failure.
5544 @xref{package Reference}, for a full description of possible fields.
5546 Once a package definition is in place, the
5547 package may actually be built using the @code{guix build} command-line
5548 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5549 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5550 package definition using the @command{guix edit} command
5551 (@pxref{Invoking guix edit}).
5552 @xref{Packaging Guidelines}, for
5553 more information on how to test package definitions, and
5554 @ref{Invoking guix lint}, for information on how to check a definition
5555 for style conformance.
5556 @vindex GUIX_PACKAGE_PATH
5557 Lastly, @pxref{Channels}, for information
5558 on how to extend the distribution by adding your own package definitions
5561 Finally, updating the package definition to a new upstream version
5562 can be partly automated by the @command{guix refresh} command
5563 (@pxref{Invoking guix refresh}).
5565 Behind the scenes, a derivation corresponding to the @code{<package>}
5566 object is first computed by the @code{package-derivation} procedure.
5567 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5568 The build actions it prescribes may then be realized by using the
5569 @code{build-derivations} procedure (@pxref{The Store}).
5571 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5572 Return the @code{<derivation>} object of @var{package} for @var{system}
5573 (@pxref{Derivations}).
5575 @var{package} must be a valid @code{<package>} object, and @var{system}
5576 must be a string denoting the target system type---e.g.,
5577 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5578 must be a connection to the daemon, which operates on the store
5579 (@pxref{The Store}).
5583 @cindex cross-compilation
5584 Similarly, it is possible to compute a derivation that cross-builds a
5585 package for some other system:
5587 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5588 @var{package} @var{target} [@var{system}]
5589 Return the @code{<derivation>} object of @var{package} cross-built from
5590 @var{system} to @var{target}.
5592 @var{target} must be a valid GNU triplet denoting the target hardware
5593 and operating system, such as @code{"mips64el-linux-gnu"}
5594 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5597 @cindex package transformations
5598 @cindex input rewriting
5599 @cindex dependency tree rewriting
5600 Packages can be manipulated in arbitrary ways. An example of a useful
5601 transformation is @dfn{input rewriting}, whereby the dependency tree of
5602 a package is rewritten by replacing specific inputs by others:
5604 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5605 [@var{rewrite-name}]
5606 Return a procedure that, when passed a package, replaces its direct and
5607 indirect dependencies (but not its implicit inputs) according to
5608 @var{replacements}. @var{replacements} is a list of package pairs; the
5609 first element of each pair is the package to replace, and the second one
5612 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5613 the name of a package and returns its new name after rewrite.
5617 Consider this example:
5620 (define libressl-instead-of-openssl
5621 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5623 (package-input-rewriting `((,openssl . ,libressl))))
5625 (define git-with-libressl
5626 (libressl-instead-of-openssl git))
5630 Here we first define a rewriting procedure that replaces @var{openssl}
5631 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5632 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5633 This is exactly what the @option{--with-input} command-line option does
5634 (@pxref{Package Transformation Options, @option{--with-input}}).
5636 The following variant of @code{package-input-rewriting} can match packages to
5637 be replaced by name rather than by identity.
5639 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5640 Return a procedure that, given a package, applies the given @var{replacements} to
5641 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5642 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5643 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5644 replacement for that package.
5647 The example above could be rewritten this way:
5650 (define libressl-instead-of-openssl
5651 ;; Replace all the packages called "openssl" with LibreSSL.
5652 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5655 The key difference here is that, this time, packages are matched by spec and
5656 not by identity. In other words, any package in the graph that is called
5657 @code{openssl} will be replaced.
5659 A more generic procedure to rewrite a package dependency graph is
5660 @code{package-mapping}: it supports arbitrary changes to nodes in the
5663 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5664 Return a procedure that, given a package, applies @var{proc} to all the packages
5665 depended on and returns the resulting package. The procedure stops recursion
5666 when @var{cut?} returns true for a given package.
5670 * package Reference:: The package data type.
5671 * origin Reference:: The origin data type.
5675 @node package Reference
5676 @subsection @code{package} Reference
5678 This section summarizes all the options available in @code{package}
5679 declarations (@pxref{Defining Packages}).
5681 @deftp {Data Type} package
5682 This is the data type representing a package recipe.
5686 The name of the package, as a string.
5688 @item @code{version}
5689 The version of the package, as a string.
5692 An object telling how the source code for the package should be
5693 acquired. Most of the time, this is an @code{origin} object, which
5694 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5695 can also be any other ``file-like'' object such as a @code{local-file},
5696 which denotes a file from the local file system (@pxref{G-Expressions,
5697 @code{local-file}}).
5699 @item @code{build-system}
5700 The build system that should be used to build the package (@pxref{Build
5703 @item @code{arguments} (default: @code{'()})
5704 The arguments that should be passed to the build system. This is a
5705 list, typically containing sequential keyword-value pairs.
5707 @item @code{inputs} (default: @code{'()})
5708 @itemx @code{native-inputs} (default: @code{'()})
5709 @itemx @code{propagated-inputs} (default: @code{'()})
5710 @cindex inputs, of packages
5711 These fields list dependencies of the package. Each one is a list of
5712 tuples, where each tuple has a label for the input (a string) as its
5713 first element, a package, origin, or derivation as its second element,
5714 and optionally the name of the output thereof that should be used, which
5715 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5716 more on package outputs). For example, the list below specifies three
5720 `(("libffi" ,libffi)
5721 ("libunistring" ,libunistring)
5722 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5725 @cindex cross compilation, package dependencies
5726 The distinction between @code{native-inputs} and @code{inputs} is
5727 necessary when considering cross-compilation. When cross-compiling,
5728 dependencies listed in @code{inputs} are built for the @emph{target}
5729 architecture; conversely, dependencies listed in @code{native-inputs}
5730 are built for the architecture of the @emph{build} machine.
5732 @code{native-inputs} is typically used to list tools needed at
5733 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5734 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5735 this area (@pxref{Invoking guix lint}).
5737 @anchor{package-propagated-inputs}
5738 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5739 specified packages will be automatically installed alongside the package
5740 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5741 package}}, for information on how @command{guix package} deals with
5744 For example this is necessary when a C/C++ library needs headers of
5745 another library to compile, or when a pkg-config file refers to another
5746 one @i{via} its @code{Requires} field.
5748 Another example where @code{propagated-inputs} is useful is for languages
5749 that lack a facility to record the run-time search path akin to the
5750 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5751 more. To ensure that libraries written in those languages can find
5752 library code they depend on at run time, run-time dependencies must be
5753 listed in @code{propagated-inputs} rather than @code{inputs}.
5755 @item @code{outputs} (default: @code{'("out")})
5756 The list of output names of the package. @xref{Packages with Multiple
5757 Outputs}, for typical uses of additional outputs.
5759 @item @code{native-search-paths} (default: @code{'()})
5760 @itemx @code{search-paths} (default: @code{'()})
5761 A list of @code{search-path-specification} objects describing
5762 search-path environment variables honored by the package.
5764 @item @code{replacement} (default: @code{#f})
5765 This must be either @code{#f} or a package object that will be used as a
5766 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5769 @item @code{synopsis}
5770 A one-line description of the package.
5772 @item @code{description}
5773 A more elaborate description of the package.
5775 @item @code{license}
5776 @cindex license, of packages
5777 The license of the package; a value from @code{(guix licenses)},
5778 or a list of such values.
5780 @item @code{home-page}
5781 The URL to the home-page of the package, as a string.
5783 @item @code{supported-systems} (default: @var{%supported-systems})
5784 The list of systems supported by the package, as strings of the form
5785 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5787 @item @code{location} (default: source location of the @code{package} form)
5788 The source location of the package. It is useful to override this when
5789 inheriting from another package, in which case this field is not
5790 automatically corrected.
5794 @deffn {Scheme Syntax} this-package
5795 When used in the @emph{lexical scope} of a package field definition, this
5796 identifier resolves to the package being defined.
5798 The example below shows how to add a package as a native input of itself when
5806 ;; When cross-compiled, Guile, for example, depends on
5807 ;; a native version of itself. Add it here.
5808 (native-inputs (if (%current-target-system)
5809 `(("self" ,this-package))
5813 It is an error to refer to @code{this-package} outside a package definition.
5816 @node origin Reference
5817 @subsection @code{origin} Reference
5819 This section summarizes all the options available in @code{origin}
5820 declarations (@pxref{Defining Packages}).
5822 @deftp {Data Type} origin
5823 This is the data type representing a source code origin.
5827 An object containing the URI of the source. The object type depends on
5828 the @code{method} (see below). For example, when using the
5829 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5830 values are: a URL represented as a string, or a list thereof.
5833 A procedure that handles the URI.
5838 @item @var{url-fetch} from @code{(guix download)}
5839 download a file from the HTTP, HTTPS, or FTP URL specified in the
5843 @item @var{git-fetch} from @code{(guix git-download)}
5844 clone the Git version control repository, and check out the revision
5845 specified in the @code{uri} field as a @code{git-reference} object; a
5846 @code{git-reference} looks like this:
5850 (url "https://git.savannah.gnu.org/git/hello.git")
5856 A bytevector containing the SHA-256 hash of the source. Typically the
5857 @code{base32} form is used here to generate the bytevector from a
5860 You can obtain this information using @code{guix download}
5861 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5864 @item @code{file-name} (default: @code{#f})
5865 The file name under which the source code should be saved. When this is
5866 @code{#f}, a sensible default value will be used in most cases. In case
5867 the source is fetched from a URL, the file name from the URL will be
5868 used. For version control checkouts, it is recommended to provide the
5869 file name explicitly because the default is not very descriptive.
5871 @item @code{patches} (default: @code{'()})
5872 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5873 file-like objects}) pointing to patches to be applied to the source.
5875 This list of patches must be unconditional. In particular, it cannot
5876 depend on the value of @code{%current-system} or
5877 @code{%current-target-system}.
5879 @item @code{snippet} (default: @code{#f})
5880 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5881 in the source directory. This is a convenient way to modify the source,
5882 sometimes more convenient than a patch.
5884 @item @code{patch-flags} (default: @code{'("-p1")})
5885 A list of command-line flags that should be passed to the @code{patch}
5888 @item @code{patch-inputs} (default: @code{#f})
5889 Input packages or derivations to the patching process. When this is
5890 @code{#f}, the usual set of inputs necessary for patching are provided,
5891 such as GNU@tie{}Patch.
5893 @item @code{modules} (default: @code{'()})
5894 A list of Guile modules that should be loaded during the patching
5895 process and while running the code in the @code{snippet} field.
5897 @item @code{patch-guile} (default: @code{#f})
5898 The Guile package that should be used in the patching process. When
5899 this is @code{#f}, a sensible default is used.
5905 @section Build Systems
5907 @cindex build system
5908 Each package definition specifies a @dfn{build system} and arguments for
5909 that build system (@pxref{Defining Packages}). This @code{build-system}
5910 field represents the build procedure of the package, as well as implicit
5911 dependencies of that build procedure.
5913 Build systems are @code{<build-system>} objects. The interface to
5914 create and manipulate them is provided by the @code{(guix build-system)}
5915 module, and actual build systems are exported by specific modules.
5917 @cindex bag (low-level package representation)
5918 Under the hood, build systems first compile package objects to
5919 @dfn{bags}. A @dfn{bag} is like a package, but with less
5920 ornamentation---in other words, a bag is a lower-level representation of
5921 a package, which includes all the inputs of that package, including some
5922 that were implicitly added by the build system. This intermediate
5923 representation is then compiled to a derivation (@pxref{Derivations}).
5925 Build systems accept an optional list of @dfn{arguments}. In package
5926 definitions, these are passed @i{via} the @code{arguments} field
5927 (@pxref{Defining Packages}). They are typically keyword arguments
5928 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5929 Guile Reference Manual}). The value of these arguments is usually
5930 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5931 by the daemon (@pxref{Derivations}).
5933 The main build system is @var{gnu-build-system}, which implements the
5934 standard build procedure for GNU and many other packages. It
5935 is provided by the @code{(guix build-system gnu)} module.
5937 @defvr {Scheme Variable} gnu-build-system
5938 @var{gnu-build-system} represents the GNU Build System, and variants
5939 thereof (@pxref{Configuration, configuration and makefile conventions,,
5940 standards, GNU Coding Standards}).
5942 @cindex build phases
5943 In a nutshell, packages using it are configured, built, and installed with
5944 the usual @code{./configure && make && make check && make install}
5945 command sequence. In practice, a few additional steps are often needed.
5946 All these steps are split up in separate @dfn{phases},
5947 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5948 modules for more details about the build phases.}:
5952 Unpack the source tarball, and change the current directory to the
5953 extracted source tree. If the source is actually a directory, copy it
5954 to the build tree, and enter that directory.
5956 @item patch-source-shebangs
5957 Patch shebangs encountered in source files so they refer to the right
5958 store file names. For instance, this changes @code{#!/bin/sh} to
5959 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5962 Run the @file{configure} script with a number of default options, such
5963 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5964 by the @code{#:configure-flags} argument.
5967 Run @code{make} with the list of flags specified with
5968 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5969 (the default), build with @code{make -j}.
5972 Run @code{make check}, or some other target specified with
5973 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5974 @code{#:parallel-tests?} argument is true (the default), run @code{make
5978 Run @code{make install} with the flags listed in @code{#:make-flags}.
5980 @item patch-shebangs
5981 Patch shebangs on the installed executable files.
5984 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5985 is false), copying them to the @code{debug} output when available
5986 (@pxref{Installing Debugging Files}).
5989 @vindex %standard-phases
5990 The build-side module @code{(guix build gnu-build-system)} defines
5991 @var{%standard-phases} as the default list of build phases.
5992 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5993 procedure implements the actual phase.
5995 The list of phases used for a particular package can be changed with the
5996 @code{#:phases} parameter. For instance, passing:
5999 #:phases (modify-phases %standard-phases (delete 'configure))
6002 means that all the phases described above will be used, except the
6003 @code{configure} phase.
6005 In addition, this build system ensures that the ``standard'' environment
6006 for GNU packages is available. This includes tools such as GCC, libc,
6007 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6008 build-system gnu)} module for a complete list). We call these the
6009 @dfn{implicit inputs} of a package, because package definitions do not
6010 have to mention them.
6013 Other @code{<build-system>} objects are defined to support other
6014 conventions and tools used by free software packages. They inherit most
6015 of @var{gnu-build-system}, and differ mainly in the set of inputs
6016 implicitly added to the build process, and in the list of phases
6017 executed. Some of these build systems are listed below.
6019 @defvr {Scheme Variable} ant-build-system
6020 This variable is exported by @code{(guix build-system ant)}. It
6021 implements the build procedure for Java packages that can be built with
6022 @url{https://ant.apache.org/, Ant build tool}.
6024 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6025 provided by the @code{icedtea} package to the set of inputs. Different
6026 packages can be specified with the @code{#:ant} and @code{#:jdk}
6027 parameters, respectively.
6029 When the original package does not provide a suitable Ant build file,
6030 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6031 build file @file{build.xml} with tasks to build the specified jar
6032 archive. In this case the parameter @code{#:source-dir} can be used to
6033 specify the source sub-directory, defaulting to ``src''.
6035 The @code{#:main-class} parameter can be used with the minimal ant
6036 buildfile to specify the main class of the resulting jar. This makes the
6037 jar file executable. The @code{#:test-include} parameter can be used to
6038 specify the list of junit tests to run. It defaults to
6039 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6040 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6041 because abstract classes cannot be run as tests.
6043 The parameter @code{#:build-target} can be used to specify the Ant task
6044 that should be run during the @code{build} phase. By default the
6045 ``jar'' task will be run.
6049 @defvr {Scheme Variable} android-ndk-build-system
6050 @cindex Android distribution
6051 @cindex Android NDK build system
6052 This variable is exported by @code{(guix build-system android-ndk)}. It
6053 implements a build procedure for Android NDK (native development kit)
6054 packages using a Guix-specific build process.
6056 The build system assumes that packages install their public interface
6057 (header) files to the subdirectory "include" of the "out" output and
6058 their libraries to the subdirectory "lib" of the "out" output.
6060 It's also assumed that the union of all the dependencies of a package
6061 has no conflicting files.
6063 For the time being, cross-compilation is not supported - so right now
6064 the libraries and header files are assumed to be host tools.
6068 @defvr {Scheme Variable} asdf-build-system/source
6069 @defvrx {Scheme Variable} asdf-build-system/sbcl
6070 @defvrx {Scheme Variable} asdf-build-system/ecl
6072 These variables, exported by @code{(guix build-system asdf)}, implement
6073 build procedures for Common Lisp packages using
6074 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6075 definition facility for Common Lisp programs and libraries.
6077 The @code{asdf-build-system/source} system installs the packages in
6078 source form, and can be loaded using any common lisp implementation, via
6079 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6080 systems in the format which a particular implementation understands.
6081 These build systems can also be used to produce executable programs, or
6082 lisp images which contain a set of packages pre-loaded.
6084 The build system uses naming conventions. For binary packages, the
6085 package name should be prefixed with the lisp implementation, such as
6086 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6088 Additionally, the corresponding source package should be labeled using
6089 the same convention as python packages (see @ref{Python Modules}), using
6090 the @code{cl-} prefix.
6092 For binary packages, each system should be defined as a Guix package.
6093 If one package @code{origin} contains several systems, package variants
6094 can be created in order to build all the systems. Source packages,
6095 which use @code{asdf-build-system/source}, may contain several systems.
6097 In order to create executable programs and images, the build-side
6098 procedures @code{build-program} and @code{build-image} can be used.
6099 They should be called in a build phase after the @code{create-symlinks}
6100 phase, so that the system which was just built can be used within the
6101 resulting image. @code{build-program} requires a list of Common Lisp
6102 expressions to be passed as the @code{#:entry-program} argument.
6104 If the system is not defined within its own @code{.asd} file of the same
6105 name, then the @code{#:asd-file} parameter should be used to specify
6106 which file the system is defined in. Furthermore, if the package
6107 defines a system for its tests in a separate file, it will be loaded
6108 before the tests are run if it is specified by the
6109 @code{#:test-asd-file} parameter. If it is not set, the files
6110 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6111 and @code{test.asd} will be tried if they exist.
6113 If for some reason the package must be named in a different way than the
6114 naming conventions suggest, the @code{#:asd-system-name} parameter can
6115 be used to specify the name of the system.
6119 @defvr {Scheme Variable} cargo-build-system
6120 @cindex Rust programming language
6121 @cindex Cargo (Rust build system)
6122 This variable is exported by @code{(guix build-system cargo)}. It
6123 supports builds of packages using Cargo, the build tool of the
6124 @uref{https://www.rust-lang.org, Rust programming language}.
6126 It adds @code{rustc} and @code{cargo} to the set of inputs.
6127 A different Rust package can be specified with the @code{#:rust} parameter.
6129 Regular cargo dependencies should be added to the package definition via the
6130 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6131 spec can be a package or a source definition. Note that the spec must
6132 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6133 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6134 should be added to the package definition via the
6135 @code{#:cargo-development-inputs} parameter.
6137 In its @code{configure} phase, this build system will make any source inputs
6138 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6139 parameters available to cargo. It will also remove an included
6140 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6141 @code{build} phase. The @code{install} phase installs any crate the binaries
6142 if they are defined by the crate.
6145 @cindex Clojure (programming language)
6146 @cindex simple Clojure build system
6147 @defvr {Scheme Variable} clojure-build-system
6148 This variable is exported by @code{(guix build-system clojure)}. It implements
6149 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6150 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6153 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6154 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6155 @code{#:zip} parameters, respectively.
6157 A list of source directories, test directories and jar names can be specified
6158 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6159 parameters, respectively. Compile directory and main class can be specified
6160 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6161 Other parameters are documented below.
6163 This build system is an extension of @var{ant-build-system}, but with the
6164 following phases changed:
6169 This phase calls @code{compile} in Clojure to compile source files and runs
6170 @command{jar} to create jars from both source files and compiled files
6171 according to the include list and exclude list specified in
6172 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6173 has priority over the include list. These lists consist of symbols
6174 representing Clojure libraries or the special keyword @code{#:all} representing
6175 all Clojure libraries found under the source directories. The parameter
6176 @code{#:omit-source?} decides if source should be included into the jars.
6179 This phase runs tests according to the include list and exclude list specified
6180 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6181 meanings are analogous to that of @code{#:aot-include} and
6182 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6183 stands for all Clojure libraries found under the test directories. The
6184 parameter @code{#:tests?} decides if tests should be run.
6187 This phase installs all jars built previously.
6190 Apart from the above, this build system also contains an additional phase:
6195 This phase installs all top-level files with base name matching
6196 @var{%doc-regex}. A different regex can be specified with the
6197 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6198 directories specified in @code{#:doc-dirs} are installed as well.
6202 @defvr {Scheme Variable} cmake-build-system
6203 This variable is exported by @code{(guix build-system cmake)}. It
6204 implements the build procedure for packages using the
6205 @url{https://www.cmake.org, CMake build tool}.
6207 It automatically adds the @code{cmake} package to the set of inputs.
6208 Which package is used can be specified with the @code{#:cmake}
6211 The @code{#:configure-flags} parameter is taken as a list of flags
6212 passed to the @command{cmake} command. The @code{#:build-type}
6213 parameter specifies in abstract terms the flags passed to the compiler;
6214 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6215 debugging information''), which roughly means that code is compiled with
6216 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6219 @defvr {Scheme Variable} dune-build-system
6220 This variable is exported by @code{(guix build-system dune)}. It
6221 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6222 tool for the OCaml programming language. It is implemented as an extension
6223 of the @code{ocaml-build-system} which is described below. As such, the
6224 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6227 It automatically adds the @code{dune} package to the set of inputs.
6228 Which package is used can be specified with the @code{#:dune}
6231 There is no @code{configure} phase because dune packages typically don't
6232 need to be configured. The @code{#:build-flags} parameter is taken as a
6233 list of flags passed to the @code{dune} command during the build.
6235 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6236 command instead of the more recent @code{dune} command while building
6237 a package. Its default value is @code{#f}.
6239 The @code{#:package} parameter can be passed to specify a package name, which
6240 is useful when a package contains multiple packages and you want to build
6241 only one of them. This is equivalent to passing the @code{-p} argument to
6245 @defvr {Scheme Variable} go-build-system
6246 This variable is exported by @code{(guix build-system go)}. It
6247 implements a build procedure for Go packages using the standard
6248 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6249 Go build mechanisms}.
6251 The user is expected to provide a value for the key @code{#:import-path}
6252 and, in some cases, @code{#:unpack-path}. The
6253 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6254 corresponds to the file system path expected by the package's build
6255 scripts and any referring packages, and provides a unique way to
6256 refer to a Go package. It is typically based on a combination of the
6257 package source code's remote URI and file system hierarchy structure. In
6258 some cases, you will need to unpack the package's source code to a
6259 different directory structure than the one indicated by the import path,
6260 and @code{#:unpack-path} should be used in such cases.
6262 Packages that provide Go libraries should install their source code into
6263 the built output. The key @code{#:install-source?}, which defaults to
6264 @code{#t}, controls whether or not the source code is installed. It can
6265 be set to @code{#f} for packages that only provide executable files.
6268 @defvr {Scheme Variable} glib-or-gtk-build-system
6269 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6270 is intended for use with packages making use of GLib or GTK+.
6272 This build system adds the following two phases to the ones defined by
6273 @var{gnu-build-system}:
6276 @item glib-or-gtk-wrap
6277 The phase @code{glib-or-gtk-wrap} ensures that programs in
6278 @file{bin/} are able to find GLib ``schemas'' and
6279 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6280 modules}. This is achieved by wrapping the programs in launch scripts
6281 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6282 environment variables.
6284 It is possible to exclude specific package outputs from that wrapping
6285 process by listing their names in the
6286 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6287 when an output is known not to contain any GLib or GTK+ binaries, and
6288 where wrapping would gratuitously add a dependency of that output on
6291 @item glib-or-gtk-compile-schemas
6292 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6293 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6294 GSettings schemas} of GLib are compiled. Compilation is performed by the
6295 @command{glib-compile-schemas} program. It is provided by the package
6296 @code{glib:bin} which is automatically imported by the build system.
6297 The @code{glib} package providing @command{glib-compile-schemas} can be
6298 specified with the @code{#:glib} parameter.
6301 Both phases are executed after the @code{install} phase.
6304 @defvr {Scheme Variable} guile-build-system
6305 This build system is for Guile packages that consist exclusively of Scheme
6306 code and that are so lean that they don't even have a makefile, let alone a
6307 @file{configure} script. It compiles Scheme code using @command{guild
6308 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6309 installs the @file{.scm} and @file{.go} files in the right place. It also
6310 installs documentation.
6312 This build system supports cross-compilation by using the @code{--target}
6313 option of @command{guild compile}.
6315 Packages built with @code{guile-build-system} must provide a Guile package in
6316 their @code{native-inputs} field.
6319 @defvr {Scheme Variable} julia-build-system
6320 This variable is exported by @code{(guix build-system julia)}. It implements
6321 the build procedure used by @uref{https://julialang.org/, julia} packages,
6322 which essentially is similar to running @command{julia -e 'using Pkg;
6323 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6324 paths to all Julia package inputs. Tests are run not run.
6326 Julia packages require the source @code{file-name} to be the real name of the
6327 package, correctly capitalized.
6329 For packages requiring shared library dependencies, you may need to write the
6330 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6331 variable = /gnu/store/library.so} for each dependency, plus a void function
6332 @code{check_deps() = nothing}.
6334 Some older packages that aren't using @file{Package.toml} yet, will require
6335 this file to be created, too. The function @code{julia-create-package-toml}
6336 helps creating the file. You need to pass the outputs and the source of the
6337 package, it's name (the same as the @code{file-name} parameter), the package
6338 uuid, the package version, and a list of dependencies specified by their name
6342 @defvr {Scheme Variable} minify-build-system
6343 This variable is exported by @code{(guix build-system minify)}. It
6344 implements a minification procedure for simple JavaScript packages.
6346 It adds @code{uglify-js} to the set of inputs and uses it to compress
6347 all JavaScript files in the @file{src} directory. A different minifier
6348 package can be specified with the @code{#:uglify-js} parameter, but it
6349 is expected that the package writes the minified code to the standard
6352 When the input JavaScript files are not all located in the @file{src}
6353 directory, the parameter @code{#:javascript-files} can be used to
6354 specify a list of file names to feed to the minifier.
6357 @defvr {Scheme Variable} ocaml-build-system
6358 This variable is exported by @code{(guix build-system ocaml)}. It implements
6359 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6360 of choosing the correct set of commands to run for each package. OCaml
6361 packages can expect many different commands to be run. This build system will
6364 When the package has a @file{setup.ml} file present at the top-level, it will
6365 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6366 @code{ocaml setup.ml -install}. The build system will assume that this file
6367 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6368 care of setting the prefix and enabling tests if they are not disabled. You
6369 can pass configure and build flags with the @code{#:configure-flags} and
6370 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6371 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6372 bypass this system in the build and install phases.
6374 When the package has a @file{configure} file, it is assumed that it is a
6375 hand-made configure script that requires a different argument format than
6376 in the @code{gnu-build-system}. You can add more flags with the
6377 @code{#:configure-flags} key.
6379 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6380 @code{#t}), it will be used and more flags can be passed to the build and
6381 install phases with the @code{#:make-flags} key.
6383 Finally, some packages do not have these files and use a somewhat standard
6384 location for its build system. In that case, the build system will run
6385 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6386 providing the path to the required findlib module. Additional flags can
6387 be passed via the @code{#:build-flags} key. Install is taken care of by
6388 @command{opam-installer}. In this case, the @code{opam} package must
6389 be added to the @code{native-inputs} field of the package definition.
6391 Note that most OCaml packages assume they will be installed in the same
6392 directory as OCaml, which is not what we want in guix. In particular, they
6393 will install @file{.so} files in their module's directory, which is usually
6394 fine because it is in the OCaml compiler directory. In guix though, these
6395 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6396 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6397 @file{.so} libraries should be installed.
6400 @defvr {Scheme Variable} python-build-system
6401 This variable is exported by @code{(guix build-system python)}. It
6402 implements the more or less standard build procedure used by Python
6403 packages, which consists in running @code{python setup.py build} and
6404 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6406 For packages that install stand-alone Python programs under @code{bin/},
6407 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6408 environment variable points to all the Python libraries they depend on.
6410 Which Python package is used to perform the build can be specified with
6411 the @code{#:python} parameter. This is a useful way to force a package
6412 to be built for a specific version of the Python interpreter, which
6413 might be necessary if the package is only compatible with a single
6414 interpreter version.
6416 By default guix calls @code{setup.py} under control of
6417 @code{setuptools}, much like @command{pip} does. Some packages are not
6418 compatible with setuptools (and pip), thus you can disable this by
6419 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6422 @defvr {Scheme Variable} perl-build-system
6423 This variable is exported by @code{(guix build-system perl)}. It
6424 implements the standard build procedure for Perl packages, which either
6425 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6426 followed by @code{Build} and @code{Build install}; or in running
6427 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6428 @code{make} and @code{make install}, depending on which of
6429 @code{Build.PL} or @code{Makefile.PL} is present in the package
6430 distribution. Preference is given to the former if both @code{Build.PL}
6431 and @code{Makefile.PL} exist in the package distribution. This
6432 preference can be reversed by specifying @code{#t} for the
6433 @code{#:make-maker?} parameter.
6435 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6436 passes flags specified by the @code{#:make-maker-flags} or
6437 @code{#:module-build-flags} parameter, respectively.
6439 Which Perl package is used can be specified with @code{#:perl}.
6442 @defvr {Scheme Variable} qt-build-system
6443 This variable is exported by @code{(guix build-system qt)}. It
6444 is intended for use with applications using Qt or KDE.
6446 This build system adds the phase @code{qt-wrap} to the ones defined by
6447 @var{cmake-build-system}, after the @code{install} phase.
6449 This phase searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6450 and output. In case some path is found, all programs in the output's
6451 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6452 are wrapped in scripts defining the necessary environment variables.
6454 It is possible to exclude specific package outputs from that wrapping process
6455 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6456 This is useful when an output is known not to contain any Qt binaries, and
6457 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6461 @defvr {Scheme Variable} r-build-system
6462 This variable is exported by @code{(guix build-system r)}. It
6463 implements the build procedure used by @uref{https://r-project.org, R}
6464 packages, which essentially is little more than running @code{R CMD
6465 INSTALL --library=/gnu/store/@dots{}} in an environment where
6466 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6467 are run after installation using the R function
6468 @code{tools::testInstalledPackage}.
6471 @defvr {Scheme Variable} rakudo-build-system
6472 This variable is exported by @code{(guix build-system rakudo)}. It
6473 implements the build procedure used by @uref{https://rakudo.org/,
6474 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6475 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6476 installs the binaries, library files and the resources, as well as wrap
6477 the files under the @code{bin/} directory. Tests can be skipped by
6478 passing @code{#f} to the @code{tests?} parameter.
6480 Which rakudo package is used can be specified with @code{rakudo}.
6481 Which perl6-tap-harness package used for the tests can be specified with
6482 @code{#:prove6} or removed by passing @code{#f} to the
6483 @code{with-prove6?} parameter.
6484 Which perl6-zef package used for tests and installing can be specified
6485 with @code{#:zef} or removed by passing @code{#f} to the
6486 @code{with-zef?} parameter.
6489 @defvr {Scheme Variable} texlive-build-system
6490 This variable is exported by @code{(guix build-system texlive)}. It is
6491 used to build TeX packages in batch mode with a specified engine. The
6492 build system sets the @code{TEXINPUTS} variable to find all TeX source
6493 files in the inputs.
6495 By default it runs @code{luatex} on all files ending on @code{ins}. A
6496 different engine and format can be specified with the
6497 @code{#:tex-format} argument. Different build targets can be specified
6498 with the @code{#:build-targets} argument, which expects a list of file
6499 names. The build system adds only @code{texlive-bin} and
6500 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6501 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6502 and @code{#:texlive-latex-base}, respectively.
6504 The @code{#:tex-directory} parameter tells the build system where to
6505 install the built files under the texmf tree.
6508 @defvr {Scheme Variable} ruby-build-system
6509 This variable is exported by @code{(guix build-system ruby)}. It
6510 implements the RubyGems build procedure used by Ruby packages, which
6511 involves running @code{gem build} followed by @code{gem install}.
6513 The @code{source} field of a package that uses this build system
6514 typically references a gem archive, since this is the format that Ruby
6515 developers use when releasing their software. The build system unpacks
6516 the gem archive, potentially patches the source, runs the test suite,
6517 repackages the gem, and installs it. Additionally, directories and
6518 tarballs may be referenced to allow building unreleased gems from Git or
6519 a traditional source release tarball.
6521 Which Ruby package is used can be specified with the @code{#:ruby}
6522 parameter. A list of additional flags to be passed to the @command{gem}
6523 command can be specified with the @code{#:gem-flags} parameter.
6526 @defvr {Scheme Variable} waf-build-system
6527 This variable is exported by @code{(guix build-system waf)}. It
6528 implements a build procedure around the @code{waf} script. The common
6529 phases---@code{configure}, @code{build}, and @code{install}---are
6530 implemented by passing their names as arguments to the @code{waf}
6533 The @code{waf} script is executed by the Python interpreter. Which
6534 Python package is used to run the script can be specified with the
6535 @code{#:python} parameter.
6538 @defvr {Scheme Variable} scons-build-system
6539 This variable is exported by @code{(guix build-system scons)}. It
6540 implements the build procedure used by the SCons software construction
6541 tool. This build system runs @code{scons} to build the package,
6542 @code{scons test} to run tests, and then @code{scons install} to install
6545 Additional flags to be passed to @code{scons} can be specified with the
6546 @code{#:scons-flags} parameter. The default build and install targets
6547 can be overridden with @code{#:build-targets} and
6548 @code{#:install-targets} respectively. The version of Python used to
6549 run SCons can be specified by selecting the appropriate SCons package
6550 with the @code{#:scons} parameter.
6553 @defvr {Scheme Variable} haskell-build-system
6554 This variable is exported by @code{(guix build-system haskell)}. It
6555 implements the Cabal build procedure used by Haskell packages, which
6556 involves running @code{runhaskell Setup.hs configure
6557 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6558 Instead of installing the package by running @code{runhaskell Setup.hs
6559 install}, to avoid trying to register libraries in the read-only
6560 compiler store directory, the build system uses @code{runhaskell
6561 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6562 addition, the build system generates the package documentation by
6563 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6564 is passed. Optional Haddock parameters can be passed with the help of
6565 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6566 not found, the build system looks for @code{Setup.lhs} instead.
6568 Which Haskell compiler is used can be specified with the @code{#:haskell}
6569 parameter which defaults to @code{ghc}.
6572 @defvr {Scheme Variable} dub-build-system
6573 This variable is exported by @code{(guix build-system dub)}. It
6574 implements the Dub build procedure used by D packages, which
6575 involves running @code{dub build} and @code{dub run}.
6576 Installation is done by copying the files manually.
6578 Which D compiler is used can be specified with the @code{#:ldc}
6579 parameter which defaults to @code{ldc}.
6582 @defvr {Scheme Variable} emacs-build-system
6583 This variable is exported by @code{(guix build-system emacs)}. It
6584 implements an installation procedure similar to the packaging system
6585 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6587 It first creates the @code{@var{package}-autoloads.el} file, then it
6588 byte compiles all Emacs Lisp files. Differently from the Emacs
6589 packaging system, the Info documentation files are moved to the standard
6590 documentation directory and the @file{dir} file is deleted. Each
6591 package is installed in its own directory under
6592 @file{share/emacs/site-lisp/guix.d}.
6595 @defvr {Scheme Variable} font-build-system
6596 This variable is exported by @code{(guix build-system font)}. It
6597 implements an installation procedure for font packages where upstream
6598 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6599 need to be copied into place. It copies font files to standard
6600 locations in the output directory.
6603 @defvr {Scheme Variable} meson-build-system
6604 This variable is exported by @code{(guix build-system meson)}. It
6605 implements the build procedure for packages that use
6606 @url{https://mesonbuild.com, Meson} as their build system.
6608 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6609 of inputs, and they can be changed with the parameters @code{#:meson}
6610 and @code{#:ninja} if needed. The default Meson is
6611 @code{meson-for-build}, which is special because it doesn't clear the
6612 @code{RUNPATH} of binaries and libraries when they are installed.
6614 This build system is an extension of @var{gnu-build-system}, but with the
6615 following phases changed to some specific for Meson:
6620 The phase runs @code{meson} with the flags specified in
6621 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6622 @code{plain} unless something else is specified in @code{#:build-type}.
6625 The phase runs @code{ninja} to build the package in parallel by default, but
6626 this can be changed with @code{#:parallel-build?}.
6629 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6630 which is @code{"test"} by default.
6633 The phase runs @code{ninja install} and can not be changed.
6636 Apart from that, the build system also adds the following phases:
6641 This phase ensures that all binaries can find the libraries they need.
6642 It searches for required libraries in subdirectories of the package being
6643 built, and adds those to @code{RUNPATH} where needed. It also removes
6644 references to libraries left over from the build phase by
6645 @code{meson-for-build}, such as test dependencies, that aren't actually
6646 required for the program to run.
6648 @item glib-or-gtk-wrap
6649 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6650 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6652 @item glib-or-gtk-compile-schemas
6653 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6654 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6658 @defvr {Scheme Variable} linux-module-build-system
6659 @var{linux-module-build-system} allows building Linux kernel modules.
6661 @cindex build phases
6662 This build system is an extension of @var{gnu-build-system}, but with the
6663 following phases changed:
6668 This phase configures the environment so that the Linux kernel's Makefile
6669 can be used to build the external kernel module.
6672 This phase uses the Linux kernel's Makefile in order to build the external
6676 This phase uses the Linux kernel's Makefile in order to install the external
6680 It is possible and useful to specify the Linux kernel to use for building
6681 the module (in the "arguments" form of a package using the
6682 linux-module-build-system, use the key #:linux to specify it).
6685 @defvr {Scheme Variable} node-build-system
6686 This variable is exported by @code{(guix build-system node)}. It
6687 implements the build procedure used by @uref{http://nodejs.org,
6688 Node.js}, which implements an approximation of the @code{npm install}
6689 command, followed by an @code{npm test} command.
6691 Which Node.js package is used to interpret the @code{npm} commands can
6692 be specified with the @code{#:node} parameter which defaults to
6696 Lastly, for packages that do not need anything as sophisticated, a
6697 ``trivial'' build system is provided. It is trivial in the sense that
6698 it provides basically no support: it does not pull any implicit inputs,
6699 and does not have a notion of build phases.
6701 @defvr {Scheme Variable} trivial-build-system
6702 This variable is exported by @code{(guix build-system trivial)}.
6704 This build system requires a @code{#:builder} argument. This argument
6705 must be a Scheme expression that builds the package output(s)---as
6706 with @code{build-expression->derivation} (@pxref{Derivations,
6707 @code{build-expression->derivation}}).
6717 Conceptually, the @dfn{store} is the place where derivations that have
6718 been built successfully are stored---by default, @file{/gnu/store}.
6719 Sub-directories in the store are referred to as @dfn{store items} or
6720 sometimes @dfn{store paths}. The store has an associated database that
6721 contains information such as the store paths referred to by each store
6722 path, and the list of @emph{valid} store items---results of successful
6723 builds. This database resides in @file{@var{localstatedir}/guix/db},
6724 where @var{localstatedir} is the state directory specified @i{via}
6725 @option{--localstatedir} at configure time, usually @file{/var}.
6727 The store is @emph{always} accessed by the daemon on behalf of its clients
6728 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6729 connect to the daemon over a Unix-domain socket, send requests to it,
6730 and read the result---these are remote procedure calls, or RPCs.
6733 Users must @emph{never} modify files under @file{/gnu/store} directly.
6734 This would lead to inconsistencies and break the immutability
6735 assumptions of Guix's functional model (@pxref{Introduction}).
6737 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6738 how to check the integrity of the store and attempt recovery from
6739 accidental modifications.
6742 The @code{(guix store)} module provides procedures to connect to the
6743 daemon, and to perform RPCs. These are described below. By default,
6744 @code{open-connection}, and thus all the @command{guix} commands,
6745 connect to the local daemon or to the URI specified by the
6746 @code{GUIX_DAEMON_SOCKET} environment variable.
6748 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6749 When set, the value of this variable should be a file name or a URI
6750 designating the daemon endpoint. When it is a file name, it denotes a
6751 Unix-domain socket to connect to. In addition to file names, the
6752 supported URI schemes are:
6757 These are for Unix-domain sockets.
6758 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6759 @file{/var/guix/daemon-socket/socket}.
6762 @cindex daemon, remote access
6763 @cindex remote access to the daemon
6764 @cindex daemon, cluster setup
6765 @cindex clusters, daemon setup
6766 These URIs denote connections over TCP/IP, without encryption nor
6767 authentication of the remote host. The URI must specify the host name
6768 and optionally a port number (by default port 44146 is used):
6771 guix://master.guix.example.org:1234
6774 This setup is suitable on local networks, such as clusters, where only
6775 trusted nodes may connect to the build daemon at
6776 @code{master.guix.example.org}.
6778 The @code{--listen} option of @command{guix-daemon} can be used to
6779 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6783 @cindex SSH access to build daemons
6784 These URIs allow you to connect to a remote daemon over
6785 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6786 A typical URL might look like this:
6789 ssh://charlie@@guix.example.org:22
6792 As for @command{guix copy}, the usual OpenSSH client configuration files
6793 are honored (@pxref{Invoking guix copy}).
6796 Additional URI schemes may be supported in the future.
6798 @c XXX: Remove this note when the protocol incurs fewer round trips
6799 @c and when (guix derivations) no longer relies on file system access.
6801 The ability to connect to remote build daemons is considered
6802 experimental as of @value{VERSION}. Please get in touch with us to
6803 share any problems or suggestions you may have (@pxref{Contributing}).
6807 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6808 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6809 @var{reserve-space?} is true, instruct it to reserve a little bit of
6810 extra space on the file system so that the garbage collector can still
6811 operate should the disk become full. Return a server object.
6813 @var{file} defaults to @code{%default-socket-path}, which is the normal
6814 location given the options that were passed to @command{configure}.
6817 @deffn {Scheme Procedure} close-connection @var{server}
6818 Close the connection to @var{server}.
6821 @defvr {Scheme Variable} current-build-output-port
6822 This variable is bound to a SRFI-39 parameter, which refers to the port
6823 where build and error logs sent by the daemon should be written.
6826 Procedures that make RPCs all take a server object as their first
6829 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6830 @cindex invalid store items
6831 Return @code{#t} when @var{path} designates a valid store item and
6832 @code{#f} otherwise (an invalid item may exist on disk but still be
6833 invalid, for instance because it is the result of an aborted or failed
6836 A @code{&store-protocol-error} condition is raised if @var{path} is not
6837 prefixed by the store directory (@file{/gnu/store}).
6840 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6841 Add @var{text} under file @var{name} in the store, and return its store
6842 path. @var{references} is the list of store paths referred to by the
6843 resulting store path.
6846 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6848 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6849 file names, or derivation/output pairs, using the specified
6850 @var{mode}---@code{(build-mode normal)} by default.
6853 Note that the @code{(guix monads)} module provides a monad as well as
6854 monadic versions of the above procedures, with the goal of making it
6855 more convenient to work with code that accesses the store (@pxref{The
6859 @i{This section is currently incomplete.}
6862 @section Derivations
6865 Low-level build actions and the environment in which they are performed
6866 are represented by @dfn{derivations}. A derivation contains the
6867 following pieces of information:
6871 The outputs of the derivation---derivations produce at least one file or
6872 directory in the store, but may produce more.
6875 @cindex build-time dependencies
6876 @cindex dependencies, build-time
6877 The inputs of the derivations---i.e., its build-time dependencies---which may
6878 be other derivations or plain files in the store (patches, build scripts,
6882 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6885 The file name of a build script in the store, along with the arguments
6889 A list of environment variables to be defined.
6893 @cindex derivation path
6894 Derivations allow clients of the daemon to communicate build actions to
6895 the store. They exist in two forms: as an in-memory representation,
6896 both on the client- and daemon-side, and as files in the store whose
6897 name end in @code{.drv}---these files are referred to as @dfn{derivation
6898 paths}. Derivations paths can be passed to the @code{build-derivations}
6899 procedure to perform the build actions they prescribe (@pxref{The
6902 @cindex fixed-output derivations
6903 Operations such as file downloads and version-control checkouts for
6904 which the expected content hash is known in advance are modeled as
6905 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6906 of a fixed-output derivation are independent of its inputs---e.g., a
6907 source code download produces the same result regardless of the download
6908 method and tools being used.
6911 @cindex run-time dependencies
6912 @cindex dependencies, run-time
6913 The outputs of derivations---i.e., the build results---have a set of
6914 @dfn{references}, as reported by the @code{references} RPC or the
6915 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6916 are the set of run-time dependencies of the build results. References are a
6917 subset of the inputs of the derivation; this subset is automatically computed
6918 by the build daemon by scanning all the files in the outputs.
6920 The @code{(guix derivations)} module provides a representation of
6921 derivations as Scheme objects, along with procedures to create and
6922 otherwise manipulate derivations. The lowest-level primitive to create
6923 a derivation is the @code{derivation} procedure:
6925 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6926 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6927 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6928 [#:system (%current-system)] [#:references-graphs #f] @
6929 [#:allowed-references #f] [#:disallowed-references #f] @
6930 [#:leaked-env-vars #f] [#:local-build? #f] @
6931 [#:substitutable? #t] [#:properties '()]
6932 Build a derivation with the given arguments, and return the resulting
6933 @code{<derivation>} object.
6935 When @var{hash} and @var{hash-algo} are given, a
6936 @dfn{fixed-output derivation} is created---i.e., one whose result is
6937 known in advance, such as a file download. If, in addition,
6938 @var{recursive?} is true, then that fixed output may be an executable
6939 file or a directory and @var{hash} must be the hash of an archive
6940 containing this output.
6942 When @var{references-graphs} is true, it must be a list of file
6943 name/store path pairs. In that case, the reference graph of each store
6944 path is exported in the build environment in the corresponding file, in
6945 a simple text format.
6947 When @var{allowed-references} is true, it must be a list of store items
6948 or outputs that the derivation's output may refer to. Likewise,
6949 @var{disallowed-references}, if true, must be a list of things the
6950 outputs may @emph{not} refer to.
6952 When @var{leaked-env-vars} is true, it must be a list of strings
6953 denoting environment variables that are allowed to ``leak'' from the
6954 daemon's environment to the build environment. This is only applicable
6955 to fixed-output derivations---i.e., when @var{hash} is true. The main
6956 use is to allow variables such as @code{http_proxy} to be passed to
6957 derivations that download files.
6959 When @var{local-build?} is true, declare that the derivation is not a
6960 good candidate for offloading and should rather be built locally
6961 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6962 where the costs of data transfers would outweigh the benefits.
6964 When @var{substitutable?} is false, declare that substitutes of the
6965 derivation's output should not be used (@pxref{Substitutes}). This is
6966 useful, for instance, when building packages that capture details of the
6967 host CPU instruction set.
6969 @var{properties} must be an association list describing ``properties'' of the
6970 derivation. It is kept as-is, uninterpreted, in the derivation.
6974 Here's an example with a shell script as its builder, assuming
6975 @var{store} is an open connection to the daemon, and @var{bash} points
6976 to a Bash executable in the store:
6979 (use-modules (guix utils)
6983 (let ((builder ; add the Bash script to the store
6984 (add-text-to-store store "my-builder.sh"
6985 "echo hello world > $out\n" '())))
6986 (derivation store "foo"
6987 bash `("-e" ,builder)
6988 #:inputs `((,bash) (,builder))
6989 #:env-vars '(("HOME" . "/homeless"))))
6990 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6993 As can be guessed, this primitive is cumbersome to use directly. A
6994 better approach is to write build scripts in Scheme, of course! The
6995 best course of action for that is to write the build code as a
6996 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6997 information, @pxref{G-Expressions}.
6999 Once upon a time, @code{gexp->derivation} did not exist and constructing
7000 derivations with build code written in Scheme was achieved with
7001 @code{build-expression->derivation}, documented below. This procedure
7002 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7004 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7005 @var{name} @var{exp} @
7006 [#:system (%current-system)] [#:inputs '()] @
7007 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7008 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7009 [#:references-graphs #f] [#:allowed-references #f] @
7010 [#:disallowed-references #f] @
7011 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7012 Return a derivation that executes Scheme expression @var{exp} as a
7013 builder for derivation @var{name}. @var{inputs} must be a list of
7014 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7015 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7016 modules from the current search path to be copied in the store,
7017 compiled, and made available in the load path during the execution of
7018 @var{exp}---e.g., @code{((guix build utils) (guix build
7019 gnu-build-system))}.
7021 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7022 to a list of output/path pairs, and where @code{%build-inputs} is bound
7023 to a list of string/output-path pairs made from @var{inputs}.
7024 Optionally, @var{env-vars} is a list of string pairs specifying the name
7025 and value of environment variables visible to the builder. The builder
7026 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7027 @var{exp} returns @code{#f}, the build is considered to have failed.
7029 @var{exp} is built using @var{guile-for-build} (a derivation). When
7030 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7031 @code{%guile-for-build} fluid is used instead.
7033 See the @code{derivation} procedure for the meaning of
7034 @var{references-graphs}, @var{allowed-references},
7035 @var{disallowed-references}, @var{local-build?}, and
7036 @var{substitutable?}.
7040 Here's an example of a single-output derivation that creates a directory
7041 containing one file:
7044 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7045 (mkdir out) ; create /gnu/store/@dots{}-goo
7046 (call-with-output-file (string-append out "/test")
7048 (display '(hello guix) p))))))
7049 (build-expression->derivation store "goo" builder))
7051 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7055 @node The Store Monad
7056 @section The Store Monad
7060 The procedures that operate on the store described in the previous
7061 sections all take an open connection to the build daemon as their first
7062 argument. Although the underlying model is functional, they either have
7063 side effects or depend on the current state of the store.
7065 The former is inconvenient: the connection to the build daemon has to be
7066 carried around in all those functions, making it impossible to compose
7067 functions that do not take that parameter with functions that do. The
7068 latter can be problematic: since store operations have side effects
7069 and/or depend on external state, they have to be properly sequenced.
7071 @cindex monadic values
7072 @cindex monadic functions
7073 This is where the @code{(guix monads)} module comes in. This module
7074 provides a framework for working with @dfn{monads}, and a particularly
7075 useful monad for our uses, the @dfn{store monad}. Monads are a
7076 construct that allows two things: associating ``context'' with values
7077 (in our case, the context is the store), and building sequences of
7078 computations (here computations include accesses to the store). Values
7079 in a monad---values that carry this additional context---are called
7080 @dfn{monadic values}; procedures that return such values are called
7081 @dfn{monadic procedures}.
7083 Consider this ``normal'' procedure:
7086 (define (sh-symlink store)
7087 ;; Return a derivation that symlinks the 'bash' executable.
7088 (let* ((drv (package-derivation store bash))
7089 (out (derivation->output-path drv))
7090 (sh (string-append out "/bin/bash")))
7091 (build-expression->derivation store "sh"
7092 `(symlink ,sh %output))))
7095 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7096 as a monadic function:
7099 (define (sh-symlink)
7100 ;; Same, but return a monadic value.
7101 (mlet %store-monad ((drv (package->derivation bash)))
7102 (gexp->derivation "sh"
7103 #~(symlink (string-append #$drv "/bin/bash")
7107 There are several things to note in the second version: the @code{store}
7108 parameter is now implicit and is ``threaded'' in the calls to the
7109 @code{package->derivation} and @code{gexp->derivation} monadic
7110 procedures, and the monadic value returned by @code{package->derivation}
7111 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7113 As it turns out, the call to @code{package->derivation} can even be
7114 omitted since it will take place implicitly, as we will see later
7115 (@pxref{G-Expressions}):
7118 (define (sh-symlink)
7119 (gexp->derivation "sh"
7120 #~(symlink (string-append #$bash "/bin/bash")
7125 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7126 @c for the funny quote.
7127 Calling the monadic @code{sh-symlink} has no effect. As someone once
7128 said, ``you exit a monad like you exit a building on fire: by running''.
7129 So, to exit the monad and get the desired effect, one must use
7130 @code{run-with-store}:
7133 (run-with-store (open-connection) (sh-symlink))
7134 @result{} /gnu/store/...-sh-symlink
7137 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7138 new ``meta-commands'' to make it easier to deal with monadic procedures:
7139 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7140 to ``run'' a single monadic value through the store:
7143 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7144 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7147 The latter enters a recursive REPL, where all the return values are
7148 automatically run through the store:
7151 scheme@@(guile-user)> ,enter-store-monad
7152 store-monad@@(guile-user) [1]> (package->derivation hello)
7153 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7154 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7155 $3 = "/gnu/store/@dots{}-foo"
7156 store-monad@@(guile-user) [1]> ,q
7157 scheme@@(guile-user)>
7161 Note that non-monadic values cannot be returned in the
7162 @code{store-monad} REPL.
7164 The main syntactic forms to deal with monads in general are provided by
7165 the @code{(guix monads)} module and are described below.
7167 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7168 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7172 @deffn {Scheme Syntax} return @var{val}
7173 Return a monadic value that encapsulates @var{val}.
7176 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7177 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7178 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7179 referred to as ``bind'', but that name denotes an unrelated procedure in
7180 Guile. Thus we use this somewhat cryptic symbol inherited from the
7181 Haskell language.}. There can be one @var{mproc} or several of them, as
7186 (with-monad %state-monad
7188 (lambda (x) (return (+ 1 x)))
7189 (lambda (x) (return (* 2 x)))))
7193 @result{} some-state
7197 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7199 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7201 Bind the variables @var{var} to the monadic values @var{mval} in
7202 @var{body}, which is a sequence of expressions. As with the bind
7203 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7204 value ``contained'' in @var{mval} and making @var{var} refer to that
7205 raw, non-monadic value within the scope of the @var{body}. The form
7206 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7207 @var{val}, as per @code{let}. The binding operations occur in sequence
7208 from left to right. The last expression of @var{body} must be a monadic
7209 expression, and its result will become the result of the @code{mlet} or
7210 @code{mlet*} when run in the @var{monad}.
7212 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7213 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7216 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7217 Bind @var{mexp} and the following monadic expressions in sequence,
7218 returning the result of the last expression. Every expression in the
7219 sequence must be a monadic expression.
7221 This is akin to @code{mlet}, except that the return values of the
7222 monadic expressions are ignored. In that sense, it is analogous to
7223 @code{begin}, but applied to monadic expressions.
7226 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7227 When @var{condition} is true, evaluate the sequence of monadic
7228 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7229 @var{condition} is false, return @code{*unspecified*} in the current
7230 monad. Every expression in the sequence must be a monadic expression.
7233 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7234 When @var{condition} is false, evaluate the sequence of monadic
7235 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7236 @var{condition} is true, return @code{*unspecified*} in the current
7237 monad. Every expression in the sequence must be a monadic expression.
7241 The @code{(guix monads)} module provides the @dfn{state monad}, which
7242 allows an additional value---the state---to be @emph{threaded} through
7243 monadic procedure calls.
7245 @defvr {Scheme Variable} %state-monad
7246 The state monad. Procedures in the state monad can access and change
7247 the state that is threaded.
7249 Consider the example below. The @code{square} procedure returns a value
7250 in the state monad. It returns the square of its argument, but also
7251 increments the current state value:
7255 (mlet %state-monad ((count (current-state)))
7256 (mbegin %state-monad
7257 (set-current-state (+ 1 count))
7260 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7265 When ``run'' through @var{%state-monad}, we obtain that additional state
7266 value, which is the number of @code{square} calls.
7269 @deffn {Monadic Procedure} current-state
7270 Return the current state as a monadic value.
7273 @deffn {Monadic Procedure} set-current-state @var{value}
7274 Set the current state to @var{value} and return the previous state as a
7278 @deffn {Monadic Procedure} state-push @var{value}
7279 Push @var{value} to the current state, which is assumed to be a list,
7280 and return the previous state as a monadic value.
7283 @deffn {Monadic Procedure} state-pop
7284 Pop a value from the current state and return it as a monadic value.
7285 The state is assumed to be a list.
7288 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7289 Run monadic value @var{mval} starting with @var{state} as the initial
7290 state. Return two values: the resulting value, and the resulting state.
7293 The main interface to the store monad, provided by the @code{(guix
7294 store)} module, is as follows.
7296 @defvr {Scheme Variable} %store-monad
7297 The store monad---an alias for @var{%state-monad}.
7299 Values in the store monad encapsulate accesses to the store. When its
7300 effect is needed, a value of the store monad must be ``evaluated'' by
7301 passing it to the @code{run-with-store} procedure (see below.)
7304 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7305 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7306 open store connection.
7309 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7310 Return as a monadic value the absolute file name in the store of the file
7311 containing @var{text}, a string. @var{references} is a list of store items that the
7312 resulting text file refers to; it defaults to the empty list.
7315 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7316 Return as a monadic value the absolute file name in the store of the file
7317 containing @var{data}, a bytevector. @var{references} is a list of store
7318 items that the resulting binary file refers to; it defaults to the empty list.
7321 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7322 [#:recursive? #t] [#:select? (const #t)]
7323 Return the name of @var{file} once interned in the store. Use
7324 @var{name} as its store name, or the basename of @var{file} if
7325 @var{name} is omitted.
7327 When @var{recursive?} is true, the contents of @var{file} are added
7328 recursively; if @var{file} designates a flat file and @var{recursive?}
7329 is true, its contents are added, and its permission bits are kept.
7331 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7332 @var{stat})} for each directory entry, where @var{file} is the entry's
7333 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7334 entries for which @var{select?} does not return true.
7336 The example below adds a file to the store, under two different names:
7339 (run-with-store (open-connection)
7340 (mlet %store-monad ((a (interned-file "README"))
7341 (b (interned-file "README" "LEGU-MIN")))
7342 (return (list a b))))
7344 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7349 The @code{(guix packages)} module exports the following package-related
7352 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7353 [#:system (%current-system)] [#:target #f] @
7356 value in the absolute file name of @var{file} within the @var{output}
7357 directory of @var{package}. When @var{file} is omitted, return the name
7358 of the @var{output} directory of @var{package}. When @var{target} is
7359 true, use it as a cross-compilation target triplet.
7362 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7363 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7364 @var{target} [@var{system}]
7365 Monadic version of @code{package-derivation} and
7366 @code{package-cross-derivation} (@pxref{Defining Packages}).
7371 @section G-Expressions
7373 @cindex G-expression
7374 @cindex build code quoting
7375 So we have ``derivations'', which represent a sequence of build actions
7376 to be performed to produce an item in the store (@pxref{Derivations}).
7377 These build actions are performed when asking the daemon to actually
7378 build the derivations; they are run by the daemon in a container
7379 (@pxref{Invoking guix-daemon}).
7381 @cindex strata of code
7382 It should come as no surprise that we like to write these build actions
7383 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7384 code@footnote{The term @dfn{stratum} in this context was coined by
7385 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7386 Kiselyov, who has written insightful
7387 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7388 on this topic}, refers to this kind of code generation as
7389 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7390 to the daemon, etc.---and the ``build code''---code that actually
7391 performs build actions, such as making directories, invoking
7392 @command{make}, etc.
7394 To describe a derivation and its build actions, one typically needs to
7395 embed build code inside host code. It boils down to manipulating build
7396 code as data, and the homoiconicity of Scheme---code has a direct
7397 representation as data---comes in handy for that. But we need more than
7398 the normal @code{quasiquote} mechanism in Scheme to construct build
7401 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7402 S-expressions adapted to build expressions. G-expressions, or
7403 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7404 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7405 @code{#$}, and @code{#$@@}), which are comparable to
7406 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7407 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7408 GNU Guile Reference Manual}). However, there are major differences:
7412 Gexps are meant to be written to a file and run or manipulated by other
7416 When a high-level object such as a package or derivation is unquoted
7417 inside a gexp, the result is as if its output file name had been
7421 Gexps carry information about the packages or derivations they refer to,
7422 and these dependencies are automatically added as inputs to the build
7423 processes that use them.
7426 @cindex lowering, of high-level objects in gexps
7427 This mechanism is not limited to package and derivation
7428 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7429 derivations or files in the store can be defined,
7430 such that these objects can also be inserted
7431 into gexps. For example, a useful type of high-level objects that can be
7432 inserted in a gexp is ``file-like objects'', which make it easy to
7433 add files to the store and to refer to them in
7434 derivations and such (see @code{local-file} and @code{plain-file}
7437 To illustrate the idea, here is an example of a gexp:
7444 (symlink (string-append #$coreutils "/bin/ls")
7448 This gexp can be passed to @code{gexp->derivation}; we obtain a
7449 derivation that builds a directory containing exactly one symlink to
7450 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7453 (gexp->derivation "the-thing" build-exp)
7456 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7457 substituted to the reference to the @var{coreutils} package in the
7458 actual build code, and @var{coreutils} is automatically made an input to
7459 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7460 output)}) is replaced by a string containing the directory name of the
7461 output of the derivation.
7463 @cindex cross compilation
7464 In a cross-compilation context, it is useful to distinguish between
7465 references to the @emph{native} build of a package---that can run on the
7466 host---versus references to cross builds of a package. To that end, the
7467 @code{#+} plays the same role as @code{#$}, but is a reference to a
7468 native package build:
7471 (gexp->derivation "vi"
7474 (mkdir (string-append #$output "/bin"))
7475 (system* (string-append #+coreutils "/bin/ln")
7477 (string-append #$emacs "/bin/emacs")
7478 (string-append #$output "/bin/vi")))
7479 #:target "mips64el-linux-gnu")
7483 In the example above, the native build of @var{coreutils} is used, so
7484 that @command{ln} can actually run on the host; but then the
7485 cross-compiled build of @var{emacs} is referenced.
7487 @cindex imported modules, for gexps
7488 @findex with-imported-modules
7489 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7490 able to use certain Guile modules from the ``host environment'' in the
7491 gexp, so those modules should be imported in the ``build environment''.
7492 The @code{with-imported-modules} form allows you to express that:
7495 (let ((build (with-imported-modules '((guix build utils))
7497 (use-modules (guix build utils))
7498 (mkdir-p (string-append #$output "/bin"))))))
7499 (gexp->derivation "empty-dir"
7502 (display "success!\n")
7507 In this example, the @code{(guix build utils)} module is automatically
7508 pulled into the isolated build environment of our gexp, such that
7509 @code{(use-modules (guix build utils))} works as expected.
7511 @cindex module closure
7512 @findex source-module-closure
7513 Usually you want the @emph{closure} of the module to be imported---i.e.,
7514 the module itself and all the modules it depends on---rather than just
7515 the module; failing to do that, attempts to use the module will fail
7516 because of missing dependent modules. The @code{source-module-closure}
7517 procedure computes the closure of a module by looking at its source file
7518 headers, which comes in handy in this case:
7521 (use-modules (guix modules)) ;for 'source-module-closure'
7523 (with-imported-modules (source-module-closure
7524 '((guix build utils)
7526 (gexp->derivation "something-with-vms"
7528 (use-modules (guix build utils)
7533 @cindex extensions, for gexps
7534 @findex with-extensions
7535 In the same vein, sometimes you want to import not just pure-Scheme
7536 modules, but also ``extensions'' such as Guile bindings to C libraries
7537 or other ``full-blown'' packages. Say you need the @code{guile-json}
7538 package available on the build side, here's how you would do it:
7541 (use-modules (gnu packages guile)) ;for 'guile-json'
7543 (with-extensions (list guile-json)
7544 (gexp->derivation "something-with-json"
7546 (use-modules (json))
7550 The syntactic form to construct gexps is summarized below.
7552 @deffn {Scheme Syntax} #~@var{exp}
7553 @deffnx {Scheme Syntax} (gexp @var{exp})
7554 Return a G-expression containing @var{exp}. @var{exp} may contain one
7555 or more of the following forms:
7559 @itemx (ungexp @var{obj})
7560 Introduce a reference to @var{obj}. @var{obj} may have one of the
7561 supported types, for example a package or a
7562 derivation, in which case the @code{ungexp} form is replaced by its
7563 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7565 If @var{obj} is a list, it is traversed and references to supported
7566 objects are substituted similarly.
7568 If @var{obj} is another gexp, its contents are inserted and its
7569 dependencies are added to those of the containing gexp.
7571 If @var{obj} is another kind of object, it is inserted as is.
7573 @item #$@var{obj}:@var{output}
7574 @itemx (ungexp @var{obj} @var{output})
7575 This is like the form above, but referring explicitly to the
7576 @var{output} of @var{obj}---this is useful when @var{obj} produces
7577 multiple outputs (@pxref{Packages with Multiple Outputs}).
7580 @itemx #+@var{obj}:output
7581 @itemx (ungexp-native @var{obj})
7582 @itemx (ungexp-native @var{obj} @var{output})
7583 Same as @code{ungexp}, but produces a reference to the @emph{native}
7584 build of @var{obj} when used in a cross compilation context.
7586 @item #$output[:@var{output}]
7587 @itemx (ungexp output [@var{output}])
7588 Insert a reference to derivation output @var{output}, or to the main
7589 output when @var{output} is omitted.
7591 This only makes sense for gexps passed to @code{gexp->derivation}.
7594 @itemx (ungexp-splicing @var{lst})
7595 Like the above, but splices the contents of @var{lst} inside the
7599 @itemx (ungexp-native-splicing @var{lst})
7600 Like the above, but refers to native builds of the objects listed in
7605 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7606 of the @code{gexp?} type (see below.)
7609 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7610 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7611 in their execution environment.
7613 Each item in @var{modules} can be the name of a module, such as
7614 @code{(guix build utils)}, or it can be a module name, followed by an
7615 arrow, followed by a file-like object:
7618 `((guix build utils)
7620 ((guix config) => ,(scheme-file "config.scm"
7621 #~(define-module @dots{}))))
7625 In the example above, the first two modules are taken from the search
7626 path, and the last one is created from the given file-like object.
7628 This form has @emph{lexical} scope: it has an effect on the gexps
7629 directly defined in @var{body}@dots{}, but not on those defined, say, in
7630 procedures called from @var{body}@dots{}.
7633 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7634 Mark the gexps defined in @var{body}@dots{} as requiring
7635 @var{extensions} in their build and execution environment.
7636 @var{extensions} is typically a list of package objects such as those
7637 defined in the @code{(gnu packages guile)} module.
7639 Concretely, the packages listed in @var{extensions} are added to the
7640 load path while compiling imported modules in @var{body}@dots{}; they
7641 are also added to the load path of the gexp returned by
7645 @deffn {Scheme Procedure} gexp? @var{obj}
7646 Return @code{#t} if @var{obj} is a G-expression.
7649 G-expressions are meant to be written to disk, either as code building
7650 some derivation, or as plain files in the store. The monadic procedures
7651 below allow you to do that (@pxref{The Store Monad}, for more
7652 information about monads.)
7654 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7655 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7656 [#:hash #f] [#:hash-algo #f] @
7657 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7658 [#:module-path @var{%load-path}] @
7659 [#:effective-version "2.2"] @
7660 [#:references-graphs #f] [#:allowed-references #f] @
7661 [#:disallowed-references #f] @
7662 [#:leaked-env-vars #f] @
7663 [#:script-name (string-append @var{name} "-builder")] @
7664 [#:deprecation-warnings #f] @
7665 [#:local-build? #f] [#:substitutable? #t] @
7666 [#:properties '()] [#:guile-for-build #f]
7667 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7668 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7669 stored in a file called @var{script-name}. When @var{target} is true,
7670 it is used as the cross-compilation target triplet for packages referred
7673 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7675 make @var{modules} available in the evaluation context of @var{exp};
7676 @var{modules} is a list of names of Guile modules searched in
7677 @var{module-path} to be copied in the store, compiled, and made available in
7678 the load path during the execution of @var{exp}---e.g., @code{((guix
7679 build utils) (guix build gnu-build-system))}.
7681 @var{effective-version} determines the string to use when adding extensions of
7682 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7684 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7687 When @var{references-graphs} is true, it must be a list of tuples of one of the
7691 (@var{file-name} @var{package})
7692 (@var{file-name} @var{package} @var{output})
7693 (@var{file-name} @var{derivation})
7694 (@var{file-name} @var{derivation} @var{output})
7695 (@var{file-name} @var{store-item})
7698 The right-hand-side of each element of @var{references-graphs} is automatically made
7699 an input of the build process of @var{exp}. In the build environment, each
7700 @var{file-name} contains the reference graph of the corresponding item, in a simple
7703 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7704 In the latter case, the list denotes store items that the result is allowed to
7705 refer to. Any reference to another store item will lead to a build error.
7706 Similarly for @var{disallowed-references}, which can list items that must not be
7707 referenced by the outputs.
7709 @var{deprecation-warnings} determines whether to show deprecation warnings while
7710 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7712 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7715 @cindex file-like objects
7716 The @code{local-file}, @code{plain-file}, @code{computed-file},
7717 @code{program-file}, and @code{scheme-file} procedures below return
7718 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7719 these objects lead to a file in the store. Consider this G-expression:
7722 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7723 #$(local-file "/tmp/my-nscd.conf"))
7726 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7727 to the store. Once expanded, for instance @i{via}
7728 @code{gexp->derivation}, the G-expression refers to that copy under
7729 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7730 does not have any effect on what the G-expression does.
7731 @code{plain-file} can be used similarly; it differs in that the file
7732 content is directly passed as a string.
7734 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7735 [#:recursive? #f] [#:select? (const #t)]
7736 Return an object representing local file @var{file} to add to the store;
7737 this object can be used in a gexp. If @var{file} is a literal string
7738 denoting a relative file name, it is looked up relative to the source
7739 file where it appears; if @var{file} is not a literal string, it is
7740 looked up relative to the current working directory at run time.
7741 @var{file} will be added to the store under @var{name}--by default the
7742 base name of @var{file}.
7744 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7745 designates a flat file and @var{recursive?} is true, its contents are added, and its
7746 permission bits are kept.
7748 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7749 @var{stat})} for each directory entry, where @var{file} is the entry's
7750 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7751 entries for which @var{select?} does not return true.
7753 This is the declarative counterpart of the @code{interned-file} monadic
7754 procedure (@pxref{The Store Monad, @code{interned-file}}).
7757 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7758 Return an object representing a text file called @var{name} with the given
7759 @var{content} (a string or a bytevector) to be added to the store.
7761 This is the declarative counterpart of @code{text-file}.
7764 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7765 [#:options '(#:local-build? #t)]
7766 Return an object representing the store item @var{name}, a file or
7767 directory computed by @var{gexp}. @var{options}
7768 is a list of additional arguments to pass to @code{gexp->derivation}.
7770 This is the declarative counterpart of @code{gexp->derivation}.
7773 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7774 [#:guile (default-guile)] [#:module-path %load-path] @
7775 [#:system (%current-system)] [#:target #f]
7776 Return an executable script @var{name} that runs @var{exp} using
7777 @var{guile}, with @var{exp}'s imported modules in its search path.
7778 Look up @var{exp}'s modules in @var{module-path}.
7780 The example below builds a script that simply invokes the @command{ls}
7784 (use-modules (guix gexp) (gnu packages base))
7786 (gexp->script "list-files"
7787 #~(execl #$(file-append coreutils "/bin/ls")
7791 When ``running'' it through the store (@pxref{The Store Monad,
7792 @code{run-with-store}}), we obtain a derivation that produces an
7793 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7796 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7798 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7802 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7803 [#:guile #f] [#:module-path %load-path]
7804 Return an object representing the executable store item @var{name} that
7805 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7806 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7808 This is the declarative counterpart of @code{gexp->script}.
7811 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7812 [#:set-load-path? #t] [#:module-path %load-path] @
7814 [#:guile (default-guile)]
7815 Return a derivation that builds a file @var{name} containing @var{exp}.
7816 When @var{splice?} is true, @var{exp} is considered to be a list of
7817 expressions that will be spliced in the resulting file.
7819 When @var{set-load-path?} is true, emit code in the resulting file to
7820 set @code{%load-path} and @code{%load-compiled-path} to honor
7821 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7824 The resulting file holds references to all the dependencies of @var{exp}
7825 or a subset thereof.
7828 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7829 Return an object representing the Scheme file @var{name} that contains
7832 This is the declarative counterpart of @code{gexp->file}.
7835 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7836 Return as a monadic value a derivation that builds a text file
7837 containing all of @var{text}. @var{text} may list, in addition to
7838 strings, objects of any type that can be used in a gexp: packages,
7839 derivations, local file objects, etc. The resulting store file holds
7840 references to all these.
7842 This variant should be preferred over @code{text-file} anytime the file
7843 to create will reference items from the store. This is typically the
7844 case when building a configuration file that embeds store file names,
7848 (define (profile.sh)
7849 ;; Return the name of a shell script in the store that
7850 ;; initializes the 'PATH' environment variable.
7851 (text-file* "profile.sh"
7852 "export PATH=" coreutils "/bin:"
7853 grep "/bin:" sed "/bin\n"))
7856 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7857 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7858 preventing them from being garbage-collected during its lifetime.
7861 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7862 Return an object representing store file @var{name} containing
7863 @var{text}. @var{text} is a sequence of strings and file-like objects,
7867 (mixed-text-file "profile"
7868 "export PATH=" coreutils "/bin:" grep "/bin")
7871 This is the declarative counterpart of @code{text-file*}.
7874 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7875 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7876 Each item in @var{files} must be a two-element list where the first element is the
7877 file name to use in the new directory, and the second element is a gexp
7878 denoting the target file. Here's an example:
7882 `(("hosts" ,(plain-file "hosts"
7883 "127.0.0.1 localhost"))
7884 ("bashrc" ,(plain-file "bashrc"
7885 "alias ls='ls --color=auto'"))))
7888 This yields an @code{etc} directory containing these two files.
7891 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7892 Return a directory that is the union of @var{things}, where @var{things} is a list of
7893 file-like objects denoting directories. For example:
7896 (directory-union "guile+emacs" (list guile emacs))
7899 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7902 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7903 Return a file-like object that expands to the concatenation of @var{obj}
7904 and @var{suffix}, where @var{obj} is a lowerable object and each
7905 @var{suffix} is a string.
7907 As an example, consider this gexp:
7910 (gexp->script "run-uname"
7911 #~(system* #$(file-append coreutils
7915 The same effect could be achieved with:
7918 (gexp->script "run-uname"
7919 #~(system* (string-append #$coreutils
7923 There is one difference though: in the @code{file-append} case, the
7924 resulting script contains the absolute file name as a string, whereas in
7925 the second case, the resulting script contains a @code{(string-append
7926 @dots{})} expression to construct the file name @emph{at run time}.
7930 Of course, in addition to gexps embedded in ``host'' code, there are
7931 also modules containing build tools. To make it clear that they are
7932 meant to be used in the build stratum, these modules are kept in the
7933 @code{(guix build @dots{})} name space.
7935 @cindex lowering, of high-level objects in gexps
7936 Internally, high-level objects are @dfn{lowered}, using their compiler,
7937 to either derivations or store items. For instance, lowering a package
7938 yields a derivation, and lowering a @code{plain-file} yields a store
7939 item. This is achieved using the @code{lower-object} monadic procedure.
7941 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7943 Return as a value in @var{%store-monad} the derivation or store item
7944 corresponding to @var{obj} for @var{system}, cross-compiling for
7945 @var{target} if @var{target} is true. @var{obj} must be an object that
7946 has an associated gexp compiler, such as a @code{<package>}.
7949 @node Invoking guix repl
7950 @section Invoking @command{guix repl}
7952 @cindex REPL, read-eval-print loop
7953 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7954 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7955 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7956 command, @command{guix repl} guarantees that all the Guix modules and all its
7957 dependencies are available in the search path. You can use it this way:
7961 scheme@@(guile-user)> ,use (gnu packages base)
7962 scheme@@(guile-user)> coreutils
7963 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7967 In addition, @command{guix repl} implements a simple machine-readable REPL
7968 protocol for use by @code{(guix inferior)}, a facility to interact with
7969 @dfn{inferiors}, separate processes running a potentially different revision
7972 The available options are as follows:
7975 @item --type=@var{type}
7976 @itemx -t @var{type}
7977 Start a REPL of the given @var{TYPE}, which can be one of the following:
7981 This is default, and it spawns a standard full-featured Guile REPL.
7983 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7984 that the @code{(guix inferior)} module speaks.
7987 @item --listen=@var{endpoint}
7988 By default, @command{guix repl} reads from standard input and writes to
7989 standard output. When this option is passed, it will instead listen for
7990 connections on @var{endpoint}. Here are examples of valid options:
7993 @item --listen=tcp:37146
7994 Accept connections on localhost on port 37146.
7996 @item --listen=unix:/tmp/socket
7997 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8001 @c *********************************************************************
8005 This section describes Guix command-line utilities. Some of them are
8006 primarily targeted at developers and users who write new package
8007 definitions, while others are more generally useful. They complement
8008 the Scheme programming interface of Guix in a convenient way.
8011 * Invoking guix build:: Building packages from the command line.
8012 * Invoking guix edit:: Editing package definitions.
8013 * Invoking guix download:: Downloading a file and printing its hash.
8014 * Invoking guix hash:: Computing the cryptographic hash of a file.
8015 * Invoking guix import:: Importing package definitions.
8016 * Invoking guix refresh:: Updating package definitions.
8017 * Invoking guix lint:: Finding errors in package definitions.
8018 * Invoking guix size:: Profiling disk usage.
8019 * Invoking guix graph:: Visualizing the graph of packages.
8020 * Invoking guix publish:: Sharing substitutes.
8021 * Invoking guix challenge:: Challenging substitute servers.
8022 * Invoking guix copy:: Copying to and from a remote store.
8023 * Invoking guix container:: Process isolation.
8024 * Invoking guix weather:: Assessing substitute availability.
8025 * Invoking guix processes:: Listing client processes.
8028 @node Invoking guix build
8029 @section Invoking @command{guix build}
8031 @cindex package building
8032 @cindex @command{guix build}
8033 The @command{guix build} command builds packages or derivations and
8034 their dependencies, and prints the resulting store paths. Note that it
8035 does not modify the user's profile---this is the job of the
8036 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8037 it is mainly useful for distribution developers.
8039 The general syntax is:
8042 guix build @var{options} @var{package-or-derivation}@dots{}
8045 As an example, the following command builds the latest versions of Emacs
8046 and of Guile, displays their build logs, and finally displays the
8047 resulting directories:
8050 guix build emacs guile
8053 Similarly, the following command builds all the available packages:
8056 guix build --quiet --keep-going \
8057 `guix package -A | cut -f1,2 --output-delimiter=@@`
8060 @var{package-or-derivation} may be either the name of a package found in
8061 the software distribution such as @code{coreutils} or
8062 @code{coreutils@@8.20}, or a derivation such as
8063 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8064 package with the corresponding name (and optionally version) is searched
8065 for among the GNU distribution modules (@pxref{Package Modules}).
8067 Alternatively, the @code{--expression} option may be used to specify a
8068 Scheme expression that evaluates to a package; this is useful when
8069 disambiguating among several same-named packages or package variants is
8072 There may be zero or more @var{options}. The available options are
8073 described in the subsections below.
8076 * Common Build Options:: Build options for most commands.
8077 * Package Transformation Options:: Creating variants of packages.
8078 * Additional Build Options:: Options specific to 'guix build'.
8079 * Debugging Build Failures:: Real life packaging experience.
8082 @node Common Build Options
8083 @subsection Common Build Options
8085 A number of options that control the build process are common to
8086 @command{guix build} and other commands that can spawn builds, such as
8087 @command{guix package} or @command{guix archive}. These are the
8092 @item --load-path=@var{directory}
8093 @itemx -L @var{directory}
8094 Add @var{directory} to the front of the package module search path
8095 (@pxref{Package Modules}).
8097 This allows users to define their own packages and make them visible to
8098 the command-line tools.
8102 Keep the build tree of failed builds. Thus, if a build fails, its build
8103 tree is kept under @file{/tmp}, in a directory whose name is shown at
8104 the end of the build log. This is useful when debugging build issues.
8105 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8108 This option implies @option{--no-offload}, and it has no effect when
8109 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8110 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8114 Keep going when some of the derivations fail to build; return only once
8115 all the builds have either completed or failed.
8117 The default behavior is to stop as soon as one of the specified
8118 derivations has failed.
8122 Do not build the derivations.
8124 @anchor{fallback-option}
8126 When substituting a pre-built binary fails, fall back to building
8127 packages locally (@pxref{Substitution Failure}).
8129 @item --substitute-urls=@var{urls}
8130 @anchor{client-substitute-urls}
8131 Consider @var{urls} the whitespace-separated list of substitute source
8132 URLs, overriding the default list of URLs of @command{guix-daemon}
8133 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8135 This means that substitutes may be downloaded from @var{urls}, provided
8136 they are signed by a key authorized by the system administrator
8137 (@pxref{Substitutes}).
8139 When @var{urls} is the empty string, substitutes are effectively
8142 @item --no-substitutes
8143 Do not use substitutes for build products. That is, always build things
8144 locally instead of allowing downloads of pre-built binaries
8145 (@pxref{Substitutes}).
8148 Do not ``graft'' packages. In practice, this means that package updates
8149 available as grafts are not applied. @xref{Security Updates}, for more
8150 information on grafts.
8152 @item --rounds=@var{n}
8153 Build each derivation @var{n} times in a row, and raise an error if
8154 consecutive build results are not bit-for-bit identical.
8156 This is a useful way to detect non-deterministic builds processes.
8157 Non-deterministic build processes are a problem because they make it
8158 practically impossible for users to @emph{verify} whether third-party
8159 binaries are genuine. @xref{Invoking guix challenge}, for more.
8161 Note that, currently, the differing build results are not kept around,
8162 so you will have to manually investigate in case of an error---e.g., by
8163 stashing one of the build results with @code{guix archive --export}
8164 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8168 Do not use offload builds to other machines (@pxref{Daemon Offload
8169 Setup}). That is, always build things locally instead of offloading
8170 builds to remote machines.
8172 @item --max-silent-time=@var{seconds}
8173 When the build or substitution process remains silent for more than
8174 @var{seconds}, terminate it and report a build failure.
8176 By default, the daemon's setting is honored (@pxref{Invoking
8177 guix-daemon, @code{--max-silent-time}}).
8179 @item --timeout=@var{seconds}
8180 Likewise, when the build or substitution process lasts for more than
8181 @var{seconds}, terminate it and report a build failure.
8183 By default, the daemon's setting is honored (@pxref{Invoking
8184 guix-daemon, @code{--timeout}}).
8186 @c Note: This option is actually not part of %standard-build-options but
8187 @c most programs honor it.
8188 @cindex verbosity, of the command-line tools
8189 @cindex build logs, verbosity
8190 @item -v @var{level}
8191 @itemx --verbosity=@var{level}
8192 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8193 output is produced, 1 is for quiet output, and 2 shows all the build log
8194 output on standard error.
8196 @item --cores=@var{n}
8198 Allow the use of up to @var{n} CPU cores for the build. The special
8199 value @code{0} means to use as many CPU cores as available.
8201 @item --max-jobs=@var{n}
8203 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8204 guix-daemon, @code{--max-jobs}}, for details about this option and the
8205 equivalent @command{guix-daemon} option.
8207 @item --debug=@var{level}
8208 Produce debugging output coming from the build daemon. @var{level} must be an
8209 integer between 0 and 5; higher means more verbose output. Setting a level of
8210 4 or more may be helpful when debugging setup issues with the build daemon.
8214 Behind the scenes, @command{guix build} is essentially an interface to
8215 the @code{package-derivation} procedure of the @code{(guix packages)}
8216 module, and to the @code{build-derivations} procedure of the @code{(guix
8217 derivations)} module.
8219 In addition to options explicitly passed on the command line,
8220 @command{guix build} and other @command{guix} commands that support
8221 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8223 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8224 Users can define this variable to a list of command line options that
8225 will automatically be used by @command{guix build} and other
8226 @command{guix} commands that can perform builds, as in the example
8230 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8233 These options are parsed independently, and the result is appended to
8234 the parsed command-line options.
8238 @node Package Transformation Options
8239 @subsection Package Transformation Options
8241 @cindex package variants
8242 Another set of command-line options supported by @command{guix build}
8243 and also @command{guix package} are @dfn{package transformation
8244 options}. These are options that make it possible to define @dfn{package
8245 variants}---for instance, packages built from different source code.
8246 This is a convenient way to create customized packages on the fly
8247 without having to type in the definitions of package variants
8248 (@pxref{Defining Packages}).
8252 @item --with-source=@var{source}
8253 @itemx --with-source=@var{package}=@var{source}
8254 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8255 Use @var{source} as the source of @var{package}, and @var{version} as
8257 @var{source} must be a file name or a URL, as for @command{guix
8258 download} (@pxref{Invoking guix download}).
8260 When @var{package} is omitted,
8261 it is taken to be the package name specified on the
8262 command line that matches the base of @var{source}---e.g.,
8263 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8264 package is @code{guile}.
8266 Likewise, when @var{version} is omitted, the version string is inferred from
8267 @var{source}; in the previous example, it is @code{2.0.10}.
8269 This option allows users to try out versions of packages other than the
8270 one provided by the distribution. The example below downloads
8271 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8272 the @code{ed} package:
8275 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8278 As a developer, @code{--with-source} makes it easy to test release
8282 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8285 @dots{} or to build from a checkout in a pristine environment:
8288 $ git clone git://git.sv.gnu.org/guix.git
8289 $ guix build guix --with-source=guix@@1.0=./guix
8292 @item --with-input=@var{package}=@var{replacement}
8293 Replace dependency on @var{package} by a dependency on
8294 @var{replacement}. @var{package} must be a package name, and
8295 @var{replacement} must be a package specification such as @code{guile}
8296 or @code{guile@@1.8}.
8298 For instance, the following command builds Guix, but replaces its
8299 dependency on the current stable version of Guile with a dependency on
8300 the legacy version of Guile, @code{guile@@2.0}:
8303 guix build --with-input=guile=guile@@2.0 guix
8306 This is a recursive, deep replacement. So in this example, both
8307 @code{guix} and its dependency @code{guile-json} (which also depends on
8308 @code{guile}) get rebuilt against @code{guile@@2.0}.
8310 This is implemented using the @code{package-input-rewriting} Scheme
8311 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8313 @item --with-graft=@var{package}=@var{replacement}
8314 This is similar to @code{--with-input} but with an important difference:
8315 instead of rebuilding the whole dependency chain, @var{replacement} is
8316 built and then @dfn{grafted} onto the binaries that were initially
8317 referring to @var{package}. @xref{Security Updates}, for more
8318 information on grafts.
8320 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8321 and all its dependencies, replacing references to the version of GnuTLS
8322 they currently refer to:
8325 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8328 This has the advantage of being much faster than rebuilding everything.
8329 But there is a caveat: it works if and only if @var{package} and
8330 @var{replacement} are strictly compatible---for example, if they provide
8331 a library, the application binary interface (ABI) of those libraries
8332 must be compatible. If @var{replacement} is somehow incompatible with
8333 @var{package}, then the resulting package may be unusable. Use with
8336 @item --with-git-url=@var{package}=@var{url}
8337 @cindex Git, using the latest commit
8338 @cindex latest commit, building
8339 Build @var{package} from the latest commit of the @code{master} branch of the
8340 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8343 For example, the following command builds the NumPy Python library against the
8344 latest commit of the master branch of Python itself:
8347 guix build python-numpy \
8348 --with-git-url=python=https://github.com/python/cpython
8351 This option can also be combined with @code{--with-branch} or
8352 @code{--with-commit} (see below).
8354 @cindex continuous integration
8355 Obviously, since it uses the latest commit of the given branch, the result of
8356 such a command varies over time. Nevertheless it is a convenient way to
8357 rebuild entire software stacks against the latest commit of one or more
8358 packages. This is particularly useful in the context of continuous
8361 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8362 consecutive accesses to the same repository. You may want to clean it up once
8363 in a while to save disk space.
8365 @item --with-branch=@var{package}=@var{branch}
8366 Build @var{package} from the latest commit of @var{branch}. If the
8367 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8368 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8369 repository URL is taken from that @code{source}. Otherwise you have to use
8370 @code{--with-git-url} to specify the URL of the Git repository.
8372 For instance, the following command builds @code{guile-sqlite3} from the
8373 latest commit of its @code{master} branch, and then builds @code{guix} (which
8374 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8375 specific @code{guile-sqlite3} build:
8378 guix build --with-branch=guile-sqlite3=master cuirass
8381 @item --with-commit=@var{package}=@var{commit}
8382 This is similar to @code{--with-branch}, except that it builds from
8383 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8384 Git commit SHA1 identifier or a tag.
8387 @node Additional Build Options
8388 @subsection Additional Build Options
8390 The command-line options presented below are specific to @command{guix
8397 Build quietly, without displaying the build log; this is equivalent to
8398 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8399 (or similar) and can always be retrieved using the @option{--log-file} option.
8401 @item --file=@var{file}
8402 @itemx -f @var{file}
8403 Build the package, derivation, or other file-like object that the code within
8404 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8406 As an example, @var{file} might contain a package definition like this
8407 (@pxref{Defining Packages}):
8410 @include package-hello.scm
8413 @item --expression=@var{expr}
8414 @itemx -e @var{expr}
8415 Build the package or derivation @var{expr} evaluates to.
8417 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8418 guile-1.8)}, which unambiguously designates this specific variant of
8419 version 1.8 of Guile.
8421 Alternatively, @var{expr} may be a G-expression, in which case it is used
8422 as a build program passed to @code{gexp->derivation}
8423 (@pxref{G-Expressions}).
8425 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8426 (@pxref{The Store Monad}). The procedure must return a derivation as a
8427 monadic value, which is then passed through @code{run-with-store}.
8431 Build the source derivations of the packages, rather than the packages
8434 For instance, @code{guix build -S gcc} returns something like
8435 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8438 The returned source tarball is the result of applying any patches and
8439 code snippets specified in the package @code{origin} (@pxref{Defining
8442 Note that @command{guix build -S} compiles the sources only of the
8443 specified packages. They do not include the sources of statically
8444 linked dependencies and by themselves are insufficient for reproducing
8448 Fetch and return the source of @var{package-or-derivation} and all their
8449 dependencies, recursively. This is a handy way to obtain a local copy
8450 of all the source code needed to build @var{packages}, allowing you to
8451 eventually build them even without network access. It is an extension
8452 of the @code{--source} option and can accept one of the following
8453 optional argument values:
8457 This value causes the @code{--sources} option to behave in the same way
8458 as the @code{--source} option.
8461 Build the source derivations of all packages, including any source that
8462 might be listed as @code{inputs}. This is the default value.
8465 $ guix build --sources tzdata
8466 The following derivations will be built:
8467 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8468 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8472 Build the source derivations of all packages, as well of all transitive
8473 inputs to the packages. This can be used e.g.@: to
8474 prefetch package source for later offline building.
8477 $ guix build --sources=transitive tzdata
8478 The following derivations will be built:
8479 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8480 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8481 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8482 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8483 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8484 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8490 @item --system=@var{system}
8491 @itemx -s @var{system}
8492 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8493 the system type of the build host. The @command{guix build} command allows
8494 you to repeat this option several times, in which case it builds for all the
8495 specified systems; other commands ignore extraneous @option{-s} options.
8498 The @code{--system} flag is for @emph{native} compilation and must not
8499 be confused with cross-compilation. See @code{--target} below for
8500 information on cross-compilation.
8503 An example use of this is on Linux-based systems, which can emulate
8504 different personalities. For instance, passing
8505 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8506 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8507 to build packages in a complete 32-bit environment.
8510 Building for an @code{armhf-linux} system is unconditionally enabled on
8511 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8512 allow for this functionality, notably the ThunderX.
8515 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8516 is enabled (@pxref{Virtualization Services,
8517 @code{qemu-binfmt-service-type}}), you can build for any system for
8518 which a QEMU @code{binfmt_misc} handler is installed.
8520 Builds for a system other than that of the machine you are using can
8521 also be offloaded to a remote machine of the right architecture.
8522 @xref{Daemon Offload Setup}, for more information on offloading.
8524 @item --target=@var{triplet}
8525 @cindex cross-compilation
8526 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8527 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8528 configuration triplets,, autoconf, Autoconf}).
8530 @anchor{build-check}
8532 @cindex determinism, checking
8533 @cindex reproducibility, checking
8534 Rebuild @var{package-or-derivation}, which are already available in the
8535 store, and raise an error if the build results are not bit-for-bit
8538 This mechanism allows you to check whether previously installed
8539 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8540 of a package is deterministic. @xref{Invoking guix challenge}, for more
8541 background information and tools.
8543 When used in conjunction with @option{--keep-failed}, the differing
8544 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8545 This makes it easy to look for differences between the two results.
8548 @cindex repairing store items
8549 @cindex corruption, recovering from
8550 Attempt to repair the specified store items, if they are corrupt, by
8551 re-downloading or rebuilding them.
8553 This operation is not atomic and thus restricted to @code{root}.
8557 Return the derivation paths, not the output paths, of the given
8560 @item --root=@var{file}
8561 @itemx -r @var{file}
8562 @cindex GC roots, adding
8563 @cindex garbage collector roots, adding
8564 Make @var{file} a symlink to the result, and register it as a garbage
8567 Consequently, the results of this @command{guix build} invocation are
8568 protected from garbage collection until @var{file} is removed. When
8569 that option is omitted, build results are eligible for garbage
8570 collection as soon as the build completes. @xref{Invoking guix gc}, for
8574 @cindex build logs, access
8575 Return the build log file names or URLs for the given
8576 @var{package-or-derivation}, or raise an error if build logs are
8579 This works regardless of how packages or derivations are specified. For
8580 instance, the following invocations are equivalent:
8583 guix build --log-file `guix build -d guile`
8584 guix build --log-file `guix build guile`
8585 guix build --log-file guile
8586 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8589 If a log is unavailable locally, and unless @code{--no-substitutes} is
8590 passed, the command looks for a corresponding log on one of the
8591 substitute servers (as specified with @code{--substitute-urls}.)
8593 So for instance, imagine you want to see the build log of GDB on MIPS,
8594 but you are actually on an @code{x86_64} machine:
8597 $ guix build --log-file gdb -s mips64el-linux
8598 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8601 You can freely access a huge library of build logs!
8604 @node Debugging Build Failures
8605 @subsection Debugging Build Failures
8607 @cindex build failures, debugging
8608 When defining a new package (@pxref{Defining Packages}), you will
8609 probably find yourself spending some time debugging and tweaking the
8610 build until it succeeds. To do that, you need to operate the build
8611 commands yourself in an environment as close as possible to the one the
8614 To that end, the first thing to do is to use the @option{--keep-failed}
8615 or @option{-K} option of @command{guix build}, which will keep the
8616 failed build tree in @file{/tmp} or whatever directory you specified as
8617 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8619 From there on, you can @command{cd} to the failed build tree and source
8620 the @file{environment-variables} file, which contains all the
8621 environment variable definitions that were in place when the build
8622 failed. So let's say you're debugging a build failure in package
8623 @code{foo}; a typical session would look like this:
8627 @dots{} @i{build fails}
8628 $ cd /tmp/guix-build-foo.drv-0
8629 $ source ./environment-variables
8633 Now, you can invoke commands as if you were the daemon (almost) and
8634 troubleshoot your build process.
8636 Sometimes it happens that, for example, a package's tests pass when you
8637 run them manually but they fail when the daemon runs them. This can
8638 happen because the daemon runs builds in containers where, unlike in our
8639 environment above, network access is missing, @file{/bin/sh} does not
8640 exist, etc. (@pxref{Build Environment Setup}).
8642 In such cases, you may need to run inspect the build process from within
8643 a container similar to the one the build daemon creates:
8648 $ cd /tmp/guix-build-foo.drv-0
8649 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8650 [env]# source ./environment-variables
8654 Here, @command{guix environment -C} creates a container and spawns a new
8655 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8656 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8657 the container, which would may find handy while debugging. The
8658 @option{--no-grafts} option makes sure we get the exact same
8659 environment, with ungrafted packages (@pxref{Security Updates}, for more
8662 To get closer to a container like that used by the build daemon, we can
8663 remove @file{/bin/sh}:
8669 (Don't worry, this is harmless: this is all happening in the throw-away
8670 container created by @command{guix environment}.)
8672 The @command{strace} command is probably not in the search path, but we
8676 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8679 In this way, not only you will have reproduced the environment variables
8680 the daemon uses, you will also be running the build process in a container
8681 similar to the one the daemon uses.
8684 @node Invoking guix edit
8685 @section Invoking @command{guix edit}
8687 @cindex @command{guix edit}
8688 @cindex package definition, editing
8689 So many packages, so many source files! The @command{guix edit} command
8690 facilitates the life of users and packagers by pointing their editor at
8691 the source file containing the definition of the specified packages.
8695 guix edit gcc@@4.9 vim
8699 launches the program specified in the @code{VISUAL} or in the
8700 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8703 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8704 have created your own packages on @code{GUIX_PACKAGE_PATH}
8705 (@pxref{Package Modules}), you will be able to edit the package
8706 recipes. In other cases, you will be able to examine the read-only recipes
8707 for packages currently in the store.
8710 @node Invoking guix download
8711 @section Invoking @command{guix download}
8713 @cindex @command{guix download}
8714 @cindex downloading package sources
8715 When writing a package definition, developers typically need to download
8716 a source tarball, compute its SHA256 hash, and write that
8717 hash in the package definition (@pxref{Defining Packages}). The
8718 @command{guix download} tool helps with this task: it downloads a file
8719 from the given URI, adds it to the store, and prints both its file name
8720 in the store and its SHA256 hash.
8722 The fact that the downloaded file is added to the store saves bandwidth:
8723 when the developer eventually tries to build the newly defined package
8724 with @command{guix build}, the source tarball will not have to be
8725 downloaded again because it is already in the store. It is also a
8726 convenient way to temporarily stash files, which may be deleted
8727 eventually (@pxref{Invoking guix gc}).
8729 The @command{guix download} command supports the same URIs as used in
8730 package definitions. In particular, it supports @code{mirror://} URIs.
8731 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8732 Guile bindings for GnuTLS are available in the user's environment; when
8733 they are not available, an error is raised. @xref{Guile Preparations,
8734 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8735 GnuTLS-Guile}, for more information.
8737 @command{guix download} verifies HTTPS server certificates by loading
8738 the certificates of X.509 authorities from the directory pointed to by
8739 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8740 Certificates}), unless @option{--no-check-certificate} is used.
8742 The following options are available:
8745 @item --format=@var{fmt}
8747 Write the hash in the format specified by @var{fmt}. For more
8748 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8750 @item --no-check-certificate
8751 Do not validate the X.509 certificates of HTTPS servers.
8753 When using this option, you have @emph{absolutely no guarantee} that you
8754 are communicating with the authentic server responsible for the given
8755 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8757 @item --output=@var{file}
8758 @itemx -o @var{file}
8759 Save the downloaded file to @var{file} instead of adding it to the
8763 @node Invoking guix hash
8764 @section Invoking @command{guix hash}
8766 @cindex @command{guix hash}
8767 The @command{guix hash} command computes the SHA256 hash of a file.
8768 It is primarily a convenience tool for anyone contributing to the
8769 distribution: it computes the cryptographic hash of a file, which can be
8770 used in the definition of a package (@pxref{Defining Packages}).
8772 The general syntax is:
8775 guix hash @var{option} @var{file}
8778 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8779 hash of data read from standard input. @command{guix hash} has the
8784 @item --format=@var{fmt}
8786 Write the hash in the format specified by @var{fmt}.
8788 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8789 (@code{hex} and @code{hexadecimal} can be used as well).
8791 If the @option{--format} option is not specified, @command{guix hash}
8792 will output the hash in @code{nix-base32}. This representation is used
8793 in the definitions of packages.
8797 Compute the hash on @var{file} recursively.
8799 In this case, the hash is computed on an archive containing @var{file},
8800 including its children if it is a directory. Some of the metadata of
8801 @var{file} is part of the archive; for instance, when @var{file} is a
8802 regular file, the hash is different depending on whether @var{file} is
8803 executable or not. Metadata such as time stamps has no impact on the
8804 hash (@pxref{Invoking guix archive}).
8805 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8810 When combined with @option{--recursive}, exclude version control system
8811 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8814 As an example, here is how you would compute the hash of a Git checkout,
8815 which is useful when using the @code{git-fetch} method (@pxref{origin
8819 $ git clone http://example.org/foo.git
8825 @node Invoking guix import
8826 @section Invoking @command{guix import}
8828 @cindex importing packages
8829 @cindex package import
8830 @cindex package conversion
8831 @cindex Invoking @command{guix import}
8832 The @command{guix import} command is useful for people who would like to
8833 add a package to the distribution with as little work as
8834 possible---a legitimate demand. The command knows of a few
8835 repositories from which it can ``import'' package metadata. The result
8836 is a package definition, or a template thereof, in the format we know
8837 (@pxref{Defining Packages}).
8839 The general syntax is:
8842 guix import @var{importer} @var{options}@dots{}
8845 @var{importer} specifies the source from which to import package
8846 metadata, and @var{options} specifies a package identifier and other
8847 options specific to @var{importer}.
8849 Some of the importers rely on the ability to run the @command{gpgv} command.
8850 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8853 Currently, the available ``importers'' are:
8857 Import metadata for the given GNU package. This provides a template
8858 for the latest version of that GNU package, including the hash of its
8859 source tarball, and its canonical synopsis and description.
8861 Additional information such as the package dependencies and its
8862 license needs to be figured out manually.
8864 For example, the following command returns a package definition for
8868 guix import gnu hello
8871 Specific command-line options are:
8874 @item --key-download=@var{policy}
8875 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8876 keys when verifying the package signature. @xref{Invoking guix
8877 refresh, @code{--key-download}}.
8882 Import metadata from the @uref{https://pypi.python.org/, Python Package
8883 Index}. Information is taken from the JSON-formatted description
8884 available at @code{pypi.python.org} and usually includes all the relevant
8885 information, including package dependencies. For maximum efficiency, it
8886 is recommended to install the @command{unzip} utility, so that the
8887 importer can unzip Python wheels and gather data from them.
8889 The command below imports metadata for the @code{itsdangerous} Python
8893 guix import pypi itsdangerous
8899 Traverse the dependency graph of the given upstream package recursively
8900 and generate package expressions for all those packages that are not yet
8906 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8907 is taken from the JSON-formatted description available at
8908 @code{rubygems.org} and includes most relevant information, including
8909 runtime dependencies. There are some caveats, however. The metadata
8910 doesn't distinguish between synopses and descriptions, so the same string
8911 is used for both fields. Additionally, the details of non-Ruby
8912 dependencies required to build native extensions is unavailable and left
8913 as an exercise to the packager.
8915 The command below imports metadata for the @code{rails} Ruby package:
8918 guix import gem rails
8924 Traverse the dependency graph of the given upstream package recursively
8925 and generate package expressions for all those packages that are not yet
8931 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8932 Information is taken from the JSON-formatted metadata provided through
8933 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8934 relevant information, such as module dependencies. License information
8935 should be checked closely. If Perl is available in the store, then the
8936 @code{corelist} utility will be used to filter core modules out of the
8937 list of dependencies.
8939 The command command below imports metadata for the @code{Acme::Boolean}
8943 guix import cpan Acme::Boolean
8948 @cindex Bioconductor
8949 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8950 central repository for the @uref{https://r-project.org, GNU@tie{}R
8951 statistical and graphical environment}.
8953 Information is extracted from the @code{DESCRIPTION} file of the package.
8955 The command command below imports metadata for the @code{Cairo}
8959 guix import cran Cairo
8962 When @code{--recursive} is added, the importer will traverse the
8963 dependency graph of the given upstream package recursively and generate
8964 package expressions for all those packages that are not yet in Guix.
8966 When @code{--archive=bioconductor} is added, metadata is imported from
8967 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8968 packages for for the analysis and comprehension of high-throughput
8969 genomic data in bioinformatics.
8971 Information is extracted from the @code{DESCRIPTION} file contained in the
8974 The command below imports metadata for the @code{GenomicRanges}
8978 guix import cran --archive=bioconductor GenomicRanges
8981 Finally, you can also import R packages that have not yet been published on
8982 CRAN or Bioconductor as long as they are in a git repository. Use
8983 @code{--archive=git} followed by the URL of the git repository:
8986 guix import cran --archive=git https://github.com/immunogenomics/harmony
8992 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8993 comprehensive TeX archive network for TeX packages that are part of the
8994 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8996 Information about the package is obtained through the XML API provided
8997 by CTAN, while the source code is downloaded from the SVN repository of
8998 the Tex Live project. This is done because the CTAN does not keep
9001 The command command below imports metadata for the @code{fontspec}
9005 guix import texlive fontspec
9008 When @code{--archive=DIRECTORY} is added, the source code is downloaded
9009 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
9010 tree in the TeX Live SVN repository, but from the specified sibling
9011 directory under the same root.
9013 The command below imports metadata for the @code{ifxetex} package from
9014 CTAN while fetching the sources from the directory
9015 @file{texmf/source/generic}:
9018 guix import texlive --archive=generic ifxetex
9022 @cindex JSON, import
9023 Import package metadata from a local JSON file. Consider the following
9024 example package definition in JSON format:
9030 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9031 "build-system": "gnu",
9032 "home-page": "https://www.gnu.org/software/hello/",
9033 "synopsis": "Hello, GNU world: An example GNU package",
9034 "description": "GNU Hello prints a greeting.",
9035 "license": "GPL-3.0+",
9036 "native-inputs": ["gettext"]
9040 The field names are the same as for the @code{<package>} record
9041 (@xref{Defining Packages}). References to other packages are provided
9042 as JSON lists of quoted package specification strings such as
9043 @code{guile} or @code{guile@@2.0}.
9045 The importer also supports a more explicit source definition using the
9046 common fields for @code{<origin>} records:
9052 "method": "url-fetch",
9053 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9055 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9062 The command below reads metadata from the JSON file @code{hello.json}
9063 and outputs a package expression:
9066 guix import json hello.json
9070 Import metadata from a local copy of the source of the
9071 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9072 relies on the @command{nix-instantiate} command of
9073 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9074 typically written in a mixture of Nix-language and Bash code. This
9075 command only imports the high-level package structure that is written in
9076 the Nix language. It normally includes all the basic fields of a
9079 When importing a GNU package, the synopsis and descriptions are replaced
9080 by their canonical upstream variant.
9082 Usually, you will first need to do:
9085 export NIX_REMOTE=daemon
9089 so that @command{nix-instantiate} does not try to open the Nix database.
9091 As an example, the command below imports the package definition of
9092 LibreOffice (more precisely, it imports the definition of the package
9093 bound to the @code{libreoffice} top-level attribute):
9096 guix import nix ~/path/to/nixpkgs libreoffice
9101 Import metadata from the Haskell community's central package archive
9102 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9103 Cabal files and includes all the relevant information, including package
9106 Specific command-line options are:
9111 Read a Cabal file from standard input.
9112 @item --no-test-dependencies
9114 Do not include dependencies required only by the test suites.
9115 @item --cabal-environment=@var{alist}
9116 @itemx -e @var{alist}
9117 @var{alist} is a Scheme alist defining the environment in which the
9118 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9119 @code{arch}, @code{impl} and a string representing the name of a flag.
9120 The value associated with a flag has to be either the symbol
9121 @code{true} or @code{false}. The value associated with other keys
9122 has to conform to the Cabal file format definition. The default value
9123 associated with the keys @code{os}, @code{arch} and @code{impl} is
9124 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9127 Traverse the dependency graph of the given upstream package recursively
9128 and generate package expressions for all those packages that are not yet
9132 The command below imports metadata for the latest version of the
9133 @code{HTTP} Haskell package without including test dependencies and
9134 specifying the value of the flag @samp{network-uri} as @code{false}:
9137 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9140 A specific package version may optionally be specified by following the
9141 package name by an at-sign and a version number as in the following example:
9144 guix import hackage mtl@@2.1.3.1
9149 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9150 It takes a package name, looks up the package version included in a
9151 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9152 release and uses the @code{hackage} importer to retrieve its metadata.
9153 Note that it is up to you to select an LTS release compatible with the
9154 GHC compiler used by Guix.
9156 Specific command-line options are:
9159 @item --no-test-dependencies
9161 Do not include dependencies required only by the test suites.
9162 @item --lts-version=@var{version}
9163 @itemx -l @var{version}
9164 @var{version} is the desired LTS release version. If omitted the latest
9168 Traverse the dependency graph of the given upstream package recursively
9169 and generate package expressions for all those packages that are not yet
9173 The command below imports metadata for the @code{HTTP} Haskell package
9174 included in the LTS Stackage release version 7.18:
9177 guix import stackage --lts-version=7.18 HTTP
9182 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9183 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9185 Specific command-line options are:
9188 @item --archive=@var{repo}
9189 @itemx -a @var{repo}
9190 @var{repo} identifies the archive repository from which to retrieve the
9191 information. Currently the supported repositories and their identifiers
9195 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9196 identifier. This is the default.
9198 Packages from @code{elpa.gnu.org} are signed with one of the keys
9199 contained in the GnuPG keyring at
9200 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9201 @code{emacs} package (@pxref{Package Installation, ELPA package
9202 signatures,, emacs, The GNU Emacs Manual}).
9205 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9206 @code{melpa-stable} identifier.
9209 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9215 Traverse the dependency graph of the given upstream package recursively
9216 and generate package expressions for all those packages that are not yet
9222 Import metadata from the crates.io Rust package repository
9223 @uref{https://crates.io, crates.io}, as in this example:
9226 guix import crate blake2-rfc
9229 The crate importer also allows you to specify a version string:
9232 guix import crate constant-time-eq@@0.1.0
9235 Additional options include:
9240 Traverse the dependency graph of the given upstream package recursively
9241 and generate package expressions for all those packages that are not yet
9248 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9249 repository used by the OCaml community.
9252 The structure of the @command{guix import} code is modular. It would be
9253 useful to have more importers for other package formats, and your help
9254 is welcome here (@pxref{Contributing}).
9256 @node Invoking guix refresh
9257 @section Invoking @command{guix refresh}
9259 @cindex @command {guix refresh}
9260 The primary audience of the @command{guix refresh} command is developers
9261 of the GNU software distribution. By default, it reports any packages
9262 provided by the distribution that are outdated compared to the latest
9263 upstream version, like this:
9267 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9268 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9271 Alternately, one can specify packages to consider, in which case a
9272 warning is emitted for packages that lack an updater:
9275 $ guix refresh coreutils guile guile-ssh
9276 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9277 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9280 @command{guix refresh} browses the upstream repository of each package and determines
9281 the highest version number of the releases therein. The command
9282 knows how to update specific types of packages: GNU packages, ELPA
9283 packages, etc.---see the documentation for @option{--type} below. There
9284 are many packages, though, for which it lacks a method to determine
9285 whether a new upstream release is available. However, the mechanism is
9286 extensible, so feel free to get in touch with us to add a new method!
9291 Consider the packages specified, and all the packages upon which they depend.
9294 $ guix refresh --recursive coreutils
9295 gnu/packages/acl.scm:35:2: warning: no updater for acl
9296 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9297 gnu/packages/xml.scm:68:2: warning: no updater for expat
9298 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9304 Sometimes the upstream name differs from the package name used in Guix,
9305 and @command{guix refresh} needs a little help. Most updaters honor the
9306 @code{upstream-name} property in package definitions, which can be used
9310 (define-public network-manager
9312 (name "network-manager")
9314 (properties '((upstream-name . "NetworkManager")))))
9317 When passed @code{--update}, it modifies distribution source files to
9318 update the version numbers and source tarball hashes of those package
9319 recipes (@pxref{Defining Packages}). This is achieved by downloading
9320 each package's latest source tarball and its associated OpenPGP
9321 signature, authenticating the downloaded tarball against its signature
9322 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9323 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9326 key used to sign the tarball is missing from the user's keyring, an
9327 attempt is made to automatically retrieve it from a public key server;
9328 when this is successful, the key is added to the user's keyring; otherwise,
9329 @command{guix refresh} reports an error.
9331 The following options are supported:
9335 @item --expression=@var{expr}
9336 @itemx -e @var{expr}
9337 Consider the package @var{expr} evaluates to.
9339 This is useful to precisely refer to a package, as in this example:
9342 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9345 This command lists the dependents of the ``final'' libc (essentially all
9350 Update distribution source files (package recipes) in place. This is
9351 usually run from a checkout of the Guix source tree (@pxref{Running
9352 Guix Before It Is Installed}):
9355 $ ./pre-inst-env guix refresh -s non-core -u
9358 @xref{Defining Packages}, for more information on package definitions.
9360 @item --select=[@var{subset}]
9361 @itemx -s @var{subset}
9362 Select all the packages in @var{subset}, one of @code{core} or
9365 The @code{core} subset refers to all the packages at the core of the
9366 distribution---i.e., packages that are used to build ``everything
9367 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9368 changing one of these packages in the distribution entails a rebuild of
9369 all the others. Thus, such updates are an inconvenience to users in
9370 terms of build time or bandwidth used to achieve the upgrade.
9372 The @code{non-core} subset refers to the remaining packages. It is
9373 typically useful in cases where an update of the core packages would be
9376 @item --manifest=@var{file}
9377 @itemx -m @var{file}
9378 Select all the packages from the manifest in @var{file}. This is useful to
9379 check if any packages of the user manifest can be updated.
9381 @item --type=@var{updater}
9382 @itemx -t @var{updater}
9383 Select only packages handled by @var{updater} (may be a comma-separated
9384 list of updaters). Currently, @var{updater} may be one of:
9388 the updater for GNU packages;
9390 the updater for GNOME packages;
9392 the updater for KDE packages;
9394 the updater for X.org packages;
9396 the updater for packages hosted on kernel.org;
9398 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9400 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9402 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9404 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9406 the updater for @uref{https://pypi.python.org, PyPI} packages.
9408 the updater for @uref{https://rubygems.org, RubyGems} packages.
9410 the updater for @uref{https://github.com, GitHub} packages.
9412 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9414 the updater for @uref{https://www.stackage.org, Stackage} packages.
9416 the updater for @uref{https://crates.io, Crates} packages.
9418 the updater for @uref{https://launchpad.net, Launchpad} packages.
9421 For instance, the following command only checks for updates of Emacs
9422 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9425 $ guix refresh --type=elpa,cran
9426 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9427 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9432 In addition, @command{guix refresh} can be passed one or more package
9433 names, as in this example:
9436 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9440 The command above specifically updates the @code{emacs} and
9441 @code{idutils} packages. The @code{--select} option would have no
9442 effect in this case.
9444 When considering whether to upgrade a package, it is sometimes
9445 convenient to know which packages would be affected by the upgrade and
9446 should be checked for compatibility. For this the following option may
9447 be used when passing @command{guix refresh} one or more package names:
9451 @item --list-updaters
9453 List available updaters and exit (see @option{--type} above.)
9455 For each updater, display the fraction of packages it covers; at the
9456 end, display the fraction of packages covered by all these updaters.
9458 @item --list-dependent
9460 List top-level dependent packages that would need to be rebuilt as a
9461 result of upgrading one or more packages.
9463 @xref{Invoking guix graph, the @code{reverse-package} type of
9464 @command{guix graph}}, for information on how to visualize the list of
9465 dependents of a package.
9469 Be aware that the @code{--list-dependent} option only
9470 @emph{approximates} the rebuilds that would be required as a result of
9471 an upgrade. More rebuilds might be required under some circumstances.
9474 $ guix refresh --list-dependent flex
9475 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9476 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9479 The command above lists a set of packages that could be built to check
9480 for compatibility with an upgraded @code{flex} package.
9484 @item --list-transitive
9485 List all the packages which one or more packages depend upon.
9488 $ guix refresh --list-transitive flex
9489 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9490 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{}
9495 The command above lists a set of packages which, when changed, would cause
9496 @code{flex} to be rebuilt.
9498 The following options can be used to customize GnuPG operation:
9502 @item --gpg=@var{command}
9503 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9504 for in @code{$PATH}.
9506 @item --keyring=@var{file}
9507 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9508 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9509 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9510 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9511 information on a tool to manipulate keybox files).
9513 When this option is omitted, @command{guix refresh} uses
9514 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9515 signing keys. OpenPGP signatures are checked against keys from this keyring;
9516 missing keys are downloaded to this keyring as well (see
9517 @option{--key-download} below.)
9519 You can export keys from your default GPG keyring into a keybox file using
9520 commands like this one:
9523 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9526 Likewise, you can fetch keys to a specific keybox file like this:
9529 gpg --no-default-keyring --keyring mykeyring.kbx \
9530 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9533 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9534 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9536 @item --key-download=@var{policy}
9537 Handle missing OpenPGP keys according to @var{policy}, which may be one
9542 Always download missing OpenPGP keys from the key server, and add them
9543 to the user's GnuPG keyring.
9546 Never try to download missing OpenPGP keys. Instead just bail out.
9549 When a package signed with an unknown OpenPGP key is encountered, ask
9550 the user whether to download it or not. This is the default behavior.
9553 @item --key-server=@var{host}
9554 Use @var{host} as the OpenPGP key server when importing a public key.
9558 The @code{github} updater uses the
9559 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9560 releases. When used repeatedly e.g.@: when refreshing all packages,
9561 GitHub will eventually refuse to answer any further API requests. By
9562 default 60 API requests per hour are allowed, and a full refresh on all
9563 GitHub packages in Guix requires more than this. Authentication with
9564 GitHub through the use of an API token alleviates these limits. To use
9565 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9566 token procured from @uref{https://github.com/settings/tokens} or
9570 @node Invoking guix lint
9571 @section Invoking @command{guix lint}
9573 @cindex @command{guix lint}
9574 @cindex package, checking for errors
9575 The @command{guix lint} command is meant to help package developers avoid
9576 common errors and use a consistent style. It runs a number of checks on
9577 a given set of packages in order to find common mistakes in their
9578 definitions. Available @dfn{checkers} include (see
9579 @code{--list-checkers} for a complete list):
9584 Validate certain typographical and stylistic rules about package
9585 descriptions and synopses.
9587 @item inputs-should-be-native
9588 Identify inputs that should most likely be native inputs.
9594 @itemx source-file-name
9595 Probe @code{home-page} and @code{source} URLs and report those that are
9596 invalid. Suggest a @code{mirror://} URL when applicable. If the
9597 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9598 URL. Check that the source file name is meaningful, e.g.@: is not just a
9599 version number or ``git-checkout'', without a declared @code{file-name}
9600 (@pxref{origin Reference}).
9602 @item source-unstable-tarball
9603 Parse the @code{source} URL to determine if a tarball from GitHub is
9604 autogenerated or if it is a release tarball. Unfortunately GitHub's
9605 autogenerated tarballs are sometimes regenerated.
9608 @cindex Software Heritage, source code archive
9609 @cindex archival of source code, Software Heritage
9610 Checks whether the package's source code is archived at
9611 @uref{https://www.softwareheritage.org, Software Heritage}.
9613 When the source code that is not archived comes from a version-control system
9614 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9615 ``save'' request so that it eventually archives it. This ensures that the
9616 source will remain available in the long term, and that Guix can fall back to
9617 Software Heritage should the source code disappear from its original host.
9618 The status of recent ``save'' requests can be
9619 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9621 When source code is a tarball obtained with @code{url-fetch}, simply print a
9622 message when it is not archived. As of this writing, Software Heritage does
9623 not allow requests to save arbitrary tarballs; we are working on ways to
9624 ensure that non-VCS source code is also archived.
9627 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9628 request rate per IP address}. When the limit is reached, @command{guix lint}
9629 prints a message and the @code{archival} checker stops doing anything until
9630 that limit has been reset.
9633 @cindex security vulnerabilities
9634 @cindex CVE, Common Vulnerabilities and Exposures
9635 Report known vulnerabilities found in the Common Vulnerabilities and
9636 Exposures (CVE) databases of the current and past year
9637 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9640 To view information about a particular vulnerability, visit pages such as:
9644 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9646 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9650 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9651 @code{CVE-2015-7554}.
9653 Package developers can specify in package recipes the
9654 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9655 name and version of the package when they differ from the name or version
9656 that Guix uses, as in this example:
9662 ;; CPE calls this package "grub2".
9663 (properties '((cpe-name . "grub2")
9664 (cpe-version . "2.3"))))
9667 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9668 Some entries in the CVE database do not specify which version of a
9669 package they apply to, and would thus ``stick around'' forever. Package
9670 developers who found CVE alerts and verified they can be ignored can
9671 declare them as in this example:
9677 ;; These CVEs no longer apply and can be safely ignored.
9678 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9681 "CVE-2011-5244")))))
9685 Warn about obvious source code formatting issues: trailing white space,
9686 use of tabulations, etc.
9689 The general syntax is:
9692 guix lint @var{options} @var{package}@dots{}
9695 If no package is given on the command line, then all packages are checked.
9696 The @var{options} may be zero or more of the following:
9699 @item --list-checkers
9701 List and describe all the available checkers that will be run on packages
9706 Only enable the checkers specified in a comma-separated list using the
9707 names returned by @code{--list-checkers}.
9709 @item --load-path=@var{directory}
9710 @itemx -L @var{directory}
9711 Add @var{directory} to the front of the package module search path
9712 (@pxref{Package Modules}).
9714 This allows users to define their own packages and make them visible to
9715 the command-line tools.
9719 @node Invoking guix size
9720 @section Invoking @command{guix size}
9723 @cindex package size
9725 @cindex @command{guix size}
9726 The @command{guix size} command helps package developers profile the
9727 disk usage of packages. It is easy to overlook the impact of an
9728 additional dependency added to a package, or the impact of using a
9729 single output for a package that could easily be split (@pxref{Packages
9730 with Multiple Outputs}). Such are the typical issues that
9731 @command{guix size} can highlight.
9733 The command can be passed one or more package specifications
9734 such as @code{gcc@@4.8}
9735 or @code{guile:debug}, or a file name in the store. Consider this
9739 $ guix size coreutils
9740 store item total self
9741 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9742 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9743 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9744 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9745 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9746 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9747 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9748 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9753 The store items listed here constitute the @dfn{transitive closure} of
9754 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9755 would be returned by:
9758 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9761 Here the output shows three columns next to store items. The first column,
9762 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9763 the store item---that is, its own size plus the size of all its
9764 dependencies. The next column, labeled ``self'', shows the size of the
9765 item itself. The last column shows the ratio of the size of the item
9766 itself to the space occupied by all the items listed here.
9768 In this example, we see that the closure of Coreutils weighs in at
9769 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9770 libraries. (That libc and GCC's libraries represent a large fraction of
9771 the closure is not a problem @i{per se} because they are always available
9772 on the system anyway.)
9774 When the package(s) passed to @command{guix size} are available in the
9775 store@footnote{More precisely, @command{guix size} looks for the
9776 @emph{ungrafted} variant of the given package(s), as returned by
9777 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9778 for information on grafts.}, @command{guix size} queries the daemon to determine its
9779 dependencies, and measures its size in the store, similar to @command{du
9780 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9783 When the given packages are @emph{not} in the store, @command{guix size}
9784 reports information based on the available substitutes
9785 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9786 store items that are not even on disk, only available remotely.
9788 You can also specify several package names:
9791 $ guix size coreutils grep sed bash
9792 store item total self
9793 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9794 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9795 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9796 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9802 In this example we see that the combination of the four packages takes
9803 102.3@tie{}MiB in total, which is much less than the sum of each closure
9804 since they have a lot of dependencies in common.
9806 The available options are:
9810 @item --substitute-urls=@var{urls}
9811 Use substitute information from @var{urls}.
9812 @xref{client-substitute-urls, the same option for @code{guix build}}.
9814 @item --sort=@var{key}
9815 Sort lines according to @var{key}, one of the following options:
9819 the size of each item (the default);
9821 the total size of the item's closure.
9824 @item --map-file=@var{file}
9825 Write a graphical map of disk usage in PNG format to @var{file}.
9827 For the example above, the map looks like this:
9829 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9830 produced by @command{guix size}}
9832 This option requires that
9833 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9834 installed and visible in Guile's module search path. When that is not
9835 the case, @command{guix size} fails as it tries to load it.
9837 @item --system=@var{system}
9838 @itemx -s @var{system}
9839 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9843 @node Invoking guix graph
9844 @section Invoking @command{guix graph}
9847 @cindex @command{guix graph}
9848 @cindex package dependencies
9849 Packages and their dependencies form a @dfn{graph}, specifically a
9850 directed acyclic graph (DAG). It can quickly become difficult to have a
9851 mental model of the package DAG, so the @command{guix graph} command
9852 provides a visual representation of the DAG. By default,
9853 @command{guix graph} emits a DAG representation in the input format of
9854 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9855 directly to the @command{dot} command of Graphviz. It can also emit an
9856 HTML page with embedded JavaScript code to display a ``chord diagram''
9857 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9858 emit Cypher queries to construct a graph in a graph database supporting
9859 the @uref{https://www.opencypher.org/, openCypher} query language.
9860 The general syntax is:
9863 guix graph @var{options} @var{package}@dots{}
9866 For example, the following command generates a PDF file representing the
9867 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9871 guix graph coreutils | dot -Tpdf > dag.pdf
9874 The output looks like this:
9876 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9878 Nice little graph, no?
9880 But there is more than one graph! The one above is concise: it is the
9881 graph of package objects, omitting implicit inputs such as GCC, libc,
9882 grep, etc. It is often useful to have such a concise graph, but
9883 sometimes one may want to see more details. @command{guix graph} supports
9884 several types of graphs, allowing you to choose the level of detail:
9888 This is the default type used in the example above. It shows the DAG of
9889 package objects, excluding implicit dependencies. It is concise, but
9890 filters out many details.
9892 @item reverse-package
9893 This shows the @emph{reverse} DAG of packages. For example:
9896 guix graph --type=reverse-package ocaml
9899 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9900 you are also interested in cases where OCaml is an implicit dependency, see
9901 @code{reverse-bag} below.)
9903 Note that for core packages this can yield huge graphs. If all you want
9904 is to know the number of packages that depend on a given package, use
9905 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9906 @option{--list-dependent}}).
9909 This is the package DAG, @emph{including} implicit inputs.
9911 For instance, the following command:
9914 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9917 ...@: yields this bigger graph:
9919 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9921 At the bottom of the graph, we see all the implicit inputs of
9922 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9924 Now, note that the dependencies of these implicit inputs---that is, the
9925 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9926 here, for conciseness.
9929 Similar to @code{bag-emerged}, but this time including all the bootstrap
9932 @item bag-with-origins
9933 Similar to @code{bag}, but also showing origins and their dependencies.
9936 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9937 it also takes implicit dependencies into account. For example:
9940 guix graph -t reverse-bag dune
9944 ...@: yields the graph of all packages that depend on Dune, directly or
9945 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9946 @i{via} @code{dune-build-system}, this shows a large number of packages,
9947 whereas @code{reverse-package} would show very few if any.
9950 This is the most detailed representation: It shows the DAG of
9951 derivations (@pxref{Derivations}) and plain store items. Compared to
9952 the above representation, many additional nodes are visible, including
9953 build scripts, patches, Guile modules, etc.
9955 For this type of graph, it is also possible to pass a @file{.drv} file
9956 name instead of a package name, as in:
9959 guix graph -t derivation `guix system build -d my-config.scm`
9963 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9964 For example, the following command shows the graph for the package
9965 module that defines the @code{guile} package:
9968 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9972 All the types above correspond to @emph{build-time dependencies}. The
9973 following graph type represents the @emph{run-time dependencies}:
9977 This is the graph of @dfn{references} of a package output, as returned
9978 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9980 If the given package output is not available in the store, @command{guix
9981 graph} attempts to obtain dependency information from substitutes.
9983 Here you can also pass a store file name instead of a package name. For
9984 example, the command below produces the reference graph of your profile
9985 (which can be big!):
9988 guix graph -t references `readlink -f ~/.guix-profile`
9992 This is the graph of the @dfn{referrers} of a store item, as returned by
9993 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9995 This relies exclusively on local information from your store. For
9996 instance, let us suppose that the current Inkscape is available in 10
9997 profiles on your machine; @command{guix graph -t referrers inkscape}
9998 will show a graph rooted at Inkscape and with those 10 profiles linked
10001 It can help determine what is preventing a store item from being garbage
10006 The available options are the following:
10009 @item --type=@var{type}
10010 @itemx -t @var{type}
10011 Produce a graph output of @var{type}, where @var{type} must be one of
10012 the values listed above.
10015 List the supported graph types.
10017 @item --backend=@var{backend}
10018 @itemx -b @var{backend}
10019 Produce a graph using the selected @var{backend}.
10021 @item --list-backends
10022 List the supported graph backends.
10024 Currently, the available backends are Graphviz and d3.js.
10026 @item --expression=@var{expr}
10027 @itemx -e @var{expr}
10028 Consider the package @var{expr} evaluates to.
10030 This is useful to precisely refer to a package, as in this example:
10033 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10036 @item --system=@var{system}
10037 @itemx -s @var{system}
10038 Display the graph for @var{system}---e.g., @code{i686-linux}.
10040 The package dependency graph is largely architecture-independent, but there
10041 are some architecture-dependent bits that this option allows you to visualize.
10043 @item --load-path=@var{directory}
10044 @itemx -L @var{directory}
10045 Add @var{directory} to the front of the package module search path
10046 (@pxref{Package Modules}).
10048 This allows users to define their own packages and make them visible to
10049 the command-line tools.
10052 On top of that, @command{guix graph} supports all the usual package
10053 transformation options (@pxref{Package Transformation Options}). This
10054 makes it easy to view the effect of a graph-rewriting transformation
10055 such as @option{--with-input}. For example, the command below outputs
10056 the graph of @code{git} once @code{openssl} has been replaced by
10057 @code{libressl} everywhere in the graph:
10060 guix graph git --with-input=openssl=libressl
10063 So many possibilities, so much fun!
10065 @node Invoking guix publish
10066 @section Invoking @command{guix publish}
10068 @cindex @command{guix publish}
10069 The purpose of @command{guix publish} is to enable users to easily share
10070 their store with others, who can then use it as a substitute server
10071 (@pxref{Substitutes}).
10073 When @command{guix publish} runs, it spawns an HTTP server which allows
10074 anyone with network access to obtain substitutes from it. This means
10075 that any machine running Guix can also act as if it were a build farm,
10076 since the HTTP interface is compatible with Cuirass, the software behind
10077 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10079 For security, each substitute is signed, allowing recipients to check
10080 their authenticity and integrity (@pxref{Substitutes}). Because
10081 @command{guix publish} uses the signing key of the system, which is only
10082 readable by the system administrator, it must be started as root; the
10083 @code{--user} option makes it drop root privileges early on.
10085 The signing key pair must be generated before @command{guix publish} is
10086 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10089 The general syntax is:
10092 guix publish @var{options}@dots{}
10095 Running @command{guix publish} without any additional arguments will
10096 spawn an HTTP server on port 8080:
10102 Once a publishing server has been authorized (@pxref{Invoking guix
10103 archive}), the daemon may download substitutes from it:
10106 guix-daemon --substitute-urls=http://example.org:8080
10109 By default, @command{guix publish} compresses archives on the fly as it
10110 serves them. This ``on-the-fly'' mode is convenient in that it requires
10111 no setup and is immediately available. However, when serving lots of
10112 clients, we recommend using the @option{--cache} option, which enables
10113 caching of the archives before they are sent to clients---see below for
10114 details. The @command{guix weather} command provides a handy way to
10115 check what a server provides (@pxref{Invoking guix weather}).
10117 As a bonus, @command{guix publish} also serves as a content-addressed
10118 mirror for source files referenced in @code{origin} records
10119 (@pxref{origin Reference}). For instance, assuming @command{guix
10120 publish} is running on @code{example.org}, the following URL returns the
10121 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10122 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10125 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10128 Obviously, these URLs only work for files that are in the store; in
10129 other cases, they return 404 (``Not Found'').
10131 @cindex build logs, publication
10132 Build logs are available from @code{/log} URLs like:
10135 http://example.org/log/gwspk@dots{}-guile-2.2.3
10139 When @command{guix-daemon} is configured to save compressed build logs,
10140 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10141 URLs return the compressed log as-is, with an appropriate
10142 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10143 running @command{guix-daemon} with @code{--log-compression=gzip} since
10144 Web browsers can automatically decompress it, which is not the case with
10147 The following options are available:
10150 @item --port=@var{port}
10151 @itemx -p @var{port}
10152 Listen for HTTP requests on @var{port}.
10154 @item --listen=@var{host}
10155 Listen on the network interface for @var{host}. The default is to
10156 accept connections from any interface.
10158 @item --user=@var{user}
10159 @itemx -u @var{user}
10160 Change privileges to @var{user} as soon as possible---i.e., once the
10161 server socket is open and the signing key has been read.
10163 @item --compression[=@var{method}[:@var{level}]]
10164 @itemx -C [@var{method}[:@var{level}]]
10165 Compress data using the given @var{method} and @var{level}. @var{method} is
10166 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10169 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10170 to different compression levels: 1 is the fastest, and 9 is the best
10171 (CPU-intensive). The default is 3.
10173 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10174 increase in CPU usage; see
10175 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10178 Unless @option{--cache} is used, compression occurs on the fly and
10179 the compressed streams are not
10180 cached. Thus, to reduce load on the machine that runs @command{guix
10181 publish}, it may be a good idea to choose a low compression level, to
10182 run @command{guix publish} behind a caching proxy, or to use
10183 @option{--cache}. Using @option{--cache} has the advantage that it
10184 allows @command{guix publish} to add @code{Content-Length} HTTP header
10187 This option can be repeated, in which case every substitute gets compressed
10188 using all the selected methods, and all of them are advertised. This is
10189 useful when users may not support all the compression methods: they can select
10190 the one they support.
10192 @item --cache=@var{directory}
10193 @itemx -c @var{directory}
10194 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10195 and only serve archives that are in cache.
10197 When this option is omitted, archives and meta-data are created
10198 on-the-fly. This can reduce the available bandwidth, especially when
10199 compression is enabled, since this may become CPU-bound. Another
10200 drawback of the default mode is that the length of archives is not known
10201 in advance, so @command{guix publish} does not add a
10202 @code{Content-Length} HTTP header to its responses, which in turn
10203 prevents clients from knowing the amount of data being downloaded.
10205 Conversely, when @option{--cache} is used, the first request for a store
10206 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10207 background process to @dfn{bake} the archive---computing its
10208 @code{.narinfo} and compressing the archive, if needed. Once the
10209 archive is cached in @var{directory}, subsequent requests succeed and
10210 are served directly from the cache, which guarantees that clients get
10211 the best possible bandwidth.
10213 The ``baking'' process is performed by worker threads. By default, one
10214 thread per CPU core is created, but this can be customized. See
10215 @option{--workers} below.
10217 When @option{--ttl} is used, cached entries are automatically deleted
10218 when they have expired.
10220 @item --workers=@var{N}
10221 When @option{--cache} is used, request the allocation of @var{N} worker
10222 threads to ``bake'' archives.
10224 @item --ttl=@var{ttl}
10225 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10226 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10227 days, @code{1m} means 1 month, and so on.
10229 This allows the user's Guix to keep substitute information in cache for
10230 @var{ttl}. However, note that @code{guix publish} does not itself
10231 guarantee that the store items it provides will indeed remain available
10232 for as long as @var{ttl}.
10234 Additionally, when @option{--cache} is used, cached entries that have
10235 not been accessed for @var{ttl} and that no longer have a corresponding
10236 item in the store, may be deleted.
10238 @item --nar-path=@var{path}
10239 Use @var{path} as the prefix for the URLs of ``nar'' files
10240 (@pxref{Invoking guix archive, normalized archives}).
10242 By default, nars are served at a URL such as
10243 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10244 change the @code{/nar} part to @var{path}.
10246 @item --public-key=@var{file}
10247 @itemx --private-key=@var{file}
10248 Use the specific @var{file}s as the public/private key pair used to sign
10249 the store items being published.
10251 The files must correspond to the same key pair (the private key is used
10252 for signing and the public key is merely advertised in the signature
10253 metadata). They must contain keys in the canonical s-expression format
10254 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10255 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10256 @file{/etc/guix/signing-key.sec} are used.
10258 @item --repl[=@var{port}]
10259 @itemx -r [@var{port}]
10260 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10261 Reference Manual}) on @var{port} (37146 by default). This is used
10262 primarily for debugging a running @command{guix publish} server.
10265 Enabling @command{guix publish} on Guix System is a one-liner: just
10266 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10267 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10268 @code{guix-publish-service-type}}).
10270 If you are instead running Guix on a ``foreign distro'', follow these
10275 If your host distro uses the systemd init system:
10278 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10279 /etc/systemd/system/
10280 # systemctl start guix-publish && systemctl enable guix-publish
10284 If your host distro uses the Upstart init system:
10287 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10288 # start guix-publish
10292 Otherwise, proceed similarly with your distro's init system.
10295 @node Invoking guix challenge
10296 @section Invoking @command{guix challenge}
10298 @cindex reproducible builds
10299 @cindex verifiable builds
10300 @cindex @command{guix challenge}
10302 Do the binaries provided by this server really correspond to the source
10303 code it claims to build? Is a package build process deterministic?
10304 These are the questions the @command{guix challenge} command attempts to
10307 The former is obviously an important question: Before using a substitute
10308 server (@pxref{Substitutes}), one had better @emph{verify} that it
10309 provides the right binaries, and thus @emph{challenge} it. The latter
10310 is what enables the former: If package builds are deterministic, then
10311 independent builds of the package should yield the exact same result,
10312 bit for bit; if a server provides a binary different from the one
10313 obtained locally, it may be either corrupt or malicious.
10315 We know that the hash that shows up in @file{/gnu/store} file names is
10316 the hash of all the inputs of the process that built the file or
10317 directory---compilers, libraries, build scripts,
10318 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10319 one store file name should map to exactly one build output.
10320 @command{guix challenge} checks whether there is, indeed, a single
10321 mapping by comparing the build outputs of several independent builds of
10322 any given store item.
10324 The command output looks like this:
10327 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10328 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10329 updating list of substitutes from 'https://guix.example.org'... 100.0%
10330 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10331 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10332 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10333 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10335 /lib/libcrypto.so.1.1
10338 /gnu/store/@dots{}-git-2.5.0 contents differ:
10339 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10340 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10341 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10343 /libexec/git-core/git-fsck
10345 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10346 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10347 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10348 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10350 /share/man/man1/pius.1.gz
10354 6,406 store items were analyzed:
10355 - 4,749 (74.1%) were identical
10356 - 525 (8.2%) differed
10357 - 1,132 (17.7%) were inconclusive
10361 In this example, @command{guix challenge} first scans the store to
10362 determine the set of locally-built derivations---as opposed to store
10363 items that were downloaded from a substitute server---and then queries
10364 all the substitute servers. It then reports those store items for which
10365 the servers obtained a result different from the local build.
10367 @cindex non-determinism, in package builds
10368 As an example, @code{guix.example.org} always gets a different answer.
10369 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10370 case of Git. This might indicate that the build process of Git is
10371 non-deterministic, meaning that its output varies as a function of
10372 various things that Guix does not fully control, in spite of building
10373 packages in isolated environments (@pxref{Features}). Most common
10374 sources of non-determinism include the addition of timestamps in build
10375 results, the inclusion of random numbers, and directory listings sorted
10376 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10379 To find out what is wrong with this Git binary, the easiest approach is
10383 guix challenge git \
10384 --diff=diffoscope \
10385 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10388 This automatically invokes @command{diffoscope}, which displays detailed
10389 information about files that differ.
10391 Alternately, we can do something along these lines (@pxref{Invoking guix
10395 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10396 | guix archive -x /tmp/git
10397 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10400 This command shows the difference between the files resulting from the
10401 local build, and the files resulting from the build on
10402 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10403 diffutils, Comparing and Merging Files}). The @command{diff} command
10404 works great for text files. When binary files differ, a better option
10405 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10406 visualize differences for all kinds of files.
10408 Once you have done that work, you can tell whether the differences are due
10409 to a non-deterministic build process or to a malicious server. We try
10410 hard to remove sources of non-determinism in packages to make it easier
10411 to verify substitutes, but of course, this is a process that
10412 involves not just Guix, but a large part of the free software community.
10413 In the meantime, @command{guix challenge} is one tool to help address
10416 If you are writing packages for Guix, you are encouraged to check
10417 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10418 same build result as you did with:
10421 $ guix challenge @var{package}
10425 where @var{package} is a package specification such as
10426 @code{guile@@2.0} or @code{glibc:debug}.
10428 The general syntax is:
10431 guix challenge @var{options} [@var{packages}@dots{}]
10434 When a difference is found between the hash of a locally-built item and
10435 that of a server-provided substitute, or among substitutes provided by
10436 different servers, the command displays it as in the example above and
10437 its exit code is 2 (other non-zero exit codes denote other kinds of
10440 The one option that matters is:
10444 @item --substitute-urls=@var{urls}
10445 Consider @var{urls} the whitespace-separated list of substitute source
10446 URLs to compare to.
10448 @item --diff=@var{mode}
10449 Upon mismatches, show differences according to @var{mode}, one of:
10452 @item @code{simple} (the default)
10453 Show the list of files that differ.
10455 @item @code{diffoscope}
10456 @itemx @var{command}
10457 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10458 two directories whose contents do not match.
10460 When @var{command} is an absolute file name, run @var{command} instead
10464 Do not show further details about the differences.
10467 Thus, unless @code{--diff=none} is passed, @command{guix challenge}
10468 downloads the store items from the given substitute servers so that it
10473 Show details about matches (identical contents) in addition to
10474 information about mismatches.
10478 @node Invoking guix copy
10479 @section Invoking @command{guix copy}
10481 @cindex copy, of store items, over SSH
10482 @cindex SSH, copy of store items
10483 @cindex sharing store items across machines
10484 @cindex transferring store items across machines
10485 The @command{guix copy} command copies items from the store of one
10486 machine to that of another machine over a secure shell (SSH)
10487 connection@footnote{This command is available only when Guile-SSH was
10488 found. @xref{Requirements}, for details.}. For example, the following
10489 command copies the @code{coreutils} package, the user's profile, and all
10490 their dependencies over to @var{host}, logged in as @var{user}:
10493 guix copy --to=@var{user}@@@var{host} \
10494 coreutils `readlink -f ~/.guix-profile`
10497 If some of the items to be copied are already present on @var{host},
10498 they are not actually sent.
10500 The command below retrieves @code{libreoffice} and @code{gimp} from
10501 @var{host}, assuming they are available there:
10504 guix copy --from=@var{host} libreoffice gimp
10507 The SSH connection is established using the Guile-SSH client, which is
10508 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10509 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10511 The key used to sign items that are sent must be accepted by the remote
10512 machine. Likewise, the key used by the remote machine to sign items you
10513 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10514 own daemon. @xref{Invoking guix archive}, for more information about
10515 store item authentication.
10517 The general syntax is:
10520 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10523 You must always specify one of the following options:
10526 @item --to=@var{spec}
10527 @itemx --from=@var{spec}
10528 Specify the host to send to or receive from. @var{spec} must be an SSH
10529 spec such as @code{example.org}, @code{charlie@@example.org}, or
10530 @code{charlie@@example.org:2222}.
10533 The @var{items} can be either package names, such as @code{gimp}, or
10534 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10536 When specifying the name of a package to send, it is first built if
10537 needed, unless @option{--dry-run} was specified. Common build options
10538 are supported (@pxref{Common Build Options}).
10541 @node Invoking guix container
10542 @section Invoking @command{guix container}
10544 @cindex @command{guix container}
10546 As of version @value{VERSION}, this tool is experimental. The interface
10547 is subject to radical change in the future.
10550 The purpose of @command{guix container} is to manipulate processes
10551 running within an isolated environment, commonly known as a
10552 ``container'', typically created by the @command{guix environment}
10553 (@pxref{Invoking guix environment}) and @command{guix system container}
10554 (@pxref{Invoking guix system}) commands.
10556 The general syntax is:
10559 guix container @var{action} @var{options}@dots{}
10562 @var{action} specifies the operation to perform with a container, and
10563 @var{options} specifies the context-specific arguments for the action.
10565 The following actions are available:
10569 Execute a command within the context of a running container.
10574 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10577 @var{pid} specifies the process ID of the running container.
10578 @var{program} specifies an executable file name within the root file
10579 system of the container. @var{arguments} are the additional options that
10580 will be passed to @var{program}.
10582 The following command launches an interactive login shell inside a
10583 Guix system container, started by @command{guix system container}, and whose
10584 process ID is 9001:
10587 guix container exec 9001 /run/current-system/profile/bin/bash --login
10590 Note that the @var{pid} cannot be the parent process of a container. It
10591 must be PID 1 of the container or one of its child processes.
10595 @node Invoking guix weather
10596 @section Invoking @command{guix weather}
10598 Occasionally you're grumpy because substitutes are lacking and you end
10599 up building packages by yourself (@pxref{Substitutes}). The
10600 @command{guix weather} command reports on substitute availability on the
10601 specified servers so you can have an idea of whether you'll be grumpy
10602 today. It can sometimes be useful info as a user, but it is primarily
10603 useful to people running @command{guix publish} (@pxref{Invoking guix
10606 @cindex statistics, for substitutes
10607 @cindex availability of substitutes
10608 @cindex substitute availability
10609 @cindex weather, substitute availability
10610 Here's a sample run:
10613 $ guix weather --substitute-urls=https://guix.example.org
10614 computing 5,872 package derivations for x86_64-linux...
10615 looking for 6,128 store items on https://guix.example.org..
10616 updating list of substitutes from 'https://guix.example.org'... 100.0%
10617 https://guix.example.org
10618 43.4% substitutes available (2,658 out of 6,128)
10619 7,032.5 MiB of nars (compressed)
10620 19,824.2 MiB on disk (uncompressed)
10621 0.030 seconds per request (182.9 seconds in total)
10622 33.5 requests per second
10624 9.8% (342 out of 3,470) of the missing items are queued
10626 x86_64-linux: 518 (59.7%)
10627 i686-linux: 221 (25.5%)
10628 aarch64-linux: 128 (14.8%)
10629 build rate: 23.41 builds per hour
10630 x86_64-linux: 11.16 builds per hour
10631 i686-linux: 6.03 builds per hour
10632 aarch64-linux: 6.41 builds per hour
10635 @cindex continuous integration, statistics
10636 As you can see, it reports the fraction of all the packages for which
10637 substitutes are available on the server---regardless of whether
10638 substitutes are enabled, and regardless of whether this server's signing
10639 key is authorized. It also reports the size of the compressed archives
10640 (``nars'') provided by the server, the size the corresponding store
10641 items occupy in the store (assuming deduplication is turned off), and
10642 the server's throughput. The second part gives continuous integration
10643 (CI) statistics, if the server supports it. In addition, using the
10644 @option{--coverage} option, @command{guix weather} can list ``important''
10645 package substitutes missing on the server (see below).
10647 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10648 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10649 challenge}, it ignores signatures on those substitutes, which is
10650 innocuous since the command only gathers statistics and cannot install
10653 The general syntax is:
10656 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10659 When @var{packages} is omitted, @command{guix weather} checks the availability
10660 of substitutes for @emph{all} the packages, or for those specified with
10661 @option{--manifest}; otherwise it only considers the specified packages. It
10662 is also possible to query specific system types with @option{--system}. The
10663 available options are listed below.
10666 @item --substitute-urls=@var{urls}
10667 @var{urls} is the space-separated list of substitute server URLs to
10668 query. When this option is omitted, the default set of substitute
10669 servers is queried.
10671 @item --system=@var{system}
10672 @itemx -s @var{system}
10673 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10674 option can be repeated, in which case @command{guix weather} will query
10675 substitutes for several system types.
10677 @item --manifest=@var{file}
10678 Instead of querying substitutes for all the packages, only ask for those
10679 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10680 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10683 @item --coverage[=@var{count}]
10684 @itemx -c [@var{count}]
10685 Report on substitute coverage for packages: list packages with at least
10686 @var{count} dependents (zero by default) for which substitutes are
10687 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10688 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10689 @var{b} usually lacks substitutes as well. The result looks like this:
10692 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10693 computing 8,983 package derivations for x86_64-linux...
10694 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10695 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10696 @value{SUBSTITUTE-URL}
10697 64.7% substitutes available (6,047 out of 9,343)
10699 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10700 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10701 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10702 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10706 What this example shows is that @code{kcoreaddons} and presumably the 58
10707 packages that depend on it have no substitutes at @code{ci.guix.info};
10708 likewise for @code{qgpgme} and the 46 packages that depend on it.
10710 If you are a Guix developer, or if you are taking care of this build farm,
10711 you'll probably want to have a closer look at these packages: they may simply
10715 @node Invoking guix processes
10716 @section Invoking @command{guix processes}
10718 The @command{guix processes} command can be useful to developers and system
10719 administrators, especially on multi-user machines and on build farms: it lists
10720 the current sessions (connections to the daemon), as well as information about
10721 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10722 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10723 listed.}. Here's an example of the information it returns:
10726 $ sudo guix processes
10729 ClientCommand: guix environment --ad-hoc python
10733 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10737 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10738 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10739 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10740 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10741 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10742 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10743 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10746 In this example we see that @command{guix-daemon} has three clients:
10747 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10748 integration tool; their process identifier (PID) is given by the
10749 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10750 @command{guix-daemon} sub-process of this particular session.
10752 The @code{LockHeld} fields show which store items are currently locked by this
10753 session, which corresponds to store items being built or substituted (the
10754 @code{LockHeld} field is not displayed when @command{guix processes} is not
10755 running as root.) Last, by looking at the @code{ChildProcess} field, we
10756 understand that these three builds are being offloaded (@pxref{Daemon Offload
10759 The output is in Recutils format so we can use the handy @command{recsel}
10760 command to select sessions of interest (@pxref{Selection Expressions,,,
10761 recutils, GNU recutils manual}). As an example, the command shows the command
10762 line and PID of the client that triggered the build of a Perl package:
10765 $ sudo guix processes | \
10766 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10768 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10771 @node System Configuration
10772 @chapter System Configuration
10774 @cindex system configuration
10775 Guix System supports a consistent whole-system configuration
10776 mechanism. By that we mean that all aspects of the global system
10777 configuration---such as the available system services, timezone and
10778 locale settings, user accounts---are declared in a single place. Such
10779 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10781 One of the advantages of putting all the system configuration under the
10782 control of Guix is that it supports transactional system upgrades, and
10783 makes it possible to roll back to a previous system instantiation,
10784 should something go wrong with the new one (@pxref{Features}). Another
10785 advantage is that it makes it easy to replicate the exact same configuration
10786 across different machines, or at different points in time, without
10787 having to resort to additional administration tools layered on top of
10788 the own tools of the system.
10789 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10791 This section describes this mechanism. First we focus on the system
10792 administrator's viewpoint---explaining how the system is configured and
10793 instantiated. Then we show how this mechanism can be extended, for
10794 instance to support new system services.
10797 * Using the Configuration System:: Customizing your GNU system.
10798 * operating-system Reference:: Detail of operating-system declarations.
10799 * File Systems:: Configuring file system mounts.
10800 * Mapped Devices:: Block device extra processing.
10801 * User Accounts:: Specifying user accounts.
10802 * Keyboard Layout:: How the system interprets key strokes.
10803 * Locales:: Language and cultural convention settings.
10804 * Services:: Specifying system services.
10805 * Setuid Programs:: Programs running with root privileges.
10806 * X.509 Certificates:: Authenticating HTTPS servers.
10807 * Name Service Switch:: Configuring libc's name service switch.
10808 * Initial RAM Disk:: Linux-Libre bootstrapping.
10809 * Bootloader Configuration:: Configuring the boot loader.
10810 * Invoking guix system:: Instantiating a system configuration.
10811 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10812 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10813 * Defining Services:: Adding new service definitions.
10816 @node Using the Configuration System
10817 @section Using the Configuration System
10819 The operating system is configured by providing an
10820 @code{operating-system} declaration in a file that can then be passed to
10821 the @command{guix system} command (@pxref{Invoking guix system}). A
10822 simple setup, with the default system services, the default Linux-Libre
10823 kernel, initial RAM disk, and boot loader looks like this:
10825 @findex operating-system
10827 @include os-config-bare-bones.texi
10830 This example should be self-describing. Some of the fields defined
10831 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10832 Others, such as @code{packages} and @code{services}, can be omitted, in
10833 which case they get a default value.
10835 Below we discuss the effect of some of the most important fields
10836 (@pxref{operating-system Reference}, for details about all the available
10837 fields), and how to @dfn{instantiate} the operating system using
10838 @command{guix system}.
10840 @unnumberedsubsec Bootloader
10842 @cindex legacy boot, on Intel machines
10843 @cindex BIOS boot, on Intel machines
10846 The @code{bootloader} field describes the method that will be used to boot
10847 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10848 mode, as in the example above. However, more recent machines rely instead on
10849 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10850 the @code{bootloader} field should contain something along these lines:
10853 (bootloader-configuration
10854 (bootloader grub-efi-bootloader)
10855 (target "/boot/efi"))
10858 @xref{Bootloader Configuration}, for more information on the available
10859 configuration options.
10861 @unnumberedsubsec Globally-Visible Packages
10863 @vindex %base-packages
10864 The @code{packages} field lists packages that will be globally visible
10865 on the system, for all user accounts---i.e., in every user's @code{PATH}
10866 environment variable---in addition to the per-user profiles
10867 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10868 provides all the tools one would expect for basic user and administrator
10869 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10870 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10871 etc. The example above adds GNU@tie{}Screen to those,
10872 taken from the @code{(gnu packages screen)}
10873 module (@pxref{Package Modules}). The
10874 @code{(list package output)} syntax can be used to add a specific output
10878 (use-modules (gnu packages))
10879 (use-modules (gnu packages dns))
10883 (packages (cons (list bind "utils")
10887 @findex specification->package
10888 Referring to packages by variable name, like @code{bind} above, has
10889 the advantage of being unambiguous; it also allows typos and such to be
10890 diagnosed right away as ``unbound variables''. The downside is that one
10891 needs to know which module defines which package, and to augment the
10892 @code{use-package-modules} line accordingly. To avoid that, one can use
10893 the @code{specification->package} procedure of the @code{(gnu packages)}
10894 module, which returns the best package for a given name or name and
10898 (use-modules (gnu packages))
10902 (packages (append (map specification->package
10903 '("tcpdump" "htop" "gnupg@@2.0"))
10907 @unnumberedsubsec System Services
10910 @vindex %base-services
10911 The @code{services} field lists @dfn{system services} to be made
10912 available when the system starts (@pxref{Services}).
10913 The @code{operating-system} declaration above specifies that, in
10914 addition to the basic services, we want the OpenSSH secure shell
10915 daemon listening on port 2222 (@pxref{Networking Services,
10916 @code{openssh-service-type}}). Under the hood,
10917 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10918 right command-line options, possibly with supporting configuration files
10919 generated as needed (@pxref{Defining Services}).
10921 @cindex customization, of services
10922 @findex modify-services
10923 Occasionally, instead of using the base services as is, you will want to
10924 customize them. To do this, use @code{modify-services} (@pxref{Service
10925 Reference, @code{modify-services}}) to modify the list.
10927 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10928 (the console log-in) in the @code{%base-services} list (@pxref{Base
10929 Services, @code{%base-services}}). To do that, you can write the
10930 following in your operating system declaration:
10933 (define %my-services
10934 ;; My very own list of services.
10935 (modify-services %base-services
10936 (guix-service-type config =>
10937 (guix-configuration
10939 (use-substitutes? #f)
10940 (extra-options '("--gc-keep-derivations"))))
10941 (mingetty-service-type config =>
10942 (mingetty-configuration
10943 (inherit config)))))
10947 (services %my-services))
10950 This changes the configuration---i.e., the service parameters---of the
10951 @code{guix-service-type} instance, and that of all the
10952 @code{mingetty-service-type} instances in the @code{%base-services} list.
10953 Observe how this is accomplished: first, we arrange for the original
10954 configuration to be bound to the identifier @code{config} in the
10955 @var{body}, and then we write the @var{body} so that it evaluates to the
10956 desired configuration. In particular, notice how we use @code{inherit}
10957 to create a new configuration which has the same values as the old
10958 configuration, but with a few modifications.
10960 @cindex encrypted disk
10961 The configuration for a typical ``desktop'' usage, with an encrypted
10962 root partition, the X11 display
10963 server, GNOME and Xfce (users can choose which of these desktop
10964 environments to use at the log-in screen by pressing @kbd{F1}), network
10965 management, power management, and more, would look like this:
10968 @include os-config-desktop.texi
10971 A graphical system with a choice of lightweight window managers
10972 instead of full-blown desktop environments would look like this:
10975 @include os-config-lightweight-desktop.texi
10978 This example refers to the @file{/boot/efi} file system by its UUID,
10979 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10980 as returned by the @command{blkid} command.
10982 @xref{Desktop Services}, for the exact list of services provided by
10983 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10984 information about the @code{nss-certs} package that is used here.
10986 Again, @code{%desktop-services} is just a list of service objects. If
10987 you want to remove services from there, you can do so using the
10988 procedures for list filtering (@pxref{SRFI-1 Filtering and
10989 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10990 following expression returns a list that contains all the services in
10991 @code{%desktop-services} minus the Avahi service:
10994 (remove (lambda (service)
10995 (eq? (service-kind service) avahi-service-type))
10999 @unnumberedsubsec Instantiating the System
11001 Assuming the @code{operating-system} declaration
11002 is stored in the @file{my-system-config.scm}
11003 file, the @command{guix system reconfigure my-system-config.scm} command
11004 instantiates that configuration, and makes it the default GRUB boot
11005 entry (@pxref{Invoking guix system}).
11007 The normal way to change the system configuration is by updating this
11008 file and re-running @command{guix system reconfigure}. One should never
11009 have to touch files in @file{/etc} or to run commands that modify the
11010 system state such as @command{useradd} or @command{grub-install}. In
11011 fact, you must avoid that since that would not only void your warranty
11012 but also prevent you from rolling back to previous versions of your
11013 system, should you ever need to.
11015 @cindex roll-back, of the operating system
11016 Speaking of roll-back, each time you run @command{guix system
11017 reconfigure}, a new @dfn{generation} of the system is created---without
11018 modifying or deleting previous generations. Old system generations get
11019 an entry in the bootloader boot menu, allowing you to boot them in case
11020 something went wrong with the latest generation. Reassuring, no? The
11021 @command{guix system list-generations} command lists the system
11022 generations available on disk. It is also possible to roll back the
11023 system via the commands @command{guix system roll-back} and
11024 @command{guix system switch-generation}.
11026 Although the @command{guix system reconfigure} command will not modify
11027 previous generations, you must take care when the current generation is not
11028 the latest (e.g., after invoking @command{guix system roll-back}), since
11029 the operation might overwrite a later generation (@pxref{Invoking guix
11032 @unnumberedsubsec The Programming Interface
11034 At the Scheme level, the bulk of an @code{operating-system} declaration
11035 is instantiated with the following monadic procedure (@pxref{The Store
11038 @deffn {Monadic Procedure} operating-system-derivation os
11039 Return a derivation that builds @var{os}, an @code{operating-system}
11040 object (@pxref{Derivations}).
11042 The output of the derivation is a single directory that refers to all
11043 the packages, configuration files, and other supporting files needed to
11044 instantiate @var{os}.
11047 This procedure is provided by the @code{(gnu system)} module. Along
11048 with @code{(gnu services)} (@pxref{Services}), this module contains the
11049 guts of Guix System. Make sure to visit it!
11052 @node operating-system Reference
11053 @section @code{operating-system} Reference
11055 This section summarizes all the options available in
11056 @code{operating-system} declarations (@pxref{Using the Configuration
11059 @deftp {Data Type} operating-system
11060 This is the data type representing an operating system configuration.
11061 By that, we mean all the global system configuration, not per-user
11062 configuration (@pxref{Using the Configuration System}).
11065 @item @code{kernel} (default: @var{linux-libre})
11066 The package object of the operating system kernel to use@footnote{Currently
11067 only the Linux-libre kernel is supported. In the future, it will be
11068 possible to use the GNU@tie{}Hurd.}.
11070 @item @code{kernel-arguments} (default: @code{'("quiet")})
11071 List of strings or gexps representing additional arguments to pass on
11072 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11074 @item @code{bootloader}
11075 The system bootloader configuration object. @xref{Bootloader Configuration}.
11078 This is the label (a string) as it appears in the bootloader's menu entry.
11079 The default label includes the kernel name and version.
11081 @item @code{keyboard-layout} (default: @code{#f})
11082 This field specifies the keyboard layout to use in the console. It can be
11083 either @code{#f}, in which case the default keyboard layout is used (usually
11084 US English), or a @code{<keyboard-layout>} record.
11086 This keyboard layout is in effect as soon as the kernel has booted. For
11087 instance, it is the keyboard layout in effect when you type a passphrase if
11088 your root file system is on a @code{luks-device-mapping} mapped device
11089 (@pxref{Mapped Devices}).
11092 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11093 that used by the graphical display server. @xref{Bootloader Configuration},
11094 for information on how to specify the bootloader's keyboard layout. @xref{X
11095 Window}, for information on how to specify the keyboard layout used by the X
11099 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11101 @cindex initial RAM disk
11102 The list of Linux kernel modules that need to be available in the
11103 initial RAM disk. @xref{Initial RAM Disk}.
11105 @item @code{initrd} (default: @code{base-initrd})
11106 A procedure that returns an initial RAM disk for the Linux
11107 kernel. This field is provided to support low-level customization and
11108 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11110 @item @code{firmware} (default: @code{%base-firmware})
11112 List of firmware packages loadable by the operating system kernel.
11114 The default includes firmware needed for Atheros- and Broadcom-based
11115 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11116 respectively). @xref{Hardware Considerations}, for more info on
11117 supported hardware.
11119 @item @code{host-name}
11122 @item @code{hosts-file}
11124 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11125 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11126 Reference Manual}). The default is a file with entries for
11127 @code{localhost} and @var{host-name}.
11129 @item @code{mapped-devices} (default: @code{'()})
11130 A list of mapped devices. @xref{Mapped Devices}.
11132 @item @code{file-systems}
11133 A list of file systems. @xref{File Systems}.
11135 @item @code{swap-devices} (default: @code{'()})
11136 @cindex swap devices
11137 A list of strings identifying devices or files to be used for ``swap
11138 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11139 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11140 It is possible to specify a swap file in a file system on a mapped
11141 device, provided that the necessary device mapping and file system are
11142 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11144 @item @code{users} (default: @code{%base-user-accounts})
11145 @itemx @code{groups} (default: @code{%base-groups})
11146 List of user accounts and groups. @xref{User Accounts}.
11148 If the @code{users} list lacks a user account with UID@tie{}0, a
11149 ``root'' account with UID@tie{}0 is automatically added.
11151 @item @code{skeletons} (default: @code{(default-skeletons)})
11152 A list target file name/file-like object tuples (@pxref{G-Expressions,
11153 file-like objects}). These are the skeleton files that will be added to
11154 the home directory of newly-created user accounts.
11156 For instance, a valid value may look like this:
11159 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11160 (".guile" ,(plain-file "guile"
11161 "(use-modules (ice-9 readline))
11162 (activate-readline)")))
11165 @item @code{issue} (default: @code{%default-issue})
11166 A string denoting the contents of the @file{/etc/issue} file, which is
11167 displayed when users log in on a text console.
11169 @item @code{packages} (default: @code{%base-packages})
11170 The set of packages installed in the global profile, which is accessible
11171 at @file{/run/current-system/profile}.
11173 The default set includes core utilities and it is good practice to
11174 install non-core utilities in user profiles (@pxref{Invoking guix
11177 @item @code{timezone}
11178 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11180 You can run the @command{tzselect} command to find out which timezone
11181 string corresponds to your region. Choosing an invalid timezone name
11182 causes @command{guix system} to fail.
11184 @item @code{locale} (default: @code{"en_US.utf8"})
11185 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11186 Library Reference Manual}). @xref{Locales}, for more information.
11188 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11189 The list of locale definitions to be compiled and that may be used at
11190 run time. @xref{Locales}.
11192 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11193 The list of GNU@tie{}libc packages whose locale data and tools are used
11194 to build the locale definitions. @xref{Locales}, for compatibility
11195 considerations that justify this option.
11197 @item @code{name-service-switch} (default: @code{%default-nss})
11198 Configuration of the libc name service switch (NSS)---a
11199 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11202 @item @code{services} (default: @code{%base-services})
11203 A list of service objects denoting system services. @xref{Services}.
11205 @cindex essential services
11206 @item @code{essential-services} (default: ...)
11207 The list of ``essential services''---i.e., things like instances of
11208 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11209 Reference}), which are derived from the operating system definition itself.
11210 As a user you should @emph{never} need to touch this field.
11212 @item @code{pam-services} (default: @code{(base-pam-services)})
11214 @cindex pluggable authentication modules
11215 Linux @dfn{pluggable authentication module} (PAM) services.
11216 @c FIXME: Add xref to PAM services section.
11218 @item @code{setuid-programs} (default: @var{%setuid-programs})
11219 List of string-valued G-expressions denoting setuid programs.
11220 @xref{Setuid Programs}.
11222 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11223 @cindex sudoers file
11224 The contents of the @file{/etc/sudoers} file as a file-like object
11225 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11227 This file specifies which users can use the @command{sudo} command, what
11228 they are allowed to do, and what privileges they may gain. The default
11229 is that only @code{root} and members of the @code{wheel} group may use
11234 @deffn {Scheme Syntax} this-operating-system
11235 When used in the @emph{lexical scope} of an operating system field definition,
11236 this identifier resolves to the operating system being defined.
11238 The example below shows how to refer to the operating system being defined in
11239 the definition of the @code{label} field:
11242 (use-modules (gnu) (guix))
11246 (label (package-full-name
11247 (operating-system-kernel this-operating-system))))
11250 It is an error to refer to @code{this-operating-system} outside an operating
11257 @section File Systems
11259 The list of file systems to be mounted is specified in the
11260 @code{file-systems} field of the operating system declaration
11261 (@pxref{Using the Configuration System}). Each file system is declared
11262 using the @code{file-system} form, like this:
11266 (mount-point "/home")
11267 (device "/dev/sda3")
11271 As usual, some of the fields are mandatory---those shown in the example
11272 above---while others can be omitted. These are described below.
11274 @deftp {Data Type} file-system
11275 Objects of this type represent file systems to be mounted. They
11276 contain the following members:
11280 This is a string specifying the type of the file system---e.g.,
11283 @item @code{mount-point}
11284 This designates the place where the file system is to be mounted.
11286 @item @code{device}
11287 This names the ``source'' of the file system. It can be one of three
11288 things: a file system label, a file system UUID, or the name of a
11289 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11290 systems without having to hard-code their actual device
11291 name@footnote{Note that, while it is tempting to use
11292 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11293 result, this is not recommended: These special device nodes are created
11294 by the udev daemon and may be unavailable at the time the device is
11297 @findex file-system-label
11298 File system labels are created using the @code{file-system-label}
11299 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11300 plain strings. Here's an example of a file system referred to by its
11301 label, as shown by the @command{e2label} command:
11305 (mount-point "/home")
11307 (device (file-system-label "my-home")))
11311 UUIDs are converted from their string representation (as shown by the
11312 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11313 @code{uuid} form expects 16-byte UUIDs as defined in
11314 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11315 form of UUID used by the ext2 family of file systems and others, but it
11316 is different from ``UUIDs'' found in FAT file systems, for instance.},
11321 (mount-point "/home")
11323 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11326 When the source of a file system is a mapped device (@pxref{Mapped
11327 Devices}), its @code{device} field @emph{must} refer to the mapped
11328 device name---e.g., @file{"/dev/mapper/root-partition"}.
11329 This is required so that
11330 the system knows that mounting the file system depends on having the
11331 corresponding device mapping established.
11333 @item @code{flags} (default: @code{'()})
11334 This is a list of symbols denoting mount flags. Recognized flags
11335 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11336 access to special files), @code{no-suid} (ignore setuid and setgid
11337 bits), @code{no-atime} (do not update file access times),
11338 @code{strict-atime} (update file access time), @code{lazy-time} (only
11339 update time on the in-memory version of the file inode), and
11340 @code{no-exec} (disallow program execution).
11341 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11342 Manual}, for more information on these flags.
11344 @item @code{options} (default: @code{#f})
11345 This is either @code{#f}, or a string denoting mount options passed to the
11346 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11347 Reference Manual}, for details and run @command{man 8 mount} for options for
11348 various file systems.
11350 @item @code{mount?} (default: @code{#t})
11351 This value indicates whether to automatically mount the file system when
11352 the system is brought up. When set to @code{#f}, the file system gets
11353 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11354 is not automatically mounted.
11356 @item @code{needed-for-boot?} (default: @code{#f})
11357 This Boolean value indicates whether the file system is needed when
11358 booting. If that is true, then the file system is mounted when the
11359 initial RAM disk (initrd) is loaded. This is always the case, for
11360 instance, for the root file system.
11362 @item @code{check?} (default: @code{#t})
11363 This Boolean indicates whether the file system needs to be checked for
11364 errors before being mounted.
11366 @item @code{create-mount-point?} (default: @code{#f})
11367 When true, the mount point is created if it does not exist yet.
11369 @item @code{dependencies} (default: @code{'()})
11370 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11371 representing file systems that must be mounted or mapped devices that
11372 must be opened before (and unmounted or closed after) this one.
11374 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11375 a dependency of @file{/sys/fs/cgroup/cpu} and
11376 @file{/sys/fs/cgroup/memory}.
11378 Another example is a file system that depends on a mapped device, for
11379 example for an encrypted partition (@pxref{Mapped Devices}).
11383 The @code{(gnu system file-systems)} exports the following useful
11386 @defvr {Scheme Variable} %base-file-systems
11387 These are essential file systems that are required on normal systems,
11388 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11389 below.) Operating system declarations should always contain at least
11393 @defvr {Scheme Variable} %pseudo-terminal-file-system
11394 This is the file system to be mounted as @file{/dev/pts}. It supports
11395 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11396 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11397 Manual}). Pseudo-terminals are used by terminal emulators such as
11401 @defvr {Scheme Variable} %shared-memory-file-system
11402 This file system is mounted as @file{/dev/shm} and is used to support
11403 memory sharing across processes (@pxref{Memory-mapped I/O,
11404 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11407 @defvr {Scheme Variable} %immutable-store
11408 This file system performs a read-only ``bind mount'' of
11409 @file{/gnu/store}, making it read-only for all the users including
11410 @code{root}. This prevents against accidental modification by software
11411 running as @code{root} or by system administrators.
11413 The daemon itself is still able to write to the store: it remounts it
11414 read-write in its own ``name space.''
11417 @defvr {Scheme Variable} %binary-format-file-system
11418 The @code{binfmt_misc} file system, which allows handling of arbitrary
11419 executable file types to be delegated to user space. This requires the
11420 @code{binfmt.ko} kernel module to be loaded.
11423 @defvr {Scheme Variable} %fuse-control-file-system
11424 The @code{fusectl} file system, which allows unprivileged users to mount
11425 and unmount user-space FUSE file systems. This requires the
11426 @code{fuse.ko} kernel module to be loaded.
11429 @node Mapped Devices
11430 @section Mapped Devices
11432 @cindex device mapping
11433 @cindex mapped devices
11434 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11435 such as a hard disk partition, can be @dfn{mapped} into another device,
11436 usually in @code{/dev/mapper/},
11437 with additional processing over the data that flows through
11438 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11439 concept of a ``mapped device'' and that of a file system: both boil down
11440 to @emph{translating} input/output operations made on a file to
11441 operations on its backing store. Thus, the Hurd implements mapped
11442 devices, like file systems, using the generic @dfn{translator} mechanism
11443 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11444 typical example is encryption device mapping: all writes to the mapped
11445 device are encrypted, and all reads are deciphered, transparently.
11446 Guix extends this notion by considering any device or set of devices that
11447 are @dfn{transformed} in some way to create a new device; for instance,
11448 RAID devices are obtained by @dfn{assembling} several other devices, such
11449 as hard disks or partitions, into a new one that behaves as one partition.
11450 Other examples, not yet implemented, are LVM logical volumes.
11452 Mapped devices are declared using the @code{mapped-device} form,
11453 defined as follows; for examples, see below.
11455 @deftp {Data Type} mapped-device
11456 Objects of this type represent device mappings that will be made when
11457 the system boots up.
11461 This is either a string specifying the name of the block device to be mapped,
11462 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11463 need to be assembled for creating a new one.
11466 This string specifies the name of the resulting mapped device. For
11467 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11468 specifying @code{"my-partition"} leads to the creation of
11469 the @code{"/dev/mapper/my-partition"} device.
11470 For RAID devices of type @code{raid-device-mapping}, the full device name
11471 such as @code{"/dev/md0"} needs to be given.
11474 This must be a @code{mapped-device-kind} object, which specifies how
11475 @var{source} is mapped to @var{target}.
11479 @defvr {Scheme Variable} luks-device-mapping
11480 This defines LUKS block device encryption using the @command{cryptsetup}
11481 command from the package with the same name. It relies on the
11482 @code{dm-crypt} Linux kernel module.
11485 @defvr {Scheme Variable} raid-device-mapping
11486 This defines a RAID device, which is assembled using the @code{mdadm}
11487 command from the package with the same name. It requires a Linux kernel
11488 module for the appropriate RAID level to be loaded, such as @code{raid456}
11489 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11492 @cindex disk encryption
11494 The following example specifies a mapping from @file{/dev/sda3} to
11495 @file{/dev/mapper/home} using LUKS---the
11496 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11497 standard mechanism for disk encryption.
11498 The @file{/dev/mapper/home}
11499 device can then be used as the @code{device} of a @code{file-system}
11500 declaration (@pxref{File Systems}).
11504 (source "/dev/sda3")
11506 (type luks-device-mapping))
11509 Alternatively, to become independent of device numbering, one may obtain
11510 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11514 cryptsetup luksUUID /dev/sda3
11517 and use it as follows:
11521 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11523 (type luks-device-mapping))
11526 @cindex swap encryption
11527 It is also desirable to encrypt swap space, since swap space may contain
11528 sensitive data. One way to accomplish that is to use a swap file in a
11529 file system on a device mapped via LUKS encryption. In this way, the
11530 swap file is encrypted because the entire device is encrypted.
11531 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11533 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11534 may be declared as follows:
11538 (source (list "/dev/sda1" "/dev/sdb1"))
11539 (target "/dev/md0")
11540 (type raid-device-mapping))
11543 The @file{/dev/md0} device can then be used as the @code{device} of a
11544 @code{file-system} declaration (@pxref{File Systems}).
11545 Note that the RAID level need not be given; it is chosen during the
11546 initial creation and formatting of the RAID device and is determined
11547 automatically later.
11550 @node User Accounts
11551 @section User Accounts
11555 @cindex user accounts
11556 User accounts and groups are entirely managed through the
11557 @code{operating-system} declaration. They are specified with the
11558 @code{user-account} and @code{user-group} forms:
11564 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11565 "audio" ;sound card
11566 "video" ;video devices such as webcams
11567 "cdrom")) ;the good ol' CD-ROM
11568 (comment "Bob's sister")
11569 (home-directory "/home/alice"))
11572 When booting or upon completion of @command{guix system reconfigure},
11573 the system ensures that only the user accounts and groups specified in
11574 the @code{operating-system} declaration exist, and with the specified
11575 properties. Thus, account or group creations or modifications made by
11576 directly invoking commands such as @command{useradd} are lost upon
11577 reconfiguration or reboot. This ensures that the system remains exactly
11580 @deftp {Data Type} user-account
11581 Objects of this type represent user accounts. The following members may
11586 The name of the user account.
11590 This is the name (a string) or identifier (a number) of the user group
11591 this account belongs to.
11593 @item @code{supplementary-groups} (default: @code{'()})
11594 Optionally, this can be defined as a list of group names that this
11595 account belongs to.
11597 @item @code{uid} (default: @code{#f})
11598 This is the user ID for this account (a number), or @code{#f}. In the
11599 latter case, a number is automatically chosen by the system when the
11600 account is created.
11602 @item @code{comment} (default: @code{""})
11603 A comment about the account, such as the account owner's full name.
11605 @item @code{home-directory}
11606 This is the name of the home directory for the account.
11608 @item @code{create-home-directory?} (default: @code{#t})
11609 Indicates whether the home directory of this account should be created
11610 if it does not exist yet.
11612 @item @code{shell} (default: Bash)
11613 This is a G-expression denoting the file name of a program to be used as
11614 the shell (@pxref{G-Expressions}).
11616 @item @code{system?} (default: @code{#f})
11617 This Boolean value indicates whether the account is a ``system''
11618 account. System accounts are sometimes treated specially; for instance,
11619 graphical login managers do not list them.
11621 @anchor{user-account-password}
11622 @cindex password, for user accounts
11623 @item @code{password} (default: @code{#f})
11624 You would normally leave this field to @code{#f}, initialize user
11625 passwords as @code{root} with the @command{passwd} command, and then let
11626 users change it with @command{passwd}. Passwords set with
11627 @command{passwd} are of course preserved across reboot and
11630 If you @emph{do} want to set an initial password for an account, then
11631 this field must contain the encrypted password, as a string. You can use the
11632 @code{crypt} procedure for this purpose:
11639 ;; Specify a SHA-512-hashed initial password.
11640 (password (crypt "InitialPassword!" "$6$abc")))
11644 The hash of this initial password will be available in a file in
11645 @file{/gnu/store}, readable by all the users, so this method must be used with
11649 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11650 more information on password encryption, and @ref{Encryption,,, guile, GNU
11651 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11657 User group declarations are even simpler:
11660 (user-group (name "students"))
11663 @deftp {Data Type} user-group
11664 This type is for, well, user groups. There are just a few fields:
11668 The name of the group.
11670 @item @code{id} (default: @code{#f})
11671 The group identifier (a number). If @code{#f}, a new number is
11672 automatically allocated when the group is created.
11674 @item @code{system?} (default: @code{#f})
11675 This Boolean value indicates whether the group is a ``system'' group.
11676 System groups have low numerical IDs.
11678 @item @code{password} (default: @code{#f})
11679 What, user groups can have a password? Well, apparently yes. Unless
11680 @code{#f}, this field specifies the password of the group.
11685 For convenience, a variable lists all the basic user groups one may
11688 @defvr {Scheme Variable} %base-groups
11689 This is the list of basic user groups that users and/or packages expect
11690 to be present on the system. This includes groups such as ``root'',
11691 ``wheel'', and ``users'', as well as groups used to control access to
11692 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11695 @defvr {Scheme Variable} %base-user-accounts
11696 This is the list of basic system accounts that programs may expect to
11697 find on a GNU/Linux system, such as the ``nobody'' account.
11699 Note that the ``root'' account is not included here. It is a
11700 special-case and is automatically added whether or not it is specified.
11703 @node Keyboard Layout
11704 @section Keyboard Layout
11706 @cindex keyboard layout
11708 To specify what each key of your keyboard does, you need to tell the operating
11709 system what @dfn{keyboard layout} you want to use. The default, when nothing
11710 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11711 However, German speakers will usually prefer the German QWERTZ layout, French
11712 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11713 or bépo, and they might even want to further customize the effect of some of
11714 the keys. This section explains how to get that done.
11716 @cindex keyboard layout, definition
11717 There are three components that will want to know about your keyboard layout:
11721 The @emph{bootloader} may want to know what keyboard layout you want to use
11722 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11723 you want, for instance, to make sure that you can type the passphrase of your
11724 encrypted root partition using the right layout.
11727 The @emph{operating system kernel}, Linux, will need that so that the console
11728 is properly configured (@pxref{operating-system Reference,
11729 @code{keyboard-layout}}).
11732 The @emph{graphical display server}, usually Xorg, also has its own idea of
11733 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11736 Guix allows you to configure all three separately but, fortunately, it allows
11737 you to share the same keyboard layout for all three components.
11739 @cindex XKB, keyboard layouts
11740 Keyboard layouts are represented by records created by the
11741 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11742 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11743 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11744 optional variant name, an optional keyboard model name, and a possibly empty
11745 list of additional options. In most cases the layout name is all you care
11746 about. Here are a few example:
11749 ;; The German QWERTZ layout. Here we assume a standard
11750 ;; "pc105" keyboard model.
11751 (keyboard-layout "de")
11753 ;; The bépo variant of the French layout.
11754 (keyboard-layout "fr" "bepo")
11756 ;; The Catalan layout.
11757 (keyboard-layout "es" "cat")
11759 ;; The Latin American Spanish layout. In addition, the
11760 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11761 ;; and the "Menu" key is used as a "Compose" key to enter
11762 ;; accented letters.
11763 (keyboard-layout "latam"
11764 #:options '("ctrl:nocaps" "compose:menu"))
11766 ;; The Russian layout for a ThinkPad keyboard.
11767 (keyboard-layout "ru" #:model "thinkpad")
11769 ;; The "US international" layout, which is the US layout plus
11770 ;; dead keys to enter accented characters. This is for an
11771 ;; Apple MacBook keyboard.
11772 (keyboard-layout "us" "intl" #:model "macbook78")
11775 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11776 for a complete list of supported layouts, variants, and models.
11778 @cindex keyboard layout, configuration
11779 Let's say you want your system to use the Turkish keyboard layout throughout
11780 your system---bootloader, console, and Xorg. Here's what your system
11781 configuration would look like:
11783 @findex set-xorg-configuration
11785 ;; Using the Turkish layout for the bootloader, the console,
11790 (keyboard-layout (keyboard-layout "tr")) ;for the console
11791 (bootloader (bootloader-configuration
11792 (bootloader grub-efi-bootloader)
11793 (target "/boot/efi")
11794 (keyboard-layout keyboard-layout))) ;for GRUB
11795 (services (cons (set-xorg-configuration
11796 (xorg-configuration ;for Xorg
11797 (keyboard-layout keyboard-layout)))
11798 %desktop-services)))
11801 In the example above, for GRUB and for Xorg, we just refer to the
11802 @code{keyboard-layout} field defined above, but we could just as well refer to
11803 a different layout. The @code{set-xorg-configuration} procedure communicates
11804 the desired Xorg configuration to the graphical log-in manager, by default
11807 We've discussed how to specify the @emph{default} keyboard layout of your
11808 system when it starts, but you can also adjust it at run time:
11812 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11813 where you can select one or more keyboard layouts.
11816 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11817 allows you to change the current layout. For example, this is how you would
11818 change the layout to US Dvorak:
11821 setxkbmap us dvorak
11825 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11826 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11827 keyboard layout categorization described above. The command below loads the
11828 French bépo layout:
11839 A @dfn{locale} defines cultural conventions for a particular language
11840 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11841 Reference Manual}). Each locale has a name that typically has the form
11842 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11843 @code{fr_LU.utf8} designates the locale for the French language, with
11844 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11846 @cindex locale definition
11847 Usually, you will want to specify the default locale for the machine
11848 using the @code{locale} field of the @code{operating-system} declaration
11849 (@pxref{operating-system Reference, @code{locale}}).
11851 The selected locale is automatically added to the @dfn{locale
11852 definitions} known to the system if needed, with its codeset inferred
11853 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11854 @code{UTF-8} codeset. Additional locale definitions can be specified in
11855 the @code{locale-definitions} slot of @code{operating-system}---this is
11856 useful, for instance, if the codeset could not be inferred from the
11857 locale name. The default set of locale definitions includes some widely
11858 used locales, but not all the available locales, in order to save space.
11860 For instance, to add the North Frisian locale for Germany, the value of
11864 (cons (locale-definition
11865 (name "fy_DE.utf8") (source "fy_DE"))
11866 %default-locale-definitions)
11869 Likewise, to save space, one might want @code{locale-definitions} to
11870 list only the locales that are actually used, as in:
11873 (list (locale-definition
11874 (name "ja_JP.eucjp") (source "ja_JP")
11875 (charset "EUC-JP")))
11879 The compiled locale definitions are available at
11880 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11881 version, which is the default location where the GNU@tie{}libc provided
11882 by Guix looks for locale data. This can be overridden using the
11883 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11884 @code{LOCPATH} and locale packages}).
11886 The @code{locale-definition} form is provided by the @code{(gnu system
11887 locale)} module. Details are given below.
11889 @deftp {Data Type} locale-definition
11890 This is the data type of a locale definition.
11895 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11896 Reference Manual}, for more information on locale names.
11898 @item @code{source}
11899 The name of the source for that locale. This is typically the
11900 @code{@var{language}_@var{territory}} part of the locale name.
11902 @item @code{charset} (default: @code{"UTF-8"})
11903 The ``character set'' or ``code set'' for that locale,
11904 @uref{https://www.iana.org/assignments/character-sets, as defined by
11910 @defvr {Scheme Variable} %default-locale-definitions
11911 A list of commonly used UTF-8 locales, used as the default
11912 value of the @code{locale-definitions} field of @code{operating-system}
11915 @cindex locale name
11916 @cindex normalized codeset in locale names
11917 These locale definitions use the @dfn{normalized codeset} for the part
11918 that follows the dot in the name (@pxref{Using gettextized software,
11919 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11920 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11921 @code{uk_UA.UTF-8}.
11924 @subsection Locale Data Compatibility Considerations
11926 @cindex incompatibility, of locale data
11927 @code{operating-system} declarations provide a @code{locale-libcs} field
11928 to specify the GNU@tie{}libc packages that are used to compile locale
11929 declarations (@pxref{operating-system Reference}). ``Why would I
11930 care?'', you may ask. Well, it turns out that the binary format of
11931 locale data is occasionally incompatible from one libc version to
11934 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11935 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11936 For instance, a program linked against libc version 2.21 is unable to
11937 read locale data produced with libc 2.22; worse, that program
11938 @emph{aborts} instead of simply ignoring the incompatible locale
11939 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11940 the incompatible locale data, which is already an improvement.}.
11941 Similarly, a program linked against libc 2.22 can read most, but not
11942 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11943 data is incompatible); thus calls to @code{setlocale} may fail, but
11944 programs will not abort.
11946 The ``problem'' with Guix is that users have a lot of freedom: They can
11947 choose whether and when to upgrade software in their profiles, and might
11948 be using a libc version different from the one the system administrator
11949 used to build the system-wide locale data.
11951 Fortunately, unprivileged users can also install their own locale data
11952 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11953 @code{GUIX_LOCPATH} and locale packages}).
11955 Still, it is best if the system-wide locale data at
11956 @file{/run/current-system/locale} is built for all the libc versions
11957 actually in use on the system, so that all the programs can access
11958 it---this is especially crucial on a multi-user system. To do that, the
11959 administrator can specify several libc packages in the
11960 @code{locale-libcs} field of @code{operating-system}:
11963 (use-package-modules base)
11967 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11970 This example would lead to a system containing locale definitions for
11971 both libc 2.21 and the current version of libc in
11972 @file{/run/current-system/locale}.
11978 @cindex system services
11979 An important part of preparing an @code{operating-system} declaration is
11980 listing @dfn{system services} and their configuration (@pxref{Using the
11981 Configuration System}). System services are typically daemons launched
11982 when the system boots, or other actions needed at that time---e.g.,
11983 configuring network access.
11985 Guix has a broad definition of ``service'' (@pxref{Service
11986 Composition}), but many services are managed by the GNU@tie{}Shepherd
11987 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11988 command allows you to list the available services, show their status,
11989 start and stop them, or do other specific operations (@pxref{Jump
11990 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11996 The above command, run as @code{root}, lists the currently defined
11997 services. The @command{herd doc} command shows a synopsis of the given
11998 service and its associated actions:
12002 Run libc's name service cache daemon (nscd).
12004 # herd doc nscd action invalidate
12005 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12008 The @command{start}, @command{stop}, and @command{restart} sub-commands
12009 have the effect you would expect. For instance, the commands below stop
12010 the nscd service and restart the Xorg display server:
12014 Service nscd has been stopped.
12015 # herd restart xorg-server
12016 Service xorg-server has been stopped.
12017 Service xorg-server has been started.
12020 The following sections document the available services, starting with
12021 the core services, that may be used in an @code{operating-system}
12025 * Base Services:: Essential system services.
12026 * Scheduled Job Execution:: The mcron service.
12027 * Log Rotation:: The rottlog service.
12028 * Networking Services:: Network setup, SSH daemon, etc.
12029 * X Window:: Graphical display.
12030 * Printing Services:: Local and remote printer support.
12031 * Desktop Services:: D-Bus and desktop services.
12032 * Sound Services:: ALSA and Pulseaudio services.
12033 * Database Services:: SQL databases, key-value stores, etc.
12034 * Mail Services:: IMAP, POP3, SMTP, and all that.
12035 * Messaging Services:: Messaging services.
12036 * Telephony Services:: Telephony services.
12037 * Monitoring Services:: Monitoring services.
12038 * Kerberos Services:: Kerberos services.
12039 * LDAP Services:: LDAP services.
12040 * Web Services:: Web servers.
12041 * Certificate Services:: TLS certificates via Let's Encrypt.
12042 * DNS Services:: DNS daemons.
12043 * VPN Services:: VPN daemons.
12044 * Network File System:: NFS related services.
12045 * Continuous Integration:: The Cuirass service.
12046 * Power Management Services:: Extending battery life.
12047 * Audio Services:: The MPD.
12048 * Virtualization Services:: Virtualization services.
12049 * Version Control Services:: Providing remote access to Git repositories.
12050 * Game Services:: Game servers.
12051 * PAM Mount Service:: Service to mount volumes when logging in.
12052 * Guix Services:: Services relating specifically to Guix.
12053 * Miscellaneous Services:: Other services.
12056 @node Base Services
12057 @subsection Base Services
12059 The @code{(gnu services base)} module provides definitions for the basic
12060 services that one expects from the system. The services exported by
12061 this module are listed below.
12063 @defvr {Scheme Variable} %base-services
12064 This variable contains a list of basic services (@pxref{Service Types
12065 and Services}, for more information on service objects) one would
12066 expect from the system: a login service (mingetty) on each tty, syslogd,
12067 the libc name service cache daemon (nscd), the udev device manager, and
12070 This is the default value of the @code{services} field of
12071 @code{operating-system} declarations. Usually, when customizing a
12072 system, you will want to append services to @code{%base-services}, like
12076 (append (list (service avahi-service-type)
12077 (service openssh-service-type))
12082 @defvr {Scheme Variable} special-files-service-type
12083 This is the service that sets up ``special files'' such as
12084 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12086 The value associated with @code{special-files-service-type} services
12087 must be a list of tuples where the first element is the ``special file''
12088 and the second element is its target. By default it is:
12090 @cindex @file{/bin/sh}
12091 @cindex @file{sh}, in @file{/bin}
12093 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12096 @cindex @file{/usr/bin/env}
12097 @cindex @file{env}, in @file{/usr/bin}
12098 If you want to add, say, @code{/usr/bin/env} to your system, you can
12102 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12103 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12106 Since this is part of @code{%base-services}, you can use
12107 @code{modify-services} to customize the set of special files
12108 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12109 to add a special file is @i{via} the @code{extra-special-file} procedure
12113 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12114 Use @var{target} as the ``special file'' @var{file}.
12116 For example, adding the following lines to the @code{services} field of
12117 your operating system declaration leads to a @file{/usr/bin/env}
12121 (extra-special-file "/usr/bin/env"
12122 (file-append coreutils "/bin/env"))
12126 @deffn {Scheme Procedure} host-name-service @var{name}
12127 Return a service that sets the host name to @var{name}.
12130 @deffn {Scheme Procedure} login-service @var{config}
12131 Return a service to run login according to @var{config}, a
12132 @code{<login-configuration>} object, which specifies the message of the day,
12133 among other things.
12136 @deftp {Data Type} login-configuration
12137 This is the data type representing the configuration of login.
12142 @cindex message of the day
12143 A file-like object containing the ``message of the day''.
12145 @item @code{allow-empty-passwords?} (default: @code{#t})
12146 Allow empty passwords by default so that first-time users can log in when
12147 the 'root' account has just been created.
12152 @deffn {Scheme Procedure} mingetty-service @var{config}
12153 Return a service to run mingetty according to @var{config}, a
12154 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12158 @deftp {Data Type} mingetty-configuration
12159 This is the data type representing the configuration of Mingetty, which
12160 provides the default implementation of virtual console log-in.
12165 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12167 @item @code{auto-login} (default: @code{#f})
12168 When true, this field must be a string denoting the user name under
12169 which the system automatically logs in. When it is @code{#f}, a
12170 user name and password must be entered to log in.
12172 @item @code{login-program} (default: @code{#f})
12173 This must be either @code{#f}, in which case the default log-in program
12174 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12175 the name of the log-in program.
12177 @item @code{login-pause?} (default: @code{#f})
12178 When set to @code{#t} in conjunction with @var{auto-login}, the user
12179 will have to press a key before the log-in shell is launched.
12181 @item @code{mingetty} (default: @var{mingetty})
12182 The Mingetty package to use.
12187 @deffn {Scheme Procedure} agetty-service @var{config}
12188 Return a service to run agetty according to @var{config}, an
12189 @code{<agetty-configuration>} object, which specifies the tty to run,
12190 among other things.
12193 @deftp {Data Type} agetty-configuration
12194 This is the data type representing the configuration of agetty, which
12195 implements virtual and serial console log-in. See the @code{agetty(8)}
12196 man page for more information.
12201 The name of the console this agetty runs on, as a string---e.g.,
12202 @code{"ttyS0"}. This argument is optional, it will default to
12203 a reasonable default serial port used by the kernel Linux.
12205 For this, if there is a value for an option @code{agetty.tty} in the kernel
12206 command line, agetty will extract the device name of the serial port
12207 from it and use that.
12209 If not and if there is a value for an option @code{console} with a tty in
12210 the Linux command line, agetty will extract the device name of the
12211 serial port from it and use that.
12213 In both cases, agetty will leave the other serial device settings
12214 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12217 @item @code{baud-rate} (default: @code{#f})
12218 A string containing a comma-separated list of one or more baud rates, in
12221 @item @code{term} (default: @code{#f})
12222 A string containing the value used for the @code{TERM} environment
12225 @item @code{eight-bits?} (default: @code{#f})
12226 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12229 @item @code{auto-login} (default: @code{#f})
12230 When passed a login name, as a string, the specified user will be logged
12231 in automatically without prompting for their login name or password.
12233 @item @code{no-reset?} (default: @code{#f})
12234 When @code{#t}, don't reset terminal cflags (control modes).
12236 @item @code{host} (default: @code{#f})
12237 This accepts a string containing the "login_host", which will be written
12238 into the @file{/var/run/utmpx} file.
12240 @item @code{remote?} (default: @code{#f})
12241 When set to @code{#t} in conjunction with @var{host}, this will add an
12242 @code{-r} fakehost option to the command line of the login program
12243 specified in @var{login-program}.
12245 @item @code{flow-control?} (default: @code{#f})
12246 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12248 @item @code{no-issue?} (default: @code{#f})
12249 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12250 not be displayed before presenting the login prompt.
12252 @item @code{init-string} (default: @code{#f})
12253 This accepts a string that will be sent to the tty or modem before
12254 sending anything else. It can be used to initialize a modem.
12256 @item @code{no-clear?} (default: @code{#f})
12257 When set to @code{#t}, agetty will not clear the screen before showing
12260 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12261 This must be either a gexp denoting the name of a log-in program, or
12262 unset, in which case the default value is the @command{login} from the
12265 @item @code{local-line} (default: @code{#f})
12266 Control the CLOCAL line flag. This accepts one of three symbols as
12267 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12268 the default value chosen by agetty is @code{'auto}.
12270 @item @code{extract-baud?} (default: @code{#f})
12271 When set to @code{#t}, instruct agetty to try to extract the baud rate
12272 from the status messages produced by certain types of modems.
12274 @item @code{skip-login?} (default: @code{#f})
12275 When set to @code{#t}, do not prompt the user for a login name. This
12276 can be used with @var{login-program} field to use non-standard login
12279 @item @code{no-newline?} (default: @code{#f})
12280 When set to @code{#t}, do not print a newline before printing the
12281 @file{/etc/issue} file.
12283 @c Is this dangerous only when used with login-program, or always?
12284 @item @code{login-options} (default: @code{#f})
12285 This option accepts a string containing options that are passed to the
12286 login program. When used with the @var{login-program}, be aware that a
12287 malicious user could try to enter a login name containing embedded
12288 options that could be parsed by the login program.
12290 @item @code{login-pause} (default: @code{#f})
12291 When set to @code{#t}, wait for any key before showing the login prompt.
12292 This can be used in conjunction with @var{auto-login} to save memory by
12293 lazily spawning shells.
12295 @item @code{chroot} (default: @code{#f})
12296 Change root to the specified directory. This option accepts a directory
12299 @item @code{hangup?} (default: @code{#f})
12300 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12301 specified terminal.
12303 @item @code{keep-baud?} (default: @code{#f})
12304 When set to @code{#t}, try to keep the existing baud rate. The baud
12305 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12308 @item @code{timeout} (default: @code{#f})
12309 When set to an integer value, terminate if no user name could be read
12310 within @var{timeout} seconds.
12312 @item @code{detect-case?} (default: @code{#f})
12313 When set to @code{#t}, turn on support for detecting an uppercase-only
12314 terminal. This setting will detect a login name containing only
12315 uppercase letters as indicating an uppercase-only terminal and turn on
12316 some upper-to-lower case conversions. Note that this will not support
12317 Unicode characters.
12319 @item @code{wait-cr?} (default: @code{#f})
12320 When set to @code{#t}, wait for the user or modem to send a
12321 carriage-return or linefeed character before displaying
12322 @file{/etc/issue} or login prompt. This is typically used with the
12323 @var{init-string} option.
12325 @item @code{no-hints?} (default: @code{#f})
12326 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12329 @item @code{no-hostname?} (default: @code{#f})
12330 By default, the hostname is printed. When this option is set to
12331 @code{#t}, no hostname will be shown at all.
12333 @item @code{long-hostname?} (default: @code{#f})
12334 By default, the hostname is only printed until the first dot. When this
12335 option is set to @code{#t}, the fully qualified hostname by
12336 @code{gethostname} or @code{getaddrinfo} is shown.
12338 @item @code{erase-characters} (default: @code{#f})
12339 This option accepts a string of additional characters that should be
12340 interpreted as backspace when the user types their login name.
12342 @item @code{kill-characters} (default: @code{#f})
12343 This option accepts a string that should be interpreted to mean "ignore
12344 all previous characters" (also called a "kill" character) when the user
12345 types their login name.
12347 @item @code{chdir} (default: @code{#f})
12348 This option accepts, as a string, a directory path that will be changed
12351 @item @code{delay} (default: @code{#f})
12352 This options accepts, as an integer, the number of seconds to sleep
12353 before opening the tty and displaying the login prompt.
12355 @item @code{nice} (default: @code{#f})
12356 This option accepts, as an integer, the nice value with which to run the
12357 @command{login} program.
12359 @item @code{extra-options} (default: @code{'()})
12360 This option provides an "escape hatch" for the user to provide arbitrary
12361 command-line arguments to @command{agetty} as a list of strings.
12366 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12367 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12368 according to @var{config}, a @code{<kmscon-configuration>} object, which
12369 specifies the tty to run, among other things.
12372 @deftp {Data Type} kmscon-configuration
12373 This is the data type representing the configuration of Kmscon, which
12374 implements virtual console log-in.
12378 @item @code{virtual-terminal}
12379 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12381 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12382 A gexp denoting the name of the log-in program. The default log-in program is
12383 @command{login} from the Shadow tool suite.
12385 @item @code{login-arguments} (default: @code{'("-p")})
12386 A list of arguments to pass to @command{login}.
12388 @item @code{auto-login} (default: @code{#f})
12389 When passed a login name, as a string, the specified user will be logged
12390 in automatically without prompting for their login name or password.
12392 @item @code{hardware-acceleration?} (default: #f)
12393 Whether to use hardware acceleration.
12395 @item @code{kmscon} (default: @var{kmscon})
12396 The Kmscon package to use.
12401 @cindex name service cache daemon
12403 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12404 [#:name-services '()]
12405 Return a service that runs the libc name service cache daemon (nscd) with the
12406 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12407 Service Switch}, for an example.
12409 For convenience, the Shepherd service for nscd provides the following actions:
12413 @cindex cache invalidation, nscd
12414 @cindex nscd, cache invalidation
12415 This invalidate the given cache. For instance, running:
12418 herd invalidate nscd hosts
12422 invalidates the host name lookup cache of nscd.
12425 Running @command{herd statistics nscd} displays information about nscd usage
12431 @defvr {Scheme Variable} %nscd-default-configuration
12432 This is the default @code{<nscd-configuration>} value (see below) used
12433 by @code{nscd-service}. It uses the caches defined by
12434 @var{%nscd-default-caches}; see below.
12437 @deftp {Data Type} nscd-configuration
12438 This is the data type representing the name service cache daemon (nscd)
12443 @item @code{name-services} (default: @code{'()})
12444 List of packages denoting @dfn{name services} that must be visible to
12445 the nscd---e.g., @code{(list @var{nss-mdns})}.
12447 @item @code{glibc} (default: @var{glibc})
12448 Package object denoting the GNU C Library providing the @command{nscd}
12451 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12452 Name of the nscd log file. This is where debugging output goes when
12453 @code{debug-level} is strictly positive.
12455 @item @code{debug-level} (default: @code{0})
12456 Integer denoting the debugging levels. Higher numbers mean that more
12457 debugging output is logged.
12459 @item @code{caches} (default: @var{%nscd-default-caches})
12460 List of @code{<nscd-cache>} objects denoting things to be cached; see
12466 @deftp {Data Type} nscd-cache
12467 Data type representing a cache database of nscd and its parameters.
12471 @item @code{database}
12472 This is a symbol representing the name of the database to be cached.
12473 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12474 @code{services}, which designate the corresponding NSS database
12475 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12477 @item @code{positive-time-to-live}
12478 @itemx @code{negative-time-to-live} (default: @code{20})
12479 A number representing the number of seconds during which a positive or
12480 negative lookup result remains in cache.
12482 @item @code{check-files?} (default: @code{#t})
12483 Whether to check for updates of the files corresponding to
12486 For instance, when @var{database} is @code{hosts}, setting this flag
12487 instructs nscd to check for updates in @file{/etc/hosts} and to take
12490 @item @code{persistent?} (default: @code{#t})
12491 Whether the cache should be stored persistently on disk.
12493 @item @code{shared?} (default: @code{#t})
12494 Whether the cache should be shared among users.
12496 @item @code{max-database-size} (default: 32@tie{}MiB)
12497 Maximum size in bytes of the database cache.
12499 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12500 @c settings, so leave them out.
12505 @defvr {Scheme Variable} %nscd-default-caches
12506 List of @code{<nscd-cache>} objects used by default by
12507 @code{nscd-configuration} (see above).
12509 It enables persistent and aggressive caching of service and host name
12510 lookups. The latter provides better host name lookup performance,
12511 resilience in the face of unreliable name servers, and also better
12512 privacy---often the result of host name lookups is in local cache, so
12513 external name servers do not even need to be queried.
12516 @anchor{syslog-configuration-type}
12519 @deftp {Data Type} syslog-configuration
12520 This data type represents the configuration of the syslog daemon.
12523 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12524 The syslog daemon to use.
12526 @item @code{config-file} (default: @code{%default-syslog.conf})
12527 The syslog configuration file to use.
12532 @anchor{syslog-service}
12534 @deffn {Scheme Procedure} syslog-service @var{config}
12535 Return a service that runs a syslog daemon according to @var{config}.
12537 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12538 information on the configuration file syntax.
12541 @defvr {Scheme Variable} guix-service-type
12542 This is the type of the service that runs the build daemon,
12543 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12544 @code{guix-configuration} record as described below.
12547 @anchor{guix-configuration-type}
12548 @deftp {Data Type} guix-configuration
12549 This data type represents the configuration of the Guix build daemon.
12550 @xref{Invoking guix-daemon}, for more information.
12553 @item @code{guix} (default: @var{guix})
12554 The Guix package to use.
12556 @item @code{build-group} (default: @code{"guixbuild"})
12557 Name of the group for build user accounts.
12559 @item @code{build-accounts} (default: @code{10})
12560 Number of build user accounts to create.
12562 @item @code{authorize-key?} (default: @code{#t})
12563 @cindex substitutes, authorization thereof
12564 Whether to authorize the substitute keys listed in
12565 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12566 (@pxref{Substitutes}).
12568 @vindex %default-authorized-guix-keys
12569 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12570 The list of authorized key files for archive imports, as a list of
12571 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12572 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12574 @item @code{use-substitutes?} (default: @code{#t})
12575 Whether to use substitutes.
12577 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12578 The list of URLs where to look for substitutes by default.
12580 @item @code{max-silent-time} (default: @code{0})
12581 @itemx @code{timeout} (default: @code{0})
12582 The number of seconds of silence and the number of seconds of activity,
12583 respectively, after which a build process times out. A value of zero
12584 disables the timeout.
12586 @item @code{log-compression} (default: @code{'bzip2})
12587 The type of compression used for build logs---one of @code{gzip},
12588 @code{bzip2}, or @code{none}.
12590 @item @code{extra-options} (default: @code{'()})
12591 List of extra command-line options for @command{guix-daemon}.
12593 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12594 File where @command{guix-daemon}'s standard output and standard error
12597 @item @code{http-proxy} (default: @code{#f})
12598 The HTTP proxy used for downloading fixed-output derivations and
12601 @item @code{tmpdir} (default: @code{#f})
12602 A directory path where the @command{guix-daemon} will perform builds.
12607 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12608 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12609 udev rules can be provided as a list of files through the @var{rules}
12610 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12611 @code{(gnu services base)} simplify the creation of such rule files.
12614 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12615 Return a udev-rule file named @var{file-name} containing the rules
12616 defined by the @var{contents} literal.
12618 In the following example, a rule for a USB device is defined to be
12619 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12620 upon detecting a USB device with a given product identifier.
12623 (define %example-udev-rule
12625 "90-usb-thing.rules"
12626 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12627 "ATTR@{product@}==\"Example\", "
12628 "RUN+=\"/path/to/script\"")))
12631 The @command{herd rules udev} command, as root, returns the name of the
12632 directory containing all the active udev rules.
12635 Here we show how the default @var{udev-service} can be extended with it.
12641 (modify-services %desktop-services
12642 (udev-service-type config =>
12643 (udev-configuration (inherit config)
12644 (rules (append (udev-configuration-rules config)
12645 (list %example-udev-rule))))))))
12648 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12649 Return a udev file named @var{file-name} containing the rules defined
12650 within @var{file}, a file-like object.
12652 The following example showcases how we can use an existing rule file.
12655 (use-modules (guix download) ;for url-fetch
12656 (guix packages) ;for origin
12659 (define %android-udev-rules
12661 "51-android-udev.rules"
12662 (let ((version "20170910"))
12665 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12666 "android-udev-rules/" version "/51-android.rules"))
12668 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12672 Additionally, Guix package definitions can be included in @var{rules} in
12673 order to extend the udev rules with the definitions found under their
12674 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12675 @var{file->udev-rule} example, we could have used the
12676 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12677 packages android)} module.
12679 The following example shows how to use the @var{android-udev-rules}
12680 package so that the Android tool @command{adb} can detect devices
12681 without root privileges. It also details how to create the
12682 @code{adbusers} group, which is required for the proper functioning of
12683 the rules defined within the @var{android-udev-rules} package. To
12684 create such a group, we must define it both as part of the
12685 @var{supplementary-groups} of our @var{user-account} declaration, as
12686 well as in the @var{groups} field of the @var{operating-system} record.
12689 (use-modules (gnu packages android) ;for android-udev-rules
12690 (gnu system shadow) ;for user-group
12695 (users (cons (user-acount
12697 (supplementary-groups
12698 '("adbusers" ;for adb
12699 "wheel" "netdev" "audio" "video")))))
12701 (groups (cons (user-group (system? #t) (name "adbusers"))
12707 (modify-services %desktop-services
12710 (udev-configuration (inherit config)
12711 (rules (cons android-udev-rules
12712 (udev-configuration-rules config))))))))
12715 @defvr {Scheme Variable} urandom-seed-service-type
12716 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12717 when rebooting. It also tries to seed @file{/dev/urandom} from
12718 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12722 @defvr {Scheme Variable} %random-seed-file
12723 This is the name of the file where some random bytes are saved by
12724 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12725 It defaults to @file{/var/lib/random-seed}.
12730 @defvr {Scheme Variable} gpm-service-type
12731 This is the type of the service that runs GPM, the @dfn{general-purpose
12732 mouse daemon}, which provides mouse support to the Linux console. GPM
12733 allows users to use the mouse in the console, notably to select, copy,
12736 The value for services of this type must be a @code{gpm-configuration}
12737 (see below). This service is not part of @code{%base-services}.
12740 @deftp {Data Type} gpm-configuration
12741 Data type representing the configuration of GPM.
12744 @item @code{options} (default: @code{%default-gpm-options})
12745 Command-line options passed to @command{gpm}. The default set of
12746 options instruct @command{gpm} to listen to mouse events on
12747 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12750 @item @code{gpm} (default: @code{gpm})
12751 The GPM package to use.
12756 @anchor{guix-publish-service-type}
12757 @deffn {Scheme Variable} guix-publish-service-type
12758 This is the service type for @command{guix publish} (@pxref{Invoking
12759 guix publish}). Its value must be a @code{guix-publish-configuration}
12760 object, as described below.
12762 This assumes that @file{/etc/guix} already contains a signing key pair as
12763 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12764 archive}). If that is not the case, the service will fail to start.
12767 @deftp {Data Type} guix-publish-configuration
12768 Data type representing the configuration of the @code{guix publish}
12772 @item @code{guix} (default: @code{guix})
12773 The Guix package to use.
12775 @item @code{port} (default: @code{80})
12776 The TCP port to listen for connections.
12778 @item @code{host} (default: @code{"localhost"})
12779 The host (and thus, network interface) to listen to. Use
12780 @code{"0.0.0.0"} to listen on all the network interfaces.
12782 @item @code{compression} (default: @code{'(("gzip" 3))})
12783 This is a list of compression method/level tuple used when compressing
12784 substitutes. For example, to compress all substitutes with @emph{both} lzip
12785 at level 7 and gzip at level 9, write:
12788 '(("lzip" 7) ("gzip" 9))
12791 Level 9 achieves the best compression ratio at the expense of increased CPU
12792 usage, whereas level 1 achieves fast compression.
12794 An empty list disables compression altogether.
12796 @item @code{nar-path} (default: @code{"nar"})
12797 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12798 publish, @code{--nar-path}}, for details.
12800 @item @code{cache} (default: @code{#f})
12801 When it is @code{#f}, disable caching and instead generate archives on
12802 demand. Otherwise, this should be the name of a directory---e.g.,
12803 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12804 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12805 @option{--cache}}, for more information on the tradeoffs involved.
12807 @item @code{workers} (default: @code{#f})
12808 When it is an integer, this is the number of worker threads used for
12809 caching; when @code{#f}, the number of processors is used.
12810 @xref{Invoking guix publish, @option{--workers}}, for more information.
12812 @item @code{ttl} (default: @code{#f})
12813 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12814 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12815 for more information.
12819 @anchor{rngd-service}
12820 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12821 [#:device "/dev/hwrng"]
12822 Return a service that runs the @command{rngd} program from @var{rng-tools}
12823 to add @var{device} to the kernel's entropy pool. The service will fail if
12824 @var{device} does not exist.
12827 @anchor{pam-limits-service}
12828 @cindex session limits
12833 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12835 Return a service that installs a configuration file for the
12836 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12837 @code{pam_limits} module}. The procedure optionally takes a list of
12838 @code{pam-limits-entry} values, which can be used to specify
12839 @code{ulimit} limits and nice priority limits to user sessions.
12841 The following limits definition sets two hard and soft limits for all
12842 login sessions of users in the @code{realtime} group:
12845 (pam-limits-service
12847 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12848 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12851 The first entry increases the maximum realtime priority for
12852 non-privileged processes; the second entry lifts any restriction of the
12853 maximum address space that can be locked in memory. These settings are
12854 commonly used for real-time audio systems.
12857 @node Scheduled Job Execution
12858 @subsection Scheduled Job Execution
12862 @cindex scheduling jobs
12863 The @code{(gnu services mcron)} module provides an interface to
12864 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12865 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12866 Unix @command{cron} daemon; the main difference is that it is
12867 implemented in Guile Scheme, which provides a lot of flexibility when
12868 specifying the scheduling of jobs and their actions.
12870 The example below defines an operating system that runs the
12871 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12872 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12873 well as the @command{mkid} command on behalf of an unprivileged user
12874 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12875 gexps to introduce job definitions that are passed to mcron
12876 (@pxref{G-Expressions}).
12879 (use-modules (guix) (gnu) (gnu services mcron))
12880 (use-package-modules base idutils)
12882 (define updatedb-job
12883 ;; Run 'updatedb' at 3AM every day. Here we write the
12884 ;; job's action as a Scheme procedure.
12885 #~(job '(next-hour '(3))
12887 (execl (string-append #$findutils "/bin/updatedb")
12889 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12891 (define garbage-collector-job
12892 ;; Collect garbage 5 minutes after midnight every day.
12893 ;; The job's action is a shell command.
12894 #~(job "5 0 * * *" ;Vixie cron syntax
12897 (define idutils-job
12898 ;; Update the index database as user "charlie" at 12:15PM
12899 ;; and 19:15PM. This runs from the user's home directory.
12900 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12901 (string-append #$idutils "/bin/mkid src")
12906 (services (cons (service mcron-service-type
12907 (mcron-configuration
12908 (jobs (list garbage-collector-job
12914 For more complex jobs defined in Scheme where you need control over the top
12915 level, for instance to introduce a @code{use-modules} form, you can move your
12916 code to a separate program using the @code{program-file} procedure of the
12917 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12921 (define %battery-alert-job
12922 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12924 '(next-minute (range 0 60 1))
12926 "battery-alert.scm"
12927 (with-imported-modules (source-module-closure
12928 '((guix build utils)))
12930 (define %min-level 20)
12931 (use-modules (guix build utils)
12934 (ice-9 textual-ports)
12936 (setenv "LC_ALL" "C") ;ensure English output
12937 (and-let* ((input-pipe (open-pipe*
12939 #$(file-append acpi "/bin/acpi")))
12940 (output (get-string-all input-pipe))
12941 (m (string-match "Discharging, ([0-9]+)%" output))
12942 (level (string->number (match:substring m 1)))
12943 ((< level %min-level)))
12944 (format #t "warning: Battery level is low (~a%)~%" level)
12945 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12948 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12949 for more information on mcron job specifications. Below is the
12950 reference of the mcron service.
12952 On a running system, you can use the @code{schedule} action of the service to
12953 visualize the mcron jobs that will be executed next:
12956 # herd schedule mcron
12960 The example above lists the next five tasks that will be executed, but you can
12961 also specify the number of tasks to display:
12964 # herd schedule mcron 10
12967 @defvr {Scheme Variable} mcron-service-type
12968 This is the type of the @code{mcron} service, whose value is an
12969 @code{mcron-configuration} object.
12971 This service type can be the target of a service extension that provides
12972 it additional job specifications (@pxref{Service Composition}). In
12973 other words, it is possible to define services that provide additional
12977 @deftp {Data Type} mcron-configuration
12978 Data type representing the configuration of mcron.
12981 @item @code{mcron} (default: @var{mcron})
12982 The mcron package to use.
12985 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12986 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12987 specifications,, mcron, GNU@tie{}mcron}).
12993 @subsection Log Rotation
12996 @cindex log rotation
12998 Log files such as those found in @file{/var/log} tend to grow endlessly,
12999 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13000 their contents in separate files, possibly compressed. The @code{(gnu
13001 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13002 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13004 The example below defines an operating system that provides log rotation
13005 with the default settings, for commonly encountered log files.
13008 (use-modules (guix) (gnu))
13009 (use-service-modules admin mcron)
13010 (use-package-modules base idutils)
13014 (services (cons (service rottlog-service-type)
13018 @defvr {Scheme Variable} rottlog-service-type
13019 This is the type of the Rottlog service, whose value is a
13020 @code{rottlog-configuration} object.
13022 Other services can extend this one with new @code{log-rotation} objects
13023 (see below), thereby augmenting the set of files to be rotated.
13025 This service type can define mcron jobs (@pxref{Scheduled Job
13026 Execution}) to run the rottlog service.
13029 @deftp {Data Type} rottlog-configuration
13030 Data type representing the configuration of rottlog.
13033 @item @code{rottlog} (default: @code{rottlog})
13034 The Rottlog package to use.
13036 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13037 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13038 rottlog, GNU Rot[t]log Manual}).
13040 @item @code{rotations} (default: @code{%default-rotations})
13041 A list of @code{log-rotation} objects as defined below.
13044 This is a list of gexps where each gexp corresponds to an mcron job
13045 specification (@pxref{Scheduled Job Execution}).
13049 @deftp {Data Type} log-rotation
13050 Data type representing the rotation of a group of log files.
13052 Taking an example from the Rottlog manual (@pxref{Period Related File
13053 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13059 (files '("/var/log/apache/*"))
13060 (options '("storedir apache-archives"
13066 The list of fields is as follows:
13069 @item @code{frequency} (default: @code{'weekly})
13070 The log rotation frequency, a symbol.
13073 The list of files or file glob patterns to rotate.
13075 @item @code{options} (default: @code{'()})
13076 The list of rottlog options for this rotation (@pxref{Configuration
13077 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13079 @item @code{post-rotate} (default: @code{#f})
13080 Either @code{#f} or a gexp to execute once the rotation has completed.
13084 @defvr {Scheme Variable} %default-rotations
13085 Specifies weekly rotation of @var{%rotated-files} and of
13086 @file{/var/log/guix-daemon.log}.
13089 @defvr {Scheme Variable} %rotated-files
13090 The list of syslog-controlled files to be rotated. By default it is:
13091 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13092 "/var/log/maillog")}.
13095 @node Networking Services
13096 @subsection Networking Services
13098 The @code{(gnu services networking)} module provides services to configure
13099 the network interface.
13101 @cindex DHCP, networking service
13102 @defvr {Scheme Variable} dhcp-client-service-type
13103 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13104 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13105 is the DHCP client package to use, @code{isc-dhcp} by default.
13108 @deffn {Scheme Procedure} dhcpd-service-type
13109 This type defines a service that runs a DHCP daemon. To create a
13110 service of this type, you must supply a @code{<dhcpd-configuration>}.
13114 (service dhcpd-service-type
13115 (dhcpd-configuration
13116 (config-file (local-file "my-dhcpd.conf"))
13117 (interfaces '("enp0s25"))))
13121 @deftp {Data Type} dhcpd-configuration
13123 @item @code{package} (default: @code{isc-dhcp})
13124 The package that provides the DHCP daemon. This package is expected to
13125 provide the daemon at @file{sbin/dhcpd} relative to its output
13126 directory. The default package is the
13127 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13128 @item @code{config-file} (default: @code{#f})
13129 The configuration file to use. This is required. It will be passed to
13130 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13131 object (@pxref{G-Expressions, file-like objects}). See @code{man
13132 dhcpd.conf} for details on the configuration file syntax.
13133 @item @code{version} (default: @code{"4"})
13134 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13135 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13136 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13138 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13139 The run directory to use. At service activation time, this directory
13140 will be created if it does not exist.
13141 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13142 The PID file to use. This corresponds to the @code{-pf} option of
13143 @code{dhcpd}. See @code{man dhcpd} for details.
13144 @item @code{interfaces} (default: @code{'()})
13145 The names of the network interfaces on which dhcpd should listen for
13146 broadcasts. If this list is not empty, then its elements (which must be
13147 strings) will be appended to the @code{dhcpd} invocation when starting
13148 the daemon. It may not be necessary to explicitly specify any
13149 interfaces here; see @code{man dhcpd} for details.
13153 @defvr {Scheme Variable} static-networking-service-type
13154 This is the type for statically-configured network interfaces.
13155 @c TODO Document <static-networking> data structures.
13158 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13159 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13160 [#:requirement @code{'(udev)}]
13161 Return a service that starts @var{interface} with address @var{ip}. If
13162 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13163 it must be a string specifying the default network gateway. @var{requirement}
13164 can be used to declare a dependency on another service before configuring the
13167 This procedure can be called several times, one for each network
13168 interface of interest. Behind the scenes what it does is extend
13169 @code{static-networking-service-type} with additional network interfaces
13175 (static-networking-service "eno1" "192.168.1.82"
13176 #:gateway "192.168.1.2"
13177 #:name-servers '("192.168.1.2"))
13184 @cindex network management
13185 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13186 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13187 management daemon that aims to simplify wired and wireless networking.
13189 This service adds the @var{wicd} package to the global profile, providing
13190 several commands to interact with the daemon and configure networking:
13191 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13192 and @command{wicd-curses} user interfaces.
13195 @cindex ModemManager
13197 @defvr {Scheme Variable} modem-manager-service-type
13198 This is the service type for the
13199 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13200 service. The value for this service type is a
13201 @code{modem-manager-configuration} record.
13203 This service is part of @code{%desktop-services} (@pxref{Desktop
13207 @deftp {Data Type} modem-manager-configuration
13208 Data type representing the configuration of ModemManager.
13211 @item @code{modem-manager} (default: @code{modem-manager})
13212 The ModemManager package to use.
13217 @cindex USB_ModeSwitch
13218 @cindex Modeswitching
13220 @defvr {Scheme Variable} usb-modeswitch-service-type
13221 This is the service type for the
13222 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13223 value for this service type is a @code{usb-modeswitch-configuration} record.
13225 When plugged in, some USB modems (and other USB devices) initially present
13226 themselves as a read-only storage medium and not as a modem. They need to be
13227 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13228 installs udev rules to automatically modeswitch these devices when they are
13231 This service is part of @code{%desktop-services} (@pxref{Desktop
13235 @deftp {Data Type} usb-modeswitch-configuration
13236 Data type representing the configuration of USB_ModeSwitch.
13239 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13240 The USB_ModeSwitch package providing the binaries for modeswitching.
13242 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13243 The package providing the device data and udev rules file used by
13246 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13247 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13248 config file shipped with USB_ModeSwitch is used which disables logging to
13249 @file{/var/log} among other default settings. If set to @code{#f}, no config
13255 @cindex NetworkManager
13257 @defvr {Scheme Variable} network-manager-service-type
13258 This is the service type for the
13259 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13260 service. The value for this service type is a
13261 @code{network-manager-configuration} record.
13263 This service is part of @code{%desktop-services} (@pxref{Desktop
13267 @deftp {Data Type} network-manager-configuration
13268 Data type representing the configuration of NetworkManager.
13271 @item @code{network-manager} (default: @code{network-manager})
13272 The NetworkManager package to use.
13274 @item @code{dns} (default: @code{"default"})
13275 Processing mode for DNS, which affects how NetworkManager uses the
13276 @code{resolv.conf} configuration file.
13280 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13281 provided by currently active connections.
13284 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13285 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13286 then update @code{resolv.conf} to point to the local nameserver.
13288 With this setting, you can share your network connection. For example when
13289 you want to share your network connection to another laptop @i{via} an
13290 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13291 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13292 and reestablish the connection (or reboot).
13294 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13295 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13296 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13297 browser on your host system, or connect to the VM @i{via} SSH
13298 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13299 host-to-guest connection, run this command once:
13302 nmcli connection add type tun \
13303 connection.interface-name tap0 \
13304 tun.mode tap tun.owner $(id -u) \
13305 ipv4.method shared \
13306 ipv4.addresses 172.28.112.1/24
13309 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13310 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13311 @command{qemu-system-...}.
13314 NetworkManager will not modify @code{resolv.conf}.
13317 @item @code{vpn-plugins} (default: @code{'()})
13318 This is the list of available plugins for virtual private networks
13319 (VPNs). An example of this is the @code{network-manager-openvpn}
13320 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13326 @deffn {Scheme Variable} connman-service-type
13327 This is the service type to run @url{https://01.org/connman,Connman},
13328 a network connection manager.
13330 Its value must be an
13331 @code{connman-configuration} record as in this example:
13334 (service connman-service-type
13335 (connman-configuration
13336 (disable-vpn? #t)))
13339 See below for details about @code{connman-configuration}.
13342 @deftp {Data Type} connman-configuration
13343 Data Type representing the configuration of connman.
13346 @item @code{connman} (default: @var{connman})
13347 The connman package to use.
13349 @item @code{disable-vpn?} (default: @code{#f})
13350 When true, disable connman's vpn plugin.
13354 @cindex WPA Supplicant
13355 @defvr {Scheme Variable} wpa-supplicant-service-type
13356 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13357 supplicant}, an authentication daemon required to authenticate against
13358 encrypted WiFi or ethernet networks.
13361 @deftp {Data Type} wpa-supplicant-configuration
13362 Data type representing the configuration of WPA Supplicant.
13364 It takes the following parameters:
13367 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13368 The WPA Supplicant package to use.
13370 @item @code{dbus?} (default: @code{#t})
13371 Whether to listen for requests on D-Bus.
13373 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13374 Where to store the PID file.
13376 @item @code{interface} (default: @code{#f})
13377 If this is set, it must specify the name of a network interface that
13378 WPA supplicant will control.
13380 @item @code{config-file} (default: @code{#f})
13381 Optional configuration file to use.
13383 @item @code{extra-options} (default: @code{'()})
13384 List of additional command-line arguments to pass to the daemon.
13389 @defvr {Scheme Variable} iptables-service-type
13390 This is the service type to set up an iptables configuration. iptables is a
13391 packet filtering framework supported by the Linux kernel. This service
13392 supports configuring iptables for both IPv4 and IPv6. A simple example
13393 configuration rejecting all incoming connections except those to the ssh port
13397 (service iptables-service-type
13398 (iptables-configuration
13399 (ipv4-rules (plain-file "iptables.rules" "*filter
13403 -A INPUT -p tcp --dport 22 -j ACCEPT
13404 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13407 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13411 -A INPUT -p tcp --dport 22 -j ACCEPT
13412 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13418 @deftp {Data Type} iptables-configuration
13419 The data type representing the configuration of iptables.
13422 @item @code{iptables} (default: @code{iptables})
13423 The iptables package that provides @code{iptables-restore} and
13424 @code{ip6tables-restore}.
13425 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13426 The iptables rules to use. It will be passed to @code{iptables-restore}.
13427 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13429 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13430 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13431 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13437 @defvr {Scheme Variable} nftables-service-type
13438 This is the service type to set up a nftables configuration. nftables is a
13439 netfilter project that aims to replace the existing iptables, ip6tables,
13440 arptables and ebtables framework. It provides a new packet filtering
13441 framework, a new user-space utility @command{nft}, and a compatibility layer
13442 for iptables. This service comes with a default ruleset
13443 @code{%default-nftables-ruleset} that rejecting all incomming connections
13444 except those to the ssh port 22. To use it, simply write:
13447 (service nftables-service-type)
13451 @deftp {Data Type} nftables-configuration
13452 The data type representing the configuration of nftables.
13455 @item @code{package} (default: @code{nftables})
13456 The nftables package that provides @command{nft}.
13457 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13458 The nftables ruleset to use. This may be any ``file-like'' object
13459 (@pxref{G-Expressions, file-like objects}).
13463 @cindex NTP (Network Time Protocol), service
13464 @cindex ntpd, service for the Network Time Protocol daemon
13465 @cindex real time clock
13466 @defvr {Scheme Variable} ntp-service-type
13467 This is the type of the service running the @uref{http://www.ntp.org,
13468 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13469 system clock synchronized with that of the specified NTP servers.
13471 The value of this service is an @code{ntpd-configuration} object, as described
13475 @deftp {Data Type} ntp-configuration
13476 This is the data type for the NTP service configuration.
13479 @item @code{servers} (default: @code{%ntp-servers})
13480 This is the list of servers (@code{<ntp-server>} records) with which
13481 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13484 @item @code{allow-large-adjustment?} (default: @code{#t})
13485 This determines whether @command{ntpd} is allowed to make an initial
13486 adjustment of more than 1,000 seconds.
13488 @item @code{ntp} (default: @code{ntp})
13489 The NTP package to use.
13493 @defvr {Scheme Variable} %ntp-servers
13494 List of host names used as the default NTP servers. These are servers of the
13495 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13498 @deftp {Data Type} ntp-server
13499 The data type representing the configuration of a NTP server.
13502 @item @code{type} (default: @code{'server})
13503 The type of the NTP server, given as a symbol. One of @code{'pool},
13504 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13506 @item @code{address}
13507 The address of the server, as a string.
13509 @item @code{options}
13510 NTPD options to use with that specific server, given as a list of option names
13511 and/or of option names and values tuples. The following example define a server
13512 to use with the options @option{iburst} and @option{prefer}, as well as
13513 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13518 (address "some.ntp.server.org")
13519 (options `(iburst (version 3) (maxpoll 16) prefer))))
13525 @deffn {Scheme Procedure} openntpd-service-type
13526 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13527 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13528 clock synchronized with that of the given servers.
13532 openntpd-service-type
13533 (openntpd-configuration
13534 (listen-on '("127.0.0.1" "::1"))
13535 (sensor '("udcf0 correction 70000"))
13536 (constraint-from '("www.gnu.org"))
13537 (constraints-from '("https://www.google.com/"))
13538 (allow-large-adjustment? #t)))
13543 @defvr {Scheme Variable} %openntpd-servers
13544 This variable is a list of the server addresses defined in
13545 @var{%ntp-servers}.
13548 @deftp {Data Type} openntpd-configuration
13550 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13551 The openntpd executable to use.
13552 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13553 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13554 @item @code{query-from} (default: @code{'()})
13555 A list of local IP address the ntpd daemon should use for outgoing queries.
13556 @item @code{sensor} (default: @code{'()})
13557 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13558 will listen to each sensor that actually exists and ignore non-existent ones.
13559 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13561 @item @code{server} (default: @code{'()})
13562 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13563 @item @code{servers} (default: @var{%openntp-servers})
13564 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13565 @item @code{constraint-from} (default: @code{'()})
13566 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13567 This time information is not used for precision but acts as an authenticated
13568 constraint, thereby reducing the impact of unauthenticated NTP
13569 man-in-the-middle attacks.
13570 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13572 @item @code{constraints-from} (default: @code{'()})
13573 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13574 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13575 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13576 @item @code{allow-large-adjustment?} (default: @code{#f})
13577 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13583 @deffn {Scheme variable} inetd-service-type
13584 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13585 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13586 connections on internet sockets, and lazily starts the specified server
13587 program when a connection is made on one of these sockets.
13589 The value of this service is an @code{inetd-configuration} object. The
13590 following example configures the @command{inetd} daemon to provide the
13591 built-in @command{echo} service, as well as an smtp service which
13592 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13593 gateway @code{hostname}:
13598 (inetd-configuration
13602 (socket-type 'stream)
13609 (socket-type 'stream)
13613 (program (file-append openssh "/bin/ssh"))
13615 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13616 "-W" "smtp-server:25" "user@@hostname")))))))
13619 See below for more details about @code{inetd-configuration}.
13622 @deftp {Data Type} inetd-configuration
13623 Data type representing the configuration of @command{inetd}.
13626 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13627 The @command{inetd} executable to use.
13629 @item @code{entries} (default: @code{'()})
13630 A list of @command{inetd} service entries. Each entry should be created
13631 by the @code{inetd-entry} constructor.
13635 @deftp {Data Type} inetd-entry
13636 Data type representing an entry in the @command{inetd} configuration.
13637 Each entry corresponds to a socket where @command{inetd} will listen for
13641 @item @code{node} (default: @code{#f})
13642 Optional string, a comma-separated list of local addresses
13643 @command{inetd} should use when listening for this service.
13644 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13645 description of all options.
13647 A string, the name must correspond to an entry in @code{/etc/services}.
13648 @item @code{socket-type}
13649 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13651 @item @code{protocol}
13652 A string, must correspond to an entry in @code{/etc/protocols}.
13653 @item @code{wait?} (default: @code{#t})
13654 Whether @command{inetd} should wait for the server to exit before
13655 listening to new service requests.
13657 A string containing the user (and, optionally, group) name of the user
13658 as whom the server should run. The group name can be specified in a
13659 suffix, separated by a colon or period, i.e.@: @code{"user"},
13660 @code{"user:group"} or @code{"user.group"}.
13661 @item @code{program} (default: @code{"internal"})
13662 The server program which will serve the requests, or @code{"internal"}
13663 if @command{inetd} should use a built-in service.
13664 @item @code{arguments} (default: @code{'()})
13665 A list strings or file-like objects, which are the server program's
13666 arguments, starting with the zeroth argument, i.e.@: the name of the
13667 program itself. For @command{inetd}'s internal services, this entry
13668 must be @code{'()} or @code{'("internal")}.
13671 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13672 detailed discussion of each configuration field.
13676 @defvr {Scheme Variable} tor-service-type
13677 This is the type for a service that runs the @uref{https://torproject.org,
13678 Tor} anonymous networking daemon. The service is configured using a
13679 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13680 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13684 @deftp {Data Type} tor-configuration
13686 @item @code{tor} (default: @code{tor})
13687 The package that provides the Tor daemon. This package is expected to provide
13688 the daemon at @file{bin/tor} relative to its output directory. The default
13689 package is the @uref{https://www.torproject.org, Tor Project's}
13692 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13693 The configuration file to use. It will be appended to a default configuration
13694 file, and the final configuration file will be passed to @code{tor} via its
13695 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13696 file-like objects}). See @code{man tor} for details on the configuration file
13699 @item @code{hidden-services} (default: @code{'()})
13700 The list of @code{<hidden-service>} records to use. For any hidden service
13701 you include in this list, appropriate configuration to enable the hidden
13702 service will be automatically added to the default configuration file. You
13703 may conveniently create @code{<hidden-service>} records using the
13704 @code{tor-hidden-service} procedure described below.
13706 @item @code{socks-socket-type} (default: @code{'tcp})
13707 The default socket type that Tor should use for its SOCKS socket. This must
13708 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13709 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13710 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13711 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13714 If you want to customize the SOCKS socket in more detail, leave
13715 @code{socks-socket-type} at its default value of @code{'tcp} and use
13716 @code{config-file} to override the default by providing your own
13717 @code{SocksPort} option.
13721 @cindex hidden service
13722 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13723 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13724 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13727 '((22 "127.0.0.1:22")
13728 (80 "127.0.0.1:8080"))
13731 In this example, port 22 of the hidden service is mapped to local port 22, and
13732 port 80 is mapped to local port 8080.
13734 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13735 the @file{hostname} file contains the @code{.onion} host name for the hidden
13738 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13739 project's documentation} for more information.
13742 The @code{(gnu services rsync)} module provides the following services:
13744 You might want an rsync daemon if you have files that you want available
13745 so anyone (or just yourself) can download existing files or upload new
13748 @deffn {Scheme Variable} rsync-service-type
13749 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13750 The value for this service type is a
13751 @command{rsync-configuration} record as in this example:
13754 (service rsync-service-type)
13757 See below for details about @code{rsync-configuration}.
13760 @deftp {Data Type} rsync-configuration
13761 Data type representing the configuration for @code{rsync-service}.
13764 @item @code{package} (default: @var{rsync})
13765 @code{rsync} package to use.
13767 @item @code{port-number} (default: @code{873})
13768 TCP port on which @command{rsync} listens for incoming connections. If port
13769 is less than @code{1024} @command{rsync} needs to be started as the
13770 @code{root} user and group.
13772 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13773 Name of the file where @command{rsync} writes its PID.
13775 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13776 Name of the file where @command{rsync} writes its lock file.
13778 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13779 Name of the file where @command{rsync} writes its log file.
13781 @item @code{use-chroot?} (default: @var{#t})
13782 Whether to use chroot for @command{rsync} shared directory.
13784 @item @code{share-path} (default: @file{/srv/rsync})
13785 Location of the @command{rsync} shared directory.
13787 @item @code{share-comment} (default: @code{"Rsync share"})
13788 Comment of the @command{rsync} shared directory.
13790 @item @code{read-only?} (default: @var{#f})
13791 Read-write permissions to shared directory.
13793 @item @code{timeout} (default: @code{300})
13794 I/O timeout in seconds.
13796 @item @code{user} (default: @var{"root"})
13797 Owner of the @code{rsync} process.
13799 @item @code{group} (default: @var{"root"})
13800 Group of the @code{rsync} process.
13802 @item @code{uid} (default: @var{"rsyncd"})
13803 User name or user ID that file transfers to and from that module should take
13804 place as when the daemon was run as @code{root}.
13806 @item @code{gid} (default: @var{"rsyncd"})
13807 Group name or group ID that will be used when accessing the module.
13812 Furthermore, @code{(gnu services ssh)} provides the following services.
13816 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13817 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13818 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13819 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13820 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13821 [#:public-key-authentication? #t] [#:initialize? #t]
13822 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13823 @var{host-key} must designate a file containing the host key, and readable
13826 When @var{daemonic?} is true, @command{lshd} will detach from the
13827 controlling terminal and log its output to syslogd, unless one sets
13828 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13829 depend on existence of syslogd service. When @var{pid-file?} is true,
13830 @command{lshd} writes its PID to the file called @var{pid-file}.
13832 When @var{initialize?} is true, automatically create the seed and host key
13833 upon service activation if they do not exist yet. This may take long and
13834 require interaction.
13836 When @var{initialize?} is false, it is up to the user to initialize the
13837 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13838 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13839 basics,,, lsh, LSH Manual}).
13841 When @var{interfaces} is empty, lshd listens for connections on all the
13842 network interfaces; otherwise, @var{interfaces} must be a list of host names
13845 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13846 passwords, and @var{root-login?} specifies whether to accept log-ins as
13849 The other options should be self-descriptive.
13854 @deffn {Scheme Variable} openssh-service-type
13855 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13856 shell daemon, @command{sshd}. Its value must be an
13857 @code{openssh-configuration} record as in this example:
13860 (service openssh-service-type
13861 (openssh-configuration
13862 (x11-forwarding? #t)
13863 (permit-root-login 'without-password)
13865 `(("alice" ,(local-file "alice.pub"))
13866 ("bob" ,(local-file "bob.pub"))))))
13869 See below for details about @code{openssh-configuration}.
13871 This service can be extended with extra authorized keys, as in this
13875 (service-extension openssh-service-type
13876 (const `(("charlie"
13877 ,(local-file "charlie.pub")))))
13881 @deftp {Data Type} openssh-configuration
13882 This is the configuration record for OpenSSH's @command{sshd}.
13885 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13886 Name of the file where @command{sshd} writes its PID.
13888 @item @code{port-number} (default: @code{22})
13889 TCP port on which @command{sshd} listens for incoming connections.
13891 @item @code{permit-root-login} (default: @code{#f})
13892 This field determines whether and when to allow logins as root. If
13893 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13894 If it's the symbol @code{'without-password}, then root logins are
13895 permitted but not with password-based authentication.
13897 @item @code{allow-empty-passwords?} (default: @code{#f})
13898 When true, users with empty passwords may log in. When false, they may
13901 @item @code{password-authentication?} (default: @code{#t})
13902 When true, users may log in with their password. When false, they have
13903 other authentication methods.
13905 @item @code{public-key-authentication?} (default: @code{#t})
13906 When true, users may log in using public key authentication. When
13907 false, users have to use other authentication method.
13909 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13910 This is used only by protocol version 2.
13912 @item @code{x11-forwarding?} (default: @code{#f})
13913 When true, forwarding of X11 graphical client connections is
13914 enabled---in other words, @command{ssh} options @option{-X} and
13915 @option{-Y} will work.
13917 @item @code{allow-agent-forwarding?} (default: @code{#t})
13918 Whether to allow agent forwarding.
13920 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13921 Whether to allow TCP forwarding.
13923 @item @code{gateway-ports?} (default: @code{#f})
13924 Whether to allow gateway ports.
13926 @item @code{challenge-response-authentication?} (default: @code{#f})
13927 Specifies whether challenge response authentication is allowed (e.g.@: via
13930 @item @code{use-pam?} (default: @code{#t})
13931 Enables the Pluggable Authentication Module interface. If set to
13932 @code{#t}, this will enable PAM authentication using
13933 @code{challenge-response-authentication?} and
13934 @code{password-authentication?}, in addition to PAM account and session
13935 module processing for all authentication types.
13937 Because PAM challenge response authentication usually serves an
13938 equivalent role to password authentication, you should disable either
13939 @code{challenge-response-authentication?} or
13940 @code{password-authentication?}.
13942 @item @code{print-last-log?} (default: @code{#t})
13943 Specifies whether @command{sshd} should print the date and time of the
13944 last user login when a user logs in interactively.
13946 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13947 Configures external subsystems (e.g.@: file transfer daemon).
13949 This is a list of two-element lists, each of which containing the
13950 subsystem name and a command (with optional arguments) to execute upon
13953 The command @command{internal-sftp} implements an in-process SFTP
13954 server. Alternately, one can specify the @command{sftp-server} command:
13956 (service openssh-service-type
13957 (openssh-configuration
13959 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13962 @item @code{accepted-environment} (default: @code{'()})
13963 List of strings describing which environment variables may be exported.
13965 Each string gets on its own line. See the @code{AcceptEnv} option in
13966 @code{man sshd_config}.
13968 This example allows ssh-clients to export the @code{COLORTERM} variable.
13969 It is set by terminal emulators, which support colors. You can use it in
13970 your shell's ressource file to enable colors for the prompt and commands
13971 if this variable is set.
13974 (service openssh-service-type
13975 (openssh-configuration
13976 (accepted-environment '("COLORTERM"))))
13979 @item @code{authorized-keys} (default: @code{'()})
13980 @cindex authorized keys, SSH
13981 @cindex SSH authorized keys
13982 This is the list of authorized keys. Each element of the list is a user
13983 name followed by one or more file-like objects that represent SSH public
13987 (openssh-configuration
13989 `(("rekado" ,(local-file "rekado.pub"))
13990 ("chris" ,(local-file "chris.pub"))
13991 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13995 registers the specified public keys for user accounts @code{rekado},
13996 @code{chris}, and @code{root}.
13998 Additional authorized keys can be specified @i{via}
13999 @code{service-extension}.
14001 Note that this does @emph{not} interfere with the use of
14002 @file{~/.ssh/authorized_keys}.
14004 @item @code{log-level} (default: @code{'info})
14005 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14006 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14007 page for @file{sshd_config} for the full list of level names.
14009 @item @code{extra-content} (default: @code{""})
14010 This field can be used to append arbitrary text to the configuration file. It
14011 is especially useful for elaborate configurations that cannot be expressed
14012 otherwise. This configuration, for example, would generally disable root
14013 logins, but permit them from one specific IP address:
14016 (openssh-configuration
14018 Match Address 192.168.0.1
14019 PermitRootLogin yes"))
14025 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14026 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14027 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14030 For example, to specify a Dropbear service listening on port 1234, add
14031 this call to the operating system's @code{services} field:
14034 (dropbear-service (dropbear-configuration
14035 (port-number 1234)))
14039 @deftp {Data Type} dropbear-configuration
14040 This data type represents the configuration of a Dropbear SSH daemon.
14043 @item @code{dropbear} (default: @var{dropbear})
14044 The Dropbear package to use.
14046 @item @code{port-number} (default: 22)
14047 The TCP port where the daemon waits for incoming connections.
14049 @item @code{syslog-output?} (default: @code{#t})
14050 Whether to enable syslog output.
14052 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14053 File name of the daemon's PID file.
14055 @item @code{root-login?} (default: @code{#f})
14056 Whether to allow @code{root} logins.
14058 @item @code{allow-empty-passwords?} (default: @code{#f})
14059 Whether to allow empty passwords.
14061 @item @code{password-authentication?} (default: @code{#t})
14062 Whether to enable password-based authentication.
14066 @defvr {Scheme Variable} %facebook-host-aliases
14067 This variable contains a string for use in @file{/etc/hosts}
14068 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14069 line contains a entry that maps a known server name of the Facebook
14070 on-line service---e.g., @code{www.facebook.com}---to the local
14071 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14073 This variable is typically used in the @code{hosts-file} field of an
14074 @code{operating-system} declaration (@pxref{operating-system Reference,
14075 @file{/etc/hosts}}):
14078 (use-modules (gnu) (guix))
14081 (host-name "mymachine")
14084 ;; Create a /etc/hosts file with aliases for "localhost"
14085 ;; and "mymachine", as well as for Facebook servers.
14086 (plain-file "hosts"
14087 (string-append (local-host-aliases host-name)
14088 %facebook-host-aliases))))
14091 This mechanism can prevent programs running locally, such as Web
14092 browsers, from accessing Facebook.
14095 The @code{(gnu services avahi)} provides the following definition.
14097 @defvr {Scheme Variable} avahi-service-type
14098 This is the service that runs @command{avahi-daemon}, a system-wide
14099 mDNS/DNS-SD responder that allows for service discovery and
14100 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14101 Its value must be a @code{zero-configuration} record---see below.
14103 This service extends the name service cache daemon (nscd) so that it can
14104 resolve @code{.local} host names using
14105 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14106 Service Switch}, for information on host name resolution.
14108 Additionally, add the @var{avahi} package to the system profile so that
14109 commands such as @command{avahi-browse} are directly usable.
14112 @deftp {Data Type} avahi-configuration
14113 Data type representation the configuration for Avahi.
14117 @item @code{host-name} (default: @code{#f})
14118 If different from @code{#f}, use that as the host name to
14119 publish for this machine; otherwise, use the machine's actual host name.
14121 @item @code{publish?} (default: @code{#t})
14122 When true, allow host names and services to be published (broadcast) over the
14125 @item @code{publish-workstation?} (default: @code{#t})
14126 When true, @command{avahi-daemon} publishes the machine's host name and IP
14127 address via mDNS on the local network. To view the host names published on
14128 your local network, you can run:
14131 avahi-browse _workstation._tcp
14134 @item @code{wide-area?} (default: @code{#f})
14135 When true, DNS-SD over unicast DNS is enabled.
14137 @item @code{ipv4?} (default: @code{#t})
14138 @itemx @code{ipv6?} (default: @code{#t})
14139 These fields determine whether to use IPv4/IPv6 sockets.
14141 @item @code{domains-to-browse} (default: @code{'()})
14142 This is a list of domains to browse.
14146 @deffn {Scheme Variable} openvswitch-service-type
14147 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14148 service, whose value should be an @code{openvswitch-configuration}
14152 @deftp {Data Type} openvswitch-configuration
14153 Data type representing the configuration of Open vSwitch, a multilayer
14154 virtual switch which is designed to enable massive network automation
14155 through programmatic extension.
14158 @item @code{package} (default: @var{openvswitch})
14159 Package object of the Open vSwitch.
14164 @defvr {Scheme Variable} pagekite-service-type
14165 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14166 a tunneling solution for making localhost servers publicly visible, even from
14167 behind restrictive firewalls or NAT without forwarded ports. The value for
14168 this service type is a @code{pagekite-configuration} record.
14170 Here's an example exposing the local HTTP and SSH daemons:
14173 (service pagekite-service-type
14174 (pagekite-configuration
14175 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14176 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14177 (extra-file "/etc/pagekite.rc")))
14181 @deftp {Data Type} pagekite-configuration
14182 Data type representing the configuration of PageKite.
14185 @item @code{package} (default: @var{pagekite})
14186 Package object of PageKite.
14188 @item @code{kitename} (default: @code{#f})
14189 PageKite name for authenticating to the frontend server.
14191 @item @code{kitesecret} (default: @code{#f})
14192 Shared secret for authenticating to the frontend server. You should probably
14193 put this inside @code{extra-file} instead.
14195 @item @code{frontend} (default: @code{#f})
14196 Connect to the named PageKite frontend server instead of the
14197 @uref{https://pagekite.net,,pagekite.net} service.
14199 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14200 List of service kites to use. Exposes HTTP on port 80 by default. The format
14201 is @code{proto:kitename:host:port:secret}.
14203 @item @code{extra-file} (default: @code{#f})
14204 Extra configuration file to read, which you are expected to create manually.
14205 Use this to add additional options and manage shared secrets out-of-band.
14211 @subsection X Window
14214 @cindex X Window System
14215 @cindex login manager
14216 Support for the X Window graphical display system---specifically
14217 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14218 there is no @code{xorg-service} procedure. Instead, the X server is
14219 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14222 @cindex GNOME, login manager
14223 GDM of course allows users to log in into window managers and desktop
14224 environments other than GNOME; for those using GNOME, GDM is required for
14225 features such as automatic screen locking.
14227 @cindex window manager
14228 To use X11, you must install at least one @dfn{window manager}---for
14229 example the @code{windowmaker} or @code{openbox} packages---preferably
14230 by adding it to the @code{packages} field of your operating system
14231 definition (@pxref{operating-system Reference, system-wide packages}).
14233 @defvr {Scheme Variable} gdm-service-type
14234 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14235 Desktop Manager} (GDM), a program that manages graphical display servers and
14236 handles graphical user logins. Its value must be a @code{gdm-configuration}
14239 @cindex session types (X11)
14240 @cindex X11 session types
14241 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14242 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14243 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14244 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14245 set of packages automatically makes them available at the log-in screen.
14247 In addition, @file{~/.xsession} files are honored. When available,
14248 @file{~/.xsession} must be an executable that starts a window manager
14249 and/or other X clients.
14252 @deftp {Data Type} gdm-configuration
14254 @item @code{auto-login?} (default: @code{#f})
14255 @itemx @code{default-user} (default: @code{#f})
14256 When @code{auto-login?} is false, GDM presents a log-in screen.
14258 When @code{auto-login?} is true, GDM logs in directly as
14259 @code{default-user}.
14261 @item @code{debug?} (default: @code{#f})
14262 When true, GDM writes debug messages to its log.
14264 @item @code{gnome-shell-assets} (default: ...)
14265 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14267 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14268 Configuration of the Xorg graphical server.
14270 @item @code{xsession} (default: @code{(xinitrc)})
14271 Script to run before starting a X session.
14273 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14274 File name of the @code{dbus-daemon} executable.
14276 @item @code{gdm} (default: @code{gdm})
14277 The GDM package to use.
14281 @defvr {Scheme Variable} slim-service-type
14282 This is the type for the SLiM graphical login manager for X11.
14284 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14285 allows users to choose a session from the log-in screen using @kbd{F1}. It
14286 also honors @file{~/.xsession} files.
14288 Unlike GDM, SLiM does not spawn the user session on a different VT after
14289 logging in, which means that you can only start one graphical session. If you
14290 want to be able to run multiple graphical sessions at the same time you have
14291 to add multiple SLiM services to your system services. The following example
14292 shows how to replace the default GDM service with two SLiM services on tty7
14296 (use-modules (gnu services)
14297 (gnu services desktop)
14298 (gnu services xorg)
14299 (srfi srfi-1)) ;for 'remove'
14303 (services (cons* (service slim-service-type (slim-configuration
14306 (service slim-service-type (slim-configuration
14309 (remove (lambda (service)
14310 (eq? (service-kind service) gdm-service-type))
14311 %desktop-services))))
14316 @deftp {Data Type} slim-configuration
14317 Data type representing the configuration of @code{slim-service-type}.
14320 @item @code{allow-empty-passwords?} (default: @code{#t})
14321 Whether to allow logins with empty passwords.
14323 @item @code{auto-login?} (default: @code{#f})
14324 @itemx @code{default-user} (default: @code{""})
14325 When @code{auto-login?} is false, SLiM presents a log-in screen.
14327 When @code{auto-login?} is true, SLiM logs in directly as
14328 @code{default-user}.
14330 @item @code{theme} (default: @code{%default-slim-theme})
14331 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14332 The graphical theme to use and its name.
14334 @item @code{auto-login-session} (default: @code{#f})
14335 If true, this must be the name of the executable to start as the default
14336 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14338 If false, a session described by one of the available @file{.desktop}
14339 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14343 You must install at least one window manager in the system profile or in
14344 your user profile. Failing to do that, if @code{auto-login-session} is
14345 false, you will be unable to log in.
14348 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14349 Configuration of the Xorg graphical server.
14351 @item @code{display} (default @code{":0"})
14352 The display on which to start the Xorg graphical server.
14354 @item @code{vt} (default @code{"vt7"})
14355 The VT on which to start the Xorg graphical server.
14357 @item @code{xauth} (default: @code{xauth})
14358 The XAuth package to use.
14360 @item @code{shepherd} (default: @code{shepherd})
14361 The Shepherd package used when invoking @command{halt} and
14364 @item @code{sessreg} (default: @code{sessreg})
14365 The sessreg package used in order to register the session.
14367 @item @code{slim} (default: @code{slim})
14368 The SLiM package to use.
14372 @defvr {Scheme Variable} %default-theme
14373 @defvrx {Scheme Variable} %default-theme-name
14374 The default SLiM theme and its name.
14378 @deftp {Data Type} sddm-configuration
14379 This is the data type representing the sddm service configuration.
14382 @item @code{display-server} (default: "x11")
14383 Select display server to use for the greeter. Valid values are "x11"
14386 @item @code{numlock} (default: "on")
14387 Valid values are "on", "off" or "none".
14389 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14390 Command to run when halting.
14392 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14393 Command to run when rebooting.
14395 @item @code{theme} (default "maldives")
14396 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
14398 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14399 Directory to look for themes.
14401 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14402 Directory to look for faces.
14404 @item @code{default-path} (default "/run/current-system/profile/bin")
14405 Default PATH to use.
14407 @item @code{minimum-uid} (default: 1000)
14408 Minimum UID displayed in SDDM and allowed for log-in.
14410 @item @code{maximum-uid} (default: 2000)
14411 Maximum UID to display in SDDM.
14413 @item @code{remember-last-user?} (default #t)
14414 Remember last user.
14416 @item @code{remember-last-session?} (default #t)
14417 Remember last session.
14419 @item @code{hide-users} (default "")
14420 Usernames to hide from SDDM greeter.
14422 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14423 Users with shells listed will be hidden from the SDDM greeter.
14425 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14426 Script to run before starting a wayland session.
14428 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14429 Directory to look for desktop files starting wayland sessions.
14431 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14432 Configuration of the Xorg graphical server.
14434 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14437 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14440 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14441 Script to run after starting xorg-server.
14443 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14444 Script to run before stopping xorg-server.
14446 @item @code{xsession-command} (default: @code{xinitrc})
14447 Script to run before starting a X session.
14449 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14450 Directory to look for desktop files starting X sessions.
14452 @item @code{minimum-vt} (default: 7)
14455 @item @code{auto-login-user} (default "")
14456 User to use for auto-login.
14458 @item @code{auto-login-session} (default "")
14459 Desktop file to use for auto-login.
14461 @item @code{relogin?} (default #f)
14462 Relogin after logout.
14467 @cindex login manager
14469 @defvr {Scheme Variable} sddm-service-type
14470 This is the type of the service to run the
14471 @uref{https://github.com/sddm/sddm,SSDM display manager}. Its value
14472 must be a @code{sddm-configuration} record (see below).
14474 Here's an example use:
14477 (service sddm-service-type
14478 (sddm-configuration
14479 (auto-login-user "alice")
14480 (auto-login-session "xfce.desktop")))
14484 @deftp {Data Type} sddm-configuration
14485 This data type represents the configuration of the SDDM login manager.
14486 The available fields are:
14489 @item @code{sddm} (default: @code{sddm})
14490 The SDDM package to use.
14492 @item @code{display-server} (default: @code{"x11"})
14493 This must be either @code{"x11"} or @code{"wayland"}.
14495 @c FIXME: Add more fields.
14497 @item @code{auto-login-user} (default: @code{""})
14498 If non-empty, this is the user account under which to log in
14501 @item @code{auto-login-session} (default: @code{""})
14502 If non-empty, this is the @file{.desktop} file name to use as the
14503 auto-login session.
14507 @cindex Xorg, configuration
14508 @deftp {Data Type} xorg-configuration
14509 This data type represents the configuration of the Xorg graphical display
14510 server. Note that there is not Xorg service; instead, the X server is started
14511 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14512 of these display managers aggregates an @code{xorg-configuration} record.
14515 @item @code{modules} (default: @code{%default-xorg-modules})
14516 This is a list of @dfn{module packages} loaded by the Xorg
14517 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14519 @item @code{fonts} (default: @code{%default-xorg-fonts})
14520 This is a list of font directories to add to the server's @dfn{font path}.
14522 @item @code{drivers} (default: @code{'()})
14523 This must be either the empty list, in which case Xorg chooses a graphics
14524 driver automatically, or a list of driver names that will be tried in this
14525 order---e.g., @code{("modesetting" "vesa")}.
14527 @item @code{resolutions} (default: @code{'()})
14528 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14529 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14532 @cindex keyboard layout, for Xorg
14533 @cindex keymap, for Xorg
14534 @item @code{keyboard-layout} (default: @code{#f})
14535 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14536 English (``qwerty'') for a 105-key PC keyboard.
14538 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14539 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14540 information on how to specify the keyboard layout.
14542 @item @code{extra-config} (default: @code{'()})
14543 This is a list of strings or objects appended to the configuration file. It
14544 is used to pass extra text to be added verbatim to the configuration file.
14546 @item @code{server} (default: @code{xorg-server})
14547 This is the package providing the Xorg server.
14549 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14550 This is the list of command-line arguments to pass to the X server. The
14551 default is @code{-nolisten tcp}.
14555 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14556 [@var{login-manager-service-type}]
14557 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14558 @var{config}, an @code{<xorg-configuration>} record.
14560 Since the Xorg configuration is embedded in the log-in manager's
14561 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14562 shorthand to set the Xorg configuration.
14565 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14566 Return a @code{startx} script in which the modules, fonts, etc. specified
14567 in @var{config}, are available. The result should be used in place of
14570 Usually the X server is started by a login manager.
14574 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14575 Add @var{package}, a package for a screen locker or screen saver whose
14576 command is @var{program}, to the set of setuid programs and add a PAM entry
14577 for it. For example:
14580 (screen-locker-service xlockmore "xlock")
14583 makes the good ol' XlockMore usable.
14587 @node Printing Services
14588 @subsection Printing Services
14590 @cindex printer support with CUPS
14591 The @code{(gnu services cups)} module provides a Guix service definition
14592 for the CUPS printing service. To add printer support to a Guix
14593 system, add a @code{cups-service} to the operating system definition:
14595 @deffn {Scheme Variable} cups-service-type
14596 The service type for the CUPS print server. Its value should be a valid
14597 CUPS configuration (see below). To use the default settings, simply
14600 (service cups-service-type)
14604 The CUPS configuration controls the basic things about your CUPS
14605 installation: what interfaces it listens on, what to do if a print job
14606 fails, how much logging to do, and so on. To actually add a printer,
14607 you have to visit the @url{http://localhost:631} URL, or use a tool such
14608 as GNOME's printer configuration services. By default, configuring a
14609 CUPS service will generate a self-signed certificate if needed, for
14610 secure connections to the print server.
14612 Suppose you want to enable the Web interface of CUPS and also add
14613 support for Epson printers @i{via} the @code{escpr} package and for HP
14614 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14615 like this (you need to use the @code{(gnu packages cups)} module):
14618 (service cups-service-type
14619 (cups-configuration
14620 (web-interface? #t)
14622 (list cups-filters escpr hplip-minimal))))
14625 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14626 package then it is suggested that you install the @code{hplip} package,
14627 either in your OS configuration file or as your user.
14629 The available configuration parameters follow. Each parameter
14630 definition is preceded by its type; for example, @samp{string-list foo}
14631 indicates that the @code{foo} parameter should be specified as a list of
14632 strings. There is also a way to specify the configuration as a string,
14633 if you have an old @code{cupsd.conf} file that you want to port over
14634 from some other system; see the end for more details.
14636 @c The following documentation was initially generated by
14637 @c (generate-documentation) in (gnu services cups). Manually maintained
14638 @c documentation is better, so we shouldn't hesitate to edit below as
14639 @c needed. However if the change you want to make to this documentation
14640 @c can be done in an automated way, it's probably easier to change
14641 @c (generate-documentation) than to make it below and have to deal with
14642 @c the churn as CUPS updates.
14645 Available @code{cups-configuration} fields are:
14647 @deftypevr {@code{cups-configuration} parameter} package cups
14651 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14652 Drivers and other extensions to the CUPS package.
14655 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14656 Configuration of where to write logs, what directories to use for print
14657 spools, and related privileged configuration parameters.
14659 Available @code{files-configuration} fields are:
14661 @deftypevr {@code{files-configuration} parameter} log-location access-log
14662 Defines the access log filename. Specifying a blank filename disables
14663 access log generation. The value @code{stderr} causes log entries to be
14664 sent to the standard error file when the scheduler is running in the
14665 foreground, or to the system log daemon when run in the background. The
14666 value @code{syslog} causes log entries to be sent to the system log
14667 daemon. The server name may be included in filenames using the string
14668 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14670 Defaults to @samp{"/var/log/cups/access_log"}.
14673 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14674 Where CUPS should cache data.
14676 Defaults to @samp{"/var/cache/cups"}.
14679 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14680 Specifies the permissions for all configuration files that the scheduler
14683 Note that the permissions for the printers.conf file are currently
14684 masked to only allow access from the scheduler user (typically root).
14685 This is done because printer device URIs sometimes contain sensitive
14686 authentication information that should not be generally known on the
14687 system. There is no way to disable this security feature.
14689 Defaults to @samp{"0640"}.
14692 @deftypevr {@code{files-configuration} parameter} log-location error-log
14693 Defines the error log filename. Specifying a blank filename disables
14694 error log generation. The value @code{stderr} causes log entries to be
14695 sent to the standard error file when the scheduler is running in the
14696 foreground, or to the system log daemon when run in the background. The
14697 value @code{syslog} causes log entries to be sent to the system log
14698 daemon. The server name may be included in filenames using the string
14699 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14701 Defaults to @samp{"/var/log/cups/error_log"}.
14704 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14705 Specifies which errors are fatal, causing the scheduler to exit. The
14710 No errors are fatal.
14713 All of the errors below are fatal.
14716 Browsing initialization errors are fatal, for example failed connections
14717 to the DNS-SD daemon.
14720 Configuration file syntax errors are fatal.
14723 Listen or Port errors are fatal, except for IPv6 failures on the
14724 loopback or @code{any} addresses.
14727 Log file creation or write errors are fatal.
14730 Bad startup file permissions are fatal, for example shared TLS
14731 certificate and key files with world-read permissions.
14734 Defaults to @samp{"all -browse"}.
14737 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14738 Specifies whether the file pseudo-device can be used for new printer
14739 queues. The URI @uref{file:///dev/null} is always allowed.
14741 Defaults to @samp{#f}.
14744 @deftypevr {@code{files-configuration} parameter} string group
14745 Specifies the group name or ID that will be used when executing external
14748 Defaults to @samp{"lp"}.
14751 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14752 Specifies the permissions for all log files that the scheduler writes.
14754 Defaults to @samp{"0644"}.
14757 @deftypevr {@code{files-configuration} parameter} log-location page-log
14758 Defines the page log filename. Specifying a blank filename disables
14759 page log generation. The value @code{stderr} causes log entries to be
14760 sent to the standard error file when the scheduler is running in the
14761 foreground, or to the system log daemon when run in the background. The
14762 value @code{syslog} causes log entries to be sent to the system log
14763 daemon. The server name may be included in filenames using the string
14764 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14766 Defaults to @samp{"/var/log/cups/page_log"}.
14769 @deftypevr {@code{files-configuration} parameter} string remote-root
14770 Specifies the username that is associated with unauthenticated accesses
14771 by clients claiming to be the root user. The default is @code{remroot}.
14773 Defaults to @samp{"remroot"}.
14776 @deftypevr {@code{files-configuration} parameter} file-name request-root
14777 Specifies the directory that contains print jobs and other HTTP request
14780 Defaults to @samp{"/var/spool/cups"}.
14783 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14784 Specifies the level of security sandboxing that is applied to print
14785 filters, backends, and other child processes of the scheduler; either
14786 @code{relaxed} or @code{strict}. This directive is currently only
14787 used/supported on macOS.
14789 Defaults to @samp{strict}.
14792 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14793 Specifies the location of TLS certificates and private keys. CUPS will
14794 look for public and private keys in this directory: a @code{.crt} files
14795 for PEM-encoded certificates and corresponding @code{.key} files for
14796 PEM-encoded private keys.
14798 Defaults to @samp{"/etc/cups/ssl"}.
14801 @deftypevr {@code{files-configuration} parameter} file-name server-root
14802 Specifies the directory containing the server configuration files.
14804 Defaults to @samp{"/etc/cups"}.
14807 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14808 Specifies whether the scheduler calls fsync(2) after writing
14809 configuration or state files.
14811 Defaults to @samp{#f}.
14814 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14815 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14818 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14819 Specifies the directory where temporary files are stored.
14821 Defaults to @samp{"/var/spool/cups/tmp"}.
14824 @deftypevr {@code{files-configuration} parameter} string user
14825 Specifies the user name or ID that is used when running external
14828 Defaults to @samp{"lp"}.
14831 @deftypevr {@code{files-configuration} parameter} string set-env
14832 Set the specified environment variable to be passed to child processes.
14834 Defaults to @samp{"variable value"}.
14838 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14839 Specifies the logging level for the AccessLog file. The @code{config}
14840 level logs when printers and classes are added, deleted, or modified and
14841 when configuration files are accessed or updated. The @code{actions}
14842 level logs when print jobs are submitted, held, released, modified, or
14843 canceled, and any of the conditions for @code{config}. The @code{all}
14844 level logs all requests.
14846 Defaults to @samp{actions}.
14849 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14850 Specifies whether to purge job history data automatically when it is no
14851 longer required for quotas.
14853 Defaults to @samp{#f}.
14856 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
14857 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
14858 For example, @samp{"_cups" "_print"} will tell network clients that both
14859 CUPS sharing and IPP Everywhere are supported.
14861 Defaults to @samp{"_cups"}.
14864 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14865 Specifies which protocols to use for local printer sharing.
14867 Defaults to @samp{dnssd}.
14870 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14871 Specifies whether the CUPS web interface is advertised.
14873 Defaults to @samp{#f}.
14876 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14877 Specifies whether shared printers are advertised.
14879 Defaults to @samp{#f}.
14882 @deftypevr {@code{cups-configuration} parameter} string classification
14883 Specifies the security classification of the server. Any valid banner
14884 name can be used, including "classified", "confidential", "secret",
14885 "topsecret", and "unclassified", or the banner can be omitted to disable
14886 secure printing functions.
14888 Defaults to @samp{""}.
14891 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14892 Specifies whether users may override the classification (cover page) of
14893 individual print jobs using the @code{job-sheets} option.
14895 Defaults to @samp{#f}.
14898 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14899 Specifies the default type of authentication to use.
14901 Defaults to @samp{Basic}.
14904 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14905 Specifies whether encryption will be used for authenticated requests.
14907 Defaults to @samp{Required}.
14910 @deftypevr {@code{cups-configuration} parameter} string default-language
14911 Specifies the default language to use for text and web content.
14913 Defaults to @samp{"en"}.
14916 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14917 Specifies the default paper size for new print queues. @samp{"Auto"}
14918 uses a locale-specific default, while @samp{"None"} specifies there is
14919 no default paper size. Specific size names are typically
14920 @samp{"Letter"} or @samp{"A4"}.
14922 Defaults to @samp{"Auto"}.
14925 @deftypevr {@code{cups-configuration} parameter} string default-policy
14926 Specifies the default access policy to use.
14928 Defaults to @samp{"default"}.
14931 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14932 Specifies whether local printers are shared by default.
14934 Defaults to @samp{#t}.
14937 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14938 Specifies the delay for updating of configuration and state files, in
14939 seconds. A value of 0 causes the update to happen as soon as possible,
14940 typically within a few milliseconds.
14942 Defaults to @samp{30}.
14945 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14946 Specifies what to do when an error occurs. Possible values are
14947 @code{abort-job}, which will discard the failed print job;
14948 @code{retry-job}, which will retry the job at a later time;
14949 @code{retry-current-job}, which retries the failed job immediately; and
14950 @code{stop-printer}, which stops the printer.
14952 Defaults to @samp{stop-printer}.
14955 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14956 Specifies the maximum cost of filters that are run concurrently, which
14957 can be used to minimize disk, memory, and CPU resource problems. A
14958 limit of 0 disables filter limiting. An average print to a
14959 non-PostScript printer needs a filter limit of about 200. A PostScript
14960 printer needs about half that (100). Setting the limit below these
14961 thresholds will effectively limit the scheduler to printing a single job
14964 Defaults to @samp{0}.
14967 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14968 Specifies the scheduling priority of filters that are run to print a
14969 job. The nice value ranges from 0, the highest priority, to 19, the
14972 Defaults to @samp{0}.
14975 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14976 Specifies whether to do reverse lookups on connecting clients. The
14977 @code{double} setting causes @code{cupsd} to verify that the hostname
14978 resolved from the address matches one of the addresses returned for that
14979 hostname. Double lookups also prevent clients with unregistered
14980 addresses from connecting to your server. Only set this option to
14981 @code{#t} or @code{double} if absolutely required.
14983 Defaults to @samp{#f}.
14986 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14987 Specifies the number of seconds to wait before killing the filters and
14988 backend associated with a canceled or held job.
14990 Defaults to @samp{30}.
14993 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14994 Specifies the interval between retries of jobs in seconds. This is
14995 typically used for fax queues but can also be used with normal print
14996 queues whose error policy is @code{retry-job} or
14997 @code{retry-current-job}.
14999 Defaults to @samp{30}.
15002 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
15003 Specifies the number of retries that are done for jobs. This is
15004 typically used for fax queues but can also be used with normal print
15005 queues whose error policy is @code{retry-job} or
15006 @code{retry-current-job}.
15008 Defaults to @samp{5}.
15011 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15012 Specifies whether to support HTTP keep-alive connections.
15014 Defaults to @samp{#t}.
15017 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15018 Specifies how long an idle client connection remains open, in seconds.
15020 Defaults to @samp{30}.
15023 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15024 Specifies the maximum size of print files, IPP requests, and HTML form
15025 data. A limit of 0 disables the limit check.
15027 Defaults to @samp{0}.
15030 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15031 Listens on the specified interfaces for connections. Valid values are
15032 of the form @var{address}:@var{port}, where @var{address} is either an
15033 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15034 indicate all addresses. Values can also be file names of local UNIX
15035 domain sockets. The Listen directive is similar to the Port directive
15036 but allows you to restrict access to specific interfaces or networks.
15039 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15040 Specifies the number of pending connections that will be allowed. This
15041 normally only affects very busy servers that have reached the MaxClients
15042 limit, but can also be triggered by large numbers of simultaneous
15043 connections. When the limit is reached, the operating system will
15044 refuse additional connections until the scheduler can accept the pending
15047 Defaults to @samp{128}.
15050 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15051 Specifies a set of additional access controls.
15053 Available @code{location-access-controls} fields are:
15055 @deftypevr {@code{location-access-controls} parameter} file-name path
15056 Specifies the URI path to which the access control applies.
15059 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15060 Access controls for all access to this path, in the same format as the
15061 @code{access-controls} of @code{operation-access-control}.
15063 Defaults to @samp{()}.
15066 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15067 Access controls for method-specific access to this path.
15069 Defaults to @samp{()}.
15071 Available @code{method-access-controls} fields are:
15073 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15074 If @code{#t}, apply access controls to all methods except the listed
15075 methods. Otherwise apply to only the listed methods.
15077 Defaults to @samp{#f}.
15080 @deftypevr {@code{method-access-controls} parameter} method-list methods
15081 Methods to which this access control applies.
15083 Defaults to @samp{()}.
15086 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15087 Access control directives, as a list of strings. Each string should be
15088 one directive, such as "Order allow,deny".
15090 Defaults to @samp{()}.
15095 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15096 Specifies the number of debugging messages that are retained for logging
15097 if an error occurs in a print job. Debug messages are logged regardless
15098 of the LogLevel setting.
15100 Defaults to @samp{100}.
15103 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15104 Specifies the level of logging for the ErrorLog file. The value
15105 @code{none} stops all logging while @code{debug2} logs everything.
15107 Defaults to @samp{info}.
15110 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15111 Specifies the format of the date and time in the log files. The value
15112 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15114 Defaults to @samp{standard}.
15117 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15118 Specifies the maximum number of simultaneous clients that are allowed by
15121 Defaults to @samp{100}.
15124 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15125 Specifies the maximum number of simultaneous clients that are allowed
15126 from a single address.
15128 Defaults to @samp{100}.
15131 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15132 Specifies the maximum number of copies that a user can print of each
15135 Defaults to @samp{9999}.
15138 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15139 Specifies the maximum time a job may remain in the @code{indefinite}
15140 hold state before it is canceled. A value of 0 disables cancellation of
15143 Defaults to @samp{0}.
15146 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15147 Specifies the maximum number of simultaneous jobs that are allowed. Set
15148 to 0 to allow an unlimited number of jobs.
15150 Defaults to @samp{500}.
15153 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15154 Specifies the maximum number of simultaneous jobs that are allowed per
15155 printer. A value of 0 allows up to MaxJobs jobs per printer.
15157 Defaults to @samp{0}.
15160 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15161 Specifies the maximum number of simultaneous jobs that are allowed per
15162 user. A value of 0 allows up to MaxJobs jobs per user.
15164 Defaults to @samp{0}.
15167 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15168 Specifies the maximum time a job may take to print before it is
15169 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15171 Defaults to @samp{10800}.
15174 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15175 Specifies the maximum size of the log files before they are rotated, in
15176 bytes. The value 0 disables log rotation.
15178 Defaults to @samp{1048576}.
15181 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15182 Specifies the maximum amount of time to allow between files in a
15183 multiple file print job, in seconds.
15185 Defaults to @samp{300}.
15188 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15189 Specifies the format of PageLog lines. Sequences beginning with percent
15190 (@samp{%}) characters are replaced with the corresponding information,
15191 while all other characters are copied literally. The following percent
15192 sequences are recognized:
15196 insert a single percent character
15199 insert the value of the specified IPP attribute
15202 insert the number of copies for the current page
15205 insert the current page number
15208 insert the current date and time in common log format
15214 insert the printer name
15217 insert the username
15220 A value of the empty string disables page logging. The string @code{%p
15221 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15222 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15225 Defaults to @samp{""}.
15228 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15229 Passes the specified environment variable(s) to child processes; a list
15232 Defaults to @samp{()}.
15235 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15236 Specifies named access control policies.
15238 Available @code{policy-configuration} fields are:
15240 @deftypevr {@code{policy-configuration} parameter} string name
15241 Name of the policy.
15244 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15245 Specifies an access list for a job's private values. @code{@@ACL} maps
15246 to the printer's requesting-user-name-allowed or
15247 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15248 owner. @code{@@SYSTEM} maps to the groups listed for the
15249 @code{system-group} field of the @code{files-config} configuration,
15250 which is reified into the @code{cups-files.conf(5)} file. Other
15251 possible elements of the access list include specific user names, and
15252 @code{@@@var{group}} to indicate members of a specific group. The
15253 access list may also be simply @code{all} or @code{default}.
15255 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15258 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15259 Specifies the list of job values to make private, or @code{all},
15260 @code{default}, or @code{none}.
15262 Defaults to @samp{"job-name job-originating-host-name
15263 job-originating-user-name phone"}.
15266 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15267 Specifies an access list for a subscription's private values.
15268 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15269 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15270 owner. @code{@@SYSTEM} maps to the groups listed for the
15271 @code{system-group} field of the @code{files-config} configuration,
15272 which is reified into the @code{cups-files.conf(5)} file. Other
15273 possible elements of the access list include specific user names, and
15274 @code{@@@var{group}} to indicate members of a specific group. The
15275 access list may also be simply @code{all} or @code{default}.
15277 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15280 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15281 Specifies the list of job values to make private, or @code{all},
15282 @code{default}, or @code{none}.
15284 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15285 notify-subscriber-user-name notify-user-data"}.
15288 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15289 Access control by IPP operation.
15291 Defaults to @samp{()}.
15295 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15296 Specifies whether job files (documents) are preserved after a job is
15297 printed. If a numeric value is specified, job files are preserved for
15298 the indicated number of seconds after printing. Otherwise a boolean
15299 value applies indefinitely.
15301 Defaults to @samp{86400}.
15304 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15305 Specifies whether the job history is preserved after a job is printed.
15306 If a numeric value is specified, the job history is preserved for the
15307 indicated number of seconds after printing. If @code{#t}, the job
15308 history is preserved until the MaxJobs limit is reached.
15310 Defaults to @samp{#t}.
15313 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15314 Specifies the amount of time to wait for job completion before
15315 restarting the scheduler.
15317 Defaults to @samp{30}.
15320 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15321 Specifies the maximum amount of memory to use when converting documents
15322 into bitmaps for a printer.
15324 Defaults to @samp{"128m"}.
15327 @deftypevr {@code{cups-configuration} parameter} string server-admin
15328 Specifies the email address of the server administrator.
15330 Defaults to @samp{"root@@localhost.localdomain"}.
15333 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15334 The ServerAlias directive is used for HTTP Host header validation when
15335 clients connect to the scheduler from external interfaces. Using the
15336 special name @code{*} can expose your system to known browser-based DNS
15337 rebinding attacks, even when accessing sites through a firewall. If the
15338 auto-discovery of alternate names does not work, we recommend listing
15339 each alternate name with a ServerAlias directive instead of using
15342 Defaults to @samp{*}.
15345 @deftypevr {@code{cups-configuration} parameter} string server-name
15346 Specifies the fully-qualified host name of the server.
15348 Defaults to @samp{"localhost"}.
15351 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15352 Specifies what information is included in the Server header of HTTP
15353 responses. @code{None} disables the Server header. @code{ProductOnly}
15354 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15355 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15356 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15357 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15358 2.0.0 (@var{uname}) IPP/2.0}.
15360 Defaults to @samp{Minimal}.
15363 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15364 Listens on the specified interfaces for encrypted connections. Valid
15365 values are of the form @var{address}:@var{port}, where @var{address} is
15366 either an IPv6 address enclosed in brackets, an IPv4 address, or
15367 @code{*} to indicate all addresses.
15369 Defaults to @samp{()}.
15372 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15373 Sets encryption options. By default, CUPS only supports encryption
15374 using TLS v1.0 or higher using known secure cipher suites. Security is
15375 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15376 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15377 suites, which are required for some older clients. The @code{AllowSSL3} option
15378 enables SSL v3.0, which is required for some older clients that do not support
15379 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15380 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15381 protocol version to TLS v1.1.
15383 Defaults to @samp{()}.
15386 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15387 Specifies whether the scheduler requires clients to strictly adhere to
15388 the IPP specifications.
15390 Defaults to @samp{#f}.
15393 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15394 Specifies the HTTP request timeout, in seconds.
15396 Defaults to @samp{300}.
15400 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15401 Specifies whether the web interface is enabled.
15403 Defaults to @samp{#f}.
15406 At this point you're probably thinking ``oh dear, Guix manual, I like
15407 you but you can stop already with the configuration options''. Indeed.
15408 However, one more point: it could be that you have an existing
15409 @code{cupsd.conf} that you want to use. In that case, you can pass an
15410 @code{opaque-cups-configuration} as the configuration of a
15411 @code{cups-service-type}.
15413 Available @code{opaque-cups-configuration} fields are:
15415 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15419 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15420 The contents of the @code{cupsd.conf}, as a string.
15423 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15424 The contents of the @code{cups-files.conf} file, as a string.
15427 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15428 strings of the same name, you could instantiate a CUPS service like
15432 (service cups-service-type
15433 (opaque-cups-configuration
15434 (cupsd.conf cupsd.conf)
15435 (cups-files.conf cups-files.conf)))
15439 @node Desktop Services
15440 @subsection Desktop Services
15442 The @code{(gnu services desktop)} module provides services that are
15443 usually useful in the context of a ``desktop'' setup---that is, on a
15444 machine running a graphical display server, possibly with graphical user
15445 interfaces, etc. It also defines services that provide specific desktop
15446 environments like GNOME, Xfce or MATE.
15448 To simplify things, the module defines a variable containing the set of
15449 services that users typically expect on a machine with a graphical
15450 environment and networking:
15452 @defvr {Scheme Variable} %desktop-services
15453 This is a list of services that builds upon @code{%base-services} and
15454 adds or adjusts services for a typical ``desktop'' setup.
15456 In particular, it adds a graphical login manager (@pxref{X Window,
15457 @code{gdm-service-type}}), screen lockers, a network management tool
15458 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15459 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15460 energy and color management services, the @code{elogind} login and seat
15461 manager, the Polkit privilege service, the GeoClue location service, the
15462 AccountsService daemon that allows authorized users change system passwords,
15463 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15464 name service switch service configured to be able to use @code{nss-mdns}
15465 (@pxref{Name Service Switch, mDNS}).
15468 The @code{%desktop-services} variable can be used as the @code{services}
15469 field of an @code{operating-system} declaration (@pxref{operating-system
15470 Reference, @code{services}}).
15472 Additionally, the @code{gnome-desktop-service-type},
15473 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15474 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15475 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15476 services like the backlight adjustment helpers and the power management
15477 utilities are added to the system, extending @code{polkit} and @code{dbus}
15478 appropriately, allowing GNOME to operate with elevated privileges on a
15479 limited number of special-purpose system interfaces. Additionally,
15480 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15481 metapackage to the system profile. Likewise, adding the Xfce service
15482 not only adds the @code{xfce} metapackage to the system profile, but it
15483 also gives the Thunar file manager the ability to open a ``root-mode''
15484 file management window, if the user authenticates using the
15485 administrator's password via the standard polkit graphical interface.
15486 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15487 appropriately, allowing MATE to operate with elevated privileges on a
15488 limited number of special-purpose system interfaces. Additionally,
15489 adding a service of type @code{mate-desktop-service-type} adds the MATE
15490 metapackage to the system profile. ``Adding Enlightenment'' means that
15491 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15492 are set as setuid, allowing Enlightenment's screen locker and other
15493 functionality to work as expetected.
15495 The desktop environments in Guix use the Xorg display server by
15496 default. If you'd like to use the newer display server protocol
15497 called Wayland, you need to use the @code{sddm-service} instead of
15498 GDM as the graphical login manager. You should then
15499 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15500 also try starting GNOME on Wayland manually from a TTY with the
15501 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15502 gnome-session``. Currently only GNOME has support for Wayland.
15504 @defvr {Scheme Variable} gnome-desktop-service-type
15505 This is the type of the service that adds the @uref{https://www.gnome.org,
15506 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15507 object (see below.)
15509 This service adds the @code{gnome} package to the system profile, and extends
15510 polkit with the actions from @code{gnome-settings-daemon}.
15513 @deftp {Data Type} gnome-desktop-configuration
15514 Configuration record for the GNOME desktop environment.
15517 @item @code{gnome} (default: @code{gnome})
15518 The GNOME package to use.
15522 @defvr {Scheme Variable} xfce-desktop-service-type
15523 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15524 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15527 This service adds the @code{xfce} package to the system profile, and
15528 extends polkit with the ability for @code{thunar} to manipulate the file
15529 system as root from within a user session, after the user has authenticated
15530 with the administrator's password.
15533 @deftp {Data Type} xfce-desktop-configuration
15534 Configuration record for the Xfce desktop environment.
15537 @item @code{xfce} (default: @code{xfce})
15538 The Xfce package to use.
15542 @deffn {Scheme Variable} mate-desktop-service-type
15543 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15544 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15545 object (see below.)
15547 This service adds the @code{mate} package to the system
15548 profile, and extends polkit with the actions from
15549 @code{mate-settings-daemon}.
15552 @deftp {Data Type} mate-desktop-configuration
15553 Configuration record for the MATE desktop environment.
15556 @item @code{mate} (default: @code{mate})
15557 The MATE package to use.
15561 @deffn {Scheme Variable} enlightenment-desktop-service-type
15562 Return a service that adds the @code{enlightenment} package to the system
15563 profile, and extends dbus with actions from @code{efl}.
15566 @deftp {Data Type} enlightenment-desktop-service-configuration
15568 @item @code{enlightenment} (default: @code{enlightenment})
15569 The enlightenment package to use.
15573 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15574 the default @code{%desktop-services} variable doesn't include any of
15575 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15576 @code{%desktop-services} in the @code{services} field of your
15577 @code{operating-system}:
15580 (use-modules (gnu))
15581 (use-service-modules desktop)
15584 ;; cons* adds items to the list given as its last argument.
15585 (services (cons* (service gnome-desktop-service-type)
15586 (service xfce-desktop-service)
15587 %desktop-services))
15591 These desktop environments will then be available as options in the
15592 graphical login window.
15594 The actual service definitions included in @code{%desktop-services} and
15595 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15596 are described below.
15598 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15599 Return a service that runs the ``system bus'', using @var{dbus}, with
15600 support for @var{services}.
15602 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15603 facility. Its system bus is used to allow system services to communicate
15604 and to be notified of system-wide events.
15606 @var{services} must be a list of packages that provide an
15607 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15608 and policy files. For example, to allow avahi-daemon to use the system bus,
15609 @var{services} must be equal to @code{(list avahi)}.
15612 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15613 Return a service that runs the @code{elogind} login and
15614 seat management daemon. @uref{https://github.com/elogind/elogind,
15615 Elogind} exposes a D-Bus interface that can be used to know which users
15616 are logged in, know what kind of sessions they have open, suspend the
15617 system, inhibit system suspend, reboot the system, and other tasks.
15619 Elogind handles most system-level power events for a computer, for
15620 example suspending the system when a lid is closed, or shutting it down
15621 when the power button is pressed.
15623 The @var{config} keyword argument specifies the configuration for
15624 elogind, and should be the result of an @code{(elogind-configuration
15625 (@var{parameter} @var{value})...)} invocation. Available parameters and
15626 their default values are:
15629 @item kill-user-processes?
15631 @item kill-only-users
15633 @item kill-exclude-users
15635 @item inhibit-delay-max-seconds
15637 @item handle-power-key
15639 @item handle-suspend-key
15641 @item handle-hibernate-key
15643 @item handle-lid-switch
15645 @item handle-lid-switch-docked
15647 @item power-key-ignore-inhibited?
15649 @item suspend-key-ignore-inhibited?
15651 @item hibernate-key-ignore-inhibited?
15653 @item lid-switch-ignore-inhibited?
15655 @item holdoff-timeout-seconds
15659 @item idle-action-seconds
15661 @item runtime-directory-size-percent
15663 @item runtime-directory-size
15667 @item suspend-state
15668 @code{("mem" "standby" "freeze")}
15671 @item hibernate-state
15673 @item hibernate-mode
15674 @code{("platform" "shutdown")}
15675 @item hybrid-sleep-state
15677 @item hybrid-sleep-mode
15678 @code{("suspend" "platform" "shutdown")}
15682 @deffn {Scheme Procedure} accountsservice-service @
15683 [#:accountsservice @var{accountsservice}]
15684 Return a service that runs AccountsService, a system service that can
15685 list available accounts, change their passwords, and so on.
15686 AccountsService integrates with PolicyKit to enable unprivileged users
15687 to acquire the capability to modify their system configuration.
15688 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15689 accountsservice web site} for more information.
15691 The @var{accountsservice} keyword argument is the @code{accountsservice}
15692 package to expose as a service.
15695 @deffn {Scheme Procedure} polkit-service @
15696 [#:polkit @var{polkit}]
15697 Return a service that runs the
15698 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15699 management service}, which allows system administrators to grant access to
15700 privileged operations in a structured way. By querying the Polkit service, a
15701 privileged system component can know when it should grant additional
15702 capabilities to ordinary users. For example, an ordinary user can be granted
15703 the capability to suspend the system if the user is logged in locally.
15706 @defvr {Scheme Variable} polkit-wheel-service
15707 Service that adds the @code{wheel} group as admins to the Polkit
15708 service. This makes it so that users in the @code{wheel} group are queried
15709 for their own passwords when performing administrative actions instead of
15710 @code{root}'s, similar to the behaviour used by @code{sudo}.
15713 @defvr {Scheme Variable} upower-service-type
15714 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15715 system-wide monitor for power consumption and battery levels, with the given
15716 configuration settings.
15718 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15719 notably used by GNOME.
15722 @deftp {Data Type} upower-configuration
15723 Data type representation the configuration for UPower.
15727 @item @code{upower} (default: @var{upower})
15728 Package to use for @code{upower}.
15730 @item @code{watts-up-pro?} (default: @code{#f})
15731 Enable the Watts Up Pro device.
15733 @item @code{poll-batteries?} (default: @code{#t})
15734 Enable polling the kernel for battery level changes.
15736 @item @code{ignore-lid?} (default: @code{#f})
15737 Ignore the lid state, this can be useful if it's incorrect on a device.
15739 @item @code{use-percentage-for-policy?} (default: @code{#f})
15740 Whether battery percentage based policy should be used. The default is to use
15741 the time left, change to @code{#t} to use the percentage.
15743 @item @code{percentage-low} (default: @code{10})
15744 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15745 at which the battery is considered low.
15747 @item @code{percentage-critical} (default: @code{3})
15748 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15749 at which the battery is considered critical.
15751 @item @code{percentage-action} (default: @code{2})
15752 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15753 at which action will be taken.
15755 @item @code{time-low} (default: @code{1200})
15756 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15757 seconds at which the battery is considered low.
15759 @item @code{time-critical} (default: @code{300})
15760 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15761 seconds at which the battery is considered critical.
15763 @item @code{time-action} (default: @code{120})
15764 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15765 seconds at which action will be taken.
15767 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15768 The action taken when @code{percentage-action} or @code{time-action} is
15769 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15771 Possible values are:
15781 @code{'hybrid-sleep}.
15787 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15788 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15789 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15790 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15791 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15794 @deffn {Scheme Variable} colord-service-type
15795 This is the type of the service that runs @command{colord}, a system
15796 service with a D-Bus
15797 interface to manage the color profiles of input and output devices such as
15798 screens and scanners. It is notably used by the GNOME Color Manager graphical
15799 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15800 site} for more information.
15803 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15804 Return a configuration allowing an application to access GeoClue
15805 location data. @var{name} is the Desktop ID of the application, without
15806 the @code{.desktop} part. If @var{allowed?} is true, the application
15807 will have access to location information by default. The boolean
15808 @var{system?} value indicates whether an application is a system component
15809 or not. Finally @var{users} is a list of UIDs of all users for which
15810 this application is allowed location info access. An empty users list
15811 means that all users are allowed.
15814 @defvr {Scheme Variable} %standard-geoclue-applications
15815 The standard list of well-known GeoClue application configurations,
15816 granting authority to the GNOME date-and-time utility to ask for the
15817 current location in order to set the time zone, and allowing the
15818 IceCat and Epiphany web browsers to request location information.
15819 IceCat and Epiphany both query the user before allowing a web page to
15820 know the user's location.
15823 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15824 [#:whitelist '()] @
15825 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15826 [#:submit-data? #f]
15827 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15828 [#:submission-nick "geoclue"] @
15829 [#:applications %standard-geoclue-applications]
15830 Return a service that runs the GeoClue location service. This service
15831 provides a D-Bus interface to allow applications to request access to a
15832 user's physical location, and optionally to add information to online
15833 location databases. See
15834 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15835 web site} for more information.
15838 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15839 [@w{#:auto-enable? #f}]
15840 Return a service that runs the @command{bluetoothd} daemon, which
15841 manages all the Bluetooth devices and provides a number of D-Bus
15842 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15843 powered automatically at boot, which can be useful when using a
15844 bluetooth keyboard or mouse.
15846 Users need to be in the @code{lp} group to access the D-Bus service.
15849 @defvr {Scheme Variable} gnome-keyring-service-type
15850 This is the type of the service that adds the
15851 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
15852 value is a @code{gnome-keyring-configuration} object (see below.)
15854 This service adds the @code{gnome-keyring} package to the system profile
15855 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
15856 a user's login keyring when they log in or setting its password with passwd.
15859 @deftp {Data Type} gnome-keyring-configuration
15860 Configuration record for the GNOME Keyring service.
15863 @item @code{keyring} (default: @code{gnome-keyring})
15864 The GNOME keyring package to use.
15866 @item @code{pam-services}
15867 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
15868 services to extend, where @var{service} is the name of an existing
15869 service to extend and @var{kind} is one of @code{login} or
15872 If @code{login} is given, it adds an optional
15873 @code{pam_gnome_keyring.so} to the auth block without arguments and to
15874 the session block with @code{auto_start}. If @code{passwd} is given, it
15875 adds an optional @code{pam_gnome_keyring.so} to the password block
15878 By default, this field contains ``gdm-password'' with the value @code{login}
15879 and ``passwd'' is with the value @code{passwd}.
15884 @node Sound Services
15885 @subsection Sound Services
15887 @cindex sound support
15889 @cindex PulseAudio, sound support
15891 The @code{(gnu services sound)} module provides a service to configure the
15892 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15893 preferred ALSA output driver.
15895 @deffn {Scheme Variable} alsa-service-type
15896 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15897 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15898 configuration file. The value for this type is a @command{alsa-configuration}
15899 record as in this example:
15902 (service alsa-service-type)
15905 See below for details about @code{alsa-configuration}.
15908 @deftp {Data Type} alsa-configuration
15909 Data type representing the configuration for @code{alsa-service}.
15912 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15913 @code{alsa-plugins} package to use.
15915 @item @code{pulseaudio?} (default: @var{#t})
15916 Whether ALSA applications should transparently be made to use the
15917 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15919 Using PulseAudio allows you to run several sound-producing applications
15920 at the same time and to individual control them @i{via}
15921 @command{pavucontrol}, among other things.
15923 @item @code{extra-options} (default: @var{""})
15924 String to append to the @file{/etc/asound.conf} file.
15929 Individual users who want to override the system configuration of ALSA can do
15930 it with the @file{~/.asoundrc} file:
15933 # In guix, we have to specify the absolute path for plugins.
15935 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15938 # Routing ALSA to jack:
15939 # <http://jackaudio.org/faq/routing_alsa.html>.
15943 0 system:playback_1
15944 1 system:playback_2
15961 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15964 @deffn {Scheme Variable} pulseaudio-service-type
15965 This is the type for the @uref{http://www.pulseaudio.org/, PulseAudio}
15966 sound server. It exists to allow system overrides of the default settings
15967 via @code{pulseaudio-configuration}, see below.
15970 This service on its own does not ensure, that the @code{pulseaudio} package
15971 exists on your machine. It merely adds configuration files for it, as
15972 detailed below. In the (admittedly unlikely) case, that you find yourself
15973 without a @code{pulseaudio} package, consider enabling it through the
15974 @code{alsa-service-type} above.
15978 @deftp {Data Type} pulseaudio-configuration
15979 Data type representing the configuration for @code{pulseaudio-service}.
15982 @item @var{client-conf} (default: @code{'()})
15983 List of settings to set in @file{client.conf}.
15984 Accepts a list of strings or a symbol-value pairs. A string will be
15985 inserted as-is with a newline added. A pair will be formatted as
15986 ``key = value'', again with a newline added.
15988 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
15989 List of settings to set in @file{daemon.conf}, formatted just like
15992 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
15993 Script file to use as as @file{default.pa}.
15995 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
15996 Script file to use as as @file{system.pa}.
16000 @deffn {Scheme Variable} ladspa-service-type
16001 This service sets the @var{LADSPA_PATH} variable, so that programs, which
16002 respect it, e.g. PulseAudio, can load LADSPA plugins.
16004 The following example will setup the service to enable modules from the
16005 @code{swh-plugins} package:
16008 (service ladspa-service-type
16009 (ladspa-configuration (plugins (list swh-plugins))))
16012 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16017 @node Database Services
16018 @subsection Database Services
16022 The @code{(gnu services databases)} module provides the following services.
16024 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16025 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16026 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16027 Return a service that runs @var{postgresql}, the PostgreSQL database
16030 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16031 creates a database cluster with @var{locale} as the default
16032 locale, stored in @var{data-directory}. It then listens on @var{port}.
16034 @cindex postgresql extension-packages
16035 Additional extensions are loaded from packages listed in
16036 @var{extension-packages}. Extensions are available at runtime. For instance,
16037 to create a geographic database using the @code{postgis} extension, a user can
16038 configure the postgresql-service as in this example:
16042 (use-package-modules databases geo)
16046 ;; postgresql is required to run `psql' but postgis is not required for
16047 ;; proper operation.
16048 (packages (cons* postgresql %base-packages))
16051 (postgresql-service #:extension-packages (list postgis))
16055 Then the extension becomes visible and you can initialise an empty geographic
16056 database in this way:
16060 > create database postgistest;
16061 > \connect postgistest;
16062 > create extension postgis;
16063 > create extension postgis_topology;
16066 There is no need to add this field for contrib extensions such as hstore or
16067 dblink as they are already loadable by postgresql. This field is only
16068 required to add extensions provided by other packages.
16071 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16072 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16075 The optional @var{config} argument specifies the configuration for
16076 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16079 @deftp {Data Type} mysql-configuration
16080 Data type representing the configuration of @var{mysql-service}.
16083 @item @code{mysql} (default: @var{mariadb})
16084 Package object of the MySQL database server, can be either @var{mariadb}
16087 For MySQL, a temporary root password will be displayed at activation time.
16088 For MariaDB, the root password is empty.
16090 @item @code{port} (default: @code{3306})
16091 TCP port on which the database server listens for incoming connections.
16095 @defvr {Scheme Variable} memcached-service-type
16096 This is the service type for the @uref{https://memcached.org/,
16097 Memcached} service, which provides a distributed in memory cache. The
16098 value for the service type is a @code{memcached-configuration} object.
16102 (service memcached-service-type)
16105 @deftp {Data Type} memcached-configuration
16106 Data type representing the configuration of memcached.
16109 @item @code{memcached} (default: @code{memcached})
16110 The Memcached package to use.
16112 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16113 Network interfaces on which to listen.
16115 @item @code{tcp-port} (default: @code{11211})
16116 Port on which to accept connections on,
16118 @item @code{udp-port} (default: @code{11211})
16119 Port on which to accept UDP connections on, a value of 0 will disable
16120 listening on a UDP socket.
16122 @item @code{additional-options} (default: @code{'()})
16123 Additional command line options to pass to @code{memcached}.
16127 @defvr {Scheme Variable} mongodb-service-type
16128 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16129 The value for the service type is a @code{mongodb-configuration} object.
16133 (service mongodb-service-type)
16136 @deftp {Data Type} mongodb-configuration
16137 Data type representing the configuration of mongodb.
16140 @item @code{mongodb} (default: @code{mongodb})
16141 The MongoDB package to use.
16143 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16144 The configuration file for MongoDB.
16146 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16147 This value is used to create the directory, so that it exists and is
16148 owned by the mongodb user. It should match the data-directory which
16149 MongoDB is configured to use through the configuration file.
16153 @defvr {Scheme Variable} redis-service-type
16154 This is the service type for the @uref{https://redis.io/, Redis}
16155 key/value store, whose value is a @code{redis-configuration} object.
16158 @deftp {Data Type} redis-configuration
16159 Data type representing the configuration of redis.
16162 @item @code{redis} (default: @code{redis})
16163 The Redis package to use.
16165 @item @code{bind} (default: @code{"127.0.0.1"})
16166 Network interface on which to listen.
16168 @item @code{port} (default: @code{6379})
16169 Port on which to accept connections on, a value of 0 will disable
16170 listening on a TCP socket.
16172 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16173 Directory in which to store the database and related files.
16177 @node Mail Services
16178 @subsection Mail Services
16182 The @code{(gnu services mail)} module provides Guix service definitions
16183 for email services: IMAP, POP3, and LMTP servers, as well as mail
16184 transport agents (MTAs). Lots of acronyms! These services are detailed
16185 in the subsections below.
16187 @subsubheading Dovecot Service
16189 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16190 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16193 By default, Dovecot does not need much configuration; the default
16194 configuration object created by @code{(dovecot-configuration)} will
16195 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16196 certificate will be generated for TLS-protected connections, though
16197 Dovecot will also listen on cleartext ports by default. There are a
16198 number of options, though, which mail administrators might need to change,
16199 and as is the case with other services, Guix allows the system
16200 administrator to specify these parameters via a uniform Scheme interface.
16202 For example, to specify that mail is located at @code{maildir~/.mail},
16203 one would instantiate the Dovecot service like this:
16206 (dovecot-service #:config
16207 (dovecot-configuration
16208 (mail-location "maildir:~/.mail")))
16211 The available configuration parameters follow. Each parameter
16212 definition is preceded by its type; for example, @samp{string-list foo}
16213 indicates that the @code{foo} parameter should be specified as a list of
16214 strings. There is also a way to specify the configuration as a string,
16215 if you have an old @code{dovecot.conf} file that you want to port over
16216 from some other system; see the end for more details.
16218 @c The following documentation was initially generated by
16219 @c (generate-documentation) in (gnu services mail). Manually maintained
16220 @c documentation is better, so we shouldn't hesitate to edit below as
16221 @c needed. However if the change you want to make to this documentation
16222 @c can be done in an automated way, it's probably easier to change
16223 @c (generate-documentation) than to make it below and have to deal with
16224 @c the churn as dovecot updates.
16226 Available @code{dovecot-configuration} fields are:
16228 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16229 The dovecot package.
16232 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16233 A list of IPs or hosts where to listen for connections. @samp{*}
16234 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16235 interfaces. If you want to specify non-default ports or anything more
16236 complex, customize the address and port fields of the
16237 @samp{inet-listener} of the specific services you are interested in.
16240 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16241 List of protocols we want to serve. Available protocols include
16242 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16244 Available @code{protocol-configuration} fields are:
16246 @deftypevr {@code{protocol-configuration} parameter} string name
16247 The name of the protocol.
16250 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16251 UNIX socket path to the master authentication server to find users.
16252 This is used by imap (for shared users) and lda.
16253 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16256 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16257 Space separated list of plugins to load.
16260 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16261 Maximum number of IMAP connections allowed for a user from each IP
16262 address. NOTE: The username is compared case-sensitively.
16263 Defaults to @samp{10}.
16268 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16269 List of services to enable. Available services include @samp{imap},
16270 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16273 Available @code{service-configuration} fields are:
16275 @deftypevr {@code{service-configuration} parameter} string kind
16276 The service kind. Valid values include @code{director},
16277 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16278 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16279 @code{tcpwrap}, @code{quota-warning}, or anything else.
16282 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16283 Listeners for the service. A listener is either a
16284 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16285 an @code{inet-listener-configuration}.
16286 Defaults to @samp{()}.
16288 Available @code{unix-listener-configuration} fields are:
16290 @deftypevr {@code{unix-listener-configuration} parameter} string path
16291 Path to the file, relative to @code{base-dir} field. This is also used as
16295 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16296 The access mode for the socket.
16297 Defaults to @samp{"0600"}.
16300 @deftypevr {@code{unix-listener-configuration} parameter} string user
16301 The user to own the socket.
16302 Defaults to @samp{""}.
16305 @deftypevr {@code{unix-listener-configuration} parameter} string group
16306 The group to own the socket.
16307 Defaults to @samp{""}.
16311 Available @code{fifo-listener-configuration} fields are:
16313 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16314 Path to the file, relative to @code{base-dir} field. This is also used as
16318 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16319 The access mode for the socket.
16320 Defaults to @samp{"0600"}.
16323 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16324 The user to own the socket.
16325 Defaults to @samp{""}.
16328 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16329 The group to own the socket.
16330 Defaults to @samp{""}.
16334 Available @code{inet-listener-configuration} fields are:
16336 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16337 The protocol to listen for.
16340 @deftypevr {@code{inet-listener-configuration} parameter} string address
16341 The address on which to listen, or empty for all addresses.
16342 Defaults to @samp{""}.
16345 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16346 The port on which to listen.
16349 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16350 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16352 Defaults to @samp{#t}.
16357 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16358 Maximum number of simultaneous client connections per process. Once
16359 this number of connections is received, the next incoming connection
16360 will prompt Dovecot to spawn another process. If set to 0,
16361 @code{default-client-limit} is used instead.
16363 Defaults to @samp{0}.
16367 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16368 Number of connections to handle before starting a new process.
16369 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16370 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16371 Defaults to @samp{1}.
16375 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16376 Maximum number of processes that can exist for this service. If set to
16377 0, @code{default-process-limit} is used instead.
16379 Defaults to @samp{0}.
16383 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16384 Number of processes to always keep waiting for more connections.
16385 Defaults to @samp{0}.
16388 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16389 If you set @samp{service-count 0}, you probably need to grow
16391 Defaults to @samp{256000000}.
16396 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16397 Dict configuration, as created by the @code{dict-configuration}
16400 Available @code{dict-configuration} fields are:
16402 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16403 A list of key-value pairs that this dict should hold.
16404 Defaults to @samp{()}.
16409 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16410 A list of passdb configurations, each one created by the
16411 @code{passdb-configuration} constructor.
16413 Available @code{passdb-configuration} fields are:
16415 @deftypevr {@code{passdb-configuration} parameter} string driver
16416 The driver that the passdb should use. Valid values include
16417 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16419 Defaults to @samp{"pam"}.
16422 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16423 Space separated list of arguments to the passdb driver.
16424 Defaults to @samp{""}.
16429 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16430 List of userdb configurations, each one created by the
16431 @code{userdb-configuration} constructor.
16433 Available @code{userdb-configuration} fields are:
16435 @deftypevr {@code{userdb-configuration} parameter} string driver
16436 The driver that the userdb should use. Valid values include
16437 @samp{passwd} and @samp{static}.
16438 Defaults to @samp{"passwd"}.
16441 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16442 Space separated list of arguments to the userdb driver.
16443 Defaults to @samp{""}.
16446 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16447 Override fields from passwd.
16448 Defaults to @samp{()}.
16453 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16454 Plug-in configuration, created by the @code{plugin-configuration}
16458 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16459 List of namespaces. Each item in the list is created by the
16460 @code{namespace-configuration} constructor.
16462 Available @code{namespace-configuration} fields are:
16464 @deftypevr {@code{namespace-configuration} parameter} string name
16465 Name for this namespace.
16468 @deftypevr {@code{namespace-configuration} parameter} string type
16469 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16470 Defaults to @samp{"private"}.
16473 @deftypevr {@code{namespace-configuration} parameter} string separator
16474 Hierarchy separator to use. You should use the same separator for
16475 all namespaces or some clients get confused. @samp{/} is usually a good
16476 one. The default however depends on the underlying mail storage
16478 Defaults to @samp{""}.
16481 @deftypevr {@code{namespace-configuration} parameter} string prefix
16482 Prefix required to access this namespace. This needs to be
16483 different for all namespaces. For example @samp{Public/}.
16484 Defaults to @samp{""}.
16487 @deftypevr {@code{namespace-configuration} parameter} string location
16488 Physical location of the mailbox. This is in the same format as
16489 mail_location, which is also the default for it.
16490 Defaults to @samp{""}.
16493 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16494 There can be only one INBOX, and this setting defines which
16496 Defaults to @samp{#f}.
16499 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16500 If namespace is hidden, it's not advertised to clients via NAMESPACE
16501 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16502 useful when converting from another server with different namespaces
16503 which you want to deprecate but still keep working. For example you can
16504 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16506 Defaults to @samp{#f}.
16509 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16510 Show the mailboxes under this namespace with the LIST command. This
16511 makes the namespace visible for clients that do not support the NAMESPACE
16512 extension. The special @code{children} value lists child mailboxes, but
16513 hides the namespace prefix.
16514 Defaults to @samp{#t}.
16517 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16518 Namespace handles its own subscriptions. If set to @code{#f}, the
16519 parent namespace handles them. The empty prefix should always have this
16521 Defaults to @samp{#t}.
16524 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16525 List of predefined mailboxes in this namespace.
16526 Defaults to @samp{()}.
16528 Available @code{mailbox-configuration} fields are:
16530 @deftypevr {@code{mailbox-configuration} parameter} string name
16531 Name for this mailbox.
16534 @deftypevr {@code{mailbox-configuration} parameter} string auto
16535 @samp{create} will automatically create this mailbox.
16536 @samp{subscribe} will both create and subscribe to the mailbox.
16537 Defaults to @samp{"no"}.
16540 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16541 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16542 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16543 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16544 Defaults to @samp{()}.
16551 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16552 Base directory where to store runtime data.
16553 Defaults to @samp{"/var/run/dovecot/"}.
16556 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16557 Greeting message for clients.
16558 Defaults to @samp{"Dovecot ready."}.
16561 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16562 List of trusted network ranges. Connections from these IPs are
16563 allowed to override their IP addresses and ports (for logging and for
16564 authentication checks). @samp{disable-plaintext-auth} is also ignored
16565 for these networks. Typically you would specify your IMAP proxy servers
16567 Defaults to @samp{()}.
16570 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16571 List of login access check sockets (e.g.@: tcpwrap).
16572 Defaults to @samp{()}.
16575 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16576 Show more verbose process titles (in ps). Currently shows user name
16577 and IP address. Useful for seeing who is actually using the IMAP
16578 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16580 Defaults to @samp{#f}.
16583 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16584 Should all processes be killed when Dovecot master process shuts down.
16585 Setting this to @code{#f} means that Dovecot can be upgraded without
16586 forcing existing client connections to close (although that could also
16587 be a problem if the upgrade is e.g.@: due to a security fix).
16588 Defaults to @samp{#t}.
16591 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16592 If non-zero, run mail commands via this many connections to doveadm
16593 server, instead of running them directly in the same process.
16594 Defaults to @samp{0}.
16597 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16598 UNIX socket or host:port used for connecting to doveadm server.
16599 Defaults to @samp{"doveadm-server"}.
16602 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16603 List of environment variables that are preserved on Dovecot startup
16604 and passed down to all of its child processes. You can also give
16605 key=value pairs to always set specific settings.
16608 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16609 Disable LOGIN command and all other plaintext authentications unless
16610 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16611 matches the local IP (i.e.@: you're connecting from the same computer),
16612 the connection is considered secure and plaintext authentication is
16613 allowed. See also ssl=required setting.
16614 Defaults to @samp{#t}.
16617 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16618 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16619 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16620 for caching to be used.
16621 Defaults to @samp{0}.
16624 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16625 Time to live for cached data. After TTL expires the cached record
16626 is no longer used, *except* if the main database lookup returns internal
16627 failure. We also try to handle password changes automatically: If
16628 user's previous authentication was successful, but this one wasn't, the
16629 cache isn't used. For now this works only with plaintext
16631 Defaults to @samp{"1 hour"}.
16634 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16635 TTL for negative hits (user not found, password mismatch).
16636 0 disables caching them completely.
16637 Defaults to @samp{"1 hour"}.
16640 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16641 List of realms for SASL authentication mechanisms that need them.
16642 You can leave it empty if you don't want to support multiple realms.
16643 Many clients simply use the first one listed here, so keep the default
16645 Defaults to @samp{()}.
16648 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16649 Default realm/domain to use if none was specified. This is used for
16650 both SASL realms and appending @@domain to username in plaintext
16652 Defaults to @samp{""}.
16655 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16656 List of allowed characters in username. If the user-given username
16657 contains a character not listed in here, the login automatically fails.
16658 This is just an extra check to make sure user can't exploit any
16659 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16660 you want to allow all characters, set this value to empty.
16661 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16664 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16665 Username character translations before it's looked up from
16666 databases. The value contains series of from -> to characters. For
16667 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16668 translated to @samp{@@}.
16669 Defaults to @samp{""}.
16672 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16673 Username formatting before it's looked up from databases. You can
16674 use the standard variables here, e.g.@: %Lu would lowercase the username,
16675 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16676 change the @samp{@@} into @samp{-AT-}. This translation is done after
16677 @samp{auth-username-translation} changes.
16678 Defaults to @samp{"%Lu"}.
16681 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16682 If you want to allow master users to log in by specifying the master
16683 username within the normal username string (i.e.@: not using SASL
16684 mechanism's support for it), you can specify the separator character
16685 here. The format is then <username><separator><master username>.
16686 UW-IMAP uses @samp{*} as the separator, so that could be a good
16688 Defaults to @samp{""}.
16691 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16692 Username to use for users logging in with ANONYMOUS SASL
16694 Defaults to @samp{"anonymous"}.
16697 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16698 Maximum number of dovecot-auth worker processes. They're used to
16699 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16700 They're automatically created and destroyed as needed.
16701 Defaults to @samp{30}.
16704 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16705 Host name to use in GSSAPI principal names. The default is to use
16706 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16707 allow all keytab entries.
16708 Defaults to @samp{""}.
16711 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16712 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16713 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16714 need to change the auth service to run as root to be able to read this
16716 Defaults to @samp{""}.
16719 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16720 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16721 and @samp{ntlm-auth} helper.
16722 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16723 Defaults to @samp{#f}.
16726 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16727 Path for Samba's @samp{ntlm-auth} helper binary.
16728 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16731 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16732 Time to delay before replying to failed authentications.
16733 Defaults to @samp{"2 secs"}.
16736 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16737 Require a valid SSL client certificate or the authentication
16739 Defaults to @samp{#f}.
16742 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16743 Take the username from client's SSL certificate, using
16744 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16746 Defaults to @samp{#f}.
16749 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16750 List of wanted authentication mechanisms. Supported mechanisms are:
16751 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16752 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16753 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16754 @samp{disable-plaintext-auth} setting.
16757 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16758 List of IPs or hostnames to all director servers, including ourself.
16759 Ports can be specified as ip:port. The default port is the same as what
16760 director service's @samp{inet-listener} is using.
16761 Defaults to @samp{()}.
16764 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16765 List of IPs or hostnames to all backend mail servers. Ranges are
16766 allowed too, like 10.0.0.10-10.0.0.30.
16767 Defaults to @samp{()}.
16770 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16771 How long to redirect users to a specific server after it no longer
16772 has any connections.
16773 Defaults to @samp{"15 min"}.
16776 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16777 How the username is translated before being hashed. Useful values
16778 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16779 are shared within domain.
16780 Defaults to @samp{"%Lu"}.
16783 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16784 Log file to use for error messages. @samp{syslog} logs to syslog,
16785 @samp{/dev/stderr} logs to stderr.
16786 Defaults to @samp{"syslog"}.
16789 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16790 Log file to use for informational messages. Defaults to
16792 Defaults to @samp{""}.
16795 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16796 Log file to use for debug messages. Defaults to
16797 @samp{info-log-path}.
16798 Defaults to @samp{""}.
16801 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16802 Syslog facility to use if you're logging to syslog. Usually if you
16803 don't want to use @samp{mail}, you'll use local0..local7. Also other
16804 standard facilities are supported.
16805 Defaults to @samp{"mail"}.
16808 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16809 Log unsuccessful authentication attempts and the reasons why they
16811 Defaults to @samp{#f}.
16814 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16815 In case of password mismatches, log the attempted password. Valid
16816 values are no, plain and sha1. sha1 can be useful for detecting brute
16817 force password attempts vs. user simply trying the same password over
16818 and over again. You can also truncate the value to n chars by appending
16819 ":n" (e.g.@: sha1:6).
16820 Defaults to @samp{"no"}.
16823 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16824 Even more verbose logging for debugging purposes. Shows for example
16826 Defaults to @samp{#f}.
16829 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16830 In case of password mismatches, log the passwords and used scheme so
16831 the problem can be debugged. Enabling this also enables
16833 Defaults to @samp{#f}.
16836 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16837 Enable mail process debugging. This can help you figure out why
16838 Dovecot isn't finding your mails.
16839 Defaults to @samp{#f}.
16842 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16843 Show protocol level SSL errors.
16844 Defaults to @samp{#f}.
16847 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16848 Prefix for each line written to log file. % codes are in
16849 strftime(3) format.
16850 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16853 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16854 List of elements we want to log. The elements which have a
16855 non-empty variable value are joined together to form a comma-separated
16859 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16860 Login log format. %s contains @samp{login-log-format-elements}
16861 string, %$ contains the data we want to log.
16862 Defaults to @samp{"%$: %s"}.
16865 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16866 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16867 of possible variables you can use.
16868 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16871 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16872 Format to use for logging mail deliveries. You can use variables:
16875 Delivery status message (e.g.@: @samp{saved to INBOX})
16887 Defaults to @samp{"msgid=%m: %$"}.
16890 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16891 Location for users' mailboxes. The default is empty, which means
16892 that Dovecot tries to find the mailboxes automatically. This won't work
16893 if the user doesn't yet have any mail, so you should explicitly tell
16894 Dovecot the full location.
16896 If you're using mbox, giving a path to the INBOX
16897 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16898 where the other mailboxes are kept. This is called the "root mail
16899 directory", and it must be the first path given in the
16900 @samp{mail-location} setting.
16902 There are a few special variables you can use, eg.:
16908 user part in user@@domain, same as %u if there's no domain
16910 domain part in user@@domain, empty if there's no domain
16915 See doc/wiki/Variables.txt for full list. Some examples:
16917 @item maildir:~/Maildir
16918 @item mbox:~/mail:INBOX=/var/mail/%u
16919 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16921 Defaults to @samp{""}.
16924 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16925 System user and group used to access mails. If you use multiple,
16926 userdb can override these by returning uid or gid fields. You can use
16927 either numbers or names. <doc/wiki/UserIds.txt>.
16928 Defaults to @samp{""}.
16931 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16933 Defaults to @samp{""}.
16936 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16937 Group to enable temporarily for privileged operations. Currently
16938 this is used only with INBOX when either its initial creation or
16939 dotlocking fails. Typically this is set to "mail" to give access to
16941 Defaults to @samp{""}.
16944 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16945 Grant access to these supplementary groups for mail processes.
16946 Typically these are used to set up access to shared mailboxes. Note
16947 that it may be dangerous to set these if users can create
16948 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16949 could allow a user to delete others' mailboxes, or ln -s
16950 /secret/shared/box ~/mail/mybox would allow reading it).
16951 Defaults to @samp{""}.
16954 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16955 Allow full file system access to clients. There's no access checks
16956 other than what the operating system does for the active UID/GID. It
16957 works with both maildir and mboxes, allowing you to prefix mailboxes
16958 names with e.g.@: /path/ or ~user/.
16959 Defaults to @samp{#f}.
16962 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16963 Don't use mmap() at all. This is required if you store indexes to
16964 shared file systems (NFS or clustered file system).
16965 Defaults to @samp{#f}.
16968 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16969 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16970 supports @samp{O_EXCL} since version 3, so this should be safe to use
16971 nowadays by default.
16972 Defaults to @samp{#t}.
16975 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16976 When to use fsync() or fdatasync() calls:
16979 Whenever necessary to avoid losing important data
16981 Useful with e.g.@: NFS when write()s are delayed
16983 Never use it (best performance, but crashes can lose data).
16985 Defaults to @samp{"optimized"}.
16988 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16989 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16990 NFS caches whenever needed. If you're using only a single mail server
16992 Defaults to @samp{#f}.
16995 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16996 Mail index files also exist in NFS. Setting this to yes requires
16997 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16998 Defaults to @samp{#f}.
17001 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
17002 Locking method for index files. Alternatives are fcntl, flock and
17003 dotlock. Dotlocking uses some tricks which may create more disk I/O
17004 than other locking methods. NFS users: flock doesn't work, remember to
17005 change @samp{mmap-disable}.
17006 Defaults to @samp{"fcntl"}.
17009 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17010 Directory in which LDA/LMTP temporarily stores incoming mails >128
17012 Defaults to @samp{"/tmp"}.
17015 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17016 Valid UID range for users. This is mostly to make sure that users can't
17017 log in as daemons or other system users. Note that denying root logins is
17018 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17020 Defaults to @samp{500}.
17023 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17025 Defaults to @samp{0}.
17028 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17029 Valid GID range for users. Users having non-valid GID as primary group ID
17030 aren't allowed to log in. If user belongs to supplementary groups with
17031 non-valid GIDs, those groups are not set.
17032 Defaults to @samp{1}.
17035 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17037 Defaults to @samp{0}.
17040 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17041 Maximum allowed length for mail keyword name. It's only forced when
17042 trying to create new keywords.
17043 Defaults to @samp{50}.
17046 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17047 List of directories under which chrooting is allowed for mail
17048 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
17049 too). This setting doesn't affect @samp{login-chroot}
17050 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17051 "/./" in home dirs are ignored. WARNING: Never add directories here
17052 which local users can modify, that may lead to root exploit. Usually
17053 this should be done only if you don't allow shell access for users.
17054 <doc/wiki/Chrooting.txt>.
17055 Defaults to @samp{()}.
17058 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17059 Default chroot directory for mail processes. This can be overridden
17060 for specific users in user database by giving /./ in user's home
17061 directory (e.g.@: /home/./user chroots into /home). Note that usually
17062 there is no real need to do chrooting, Dovecot doesn't allow users to
17063 access files outside their mail directory anyway. If your home
17064 directories are prefixed with the chroot directory, append "/."@: to
17065 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17066 Defaults to @samp{""}.
17069 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17070 UNIX socket path to master authentication server to find users.
17071 This is used by imap (for shared users) and lda.
17072 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17075 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17076 Directory where to look up mail plugins.
17077 Defaults to @samp{"/usr/lib/dovecot"}.
17080 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17081 List of plugins to load for all services. Plugins specific to IMAP,
17082 LDA, etc.@: are added to this list in their own .conf files.
17083 Defaults to @samp{()}.
17086 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17087 The minimum number of mails in a mailbox before updates are done to
17088 cache file. This allows optimizing Dovecot's behavior to do less disk
17089 writes at the cost of more disk reads.
17090 Defaults to @samp{0}.
17093 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17094 When IDLE command is running, mailbox is checked once in a while to
17095 see if there are any new mails or other changes. This setting defines
17096 the minimum time to wait between those checks. Dovecot can also use
17097 dnotify, inotify and kqueue to find out immediately when changes
17099 Defaults to @samp{"30 secs"}.
17102 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17103 Save mails with CR+LF instead of plain LF. This makes sending those
17104 mails take less CPU, especially with sendfile() syscall with Linux and
17105 FreeBSD. But it also creates a bit more disk I/O which may just make it
17106 slower. Also note that if other software reads the mboxes/maildirs,
17107 they may handle the extra CRs wrong and cause problems.
17108 Defaults to @samp{#f}.
17111 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17112 By default LIST command returns all entries in maildir beginning
17113 with a dot. Enabling this option makes Dovecot return only entries
17114 which are directories. This is done by stat()ing each entry, so it
17115 causes more disk I/O.
17116 (For systems setting struct @samp{dirent->d_type} this check is free
17117 and it's done always regardless of this setting).
17118 Defaults to @samp{#f}.
17121 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17122 When copying a message, do it with hard links whenever possible.
17123 This makes the performance much better, and it's unlikely to have any
17125 Defaults to @samp{#t}.
17128 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17129 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17130 directory only when its mtime changes unexpectedly or when we can't find
17131 the mail otherwise.
17132 Defaults to @samp{#f}.
17135 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17136 Which locking methods to use for locking mbox. There are four
17141 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17142 solution. If you want to use /var/mail/ like directory, the users will
17143 need write access to that directory.
17145 Same as dotlock, but if it fails because of permissions or because there
17146 isn't enough disk space, just skip it.
17148 Use this if possible. Works with NFS too if lockd is used.
17150 May not exist in all systems. Doesn't work with NFS.
17152 May not exist in all systems. Doesn't work with NFS.
17155 You can use multiple locking methods; if you do the order they're declared
17156 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17157 locking methods as well. Some operating systems don't allow using some of
17158 them simultaneously.
17161 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17165 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17166 Maximum time to wait for lock (all of them) before aborting.
17167 Defaults to @samp{"5 mins"}.
17170 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17171 If dotlock exists but the mailbox isn't modified in any way,
17172 override the lock file after this much time.
17173 Defaults to @samp{"2 mins"}.
17176 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17177 When mbox changes unexpectedly we have to fully read it to find out
17178 what changed. If the mbox is large this can take a long time. Since
17179 the change is usually just a newly appended mail, it'd be faster to
17180 simply read the new mails. If this setting is enabled, Dovecot does
17181 this but still safely fallbacks to re-reading the whole mbox file
17182 whenever something in mbox isn't how it's expected to be. The only real
17183 downside to this setting is that if some other MUA changes message
17184 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17185 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17186 Defaults to @samp{#t}.
17189 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17190 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17191 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17192 @samp{mbox-dirty-syncs} is ignored.
17193 Defaults to @samp{#f}.
17196 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17197 Delay writing mbox headers until doing a full write sync (EXPUNGE
17198 and CHECK commands and when closing the mailbox). This is especially
17199 useful for POP3 where clients often delete all mails. The downside is
17200 that our changes aren't immediately visible to other MUAs.
17201 Defaults to @samp{#t}.
17204 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17205 If mbox size is smaller than this (e.g.@: 100k), don't write index
17206 files. If an index file already exists it's still read, just not
17208 Defaults to @samp{0}.
17211 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17212 Maximum dbox file size until it's rotated.
17213 Defaults to @samp{10000000}.
17216 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17217 Maximum dbox file age until it's rotated. Typically in days. Day
17218 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17220 Defaults to @samp{"1d"}.
17223 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17224 When creating new mdbox files, immediately preallocate their size to
17225 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17226 with some file systems (ext4, xfs).
17227 Defaults to @samp{#f}.
17230 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17231 sdbox and mdbox support saving mail attachments to external files,
17232 which also allows single instance storage for them. Other backends
17233 don't support this for now.
17235 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17237 Directory root where to store mail attachments. Disabled, if empty.
17238 Defaults to @samp{""}.
17241 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17242 Attachments smaller than this aren't saved externally. It's also
17243 possible to write a plugin to disable saving specific attachments
17245 Defaults to @samp{128000}.
17248 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17249 File system backend to use for saving attachments:
17252 No SiS done by Dovecot (but this might help FS's own deduplication)
17254 SiS with immediate byte-by-byte comparison during saving
17255 @item sis-queue posix
17256 SiS with delayed comparison and deduplication.
17258 Defaults to @samp{"sis posix"}.
17261 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17262 Hash format to use in attachment filenames. You can add any text and
17263 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17264 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17265 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17266 Defaults to @samp{"%@{sha1@}"}.
17269 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17271 Defaults to @samp{100}.
17274 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17276 Defaults to @samp{1000}.
17279 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17280 Default VSZ (virtual memory size) limit for service processes.
17281 This is mainly intended to catch and kill processes that leak memory
17282 before they eat up everything.
17283 Defaults to @samp{256000000}.
17286 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17287 Login user is internally used by login processes. This is the most
17288 untrusted user in Dovecot system. It shouldn't have access to anything
17290 Defaults to @samp{"dovenull"}.
17293 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17294 Internal user is used by unprivileged processes. It should be
17295 separate from login user, so that login processes can't disturb other
17297 Defaults to @samp{"dovecot"}.
17300 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17301 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17302 Defaults to @samp{"required"}.
17305 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17306 PEM encoded X.509 SSL/TLS certificate (public key).
17307 Defaults to @samp{"</etc/dovecot/default.pem"}.
17310 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17311 PEM encoded SSL/TLS private key. The key is opened before
17312 dropping root privileges, so keep the key file unreadable by anyone but
17314 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17317 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17318 If key file is password protected, give the password here.
17319 Alternatively give it when starting dovecot with -p parameter. Since
17320 this file is often world-readable, you may want to place this setting
17321 instead to a different.
17322 Defaults to @samp{""}.
17325 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17326 PEM encoded trusted certificate authority. Set this only if you
17327 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17328 contain the CA certificate(s) followed by the matching
17329 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17330 Defaults to @samp{""}.
17333 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17334 Require that CRL check succeeds for client certificates.
17335 Defaults to @samp{#t}.
17338 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17339 Request client to send a certificate. If you also want to require
17340 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17341 Defaults to @samp{#f}.
17344 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17345 Which field from certificate to use for username. commonName and
17346 x500UniqueIdentifier are the usual choices. You'll also need to set
17347 @samp{auth-ssl-username-from-cert? #t}.
17348 Defaults to @samp{"commonName"}.
17351 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17352 Minimum SSL protocol version to accept.
17353 Defaults to @samp{"TLSv1"}.
17356 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17357 SSL ciphers to use.
17358 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17361 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17362 SSL crypto device to use, for valid values run "openssl engine".
17363 Defaults to @samp{""}.
17366 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17367 Address to use when sending rejection mails.
17368 %d expands to recipient domain.
17369 Defaults to @samp{"postmaster@@%d"}.
17372 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17373 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17374 and in LMTP replies. Default is the system's real hostname@@domain.
17375 Defaults to @samp{""}.
17378 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17379 If user is over quota, return with temporary failure instead of
17381 Defaults to @samp{#f}.
17384 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17385 Binary to use for sending mails.
17386 Defaults to @samp{"/usr/sbin/sendmail"}.
17389 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17390 If non-empty, send mails via this SMTP host[:port] instead of
17392 Defaults to @samp{""}.
17395 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17396 Subject: header to use for rejection mails. You can use the same
17397 variables as for @samp{rejection-reason} below.
17398 Defaults to @samp{"Rejected: %s"}.
17401 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17402 Human readable error message for rejection mails. You can use
17415 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17418 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17419 Delimiter character between local-part and detail in email
17421 Defaults to @samp{"+"}.
17424 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17425 Header where the original recipient address (SMTP's RCPT TO:
17426 address) is taken from if not available elsewhere. With dovecot-lda -a
17427 parameter overrides this. A commonly used header for this is
17429 Defaults to @samp{""}.
17432 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17433 Should saving a mail to a nonexistent mailbox automatically create
17435 Defaults to @samp{#f}.
17438 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17439 Should automatically created mailboxes be also automatically
17441 Defaults to @samp{#f}.
17444 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17445 Maximum IMAP command line length. Some clients generate very long
17446 command lines with huge mailboxes, so you may need to raise this if you
17447 get "Too long argument" or "IMAP command line too large" errors
17449 Defaults to @samp{64000}.
17452 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17453 IMAP logout format string:
17456 total number of bytes read from client
17458 total number of bytes sent to client.
17460 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17461 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@}"}.
17464 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17465 Override the IMAP CAPABILITY response. If the value begins with '+',
17466 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17467 Defaults to @samp{""}.
17470 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17471 How long to wait between "OK Still here" notifications when client
17473 Defaults to @samp{"2 mins"}.
17476 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17477 ID field names and values to send to clients. Using * as the value
17478 makes Dovecot use the default value. The following fields have default
17479 values currently: name, version, os, os-version, support-url,
17481 Defaults to @samp{""}.
17484 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17485 ID fields sent by client to log. * means everything.
17486 Defaults to @samp{""}.
17489 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17490 Workarounds for various client bugs:
17493 @item delay-newmail
17494 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17495 CHECK commands. Some clients ignore them otherwise, for example OSX
17496 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17497 may show user "Message no longer in server" errors. Note that OE6
17498 still breaks even with this workaround if synchronization is set to
17501 @item tb-extra-mailbox-sep
17502 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17503 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17504 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17506 @item tb-lsub-flags
17507 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17508 This makes Thunderbird realize they aren't selectable and show them
17509 greyed out, instead of only later giving "not selectable" popup error.
17511 Defaults to @samp{()}.
17514 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17515 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17516 Defaults to @samp{""}.
17520 Whew! Lots of configuration options. The nice thing about it though is
17521 that Guix has a complete interface to Dovecot's configuration
17522 language. This allows not only a nice way to declare configurations,
17523 but also offers reflective capabilities as well: users can write code to
17524 inspect and transform configurations from within Scheme.
17526 However, it could be that you just want to get a @code{dovecot.conf} up
17527 and running. In that case, you can pass an
17528 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17529 @code{dovecot-service}. As its name indicates, an opaque configuration
17530 does not have easy reflective capabilities.
17532 Available @code{opaque-dovecot-configuration} fields are:
17534 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17535 The dovecot package.
17538 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17539 The contents of the @code{dovecot.conf}, as a string.
17542 For example, if your @code{dovecot.conf} is just the empty string, you
17543 could instantiate a dovecot service like this:
17546 (dovecot-service #:config
17547 (opaque-dovecot-configuration
17551 @subsubheading OpenSMTPD Service
17553 @deffn {Scheme Variable} opensmtpd-service-type
17554 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17555 service, whose value should be an @code{opensmtpd-configuration} object
17556 as in this example:
17559 (service opensmtpd-service-type
17560 (opensmtpd-configuration
17561 (config-file (local-file "./my-smtpd.conf"))))
17565 @deftp {Data Type} opensmtpd-configuration
17566 Data type representing the configuration of opensmtpd.
17569 @item @code{package} (default: @var{opensmtpd})
17570 Package object of the OpenSMTPD SMTP server.
17572 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17573 File-like object of the OpenSMTPD configuration file to use. By default
17574 it listens on the loopback network interface, and allows for mail from
17575 users and daemons on the local machine, as well as permitting email to
17576 remote servers. Run @command{man smtpd.conf} for more information.
17581 @subsubheading Exim Service
17583 @cindex mail transfer agent (MTA)
17584 @cindex MTA (mail transfer agent)
17587 @deffn {Scheme Variable} exim-service-type
17588 This is the type of the @uref{https://exim.org, Exim} mail transfer
17589 agent (MTA), whose value should be an @code{exim-configuration} object
17590 as in this example:
17593 (service exim-service-type
17594 (exim-configuration
17595 (config-file (local-file "./my-exim.conf"))))
17599 In order to use an @code{exim-service-type} service you must also have a
17600 @code{mail-aliases-service-type} service present in your
17601 @code{operating-system} (even if it has no aliases).
17603 @deftp {Data Type} exim-configuration
17604 Data type representing the configuration of exim.
17607 @item @code{package} (default: @var{exim})
17608 Package object of the Exim server.
17610 @item @code{config-file} (default: @code{#f})
17611 File-like object of the Exim configuration file to use. If its value is
17612 @code{#f} then use the default configuration file from the package
17613 provided in @code{package}. The resulting configuration file is loaded
17614 after setting the @code{exim_user} and @code{exim_group} configuration
17620 @subsubheading Getmail service
17625 @deffn {Scheme Variable} getmail-service-type
17626 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17627 mail retriever, whose value should be an @code{getmail-configuration}.
17630 Available @code{getmail-configuration} fields are:
17632 @deftypevr {@code{getmail-configuration} parameter} symbol name
17633 A symbol to identify the getmail service.
17635 Defaults to @samp{"unset"}.
17639 @deftypevr {@code{getmail-configuration} parameter} package package
17640 The getmail package to use.
17644 @deftypevr {@code{getmail-configuration} parameter} string user
17645 The user to run getmail as.
17647 Defaults to @samp{"getmail"}.
17651 @deftypevr {@code{getmail-configuration} parameter} string group
17652 The group to run getmail as.
17654 Defaults to @samp{"getmail"}.
17658 @deftypevr {@code{getmail-configuration} parameter} string directory
17659 The getmail directory to use.
17661 Defaults to @samp{"/var/lib/getmail/default"}.
17665 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17666 The getmail configuration file to use.
17668 Available @code{getmail-configuration-file} fields are:
17670 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17671 What mail account to retrieve mail from, and how to access that account.
17673 Available @code{getmail-retriever-configuration} fields are:
17675 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17676 The type of mail retriever to use. Valid values include @samp{passwd}
17679 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17683 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17684 Space separated list of arguments to the userdb driver.
17686 Defaults to @samp{unset}.
17690 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17691 Space separated list of arguments to the userdb driver.
17693 Defaults to @samp{unset}.
17697 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17698 Space separated list of arguments to the userdb driver.
17700 Defaults to @samp{#f}.
17704 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17705 Override fields from passwd.
17707 Defaults to @samp{""}.
17711 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17712 Override fields from passwd.
17714 Defaults to @samp{()}.
17718 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17719 PEM-formatted key file to use for the TLS negotiation
17721 Defaults to @samp{""}.
17725 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17726 PEM-formatted certificate file to use for the TLS negotiation
17728 Defaults to @samp{""}.
17732 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17733 CA certificates to use
17735 Defaults to @samp{""}.
17739 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17740 Extra retriever parameters
17742 Defaults to @samp{()}.
17748 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17749 What to do with retrieved messages.
17751 Available @code{getmail-destination-configuration} fields are:
17753 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17754 The type of mail destination. Valid values include @samp{Maildir},
17755 @samp{Mboxrd} and @samp{MDA_external}.
17757 Defaults to @samp{unset}.
17761 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17762 The path option for the mail destination. The behaviour depends on the
17765 Defaults to @samp{""}.
17769 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17770 Extra destination parameters
17772 Defaults to @samp{()}.
17778 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17781 Available @code{getmail-options-configuration} fields are:
17783 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17784 If set to @samp{0}, getmail will only print warnings and errors. A
17785 value of @samp{1} means that messages will be printed about retrieving
17786 and deleting messages. If set to @samp{2}, getmail will print messages
17787 about each of it's actions.
17789 Defaults to @samp{1}.
17793 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17794 If true, getmail will retrieve all available messages. Otherwise it
17795 will only retrieve messages it hasn't seen previously.
17797 Defaults to @samp{#t}.
17801 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17802 If set to true, messages will be deleted from the server after
17803 retrieving and successfully delivering them. Otherwise, messages will
17804 be left on the server.
17806 Defaults to @samp{#f}.
17810 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17811 Getmail will delete messages this number of days after seeing them, if
17812 they have been delivered. This means messages will be left on the
17813 server this number of days after delivering them. A value of @samp{0}
17814 disabled this feature.
17816 Defaults to @samp{0}.
17820 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17821 Delete messages larger than this of bytes after retrieving them, even if
17822 the delete and delete-after options are disabled. A value of @samp{0}
17823 disables this feature.
17825 Defaults to @samp{0}.
17829 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17830 Retrieve messages totalling up to this number of bytes before closing
17831 the session with the server. A value of @samp{0} disables this feature.
17833 Defaults to @samp{0}.
17837 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17838 Don't retrieve messages larger than this number of bytes. A value of
17839 @samp{0} disables this feature.
17841 Defaults to @samp{0}.
17845 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17846 If true, getmail will add a Delivered-To header to messages.
17848 Defaults to @samp{#t}.
17852 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17853 If set, getmail adds a Received header to the messages.
17855 Defaults to @samp{#t}.
17859 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17860 Getmail will record a log of its actions to the named file. A value of
17861 @samp{""} disables this feature.
17863 Defaults to @samp{""}.
17867 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17868 If true, getmail will record a log of its actions using the system
17871 Defaults to @samp{#t}.
17875 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17876 If true, getmail will log information about messages not retrieved and
17877 the reason for not retrieving them, as well as starting and ending
17880 Defaults to @samp{#t}.
17884 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17885 Extra options to include.
17887 Defaults to @samp{()}.
17895 @deftypevr {@code{getmail-configuration} parameter} list idle
17896 A list of mailboxes that getmail should wait on the server for new mail
17897 notifications. This depends on the server supporting the IDLE
17900 Defaults to @samp{()}.
17904 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17905 Environment variables to set for getmail.
17907 Defaults to @samp{()}.
17911 @subsubheading Mail Aliases Service
17913 @cindex email aliases
17914 @cindex aliases, for email addresses
17916 @deffn {Scheme Variable} mail-aliases-service-type
17917 This is the type of the service which provides @code{/etc/aliases},
17918 specifying how to deliver mail to users on this system.
17921 (service mail-aliases-service-type
17922 '(("postmaster" "bob")
17923 ("bob" "bob@@example.com" "bob@@example2.com")))
17927 The configuration for a @code{mail-aliases-service-type} service is an
17928 association list denoting how to deliver mail that comes to this
17929 system. Each entry is of the form @code{(alias addresses ...)}, with
17930 @code{alias} specifying the local alias and @code{addresses} specifying
17931 where to deliver this user's mail.
17933 The aliases aren't required to exist as users on the local system. In
17934 the above example, there doesn't need to be a @code{postmaster} entry in
17935 the @code{operating-system}'s @code{user-accounts} in order to deliver
17936 the @code{postmaster} mail to @code{bob} (which subsequently would
17937 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17939 @subsubheading GNU Mailutils IMAP4 Daemon
17940 @cindex GNU Mailutils IMAP4 Daemon
17942 @deffn {Scheme Variable} imap4d-service-type
17943 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17944 mailutils, GNU Mailutils Manual}), whose value should be an
17945 @code{imap4d-configuration} object as in this example:
17948 (service imap4d-service-type
17949 (imap4d-configuration
17950 (config-file (local-file "imap4d.conf"))))
17954 @deftp {Data Type} imap4d-configuration
17955 Data type representing the configuration of @command{imap4d}.
17958 @item @code{package} (default: @code{mailutils})
17959 The package that provides @command{imap4d}.
17961 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17962 File-like object of the configuration file to use, by default it will listen
17963 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17964 Mailutils Manual}, for details.
17969 @node Messaging Services
17970 @subsection Messaging Services
17975 The @code{(gnu services messaging)} module provides Guix service
17976 definitions for messaging services: currently only Prosody is supported.
17978 @subsubheading Prosody Service
17980 @deffn {Scheme Variable} prosody-service-type
17981 This is the type for the @uref{https://prosody.im, Prosody XMPP
17982 communication server}. Its value must be a @code{prosody-configuration}
17983 record as in this example:
17986 (service prosody-service-type
17987 (prosody-configuration
17988 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17991 (int-component-configuration
17992 (hostname "conference.example.net")
17994 (mod-muc (mod-muc-configuration)))))
17997 (virtualhost-configuration
17998 (domain "example.net"))))))
18001 See below for details about @code{prosody-configuration}.
18005 By default, Prosody does not need much configuration. Only one
18006 @code{virtualhosts} field is needed: it specifies the domain you wish
18009 You can perform various sanity checks on the generated configuration
18010 with the @code{prosodyctl check} command.
18012 Prosodyctl will also help you to import certificates from the
18013 @code{letsencrypt} directory so that the @code{prosody} user can access
18014 them. See @url{https://prosody.im/doc/letsencrypt}.
18017 prosodyctl --root cert import /etc/letsencrypt/live
18020 The available configuration parameters follow. Each parameter
18021 definition is preceded by its type; for example, @samp{string-list foo}
18022 indicates that the @code{foo} parameter should be specified as a list of
18023 strings. Types starting with @code{maybe-} denote parameters that won't
18024 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18026 There is also a way to specify the configuration as a string, if you
18027 have an old @code{prosody.cfg.lua} file that you want to port over from
18028 some other system; see the end for more details.
18030 The @code{file-object} type designates either a file-like object
18031 (@pxref{G-Expressions, file-like objects}) or a file name.
18033 @c The following documentation was initially generated by
18034 @c (generate-documentation) in (gnu services messaging). Manually maintained
18035 @c documentation is better, so we shouldn't hesitate to edit below as
18036 @c needed. However if the change you want to make to this documentation
18037 @c can be done in an automated way, it's probably easier to change
18038 @c (generate-documentation) than to make it below and have to deal with
18039 @c the churn as Prosody updates.
18041 Available @code{prosody-configuration} fields are:
18043 @deftypevr {@code{prosody-configuration} parameter} package prosody
18044 The Prosody package.
18047 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18048 Location of the Prosody data storage directory. See
18049 @url{https://prosody.im/doc/configure}.
18050 Defaults to @samp{"/var/lib/prosody"}.
18053 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18054 Additional plugin directories. They are searched in all the specified
18055 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18056 Defaults to @samp{()}.
18059 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18060 Every virtual host and component needs a certificate so that clients and
18061 servers can securely verify its identity. Prosody will automatically load
18062 certificates/keys from the directory specified here.
18063 Defaults to @samp{"/etc/prosody/certs"}.
18066 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18067 This is a list of accounts that are admins for the server. Note that you
18068 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18069 @url{https://prosody.im/doc/creating_accounts}.
18070 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18071 Defaults to @samp{()}.
18074 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18075 Enable use of libevent for better performance under high load. See
18076 @url{https://prosody.im/doc/libevent}.
18077 Defaults to @samp{#f}.
18080 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18081 This is the list of modules Prosody will load on startup. It looks for
18082 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18083 Documentation on modules can be found at:
18084 @url{https://prosody.im/doc/modules}.
18085 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18088 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18089 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18090 should you want to disable them then add them to this list.
18091 Defaults to @samp{()}.
18094 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18095 Path to a text file where the shared groups are defined. If this path is
18096 empty then @samp{mod_groups} does nothing. See
18097 @url{https://prosody.im/doc/modules/mod_groups}.
18098 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18101 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18102 Disable account creation by default, for security. See
18103 @url{https://prosody.im/doc/creating_accounts}.
18104 Defaults to @samp{#f}.
18107 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18108 These are the SSL/TLS-related settings. Most of them are disabled so to
18109 use Prosody's defaults. If you do not completely understand these options, do
18110 not add them to your config, it is easy to lower the security of your server
18111 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18113 Available @code{ssl-configuration} fields are:
18115 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18116 This determines what handshake to use.
18119 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18120 Path to your private key file.
18123 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18124 Path to your certificate file.
18127 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18128 Path to directory containing root certificates that you wish Prosody to
18129 trust when verifying the certificates of remote servers.
18130 Defaults to @samp{"/etc/ssl/certs"}.
18133 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18134 Path to a file containing root certificates that you wish Prosody to trust.
18135 Similar to @code{capath} but with all certificates concatenated together.
18138 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18139 A list of verification options (these mostly map to OpenSSL's
18140 @code{set_verify()} flags).
18143 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18144 A list of general options relating to SSL/TLS. These map to OpenSSL's
18145 @code{set_options()}. For a full list of options available in LuaSec, see the
18149 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18150 How long a chain of certificate authorities to check when looking for a
18151 trusted root certificate.
18154 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18155 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18156 clients, and in what order.
18159 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18160 A path to a file containing parameters for Diffie-Hellman key exchange. You
18161 can create such a file with:
18162 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18165 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18166 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18167 @samp{"secp384r1"}.
18170 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18171 A list of "extra" verification options.
18174 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18175 Password for encrypted private keys.
18180 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18181 Whether to force all client-to-server connections to be encrypted or not.
18182 See @url{https://prosody.im/doc/modules/mod_tls}.
18183 Defaults to @samp{#f}.
18186 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18187 Set of mechanisms that will never be offered. See
18188 @url{https://prosody.im/doc/modules/mod_saslauth}.
18189 Defaults to @samp{("DIGEST-MD5")}.
18192 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18193 Whether to force all server-to-server connections to be encrypted or not.
18194 See @url{https://prosody.im/doc/modules/mod_tls}.
18195 Defaults to @samp{#f}.
18198 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18199 Whether to require encryption and certificate authentication. This
18200 provides ideal security, but requires servers you communicate with to support
18201 encryption AND present valid, trusted certificates. See
18202 @url{https://prosody.im/doc/s2s#security}.
18203 Defaults to @samp{#f}.
18206 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18207 Many servers don't support encryption or have invalid or self-signed
18208 certificates. You can list domains here that will not be required to
18209 authenticate using certificates. They will be authenticated using DNS. See
18210 @url{https://prosody.im/doc/s2s#security}.
18211 Defaults to @samp{()}.
18214 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18215 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18216 valid certificates for some domains by specifying a list here. See
18217 @url{https://prosody.im/doc/s2s#security}.
18218 Defaults to @samp{()}.
18221 @deftypevr {@code{prosody-configuration} parameter} string authentication
18222 Select the authentication backend to use. The default provider stores
18223 passwords in plaintext and uses Prosody's configured data storage to store the
18224 authentication data. If you do not trust your server please see
18225 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18226 about using the hashed backend. See also
18227 @url{https://prosody.im/doc/authentication}
18228 Defaults to @samp{"internal_plain"}.
18231 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18232 Set logging options. Advanced logging configuration is not yet supported
18233 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18234 Defaults to @samp{"*syslog"}.
18237 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18238 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18239 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18242 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18243 Maximum allowed size of the HTTP body (in bytes).
18246 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18247 Some modules expose their own URL in various ways. This URL is built
18248 from the protocol, host and port used. If Prosody sits behind a proxy, the
18249 public URL will be @code{http-external-url} instead. See
18250 @url{https://prosody.im/doc/http#external_url}.
18253 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18254 A host in Prosody is a domain on which user accounts can be created. For
18255 example if you want your users to have addresses like
18256 @samp{"john.smith@@example.com"} then you need to add a host
18257 @samp{"example.com"}. All options in this list will apply only to this host.
18259 Note: the name "virtual" host is used in configuration to avoid confusion with
18260 the actual physical host that Prosody is installed on. A single Prosody
18261 instance can serve many domains, each one defined as a VirtualHost entry in
18262 Prosody's configuration. Conversely a server that hosts a single domain would
18263 have just one VirtualHost entry.
18265 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18267 Available @code{virtualhost-configuration} fields are:
18269 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:
18270 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18271 Domain you wish Prosody to serve.
18276 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18277 Components are extra services on a server which are available to clients,
18278 usually on a subdomain of the main server (such as
18279 @samp{"mycomponent.example.com"}). Example components might be chatroom
18280 servers, user directories, or gateways to other protocols.
18282 Internal components are implemented with Prosody-specific plugins. To add an
18283 internal component, you simply fill the hostname field, and the plugin you wish
18284 to use for the component.
18286 See @url{https://prosody.im/doc/components}.
18287 Defaults to @samp{()}.
18289 Available @code{int-component-configuration} fields are:
18291 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:
18292 @deftypevr {@code{int-component-configuration} parameter} string hostname
18293 Hostname of the component.
18296 @deftypevr {@code{int-component-configuration} parameter} string plugin
18297 Plugin you wish to use for the component.
18300 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18301 Multi-user chat (MUC) is Prosody's module for allowing you to create
18302 hosted chatrooms/conferences for XMPP users.
18304 General information on setting up and using multi-user chatrooms can be found
18305 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18306 which you should read if you are new to XMPP chatrooms.
18308 See also @url{https://prosody.im/doc/modules/mod_muc}.
18310 Available @code{mod-muc-configuration} fields are:
18312 @deftypevr {@code{mod-muc-configuration} parameter} string name
18313 The name to return in service discovery responses.
18314 Defaults to @samp{"Prosody Chatrooms"}.
18317 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18318 If @samp{#t}, this will only allow admins to create new chatrooms.
18319 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18320 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18321 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18322 restricts to service administrators only.
18323 Defaults to @samp{#f}.
18326 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18327 Maximum number of history messages that will be sent to the member that has
18328 just joined the room.
18329 Defaults to @samp{20}.
18336 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18337 External components use XEP-0114, which most standalone components
18338 support. To add an external component, you simply fill the hostname field. See
18339 @url{https://prosody.im/doc/components}.
18340 Defaults to @samp{()}.
18342 Available @code{ext-component-configuration} fields are:
18344 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:
18345 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18346 Password which the component will use to log in.
18349 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18350 Hostname of the component.
18355 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18356 Port(s) Prosody listens on for component connections.
18357 Defaults to @samp{(5347)}.
18360 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18361 Interface Prosody listens on for component connections.
18362 Defaults to @samp{"127.0.0.1"}.
18365 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18366 Raw content that will be added to the configuration file.
18369 It could be that you just want to get a @code{prosody.cfg.lua}
18370 up and running. In that case, you can pass an
18371 @code{opaque-prosody-configuration} record as the value of
18372 @code{prosody-service-type}. As its name indicates, an opaque configuration
18373 does not have easy reflective capabilities.
18374 Available @code{opaque-prosody-configuration} fields are:
18376 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18377 The prosody package.
18380 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18381 The contents of the @code{prosody.cfg.lua} to use.
18384 For example, if your @code{prosody.cfg.lua} is just the empty
18385 string, you could instantiate a prosody service like this:
18388 (service prosody-service-type
18389 (opaque-prosody-configuration
18390 (prosody.cfg.lua "")))
18393 @c end of Prosody auto-generated documentation
18395 @subsubheading BitlBee Service
18397 @cindex IRC (Internet Relay Chat)
18398 @cindex IRC gateway
18399 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18400 interface to a variety of messaging protocols such as XMPP.
18402 @defvr {Scheme Variable} bitlbee-service-type
18403 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18404 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18407 To have BitlBee listen on port 6667 on localhost, add this line to your
18411 (service bitlbee-service-type)
18415 @deftp {Data Type} bitlbee-configuration
18416 This is the configuration for BitlBee, with the following fields:
18419 @item @code{interface} (default: @code{"127.0.0.1"})
18420 @itemx @code{port} (default: @code{6667})
18421 Listen on the network interface corresponding to the IP address
18422 specified in @var{interface}, on @var{port}.
18424 When @var{interface} is @code{127.0.0.1}, only local clients can
18425 connect; when it is @code{0.0.0.0}, connections can come from any
18426 networking interface.
18428 @item @code{bitlbee} (default: @code{bitlbee})
18429 The BitlBee package to use.
18431 @item @code{plugins} (default: @code{'()})
18432 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18434 @item @code{extra-settings} (default: @code{""})
18435 Configuration snippet added as-is to the BitlBee configuration file.
18439 @subsubheading Quassel Service
18441 @cindex IRC (Internet Relay Chat)
18442 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18443 meaning that one or more clients can attach to and detach from the
18446 @defvr {Scheme Variable} quassel-service-type
18447 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18448 IRC backend daemon. Its value is a @code{quassel-configuration}
18452 @deftp {Data Type} quassel-configuration
18453 This is the configuration for Quassel, with the following fields:
18456 @item @code{quassel} (default: @code{quassel})
18457 The Quassel package to use.
18459 @item @code{interface} (default: @code{"::,0.0.0.0"})
18460 @item @code{port} (default: @code{4242})
18461 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18462 interfaces specified in the comma delimited @var{interface}, on
18465 @item @code{loglevel} (default: @code{"Info"})
18466 The level of logging desired. Accepted values are Debug, Info, Warning
18471 @node Telephony Services
18472 @subsection Telephony Services
18474 @cindex Murmur (VoIP server)
18475 @cindex VoIP server
18476 This section describes how to set up and run a Murmur server. Murmur is
18477 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18480 @deftp {Data Type} murmur-configuration
18481 The service type for the Murmur server. An example configuration can
18485 (service murmur-service-type
18486 (murmur-configuration
18488 "Welcome to this Mumble server running on Guix!")
18489 (cert-required? #t) ;disallow text password logins
18490 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18491 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18494 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18495 password with the command that is printed during the activation phase.
18497 It is recommended to register a normal Mumble user account
18498 and grant it admin or moderator rights.
18499 You can use the @code{mumble} client to
18500 login as new normal user, register yourself, and log out.
18501 For the next step login with the name @code{SuperUser} use
18502 the @code{SuperUser} password that you set previously,
18503 and grant your newly registered mumble user administrator or moderator
18504 rights and create some channels.
18506 Available @code{murmur-configuration} fields are:
18509 @item @code{package} (default: @code{mumble})
18510 Package that contains @code{bin/murmurd}.
18512 @item @code{user} (default: @code{"murmur"})
18513 User who will run the Murmur server.
18515 @item @code{group} (default: @code{"murmur"})
18516 Group of the user who will run the murmur server.
18518 @item @code{port} (default: @code{64738})
18519 Port on which the server will listen.
18521 @item @code{welcome-text} (default: @code{""})
18522 Welcome text sent to clients when they connect.
18524 @item @code{server-password} (default: @code{""})
18525 Password the clients have to enter in order to connect.
18527 @item @code{max-users} (default: @code{100})
18528 Maximum of users that can be connected to the server at once.
18530 @item @code{max-user-bandwidth} (default: @code{#f})
18531 Maximum voice traffic a user can send per second.
18533 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18534 File name of the sqlite database.
18535 The service's user will become the owner of the directory.
18537 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18538 File name of the log file.
18539 The service's user will become the owner of the directory.
18541 @item @code{autoban-attempts} (default: @code{10})
18542 Maximum number of logins a user can make in @code{autoban-timeframe}
18543 without getting auto banned for @code{autoban-time}.
18545 @item @code{autoban-timeframe} (default: @code{120})
18546 Timeframe for autoban in seconds.
18548 @item @code{autoban-time} (default: @code{300})
18549 Amount of time in seconds for which a client gets banned
18550 when violating the autoban limits.
18552 @item @code{opus-threshold} (default: @code{100})
18553 Percentage of clients that need to support opus
18554 before switching over to opus audio codec.
18556 @item @code{channel-nesting-limit} (default: @code{10})
18557 How deep channels can be nested at maximum.
18559 @item @code{channelname-regex} (default: @code{#f})
18560 A string in form of a Qt regular expression that channel names must conform to.
18562 @item @code{username-regex} (default: @code{#f})
18563 A string in form of a Qt regular expression that user names must conform to.
18565 @item @code{text-message-length} (default: @code{5000})
18566 Maximum size in bytes that a user can send in one text chat message.
18568 @item @code{image-message-length} (default: @code{(* 128 1024)})
18569 Maximum size in bytes that a user can send in one image message.
18571 @item @code{cert-required?} (default: @code{#f})
18572 If it is set to @code{#t} clients that use weak password authentication
18573 will not be accepted. Users must have completed the certificate wizard to join.
18575 @item @code{remember-channel?} (default: @code{#f})
18576 Should murmur remember the last channel each user was in when they disconnected
18577 and put them into the remembered channel when they rejoin.
18579 @item @code{allow-html?} (default: @code{#f})
18580 Should html be allowed in text messages, user comments, and channel descriptions.
18582 @item @code{allow-ping?} (default: @code{#f})
18583 Setting to true exposes the current user count, the maximum user count, and
18584 the server's maximum bandwidth per client to unauthenticated users. In the
18585 Mumble client, this information is shown in the Connect dialog.
18587 Disabling this setting will prevent public listing of the server.
18589 @item @code{bonjour?} (default: @code{#f})
18590 Should the server advertise itself in the local network through the bonjour protocol.
18592 @item @code{send-version?} (default: @code{#f})
18593 Should the murmur server version be exposed in ping requests.
18595 @item @code{log-days} (default: @code{31})
18596 Murmur also stores logs in the database, which are accessible via RPC.
18597 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18598 or -1 to disable logging to the database.
18600 @item @code{obfuscate-ips?} (default: @code{#t})
18601 Should logged ips be obfuscated to protect the privacy of users.
18603 @item @code{ssl-cert} (default: @code{#f})
18604 File name of the SSL/TLS certificate used for encrypted connections.
18607 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18609 @item @code{ssl-key} (default: @code{#f})
18610 Filepath to the ssl private key used for encrypted connections.
18612 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18615 @item @code{ssl-dh-params} (default: @code{#f})
18616 File name of a PEM-encoded file with Diffie-Hellman parameters
18617 for the SSL/TLS encryption. Alternatively you set it to
18618 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18619 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18621 @item @code{ssl-ciphers} (default: @code{#f})
18622 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18625 This option is specified using
18626 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18627 OpenSSL cipher list notation}.
18629 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18630 before setting it here, to get a feel for which cipher suites you will get.
18631 After setting this option, it is recommend that you inspect your Murmur log
18632 to ensure that Murmur is using the cipher suites that you expected it to.
18634 Note: Changing this option may impact the backwards compatibility of your
18635 Murmur server, and can remove the ability for older Mumble clients to be able
18638 @item @code{public-registration} (default: @code{#f})
18639 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18641 You can optionally register your server in the public server list that the
18642 @code{mumble} client shows on startup.
18643 You cannot register your server if you have set a @code{server-password},
18644 or set @code{allow-ping} to @code{#f}.
18646 It might take a few hours until it shows up in the public list.
18648 @item @code{file} (default: @code{#f})
18649 Optional alternative override for this configuration.
18653 @deftp {Data Type} murmur-public-registration-configuration
18654 Configuration for public registration of a murmur service.
18658 This is a display name for your server. Not to be confused with the hostname.
18660 @item @code{password}
18661 A password to identify your registration.
18662 Subsequent updates will need the same password. Don't lose your password.
18665 This should be a @code{http://} or @code{https://} link to your web
18668 @item @code{hostname} (default: @code{#f})
18669 By default your server will be listed by its IP address.
18670 If it is set your server will be linked by this host name instead.
18676 @node Monitoring Services
18677 @subsection Monitoring Services
18679 @subsubheading Tailon Service
18681 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18682 viewing and searching log files.
18684 The following example will configure the service with default values.
18685 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18688 (service tailon-service-type)
18691 The following example customises more of the Tailon configuration,
18692 adding @command{sed} to the list of allowed commands.
18695 (service tailon-service-type
18696 (tailon-configuration
18698 (tailon-configuration-file
18699 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18703 @deftp {Data Type} tailon-configuration
18704 Data type representing the configuration of Tailon.
18705 This type has the following parameters:
18708 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18709 The configuration file to use for Tailon. This can be set to a
18710 @dfn{tailon-configuration-file} record value, or any gexp
18711 (@pxref{G-Expressions}).
18713 For example, to instead use a local file, the @code{local-file} function
18717 (service tailon-service-type
18718 (tailon-configuration
18719 (config-file (local-file "./my-tailon.conf"))))
18722 @item @code{package} (default: @code{tailon})
18723 The tailon package to use.
18728 @deftp {Data Type} tailon-configuration-file
18729 Data type representing the configuration options for Tailon.
18730 This type has the following parameters:
18733 @item @code{files} (default: @code{(list "/var/log")})
18734 List of files to display. The list can include strings for a single file
18735 or directory, or a list, where the first item is the name of a
18736 subsection, and the remaining items are the files or directories in that
18739 @item @code{bind} (default: @code{"localhost:8080"})
18740 Address and port to which Tailon should bind on.
18742 @item @code{relative-root} (default: @code{#f})
18743 URL path to use for Tailon, set to @code{#f} to not use a path.
18745 @item @code{allow-transfers?} (default: @code{#t})
18746 Allow downloading the log files in the web interface.
18748 @item @code{follow-names?} (default: @code{#t})
18749 Allow tailing of not-yet existent files.
18751 @item @code{tail-lines} (default: @code{200})
18752 Number of lines to read initially from each file.
18754 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18755 Commands to allow running. By default, @code{sed} is disabled.
18757 @item @code{debug?} (default: @code{#f})
18758 Set @code{debug?} to @code{#t} to show debug messages.
18760 @item @code{wrap-lines} (default: @code{#t})
18761 Initial line wrapping state in the web interface. Set to @code{#t} to
18762 initially wrap lines (the default), or to @code{#f} to initially not
18765 @item @code{http-auth} (default: @code{#f})
18766 HTTP authentication type to use. Set to @code{#f} to disable
18767 authentication (the default). Supported values are @code{"digest"} or
18770 @item @code{users} (default: @code{#f})
18771 If HTTP authentication is enabled (see @code{http-auth}), access will be
18772 restricted to the credentials provided here. To configure users, use a
18773 list of pairs, where the first element of the pair is the username, and
18774 the 2nd element of the pair is the password.
18777 (tailon-configuration-file
18778 (http-auth "basic")
18779 (users '(("user1" . "password1")
18780 ("user2" . "password2"))))
18787 @subsubheading Darkstat Service
18789 Darkstat is a packet sniffer that captures network traffic, calculates
18790 statistics about usage, and serves reports over HTTP.
18792 @defvar {Scheme Variable} darkstat-service-type
18793 This is the service type for the
18794 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18795 service, its value must be a @code{darkstat-configuration} record as in
18799 (service darkstat-service-type
18800 (darkstat-configuration
18801 (interface "eno1")))
18805 @deftp {Data Type} darkstat-configuration
18806 Data type representing the configuration of @command{darkstat}.
18809 @item @code{package} (default: @code{darkstat})
18810 The darkstat package to use.
18812 @item @code{interface}
18813 Capture traffic on the specified network interface.
18815 @item @code{port} (default: @code{"667"})
18816 Bind the web interface to the specified port.
18818 @item @code{bind-address} (default: @code{"127.0.0.1"})
18819 Bind the web interface to the specified address.
18821 @item @code{base} (default: @code{"/"})
18822 Specify the path of the base URL. This can be useful if
18823 @command{darkstat} is accessed via a reverse proxy.
18828 @subsubheading Prometheus Node Exporter Service
18830 @cindex prometheus-node-exporter
18831 The Prometheus ``node exporter'' makes hardware and operating system statistics
18832 provided by the Linux kernel available for the Prometheus monitoring system.
18833 This service should be deployed on all physical nodes and virtual machines,
18834 where monitoring these statistics is desirable.
18836 @defvar {Scheme variable} prometheus-node-exporter-service-type
18837 This is the service type for the
18838 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18839 service, its value must be a @code{prometheus-node-exporter-configuration}
18840 record as in this example:
18843 (service prometheus-node-exporter-service-type
18844 (prometheus-node-exporter-configuration
18845 (web-listen-address ":9100")))
18849 @deftp {Data Type} prometheus-node-exporter-configuration
18850 Data type representing the configuration of @command{node_exporter}.
18853 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18854 The prometheus-node-exporter package to use.
18856 @item @code{web-listen-address} (default: @code{":9100"})
18857 Bind the web interface to the specified address.
18862 @subsubheading Zabbix server
18863 @cindex zabbix zabbix-server
18864 Zabbix provides monitoring metrics, among others network utilization, CPU load
18865 and disk space consumption:
18868 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18869 @item Auto-discovery of servers and network devices and interfaces.
18870 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18871 @item Distributed monitoring with centralized web administration.
18872 @item Native high performance agents.
18873 @item SLA, and ITIL KPI metrics on reporting.
18874 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18875 @item Remote command execution through Zabbix proxies.
18878 @c %start of fragment
18880 Available @code{zabbix-server-configuration} fields are:
18882 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18883 The zabbix-server package.
18887 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18888 User who will run the Zabbix server.
18890 Defaults to @samp{"zabbix"}.
18894 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18895 Group who will run the Zabbix server.
18897 Defaults to @samp{"zabbix"}.
18901 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18902 Database host name.
18904 Defaults to @samp{"127.0.0.1"}.
18908 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18911 Defaults to @samp{"zabbix"}.
18915 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18918 Defaults to @samp{"zabbix"}.
18922 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18923 Database password. Please, use @code{include-files} with
18924 @code{DBPassword=SECRET} inside a specified file instead.
18926 Defaults to @samp{""}.
18930 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18933 Defaults to @samp{5432}.
18937 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18938 Specifies where log messages are written to:
18942 @code{system} - syslog.
18945 @code{file} - file specified with @code{log-file} parameter.
18948 @code{console} - standard output.
18952 Defaults to @samp{""}.
18956 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18957 Log file name for @code{log-type} @code{file} parameter.
18959 Defaults to @samp{"/var/log/zabbix/server.log"}.
18963 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18966 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18970 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18971 The location of certificate authority (CA) files for SSL server
18972 certificate verification.
18974 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18978 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18979 Location of SSL client certificates.
18981 Defaults to @samp{"/etc/ssl/certs"}.
18985 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18986 Extra options will be appended to Zabbix server configuration file.
18988 Defaults to @samp{""}.
18992 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18993 You may include individual files or all files in a directory in the
18994 configuration file.
18996 Defaults to @samp{()}.
19000 @c %end of fragment
19002 @subsubheading Zabbix agent
19003 @cindex zabbix zabbix-agent
19005 Zabbix agent gathers information for Zabbix server.
19007 @c %start of fragment
19009 Available @code{zabbix-agent-configuration} fields are:
19011 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19012 The zabbix-agent package.
19016 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19017 User who will run the Zabbix agent.
19019 Defaults to @samp{"zabbix"}.
19023 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19024 Group who will run the Zabbix agent.
19026 Defaults to @samp{"zabbix"}.
19030 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19031 Unique, case sensitive hostname which is required for active checks and
19032 must match hostname as configured on the server.
19034 Defaults to @samp{"Zabbix server"}.
19038 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19039 Specifies where log messages are written to:
19043 @code{system} - syslog.
19046 @code{file} - file specified with @code{log-file} parameter.
19049 @code{console} - standard output.
19053 Defaults to @samp{""}.
19057 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19058 Log file name for @code{log-type} @code{file} parameter.
19060 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19064 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19067 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19071 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19072 List of IP addresses, optionally in CIDR notation, or hostnames of
19073 Zabbix servers and Zabbix proxies. Incoming connections will be
19074 accepted only from the hosts listed here.
19076 Defaults to @samp{("127.0.0.1")}.
19080 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19081 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19082 proxies for active checks. If port is not specified, default port is
19083 used. If this parameter is not specified, active checks are disabled.
19085 Defaults to @samp{("127.0.0.1")}.
19089 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19090 Extra options will be appended to Zabbix server configuration file.
19092 Defaults to @samp{""}.
19096 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19097 You may include individual files or all files in a directory in the
19098 configuration file.
19100 Defaults to @samp{()}.
19104 @c %end of fragment
19106 @subsubheading Zabbix front-end
19107 @cindex zabbix zabbix-front-end
19109 This service provides a WEB interface to Zabbix server.
19111 @c %start of fragment
19113 Available @code{zabbix-front-end-configuration} fields are:
19115 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19116 NGINX configuration.
19120 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19121 Database host name.
19123 Defaults to @samp{"localhost"}.
19127 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19130 Defaults to @samp{5432}.
19134 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19137 Defaults to @samp{"zabbix"}.
19141 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19144 Defaults to @samp{"zabbix"}.
19148 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19149 Database password. Please, use @code{db-secret-file} instead.
19151 Defaults to @samp{""}.
19155 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19156 Secret file which will be appended to @file{zabbix.conf.php} file. This
19157 file contains credentials for use by Zabbix front-end. You are expected
19158 to create it manually.
19160 Defaults to @samp{""}.
19164 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19165 Zabbix server hostname.
19167 Defaults to @samp{"localhost"}.
19171 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19172 Zabbix server port.
19174 Defaults to @samp{10051}.
19179 @c %end of fragment
19181 @node Kerberos Services
19182 @subsection Kerberos Services
19185 The @code{(gnu services kerberos)} module provides services relating to
19186 the authentication protocol @dfn{Kerberos}.
19188 @subsubheading Krb5 Service
19190 Programs using a Kerberos client library normally
19191 expect a configuration file in @file{/etc/krb5.conf}.
19192 This service generates such a file from a definition provided in the
19193 operating system declaration.
19194 It does not cause any daemon to be started.
19196 No ``keytab'' files are provided by this service---you must explicitly create them.
19197 This service is known to work with the MIT client library, @code{mit-krb5}.
19198 Other implementations have not been tested.
19200 @defvr {Scheme Variable} krb5-service-type
19201 A service type for Kerberos 5 clients.
19205 Here is an example of its use:
19207 (service krb5-service-type
19208 (krb5-configuration
19209 (default-realm "EXAMPLE.COM")
19210 (allow-weak-crypto? #t)
19213 (name "EXAMPLE.COM")
19214 (admin-server "groucho.example.com")
19215 (kdc "karl.example.com"))
19218 (admin-server "kerb-admin.argrx.edu")
19219 (kdc "keys.argrx.edu"))))))
19223 This example provides a Kerberos@tie{}5 client configuration which:
19225 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19226 of which have distinct administration servers and key distribution centers;
19227 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19228 specified by clients;
19229 @item Accepts services which only support encryption types known to be weak.
19232 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19233 Only the most commonly used ones are described here.
19234 For a full list, and more detailed explanation of each, see the MIT
19235 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19239 @deftp {Data Type} krb5-realm
19240 @cindex realm, kerberos
19243 This field is a string identifying the name of the realm.
19244 A common convention is to use the fully qualified DNS name of your organization,
19245 converted to upper case.
19247 @item @code{admin-server}
19248 This field is a string identifying the host where the administration server is
19252 This field is a string identifying the key distribution center
19257 @deftp {Data Type} krb5-configuration
19260 @item @code{allow-weak-crypto?} (default: @code{#f})
19261 If this flag is @code{#t} then services which only offer encryption algorithms
19262 known to be weak will be accepted.
19264 @item @code{default-realm} (default: @code{#f})
19265 This field should be a string identifying the default Kerberos
19266 realm for the client.
19267 You should set this field to the name of your Kerberos realm.
19268 If this value is @code{#f}
19269 then a realm must be specified with every Kerberos principal when invoking programs
19270 such as @command{kinit}.
19272 @item @code{realms}
19273 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19275 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19281 @subsubheading PAM krb5 Service
19284 The @code{pam-krb5} service allows for login authentication and password
19285 management via Kerberos.
19286 You will need this service if you want PAM enabled applications to authenticate
19287 users using Kerberos.
19289 @defvr {Scheme Variable} pam-krb5-service-type
19290 A service type for the Kerberos 5 PAM module.
19293 @deftp {Data Type} pam-krb5-configuration
19294 Data type representing the configuration of the Kerberos 5 PAM module.
19295 This type has the following parameters:
19297 @item @code{pam-krb5} (default: @code{pam-krb5})
19298 The pam-krb5 package to use.
19300 @item @code{minimum-uid} (default: @code{1000})
19301 The smallest user ID for which Kerberos authentications should be attempted.
19302 Local accounts with lower values will silently fail to authenticate.
19307 @node LDAP Services
19308 @subsection LDAP Services
19310 @cindex nslcd, LDAP service
19312 The @code{(gnu services authentication)} module provides the
19313 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19314 server. In addition to configuring the service itself, you may want to add
19315 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19316 Switch} for detailed information.
19318 Here is a simple operating system declaration with a default configuration of
19319 the @code{nslcd-service-type} and a Name Service Switch configuration that
19320 consults the @code{ldap} name service last:
19323 (use-service-modules authentication)
19324 (use-modules (gnu system nss))
19330 (service nslcd-service-type)
19331 (service dhcp-client-service-type)
19333 (name-service-switch
19334 (let ((services (list (name-service (name "db"))
19335 (name-service (name "files"))
19336 (name-service (name "ldap")))))
19337 (name-service-switch
19338 (inherit %mdns-host-lookup-nss)
19339 (password services)
19342 (netgroup services)
19343 (gshadow services)))))
19346 @c %start of generated documentation for nslcd-configuration
19348 Available @code{nslcd-configuration} fields are:
19350 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19351 The @code{nss-pam-ldapd} package to use.
19355 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19356 The number of threads to start that can handle requests and perform LDAP
19357 queries. Each thread opens a separate connection to the LDAP server.
19358 The default is to start 5 threads.
19360 Defaults to @samp{disabled}.
19364 @deftypevr {@code{nslcd-configuration} parameter} string uid
19365 This specifies the user id with which the daemon should be run.
19367 Defaults to @samp{"nslcd"}.
19371 @deftypevr {@code{nslcd-configuration} parameter} string gid
19372 This specifies the group id with which the daemon should be run.
19374 Defaults to @samp{"nslcd"}.
19378 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19379 This option controls the way logging is done via a list containing
19380 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19381 or "syslog", or an absolute file name. The LEVEL argument is optional
19382 and specifies the log level. The log level may be one of the following
19383 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19384 messages with the specified log level or higher are logged.
19386 Defaults to @samp{("/var/log/nslcd" info)}.
19390 @deftypevr {@code{nslcd-configuration} parameter} list uri
19391 The list of LDAP server URIs. Normally, only the first server will be
19392 used with the following servers as fall-back.
19394 Defaults to @samp{("ldap://localhost:389/")}.
19398 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19399 The version of the LDAP protocol to use. The default is to use the
19400 maximum version supported by the LDAP library.
19402 Defaults to @samp{disabled}.
19406 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19407 Specifies the distinguished name with which to bind to the directory
19408 server for lookups. The default is to bind anonymously.
19410 Defaults to @samp{disabled}.
19414 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19415 Specifies the credentials with which to bind. This option is only
19416 applicable when used with binddn.
19418 Defaults to @samp{disabled}.
19422 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19423 Specifies the distinguished name to use when the root user tries to
19424 modify a user's password using the PAM module.
19426 Defaults to @samp{disabled}.
19430 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19431 Specifies the credentials with which to bind if the root user tries to
19432 change a user's password. This option is only applicable when used with
19435 Defaults to @samp{disabled}.
19439 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19440 Specifies the SASL mechanism to be used when performing SASL
19443 Defaults to @samp{disabled}.
19447 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19448 Specifies the SASL realm to be used when performing SASL authentication.
19450 Defaults to @samp{disabled}.
19454 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19455 Specifies the authentication identity to be used when performing SASL
19458 Defaults to @samp{disabled}.
19462 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19463 Specifies the authorization identity to be used when performing SASL
19466 Defaults to @samp{disabled}.
19470 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19471 Determines whether the LDAP server host name should be canonicalised. If
19472 this is enabled the LDAP library will do a reverse host name lookup. By
19473 default, it is left up to the LDAP library whether this check is
19476 Defaults to @samp{disabled}.
19480 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19481 Set the name for the GSS-API Kerberos credentials cache.
19483 Defaults to @samp{disabled}.
19487 @deftypevr {@code{nslcd-configuration} parameter} string base
19488 The directory search base.
19490 Defaults to @samp{"dc=example,dc=com"}.
19494 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19495 Specifies the search scope (subtree, onelevel, base or children). The
19496 default scope is subtree; base scope is almost never useful for name
19497 service lookups; children scope is not supported on all servers.
19499 Defaults to @samp{(subtree)}.
19503 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19504 Specifies the policy for dereferencing aliases. The default policy is
19505 to never dereference aliases.
19507 Defaults to @samp{disabled}.
19511 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19512 Specifies whether automatic referral chasing should be enabled. The
19513 default behaviour is to chase referrals.
19515 Defaults to @samp{disabled}.
19519 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19520 This option allows for custom attributes to be looked up instead of the
19521 default RFC 2307 attributes. It is a list of maps, each consisting of
19522 the name of a map, the RFC 2307 attribute to match and the query
19523 expression for the attribute as it is available in the directory.
19525 Defaults to @samp{()}.
19529 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19530 A list of filters consisting of the name of a map to which the filter
19531 applies and an LDAP search filter expression.
19533 Defaults to @samp{()}.
19537 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19538 Specifies the time limit in seconds to use when connecting to the
19539 directory server. The default value is 10 seconds.
19541 Defaults to @samp{disabled}.
19545 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19546 Specifies the time limit (in seconds) to wait for a response from the
19547 LDAP server. A value of zero, which is the default, is to wait
19548 indefinitely for searches to be completed.
19550 Defaults to @samp{disabled}.
19554 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19555 Specifies the period if inactivity (in seconds) after which the con‐
19556 nection to the LDAP server will be closed. The default is not to time
19559 Defaults to @samp{disabled}.
19563 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19564 Specifies the number of seconds to sleep when connecting to all LDAP
19565 servers fails. By default one second is waited between the first
19566 failure and the first retry.
19568 Defaults to @samp{disabled}.
19572 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19573 Specifies the time after which the LDAP server is considered to be
19574 permanently unavailable. Once this time is reached retries will be done
19575 only once per this time period. The default value is 10 seconds.
19577 Defaults to @samp{disabled}.
19581 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19582 Specifies whether to use SSL/TLS or not (the default is not to). If
19583 'start-tls is specified then StartTLS is used rather than raw LDAP over
19586 Defaults to @samp{disabled}.
19590 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19591 Specifies what checks to perform on a server-supplied certificate. The
19592 meaning of the values is described in the ldap.conf(5) manual page.
19594 Defaults to @samp{disabled}.
19598 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19599 Specifies the directory containing X.509 certificates for peer authen‐
19600 tication. This parameter is ignored when using GnuTLS.
19602 Defaults to @samp{disabled}.
19606 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19607 Specifies the path to the X.509 certificate for peer authentication.
19609 Defaults to @samp{disabled}.
19613 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19614 Specifies the path to an entropy source. This parameter is ignored when
19617 Defaults to @samp{disabled}.
19621 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19622 Specifies the ciphers to use for TLS as a string.
19624 Defaults to @samp{disabled}.
19628 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19629 Specifies the path to the file containing the local certificate for
19630 client TLS authentication.
19632 Defaults to @samp{disabled}.
19636 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19637 Specifies the path to the file containing the private key for client TLS
19640 Defaults to @samp{disabled}.
19644 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19645 Set this to a number greater than 0 to request paged results from the
19646 LDAP server in accordance with RFC2696. The default (0) is to not
19647 request paged results.
19649 Defaults to @samp{disabled}.
19653 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19654 This option prevents group membership lookups through LDAP for the
19655 specified users. Alternatively, the value 'all-local may be used. With
19656 that value nslcd builds a full list of non-LDAP users on startup.
19658 Defaults to @samp{disabled}.
19662 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19663 This option ensures that LDAP users with a numeric user id lower than
19664 the specified value are ignored.
19666 Defaults to @samp{disabled}.
19670 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19671 This option specifies an offset that is added to all LDAP numeric user
19672 ids. This can be used to avoid user id collisions with local users.
19674 Defaults to @samp{disabled}.
19678 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19679 This option specifies an offset that is added to all LDAP numeric group
19680 ids. This can be used to avoid user id collisions with local groups.
19682 Defaults to @samp{disabled}.
19686 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19687 If this option is set, the member attribute of a group may point to
19688 another group. Members of nested groups are also returned in the higher
19689 level group and parent groups are returned when finding groups for a
19690 specific user. The default is not to perform extra searches for nested
19693 Defaults to @samp{disabled}.
19697 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19698 If this option is set, the group member list is not retrieved when
19699 looking up groups. Lookups for finding which groups a user belongs to
19700 will remain functional so the user will likely still get the correct
19701 groups assigned on login.
19703 Defaults to @samp{disabled}.
19707 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19708 If this option is set, functions which cause all user/group entries to
19709 be loaded from the directory will not succeed in doing so. This can
19710 dramatically reduce LDAP server load in situations where there are a
19711 great number of users and/or groups. This option is not recommended for
19712 most configurations.
19714 Defaults to @samp{disabled}.
19718 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19719 This option can be used to specify how user and group names are verified
19720 within the system. This pattern is used to check all user and group
19721 names that are requested and returned from LDAP.
19723 Defaults to @samp{disabled}.
19727 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19728 This specifies whether or not to perform searches using case-insensitive
19729 matching. Enabling this could open up the system to authorization
19730 bypass vulnerabilities and introduce nscd cache poisoning
19731 vulnerabilities which allow denial of service.
19733 Defaults to @samp{disabled}.
19737 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19738 This option specifies whether password policy controls are requested and
19739 handled from the LDAP server when performing user authentication.
19741 Defaults to @samp{disabled}.
19745 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19746 By default nslcd performs an LDAP search with the user's credentials
19747 after BIND (authentication) to ensure that the BIND operation was
19748 successful. The default search is a simple check to see if the user's
19749 DN exists. A search filter can be specified that will be used instead.
19750 It should return at least one entry.
19752 Defaults to @samp{disabled}.
19756 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19757 This option allows flexible fine tuning of the authorisation check that
19758 should be performed. The search filter specified is executed and if any
19759 entries match, access is granted, otherwise access is denied.
19761 Defaults to @samp{disabled}.
19765 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19766 If this option is set password modification using pam_ldap will be
19767 denied and the specified message will be presented to the user instead.
19768 The message can be used to direct the user to an alternative means of
19769 changing their password.
19771 Defaults to @samp{disabled}.
19775 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19776 List of pam service names for which LDAP authentication should suffice.
19778 Defaults to @samp{()}.
19782 @c %end of generated documentation for nslcd-configuration
19786 @subsection Web Services
19791 The @code{(gnu services web)} module provides the Apache HTTP Server,
19792 the nginx web server, and also a fastcgi wrapper daemon.
19794 @subsubheading Apache HTTP Server
19796 @deffn {Scheme Variable} httpd-service-type
19797 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19798 (@dfn{httpd}). The value for this service type is a
19799 @code{httpd-configuration} record.
19801 A simple example configuration is given below.
19804 (service httpd-service-type
19805 (httpd-configuration
19808 (server-name "www.example.com")
19809 (document-root "/srv/http/www.example.com")))))
19812 Other services can also extend the @code{httpd-service-type} to add to
19816 (simple-service 'www.example.com-server httpd-service-type
19820 (list (string-join '("ServerName www.example.com"
19821 "DocumentRoot /srv/http/www.example.com")
19826 The details for the @code{httpd-configuration}, @code{httpd-module},
19827 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19830 @deffn {Data Type} httpd-configuration
19831 This data type represents the configuration for the httpd service.
19834 @item @code{package} (default: @code{httpd})
19835 The httpd package to use.
19837 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19838 The pid file used by the shepherd-service.
19840 @item @code{config} (default: @code{(httpd-config-file)})
19841 The configuration file to use with the httpd service. The default value
19842 is a @code{httpd-config-file} record, but this can also be a different
19843 G-expression that generates a file, for example a @code{plain-file}. A
19844 file outside of the store can also be specified through a string.
19849 @deffn {Data Type} httpd-module
19850 This data type represents a module for the httpd service.
19854 The name of the module.
19857 The file for the module. This can be relative to the httpd package being
19858 used, the absolute location of a file, or a G-expression for a file
19859 within the store, for example @code{(file-append mod-wsgi
19860 "/modules/mod_wsgi.so")}.
19865 @defvr {Scheme Variable} %default-httpd-modules
19866 A default list of @code{httpd-module} objects.
19869 @deffn {Data Type} httpd-config-file
19870 This data type represents a configuration file for the httpd service.
19873 @item @code{modules} (default: @code{%default-httpd-modules})
19874 The modules to load. Additional modules can be added here, or loaded by
19875 additional configuration.
19877 For example, in order to handle requests for PHP files, you can use Apache’s
19878 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19881 (service httpd-service-type
19882 (httpd-configuration
19887 (name "proxy_module")
19888 (file "modules/mod_proxy.so"))
19890 (name "proxy_fcgi_module")
19891 (file "modules/mod_proxy_fcgi.so"))
19892 %default-httpd-modules))
19893 (extra-config (list "\
19894 <FilesMatch \\.php$>
19895 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19896 </FilesMatch>"))))))
19897 (service php-fpm-service-type
19898 (php-fpm-configuration
19899 (socket "/var/run/php-fpm.sock")
19900 (socket-group "httpd")))
19903 @item @code{server-root} (default: @code{httpd})
19904 The @code{ServerRoot} in the configuration file, defaults to the httpd
19905 package. Directives including @code{Include} and @code{LoadModule} are
19906 taken as relative to the server root.
19908 @item @code{server-name} (default: @code{#f})
19909 The @code{ServerName} in the configuration file, used to specify the
19910 request scheme, hostname and port that the server uses to identify
19913 This doesn't need to be set in the server config, and can be specifyed
19914 in virtual hosts. The default is @code{#f} to not specify a
19917 @item @code{document-root} (default: @code{"/srv/http"})
19918 The @code{DocumentRoot} from which files will be served.
19920 @item @code{listen} (default: @code{'("80")})
19921 The list of values for the @code{Listen} directives in the config
19922 file. The value should be a list of strings, when each string can
19923 specify the port number to listen on, and optionally the IP address and
19926 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19927 The @code{PidFile} to use. This should match the @code{pid-file} set in
19928 the @code{httpd-configuration} so that the Shepherd service is
19929 configured correctly.
19931 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19932 The @code{ErrorLog} to which the server will log errors.
19934 @item @code{user} (default: @code{"httpd"})
19935 The @code{User} which the server will answer requests as.
19937 @item @code{group} (default: @code{"httpd"})
19938 The @code{Group} which the server will answer requests as.
19940 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19941 A flat list of strings and G-expressions which will be added to the end
19942 of the configuration file.
19944 Any values which the service is extended with will be appended to this
19950 @deffn {Data Type} httpd-virtualhost
19951 This data type represents a virtualhost configuration block for the httpd service.
19953 These should be added to the extra-config for the httpd-service.
19956 (simple-service 'www.example.com-server httpd-service-type
19960 (list (string-join '("ServerName www.example.com"
19961 "DocumentRoot /srv/http/www.example.com")
19966 @item @code{addresses-and-ports}
19967 The addresses and ports for the @code{VirtualHost} directive.
19969 @item @code{contents}
19970 The contents of the @code{VirtualHost} directive, this should be a list
19971 of strings and G-expressions.
19976 @subsubheading NGINX
19978 @deffn {Scheme Variable} nginx-service-type
19979 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19980 value for this service type is a @code{<nginx-configuration>} record.
19982 A simple example configuration is given below.
19985 (service nginx-service-type
19986 (nginx-configuration
19988 (list (nginx-server-configuration
19989 (server-name '("www.example.com"))
19990 (root "/srv/http/www.example.com"))))))
19993 In addition to adding server blocks to the service configuration
19994 directly, this service can be extended by other services to add server
19995 blocks, as in this example:
19998 (simple-service 'my-extra-server nginx-service-type
19999 (list (nginx-server-configuration
20000 (root "/srv/http/extra-website")
20001 (try-files (list "$uri" "$uri/index.html")))))
20005 At startup, @command{nginx} has not yet read its configuration file, so
20006 it uses a default file to log error messages. If it fails to load its
20007 configuration file, that is where error messages are logged. After the
20008 configuration file is loaded, the default error log file changes as per
20009 configuration. In our case, startup error messages can be found in
20010 @file{/var/run/nginx/logs/error.log}, and after configuration in
20011 @file{/var/log/nginx/error.log}. The second location can be changed
20012 with the @var{log-directory} configuration option.
20014 @deffn {Data Type} nginx-configuration
20015 This data type represents the configuration for NGinx. Some
20016 configuration can be done through this and the other provided record
20017 types, or alternatively, a config file can be provided.
20020 @item @code{nginx} (default: @code{nginx})
20021 The nginx package to use.
20023 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20024 The directory to which NGinx will write log files.
20026 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20027 The directory in which NGinx will create a pid file, and write temporary
20030 @item @code{server-blocks} (default: @code{'()})
20031 A list of @dfn{server blocks} to create in the generated configuration
20032 file, the elements should be of type
20033 @code{<nginx-server-configuration>}.
20035 The following example would setup NGinx to serve @code{www.example.com}
20036 from the @code{/srv/http/www.example.com} directory, without using
20039 (service nginx-service-type
20040 (nginx-configuration
20042 (list (nginx-server-configuration
20043 (server-name '("www.example.com"))
20044 (root "/srv/http/www.example.com"))))))
20047 @item @code{upstream-blocks} (default: @code{'()})
20048 A list of @dfn{upstream blocks} to create in the generated configuration
20049 file, the elements should be of type
20050 @code{<nginx-upstream-configuration>}.
20052 Configuring upstreams through the @code{upstream-blocks} can be useful
20053 when combined with @code{locations} in the
20054 @code{<nginx-server-configuration>} records. The following example
20055 creates a server configuration with one location configuration, that
20056 will proxy requests to a upstream configuration, which will handle
20057 requests with two servers.
20062 (nginx-configuration
20064 (list (nginx-server-configuration
20065 (server-name '("www.example.com"))
20066 (root "/srv/http/www.example.com")
20069 (nginx-location-configuration
20071 (body '("proxy_pass http://server-proxy;"))))))))
20073 (list (nginx-upstream-configuration
20074 (name "server-proxy")
20075 (servers (list "server1.example.com"
20076 "server2.example.com")))))))
20079 @item @code{file} (default: @code{#f})
20080 If a configuration @var{file} is provided, this will be used, rather than
20081 generating a configuration file from the provided @code{log-directory},
20082 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20083 proper operation, these arguments should match what is in @var{file} to ensure
20084 that the directories are created when the service is activated.
20086 This can be useful if you have an existing configuration file, or it's
20087 not possible to do what is required through the other parts of the
20088 nginx-configuration record.
20090 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20091 Bucket size for the server names hash tables, defaults to @code{#f} to
20092 use the size of the processors cache line.
20094 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20095 Maximum bucket size for the server names hash tables.
20097 @item @code{modules} (default: @code{'()})
20098 List of nginx dynamic modules to load. This should be a list of file
20099 names of loadable modules, as in this example:
20104 (file-append nginx-accept-language-module "\
20105 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20108 @item @code{extra-content} (default: @code{""})
20109 Extra content for the @code{http} block. Should be string or a string
20110 valued G-expression.
20115 @deftp {Data Type} nginx-server-configuration
20116 Data type representing the configuration of an nginx server block.
20117 This type has the following parameters:
20120 @item @code{listen} (default: @code{'("80" "443 ssl")})
20121 Each @code{listen} directive sets the address and port for IP, or the
20122 path for a UNIX-domain socket on which the server will accept requests.
20123 Both address and port, or only address or only port can be specified.
20124 An address may also be a hostname, for example:
20127 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20130 @item @code{server-name} (default: @code{(list 'default)})
20131 A list of server names this server represents. @code{'default} represents the
20132 default server for connections matching no other server.
20134 @item @code{root} (default: @code{"/srv/http"})
20135 Root of the website nginx will serve.
20137 @item @code{locations} (default: @code{'()})
20138 A list of @dfn{nginx-location-configuration} or
20139 @dfn{nginx-named-location-configuration} records to use within this
20142 @item @code{index} (default: @code{(list "index.html")})
20143 Index files to look for when clients ask for a directory. If it cannot be found,
20144 Nginx will send the list of files in the directory.
20146 @item @code{try-files} (default: @code{'()})
20147 A list of files whose existence is checked in the specified order.
20148 @code{nginx} will use the first file it finds to process the request.
20150 @item @code{ssl-certificate} (default: @code{#f})
20151 Where to find the certificate for secure connections. Set it to @code{#f} if
20152 you don't have a certificate or you don't want to use HTTPS.
20154 @item @code{ssl-certificate-key} (default: @code{#f})
20155 Where to find the private key for secure connections. Set it to @code{#f} if
20156 you don't have a key or you don't want to use HTTPS.
20158 @item @code{server-tokens?} (default: @code{#f})
20159 Whether the server should add its configuration to response.
20161 @item @code{raw-content} (default: @code{'()})
20162 A list of raw lines added to the server block.
20167 @deftp {Data Type} nginx-upstream-configuration
20168 Data type representing the configuration of an nginx @code{upstream}
20169 block. This type has the following parameters:
20173 Name for this group of servers.
20175 @item @code{servers}
20176 Specify the addresses of the servers in the group. The address can be
20177 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20178 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20179 prefix @samp{unix:}. For addresses using an IP address or domain name,
20180 the default port is 80, and a different port can be specified
20186 @deftp {Data Type} nginx-location-configuration
20187 Data type representing the configuration of an nginx @code{location}
20188 block. This type has the following parameters:
20192 URI which this location block matches.
20194 @anchor{nginx-location-configuration body}
20196 Body of the location block, specified as a list of strings. This can contain
20198 configuration directives. For example, to pass requests to a upstream
20199 server group defined using an @code{nginx-upstream-configuration} block,
20200 the following directive would be specified in the body @samp{(list "proxy_pass
20201 http://upstream-name;")}.
20206 @deftp {Data Type} nginx-named-location-configuration
20207 Data type representing the configuration of an nginx named location
20208 block. Named location blocks are used for request redirection, and not
20209 used for regular request processing. This type has the following
20214 Name to identify this location block.
20217 @xref{nginx-location-configuration body}, as the body for named location
20218 blocks can be used in a similar way to the
20219 @code{nginx-location-configuration body}. One restriction is that the
20220 body of a named location block cannot contain location blocks.
20225 @subsubheading Varnish Cache
20227 Varnish is a fast cache server that sits in between web applications
20228 and end users. It proxies requests from clients and caches the
20229 accessed URLs such that multiple requests for the same resource only
20230 creates one request to the back-end.
20232 @defvr {Scheme Variable} varnish-service-type
20233 Service type for the Varnish daemon.
20236 @deftp {Data Type} varnish-configuration
20237 Data type representing the @code{varnish} service configuration.
20238 This type has the following parameters:
20241 @item @code{package} (default: @code{varnish})
20242 The Varnish package to use.
20244 @item @code{name} (default: @code{"default"})
20245 A name for this Varnish instance. Varnish will create a directory in
20246 @file{/var/varnish/} with this name and keep temporary files there. If
20247 the name starts with a forward slash, it is interpreted as an absolute
20250 Pass the @code{-n} argument to other Varnish programs to connect to the
20251 named instance, e.g.@: @command{varnishncsa -n default}.
20253 @item @code{backend} (default: @code{"localhost:8080"})
20254 The backend to use. This option has no effect if @code{vcl} is set.
20256 @item @code{vcl} (default: #f)
20257 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20258 is @code{#f}, Varnish will proxy @code{backend} using the default
20259 configuration. Otherwise this must be a file-like object with valid
20262 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20263 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
20264 can do something along these lines:
20267 (define %gnu-mirror
20268 (plain-file "gnu.vcl"
20270 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20274 (services (cons (service varnish-service-type
20275 (varnish-configuration
20277 (vcl %gnu-mirror)))
20281 The configuration of an already running Varnish instance can be inspected
20282 and changed using the @command{varnishadm} program.
20284 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20285 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20286 comprehensive documentation on Varnish and its configuration language.
20288 @item @code{listen} (default: @code{'("localhost:80")})
20289 List of addresses Varnish will listen on.
20291 @item @code{storage} (default: @code{'("malloc,128m")})
20292 List of storage backends that will be available in VCL.
20294 @item @code{parameters} (default: @code{'()})
20295 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20297 @item @code{extra-options} (default: @code{'()})
20298 Additional arguments to pass to the @command{varnishd} process.
20303 @subsubheading Patchwork
20305 Patchwork is a patch tracking system. It can collect patches sent to a
20306 mailing list, and display them in a web interface.
20308 @defvr {Scheme Variable} patchwork-service-type
20309 Service type for Patchwork.
20312 The following example is an example of a minimal service for Patchwork, for
20313 the @code{patchwork.example.com} domain.
20316 (service patchwork-service-type
20317 (patchwork-configuration
20318 (domain "patchwork.example.com")
20320 (patchwork-settings-module
20321 (allowed-hosts (list domain))
20322 (default-from-email "patchwork@@patchwork.example.com")))
20323 (getmail-retriever-config
20324 (getmail-retriever-configuration
20325 (type "SimpleIMAPSSLRetriever")
20326 (server "imap.example.com")
20328 (username "patchwork")
20330 (list (file-append coreutils "/bin/cat")
20331 "/etc/getmail-patchwork-imap-password"))
20333 '((mailboxes . ("Patches"))))))))
20337 There are three records for configuring the Patchwork service. The
20338 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20339 within the HTTPD service.
20341 The @code{settings-module} field within the @code{<patchwork-configuration>}
20342 record can be populated with the @code{<patchwork-settings-module>} record,
20343 which describes a settings module that is generated within the Guix store.
20345 For the @code{database-configuration} field within the
20346 @code{<patchwork-settings-module>}, the
20347 @code{<patchwork-database-configuration>} must be used.
20349 @deftp {Data Type} patchwork-configuration
20350 Data type representing the Patchwork service configuration. This type has the
20351 following parameters:
20354 @item @code{patchwork} (default: @code{patchwork})
20355 The Patchwork package to use.
20357 @item @code{domain}
20358 The domain to use for Patchwork, this is used in the HTTPD service virtual
20361 @item @code{settings-module}
20362 The settings module to use for Patchwork. As a Django application, Patchwork
20363 is configured with a Python module containing the settings. This can either be
20364 an instance of the @code{<patchwork-settings-module>} record, any other record
20365 that represents the settings in the store, or a directory outside of the
20368 @item @code{static-path} (default: @code{"/static/"})
20369 The path under which the HTTPD service should serve the static files.
20371 @item @code{getmail-retriever-config}
20372 The getmail-retriever-configuration record value to use with
20373 Patchwork. Getmail will be configured with this value, the messages will be
20374 delivered to Patchwork.
20379 @deftp {Data Type} patchwork-settings-module
20380 Data type representing a settings module for Patchwork. Some of these
20381 settings relate directly to Patchwork, but others relate to Django, the web
20382 framework used by Patchwork, or the Django Rest Framework library. This type
20383 has the following parameters:
20386 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20387 The database connection settings used for Patchwork. See the
20388 @code{<patchwork-database-configuration>} record type for more information.
20390 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20391 Patchwork, as a Django web application uses a secret key for cryptographically
20392 signing values. This file should contain a unique unpredictable value.
20394 If this file does not exist, it will be created and populated with a random
20395 value by the patchwork-setup shepherd service.
20397 This setting relates to Django.
20399 @item @code{allowed-hosts}
20400 A list of valid hosts for this Patchwork service. This should at least include
20401 the domain specified in the @code{<patchwork-configuration>} record.
20403 This is a Django setting.
20405 @item @code{default-from-email}
20406 The email address from which Patchwork should send email by default.
20408 This is a Patchwork setting.
20410 @item @code{static-url} (default: @code{#f})
20411 The URL to use when serving static assets. It can be part of a URL, or a full
20412 URL, but must end in a @code{/}.
20414 If the default value is used, the @code{static-path} value from the
20415 @code{<patchwork-configuration>} record will be used.
20417 This is a Django setting.
20419 @item @code{admins} (default: @code{'()})
20420 Email addresses to send the details of errors that occur. Each value should
20421 be a list containing two elements, the name and then the email address.
20423 This is a Django setting.
20425 @item @code{debug?} (default: @code{#f})
20426 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20427 messages will be shown.
20429 This is a Django setting.
20431 @item @code{enable-rest-api?} (default: @code{#t})
20432 Whether to enable the Patchwork REST API.
20434 This is a Patchwork setting.
20436 @item @code{enable-xmlrpc?} (default: @code{#t})
20437 Whether to enable the XML RPC API.
20439 This is a Patchwork setting.
20441 @item @code{force-https-links?} (default: @code{#t})
20442 Whether to use HTTPS links on Patchwork pages.
20444 This is a Patchwork setting.
20446 @item @code{extra-settings} (default: @code{""})
20447 Extra code to place at the end of the Patchwork settings module.
20452 @deftp {Data Type} patchwork-database-configuration
20453 Data type representing the database configuration for Patchwork.
20456 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20457 The database engine to use.
20459 @item @code{name} (default: @code{"patchwork"})
20460 The name of the database to use.
20462 @item @code{user} (default: @code{"httpd"})
20463 The user to connect to the database as.
20465 @item @code{password} (default: @code{""})
20466 The password to use when connecting to the database.
20468 @item @code{host} (default: @code{""})
20469 The host to make the database connection to.
20471 @item @code{port} (default: @code{""})
20472 The port on which to connect to the database.
20477 @subsubheading Mumi
20479 @cindex Mumi, Debbugs Web interface
20480 @cindex Debbugs, Mumi Web interface
20481 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
20482 Web interface to the Debbugs bug tracker, by default for
20483 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
20484 but it also fetches and indexes mail retrieved from Debbugs.
20486 @defvr {Scheme Variable} mumi-service-type
20487 This is the service type for Mumi.
20490 @subsubheading FastCGI
20493 FastCGI is an interface between the front-end and the back-end of a web
20494 service. It is a somewhat legacy facility; new web services should
20495 generally just talk HTTP between the front-end and the back-end.
20496 However there are a number of back-end services such as PHP or the
20497 optimized HTTP Git repository access that use FastCGI, so we have
20498 support for it in Guix.
20500 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20501 dispatch some subset of its requests to the fastcgi backend, which
20502 listens on a local TCP or UNIX socket. There is an intermediary
20503 @code{fcgiwrap} program that sits between the actual backend process and
20504 the web server. The front-end indicates which backend program to run,
20505 passing that information to the @code{fcgiwrap} process.
20507 @defvr {Scheme Variable} fcgiwrap-service-type
20508 A service type for the @code{fcgiwrap} FastCGI proxy.
20511 @deftp {Data Type} fcgiwrap-configuration
20512 Data type representing the configuration of the @code{fcgiwrap} service.
20513 This type has the following parameters:
20515 @item @code{package} (default: @code{fcgiwrap})
20516 The fcgiwrap package to use.
20518 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20519 The socket on which the @code{fcgiwrap} process should listen, as a
20520 string. Valid @var{socket} values include
20521 @code{unix:@var{/path/to/unix/socket}},
20522 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20523 @code{tcp6:[@var{ipv6_addr}]:port}.
20525 @item @code{user} (default: @code{fcgiwrap})
20526 @itemx @code{group} (default: @code{fcgiwrap})
20527 The user and group names, as strings, under which to run the
20528 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20529 the user asks for the specific user or group names @code{fcgiwrap} that
20530 the corresponding user and/or group is present on the system.
20532 It is possible to configure a FastCGI-backed web service to pass HTTP
20533 authentication information from the front-end to the back-end, and to
20534 allow @code{fcgiwrap} to run the back-end process as a corresponding
20535 local user. To enable this capability on the back-end, run
20536 @code{fcgiwrap} as the @code{root} user and group. Note that this
20537 capability also has to be configured on the front-end as well.
20542 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20543 with some additional features useful for sites of any size.
20545 These features include:
20547 @item Adaptive process spawning
20548 @item Basic statistics (similar to Apache's mod_status)
20549 @item Advanced process management with graceful stop/start
20550 @item Ability to start workers with different uid/gid/chroot/environment
20551 and different php.ini (replaces safe_mode)
20552 @item Stdout & stderr logging
20553 @item Emergency restart in case of accidental opcode cache destruction
20554 @item Accelerated upload support
20555 @item Support for a "slowlog"
20556 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20557 a special function to finish request & flush all data while continuing to do
20558 something time-consuming (video converting, stats processing, etc.)
20560 ...@: and much more.
20562 @defvr {Scheme Variable} php-fpm-service-type
20563 A Service type for @code{php-fpm}.
20566 @deftp {Data Type} php-fpm-configuration
20567 Data Type for php-fpm service configuration.
20569 @item @code{php} (default: @code{php})
20570 The php package to use.
20571 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20572 The address on which to accept FastCGI requests. Valid syntaxes are:
20574 @item @code{"ip.add.re.ss:port"}
20575 Listen on a TCP socket to a specific address on a specific port.
20576 @item @code{"port"}
20577 Listen on a TCP socket to all addresses on a specific port.
20578 @item @code{"/path/to/unix/socket"}
20579 Listen on a unix socket.
20582 @item @code{user} (default: @code{php-fpm})
20583 User who will own the php worker processes.
20584 @item @code{group} (default: @code{php-fpm})
20585 Group of the worker processes.
20586 @item @code{socket-user} (default: @code{php-fpm})
20587 User who can speak to the php-fpm socket.
20588 @item @code{socket-group} (default: @code{nginx})
20589 Group that can speak to the php-fpm socket.
20590 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20591 The process id of the php-fpm process is written to this file
20592 once the service has started.
20593 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20594 Log for the php-fpm master process.
20595 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20596 Detailed settings for the php-fpm process manager.
20599 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20600 @item @code{<php-fpm-static-process-manager-configuration>}
20601 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20603 @item @code{display-errors} (default @code{#f})
20604 Determines whether php errors and warning should be sent to clients
20605 and displayed in their browsers.
20606 This is useful for local php development, but a security risk for public sites,
20607 as error messages can reveal passwords and personal data.
20608 @item @code{timezone} (default @code{#f})
20609 Specifies @code{php_admin_value[date.timezone]} parameter.
20610 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20611 This file will log the @code{stderr} outputs of php worker processes.
20612 Can be set to @code{#f} to disable logging.
20613 @item @code{file} (default @code{#f})
20614 An optional override of the whole configuration.
20615 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20619 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20620 Data Type for the @code{dynamic} php-fpm process manager. With the
20621 @code{dynamic} process manager, spare worker processes are kept around
20622 based on it's configured limits.
20624 @item @code{max-children} (default: @code{5})
20625 Maximum of worker processes.
20626 @item @code{start-servers} (default: @code{2})
20627 How many worker processes should be started on start-up.
20628 @item @code{min-spare-servers} (default: @code{1})
20629 How many spare worker processes should be kept around at minimum.
20630 @item @code{max-spare-servers} (default: @code{3})
20631 How many spare worker processes should be kept around at maximum.
20635 @deftp {Data type} php-fpm-static-process-manager-configuration
20636 Data Type for the @code{static} php-fpm process manager. With the
20637 @code{static} process manager, an unchanging number of worker processes
20640 @item @code{max-children} (default: @code{5})
20641 Maximum of worker processes.
20645 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20646 Data Type for the @code{on-demand} php-fpm process manager. With the
20647 @code{on-demand} process manager, worker processes are only created as
20650 @item @code{max-children} (default: @code{5})
20651 Maximum of worker processes.
20652 @item @code{process-idle-timeout} (default: @code{10})
20653 The time in seconds after which a process with no requests is killed.
20658 @deffn {Scheme Procedure} nginx-php-fpm-location @
20659 [#:nginx-package nginx] @
20660 [socket (string-append "/var/run/php" @
20661 (version-major (package-version php)) @
20663 A helper function to quickly add php to an @code{nginx-server-configuration}.
20666 A simple services setup for nginx with php can look like this:
20668 (services (cons* (service dhcp-client-service-type)
20669 (service php-fpm-service-type)
20670 (service nginx-service-type
20671 (nginx-server-configuration
20672 (server-name '("example.com"))
20673 (root "/srv/http/")
20675 (list (nginx-php-location)))
20677 (ssl-certificate #f)
20678 (ssl-certificate-key #f)))
20682 @cindex cat-avatar-generator
20683 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20684 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20685 the hash of a user's email address.
20687 @deffn {Scheme Procedure} cat-avatar-generator-service @
20688 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20689 [#:package cat-avatar-generator] @
20690 [#:configuration (nginx-server-configuration)]
20691 Returns an nginx-server-configuration that inherits @code{configuration}. It
20692 extends the nginx configuration to add a server block that serves @code{package},
20693 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20694 be able to use @code{cache-dir} as its cache directory.
20697 A simple setup for cat-avatar-generator can look like this:
20699 (services (cons* (cat-avatar-generator-service
20701 (nginx-server-configuration
20702 (server-name '("example.com"))))
20707 @subsubheading Hpcguix-web
20709 @cindex hpcguix-web
20710 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20711 program is a customizable web interface to browse Guix packages,
20712 initially designed for users of high-performance computing (HPC)
20715 @defvr {Scheme Variable} hpcguix-web-service-type
20716 The service type for @code{hpcguix-web}.
20719 @deftp {Data Type} hpcguix-web-configuration
20720 Data type for the hpcguix-web service configuration.
20724 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20725 configuration. The main items available in this spec are:
20728 @item @code{title-prefix} (default: @code{"hpcguix | "})
20729 The page title prefix.
20731 @item @code{guix-command} (default: @code{"guix"})
20732 The @command{guix} command.
20734 @item @code{package-filter-proc} (default: @code{(const #t)})
20735 A procedure specifying how to filter packages that are displayed.
20737 @item @code{package-page-extension-proc} (default: @code{(const '())})
20738 Extension package for @code{hpcguix-web}.
20740 @item @code{menu} (default: @code{'()})
20741 Additional entry in page @code{menu}.
20743 @item @code{channels} (default: @code{%default-channels})
20744 List of channels from which the package list is built (@pxref{Channels}).
20746 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20747 The expiration time, in seconds, after which the package list is rebuilt from
20748 the latest instances of the given channels.
20751 See the hpcguix-web repository for a
20752 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20755 @item @code{package} (default: @code{hpcguix-web})
20756 The hpcguix-web package to use.
20760 A typical hpcguix-web service declaration looks like this:
20763 (service hpcguix-web-service-type
20764 (hpcguix-web-configuration
20766 #~(define site-config
20767 (hpcweb-configuration
20768 (title-prefix "Guix-HPC - ")
20769 (menu '(("/about" "ABOUT"))))))))
20773 The hpcguix-web service periodically updates the package list it publishes by
20774 pulling channels from Git. To that end, it needs to access X.509 certificates
20775 so that it can authenticate Git servers when communicating over HTTPS, and it
20776 assumes that @file{/etc/ssl/certs} contains those certificates.
20778 Thus, make sure to add @code{nss-certs} or another certificate package to the
20779 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20780 more information on X.509 certificates.
20783 @node Certificate Services
20784 @subsection Certificate Services
20787 @cindex HTTP, HTTPS
20788 @cindex Let's Encrypt
20789 @cindex TLS certificates
20790 The @code{(gnu services certbot)} module provides a service to
20791 automatically obtain a valid TLS certificate from the Let's Encrypt
20792 certificate authority. These certificates can then be used to serve
20793 content securely over HTTPS or other TLS-based protocols, with the
20794 knowledge that the client will be able to verify the server's
20797 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20798 @code{certbot} tool to automate the certification process. This tool
20799 first securely generates a key on the server. It then makes a request
20800 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20801 checks that the request originates from the host in question by using a
20802 challenge-response protocol, requiring the server to provide its
20803 response over HTTP. If that protocol completes successfully, the CA
20804 signs the key, resulting in a certificate. That certificate is valid
20805 for a limited period of time, and therefore to continue to provide TLS
20806 services, the server needs to periodically ask the CA to renew its
20809 The certbot service automates this process: the initial key
20810 generation, the initial certification request to the Let's Encrypt
20811 service, the web server challenge/response integration, writing the
20812 certificate to disk, the automated periodic renewals, and the deployment
20813 tasks associated with the renewal (e.g.@: reloading services, copying keys
20814 with different permissions).
20816 Certbot is run twice a day, at a random minute within the hour. It
20817 won't do anything until your certificates are due for renewal or
20818 revoked, but running it regularly would give your service a chance of
20819 staying online in case a Let's Encrypt-initiated revocation happened for
20822 By using this service, you agree to the ACME Subscriber Agreement, which
20823 can be found there:
20824 @url{https://acme-v01.api.letsencrypt.org/directory}.
20826 @defvr {Scheme Variable} certbot-service-type
20827 A service type for the @code{certbot} Let's Encrypt client. Its value
20828 must be a @code{certbot-configuration} record as in this example:
20831 (define %nginx-deploy-hook
20833 "nginx-deploy-hook"
20834 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20835 (kill pid SIGHUP))))
20837 (service certbot-service-type
20838 (certbot-configuration
20839 (email "foo@@example.net")
20842 (certificate-configuration
20843 (domains '("example.net" "www.example.net"))
20844 (deploy-hook %nginx-deploy-hook))
20845 (certificate-configuration
20846 (domains '("bar.example.net")))))))
20849 See below for details about @code{certbot-configuration}.
20852 @deftp {Data Type} certbot-configuration
20853 Data type representing the configuration of the @code{certbot} service.
20854 This type has the following parameters:
20857 @item @code{package} (default: @code{certbot})
20858 The certbot package to use.
20860 @item @code{webroot} (default: @code{/var/www})
20861 The directory from which to serve the Let's Encrypt challenge/response
20864 @item @code{certificates} (default: @code{()})
20865 A list of @code{certificates-configuration}s for which to generate
20866 certificates and request signatures. Each certificate has a @code{name}
20867 and several @code{domains}.
20870 Mandatory email used for registration, recovery contact, and important
20871 account notifications.
20873 @item @code{rsa-key-size} (default: @code{2048})
20874 Size of the RSA key.
20876 @item @code{default-location} (default: @i{see below})
20877 The default @code{nginx-location-configuration}. Because @code{certbot}
20878 needs to be able to serve challenges and responses, it needs to be able
20879 to run a web server. It does so by extending the @code{nginx} web
20880 service with an @code{nginx-server-configuration} listening on the
20881 @var{domains} on port 80, and which has a
20882 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20883 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20884 these nginx configuration data types.
20886 Requests to other URL paths will be matched by the
20887 @code{default-location}, which if present is added to all
20888 @code{nginx-server-configuration}s.
20890 By default, the @code{default-location} will issue a redirect from
20891 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20892 you to define what to serve on your site via @code{https}.
20894 Pass @code{#f} to not issue a default location.
20898 @deftp {Data Type} certificate-configuration
20899 Data type representing the configuration of a certificate.
20900 This type has the following parameters:
20903 @item @code{name} (default: @i{see below})
20904 This name is used by Certbot for housekeeping and in file paths; it
20905 doesn't affect the content of the certificate itself. To see
20906 certificate names, run @code{certbot certificates}.
20908 Its default is the first provided domain.
20910 @item @code{domains} (default: @code{()})
20911 The first domain provided will be the subject CN of the certificate, and
20912 all domains will be Subject Alternative Names on the certificate.
20914 @item @code{challenge} (default: @code{#f})
20915 The challenge type that has to be run by certbot. If @code{#f} is specified,
20916 default to the HTTP challenge. If a value is specified, defaults to the
20917 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20918 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
20919 and gives Let's Encrypt permission to log the public IP address of the
20920 requesting machine.
20922 @item @code{authentication-hook} (default: @code{#f})
20923 Command to be run in a shell once for each certificate challenge to be
20924 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20925 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20926 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20927 file name of the resource requested when performing an HTTP-01 challenge.
20929 @item @code{cleanup-hook} (default: @code{#f})
20930 Command to be run in a shell once for each certificate challenge that
20931 have been answered by the @code{auth-hook}. For this command, the shell
20932 variables available in the @code{auth-hook} script are still available, and
20933 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20934 of the @code{auth-hook} script.
20936 @item @code{deploy-hook} (default: @code{#f})
20937 Command to be run in a shell once for each successfully issued
20938 certificate. For this command, the shell variable
20939 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20940 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20941 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20942 contain a space-delimited list of renewed certificate domains (for
20943 example, @samp{"example.com www.example.com"}.
20948 For each @code{certificate-configuration}, the certificate is saved to
20949 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20950 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20952 @subsection DNS Services
20953 @cindex DNS (domain name system)
20954 @cindex domain name system (DNS)
20956 The @code{(gnu services dns)} module provides services related to the
20957 @dfn{domain name system} (DNS). It provides a server service for hosting
20958 an @emph{authoritative} DNS server for multiple zones, slave or master.
20959 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20960 caching and forwarding DNS server for the LAN, which uses
20961 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20963 @subsubheading Knot Service
20965 An example configuration of an authoritative server for two zones, one master
20969 (define-zone-entries example.org.zone
20970 ;; Name TTL Class Type Data
20971 ("@@" "" "IN" "A" "127.0.0.1")
20972 ("@@" "" "IN" "NS" "ns")
20973 ("ns" "" "IN" "A" "127.0.0.1"))
20975 (define master-zone
20976 (knot-zone-configuration
20977 (domain "example.org")
20979 (origin "example.org")
20980 (entries example.org.zone)))))
20983 (knot-zone-configuration
20984 (domain "plop.org")
20985 (dnssec-policy "default")
20986 (master (list "plop-master"))))
20988 (define plop-master
20989 (knot-remote-configuration
20991 (address (list "208.76.58.171"))))
20995 (services (cons* (service knot-service-type
20996 (knot-configuration
20997 (remotes (list plop-master))
20998 (zones (list master-zone slave-zone))))
21003 @deffn {Scheme Variable} knot-service-type
21004 This is the type for the Knot DNS server.
21006 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
21007 zones, that is to say domain names you would buy from a registrar. This server
21008 is not a resolver, meaning that it can only resolve names for which it is
21009 authoritative. This server can be configured to serve zones as a master server
21010 or a slave server as a per-zone basis. Slave zones will get their data from
21011 masters, and will serve it as an authoritative server. From the point of view
21012 of a resolver, there is no difference between master and slave.
21014 The following data types are used to configure the Knot DNS server:
21017 @deftp {Data Type} knot-key-configuration
21018 Data type representing a key.
21019 This type has the following parameters:
21022 @item @code{id} (default: @code{""})
21023 An identifier for other configuration fields to refer to this key. IDs must
21024 be unique and must not be empty.
21026 @item @code{algorithm} (default: @code{#f})
21027 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21028 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21029 and @code{'hmac-sha512}.
21031 @item @code{secret} (default: @code{""})
21032 The secret key itself.
21037 @deftp {Data Type} knot-acl-configuration
21038 Data type representing an Access Control List (ACL) configuration.
21039 This type has the following parameters:
21042 @item @code{id} (default: @code{""})
21043 An identifier for ether configuration fields to refer to this key. IDs must be
21044 unique and must not be empty.
21046 @item @code{address} (default: @code{'()})
21047 An ordered list of IP addresses, network subnets, or network ranges represented
21048 with strings. The query must match one of them. Empty value means that
21049 address match is not required.
21051 @item @code{key} (default: @code{'()})
21052 An ordered list of references to keys represented with strings. The string
21053 must match a key ID defined in a @code{knot-key-configuration}. No key means
21054 that a key is not require to match that ACL.
21056 @item @code{action} (default: @code{'()})
21057 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21058 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21059 and @code{'update}.
21061 @item @code{deny?} (default: @code{#f})
21062 When true, the ACL defines restrictions. Listed actions are forbidden. When
21063 false, listed actions are allowed.
21068 @deftp {Data Type} zone-entry
21069 Data type represnting a record entry in a zone file.
21070 This type has the following parameters:
21073 @item @code{name} (default: @code{"@@"})
21074 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21075 are relative to the origin of the zone. For example, in the @code{example.org}
21076 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21077 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21078 refers to @code{ns.example.org}.
21080 @item @code{ttl} (default: @code{""})
21081 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21083 @item @code{class} (default: @code{"IN"})
21084 The class of the record. Knot currently supports only @code{"IN"} and
21085 partially @code{"CH"}.
21087 @item @code{type} (default: @code{"A"})
21088 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21089 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21092 @item @code{data} (default: @code{""})
21093 The data contained in the record. For instance an IP address associated with
21094 an A record, or a domain name associated with an NS record. Remember that
21095 domain names are relative to the origin unless they end with a dot.
21100 @deftp {Data Type} zone-file
21101 Data type representing the content of a zone file.
21102 This type has the following parameters:
21105 @item @code{entries} (default: @code{'()})
21106 The list of entries. The SOA record is taken care of, so you don't need to
21107 put it in the list of entries. This list should probably contain an entry
21108 for your primary authoritative DNS server. Other than using a list of entries
21109 directly, you can use @code{define-zone-entries} to define a object containing
21110 the list of entries more easily, that you can later pass to the @code{entries}
21111 field of the @code{zone-file}.
21113 @item @code{origin} (default: @code{""})
21114 The name of your zone. This parameter cannot be empty.
21116 @item @code{ns} (default: @code{"ns"})
21117 The domain of your primary authoritative DNS server. The name is relative to
21118 the origin, unless it ends with a dot. It is mandatory that this primary
21119 DNS server corresponds to an NS record in the zone and that it is associated
21120 to an IP address in the list of entries.
21122 @item @code{mail} (default: @code{"hostmaster"})
21123 An email address people can contact you at, as the owner of the zone. This
21124 is translated as @code{<mail>@@<origin>}.
21126 @item @code{serial} (default: @code{1})
21127 The serial number of the zone. As this is used to keep track of changes by
21128 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21129 Always increment it when you make a change in your zone.
21131 @item @code{refresh} (default: @code{(* 2 24 3600)})
21132 The frequency at which slaves will do a zone transfer. This value is a number
21133 of seconds. It can be computed by multiplications or with
21134 @code{(string->duration)}.
21136 @item @code{retry} (default: @code{(* 15 60)})
21137 The period after which a slave will retry to contact its master when it fails
21138 to do so a first time.
21140 @item @code{expiry} (default: @code{(* 14 24 3600)})
21141 Default TTL of records. Existing records are considered correct for at most
21142 this amount of time. After this period, resolvers will invalidate their cache
21143 and check again that it still exists.
21145 @item @code{nx} (default: @code{3600})
21146 Default TTL of inexistant records. This delay is usually short because you want
21147 your new domains to reach everyone quickly.
21152 @deftp {Data Type} knot-remote-configuration
21153 Data type representing a remote configuration.
21154 This type has the following parameters:
21157 @item @code{id} (default: @code{""})
21158 An identifier for other configuration fields to refer to this remote. IDs must
21159 be unique and must not be empty.
21161 @item @code{address} (default: @code{'()})
21162 An ordered list of destination IP addresses. Addresses are tried in sequence.
21163 An optional port can be given with the @@ separator. For instance:
21164 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21166 @item @code{via} (default: @code{'()})
21167 An ordered list of source IP addresses. An empty list will have Knot choose
21168 an appropriate source IP. An optional port can be given with the @@ separator.
21169 The default is to choose at random.
21171 @item @code{key} (default: @code{#f})
21172 A reference to a key, that is a string containing the identifier of a key
21173 defined in a @code{knot-key-configuration} field.
21178 @deftp {Data Type} knot-keystore-configuration
21179 Data type representing a keystore to hold dnssec keys.
21180 This type has the following parameters:
21183 @item @code{id} (default: @code{""})
21184 The id of the keystore. It must not be empty.
21186 @item @code{backend} (default: @code{'pem})
21187 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21189 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21190 The configuration string of the backend. An example for the PKCS#11 is:
21191 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21192 For the pem backend, the string reprensents a path in the file system.
21197 @deftp {Data Type} knot-policy-configuration
21198 Data type representing a dnssec policy. Knot DNS is able to automatically
21199 sign your zones. It can either generate and manage your keys automatically or
21200 use keys that you generate.
21202 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21203 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21204 zone. In order to be trusted, the KSK needs to be present in the parent zone
21205 (usually a top-level domain). If your registrar supports dnssec, you will
21206 have to send them your KSK's hash so they can add a DS record in their zone.
21207 This is not automated and need to be done each time you change your KSK.
21209 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21210 easily and use weaker cryptographic functions (they use lower parameters) in
21211 order to sign records quickly, so they are changed often. The KSK however
21212 requires manual interaction with the registrar, so they are changed less often
21213 and use stronger parameters because they sign only one record.
21215 This type has the following parameters:
21218 @item @code{id} (default: @code{""})
21219 The id of the policy. It must not be empty.
21221 @item @code{keystore} (default: @code{"default"})
21222 A reference to a keystore, that is a string containing the identifier of a
21223 keystore defined in a @code{knot-keystore-configuration} field. The
21224 @code{"default"} identifier means the default keystore (a kasp database that
21225 was setup by this service).
21227 @item @code{manual?} (default: @code{#f})
21228 Whether the key management is manual or automatic.
21230 @item @code{single-type-signing?} (default: @code{#f})
21231 When @code{#t}, use the Single-Type Signing Scheme.
21233 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21234 An algorithm of signing keys and issued signatures.
21236 @item @code{ksk-size} (default: @code{256})
21237 The length of the KSK. Note that this value is correct for the default
21238 algorithm, but would be unsecure for other algorithms.
21240 @item @code{zsk-size} (default: @code{256})
21241 The length of the ZSK. Note that this value is correct for the default
21242 algorithm, but would be unsecure for other algorithms.
21244 @item @code{dnskey-ttl} (default: @code{'default})
21245 The TTL value for DNSKEY records added into zone apex. The special
21246 @code{'default} value means same as the zone SOA TTL.
21248 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21249 The period between ZSK publication and the next rollover initiation.
21251 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21252 An extra delay added for each key rollover step. This value should be high
21253 enough to cover propagation of data from the master server to all slaves.
21255 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21256 A validity period of newly issued signatures.
21258 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21259 A period how long before a signature expiration the signature will be refreshed.
21261 @item @code{nsec3?} (default: @code{#f})
21262 When @code{#t}, NSEC3 will be used instead of NSEC.
21264 @item @code{nsec3-iterations} (default: @code{5})
21265 The number of additional times the hashing is performed.
21267 @item @code{nsec3-salt-length} (default: @code{8})
21268 The length of a salt field in octets, which is appended to the original owner
21269 name before hashing.
21271 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21272 The validity period of newly issued salt field.
21277 @deftp {Data Type} knot-zone-configuration
21278 Data type representing a zone served by Knot.
21279 This type has the following parameters:
21282 @item @code{domain} (default: @code{""})
21283 The domain served by this configuration. It must not be empty.
21285 @item @code{file} (default: @code{""})
21286 The file where this zone is saved. This parameter is ignored by master zones.
21287 Empty means default location that depends on the domain name.
21289 @item @code{zone} (default: @code{(zone-file)})
21290 The content of the zone file. This parameter is ignored by slave zones. It
21291 must contain a zone-file record.
21293 @item @code{master} (default: @code{'()})
21294 A list of master remotes. When empty, this zone is a master. When set, this
21295 zone is a slave. This is a list of remotes identifiers.
21297 @item @code{ddns-master} (default: @code{#f})
21298 The main master. When empty, it defaults to the first master in the list of
21301 @item @code{notify} (default: @code{'()})
21302 A list of slave remote identifiers.
21304 @item @code{acl} (default: @code{'()})
21305 A list of acl identifiers.
21307 @item @code{semantic-checks?} (default: @code{#f})
21308 When set, this adds more semantic checks to the zone.
21310 @item @code{disable-any?} (default: @code{#f})
21311 When set, this forbids queries of the ANY type.
21313 @item @code{zonefile-sync} (default: @code{0})
21314 The delay between a modification in memory and on disk. 0 means immediate
21317 @item @code{zonefile-load} (default: @code{#f})
21318 The way the zone file contents are applied during zone load. Possible values
21322 @item @code{#f} for using the default value from Knot,
21323 @item @code{'none} for not using the zone file at all,
21324 @item @code{'difference} for computing the difference between already available
21325 contents and zone contents and applying it to the current zone contents,
21326 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21327 ignoring the SOA serial in the zone file, while the server takes care of it
21329 @item @code{'whole} for loading zone contents from the zone file.
21332 @item @code{journal-content} (default: @code{#f})
21333 The way the journal is used to store zone and its changes. Possible values
21334 are @code{'none} to not use it at all, @code{'changes} to store changes and
21335 @code{'all} to store contents. @code{#f} does not set this option, so the
21336 default value from Knot is used.
21338 @item @code{max-journal-usage} (default: @code{#f})
21339 The maximum size for the journal on disk. @code{#f} does not set this option,
21340 so the default value from Knot is used.
21342 @item @code{max-journal-depth} (default: @code{#f})
21343 The maximum size of the history. @code{#f} does not set this option, so the
21344 default value from Knot is used.
21346 @item @code{max-zone-size} (default: @code{#f})
21347 The maximum size of the zone file. This limit is enforced for incoming
21348 transfer and updates. @code{#f} does not set this option, so the default
21349 value from Knot is used.
21351 @item @code{dnssec-policy} (default: @code{#f})
21352 A reference to a @code{knot-policy-configuration} record, or the special
21353 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21356 @item @code{serial-policy} (default: @code{'increment})
21357 A policy between @code{'increment} and @code{'unixtime}.
21362 @deftp {Data Type} knot-configuration
21363 Data type representing the Knot configuration.
21364 This type has the following parameters:
21367 @item @code{knot} (default: @code{knot})
21370 @item @code{run-directory} (default: @code{"/var/run/knot"})
21371 The run directory. This directory will be used for pid file and sockets.
21373 @item @code{includes} (default: @code{'()})
21374 A list of strings or file-like objects denoting other files that must be
21375 included at the top of the configuration file.
21377 @cindex secrets, Knot service
21378 This can be used to manage secrets out-of-band. For example, secret
21379 keys may be stored in an out-of-band file not managed by Guix, and
21380 thus not visible in @file{/gnu/store}---e.g., you could store secret
21381 key configuration in @file{/etc/knot/secrets.conf} and add this file
21382 to the @code{includes} list.
21384 One can generate a secret tsig key (for nsupdate and zone transfers with the
21385 keymgr command from the knot package. Note that the package is not automatically
21386 installed by the service. The following example shows how to generate a new
21390 keymgr -t mysecret > /etc/knot/secrets.conf
21391 chmod 600 /etc/knot/secrets.conf
21394 Also note that the generated key will be named @var{mysecret}, so it is the
21395 name that needs to be used in the @var{key} field of the
21396 @code{knot-acl-configuration} record and in other places that need to refer
21399 It can also be used to add configuration not supported by this interface.
21401 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21402 An ip address on which to listen.
21404 @item @code{listen-v6} (default: @code{"::"})
21405 An ip address on which to listen.
21407 @item @code{listen-port} (default: @code{53})
21408 A port on which to listen.
21410 @item @code{keys} (default: @code{'()})
21411 The list of knot-key-configuration used by this configuration.
21413 @item @code{acls} (default: @code{'()})
21414 The list of knot-acl-configuration used by this configuration.
21416 @item @code{remotes} (default: @code{'()})
21417 The list of knot-remote-configuration used by this configuration.
21419 @item @code{zones} (default: @code{'()})
21420 The list of knot-zone-configuration used by this configuration.
21425 @subsubheading Knot Resolver Service
21427 @deffn {Scheme Variable} knot-resolver-service-type
21428 This this the type of the knot resolver service, whose value should be
21429 an @code{knot-resolver-configuration} object as in this example:
21432 (service knot-resolver-service-type
21433 (knot-resolver-configuration
21434 (kresd-config-file (plain-file "kresd.conf" "
21435 net.listen('192.168.0.1', 5353)
21436 user('knot-resolver', 'knot-resolver')
21437 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21438 cache.size = 100 * MB
21442 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21445 @deftp {Data Type} knot-resolver-configuration
21446 Data type representing the configuration of knot-resolver.
21449 @item @code{package} (default: @var{knot-resolver})
21450 Package object of the knot DNS resolver.
21452 @item @code{kresd-config-file} (default: %kresd.conf)
21453 File-like object of the kresd configuration file to use, by default it
21454 will listen on @code{127.0.0.1} and @code{::1}.
21456 @item @code{garbage-collection-interval} (default: 1000)
21457 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21463 @subsubheading Dnsmasq Service
21465 @deffn {Scheme Variable} dnsmasq-service-type
21466 This is the type of the dnsmasq service, whose value should be an
21467 @code{dnsmasq-configuration} object as in this example:
21470 (service dnsmasq-service-type
21471 (dnsmasq-configuration
21473 (servers '("192.168.1.1"))))
21477 @deftp {Data Type} dnsmasq-configuration
21478 Data type representing the configuration of dnsmasq.
21481 @item @code{package} (default: @var{dnsmasq})
21482 Package object of the dnsmasq server.
21484 @item @code{no-hosts?} (default: @code{#f})
21485 When true, don't read the hostnames in /etc/hosts.
21487 @item @code{port} (default: @code{53})
21488 The port to listen on. Setting this to zero completely disables DNS
21489 responses, leaving only DHCP and/or TFTP functions.
21491 @item @code{local-service?} (default: @code{#t})
21492 Accept DNS queries only from hosts whose address is on a local subnet,
21493 ie a subnet for which an interface exists on the server.
21495 @item @code{listen-addresses} (default: @code{'()})
21496 Listen on the given IP addresses.
21498 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21499 The file to read the IP address of the upstream nameservers from.
21501 @item @code{no-resolv?} (default: @code{#f})
21502 When true, don't read @var{resolv-file}.
21504 @item @code{servers} (default: @code{'()})
21505 Specify IP address of upstream servers directly.
21507 @item @code{cache-size} (default: @code{150})
21508 Set the size of dnsmasq's cache. Setting the cache size to zero
21511 @item @code{negative-cache?} (default: @code{#t})
21512 When false, disable negative caching.
21517 @subsubheading ddclient Service
21520 The ddclient service described below runs the ddclient daemon, which takes
21521 care of automatically updating DNS entries for service providers such as
21522 @uref{https://dyn.com/dns/, Dyn}.
21524 The following example show instantiates the service with its default
21528 (service ddclient-service-type)
21531 Note that ddclient needs to access credentials that are stored in a
21532 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21533 @code{secret-file} below.) You are expected to create this file manually, in
21534 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21535 service configuration, for instance by using @code{plain-file}, but it will be
21536 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21537 @file{share/ddclient} directory of the @code{ddclient} package.
21539 @c %start of fragment
21541 Available @code{ddclient-configuration} fields are:
21543 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21544 The ddclient package.
21548 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21549 The period after which ddclient will retry to check IP and domain name.
21551 Defaults to @samp{300}.
21555 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21556 Use syslog for the output.
21558 Defaults to @samp{#t}.
21562 @deftypevr {@code{ddclient-configuration} parameter} string mail
21565 Defaults to @samp{"root"}.
21569 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21570 Mail failed update to user.
21572 Defaults to @samp{"root"}.
21576 @deftypevr {@code{ddclient-configuration} parameter} string pid
21577 The ddclient PID file.
21579 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21583 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21584 Enable SSL support.
21586 Defaults to @samp{#t}.
21590 @deftypevr {@code{ddclient-configuration} parameter} string user
21591 Specifies the user name or ID that is used when running ddclient
21594 Defaults to @samp{"ddclient"}.
21598 @deftypevr {@code{ddclient-configuration} parameter} string group
21599 Group of the user who will run the ddclient program.
21601 Defaults to @samp{"ddclient"}.
21605 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21606 Secret file which will be appended to @file{ddclient.conf} file. This
21607 file contains credentials for use by ddclient. You are expected to
21608 create it manually.
21610 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21614 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21615 Extra options will be appended to @file{ddclient.conf} file.
21617 Defaults to @samp{()}.
21622 @c %end of fragment
21626 @subsection VPN Services
21627 @cindex VPN (virtual private network)
21628 @cindex virtual private network (VPN)
21630 The @code{(gnu services vpn)} module provides services related to
21631 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21632 your machine to connect to a VPN, and a @emph{server} service for your machine
21633 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21635 @deffn {Scheme Procedure} openvpn-client-service @
21636 [#:config (openvpn-client-configuration)]
21638 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21641 @deffn {Scheme Procedure} openvpn-server-service @
21642 [#:config (openvpn-server-configuration)]
21644 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21646 Both can be run simultaneously.
21649 @c %automatically generated documentation
21651 Available @code{openvpn-client-configuration} fields are:
21653 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21654 The OpenVPN package.
21658 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21659 The OpenVPN pid file.
21661 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21665 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21666 The protocol (UDP or TCP) used to open a channel between clients and
21669 Defaults to @samp{udp}.
21673 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21674 The device type used to represent the VPN connection.
21676 Defaults to @samp{tun}.
21680 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21681 The certificate authority to check connections against.
21683 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21687 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21688 The certificate of the machine the daemon is running on. It should be
21689 signed by the authority given in @code{ca}.
21691 Defaults to @samp{"/etc/openvpn/client.crt"}.
21695 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21696 The key of the machine the daemon is running on. It must be the key whose
21697 certificate is @code{cert}.
21699 Defaults to @samp{"/etc/openvpn/client.key"}.
21703 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21704 Whether to use the lzo compression algorithm.
21706 Defaults to @samp{#t}.
21710 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21711 Don't re-read key files across SIGUSR1 or --ping-restart.
21713 Defaults to @samp{#t}.
21717 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21718 Don't close and reopen TUN/TAP device or run up/down scripts across
21719 SIGUSR1 or --ping-restart restarts.
21721 Defaults to @samp{#t}.
21725 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21728 Defaults to @samp{3}.
21732 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21733 Add an additional layer of HMAC authentication on top of the TLS control
21734 channel to protect against DoS attacks.
21736 Defaults to @samp{#f}.
21740 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21741 Whether to check the server certificate has server usage extension.
21743 Defaults to @samp{#t}.
21747 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21748 Bind to a specific local port number.
21750 Defaults to @samp{#f}.
21754 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21755 Retry resolving server address.
21757 Defaults to @samp{#t}.
21761 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21762 A list of remote servers to connect to.
21764 Defaults to @samp{()}.
21766 Available @code{openvpn-remote-configuration} fields are:
21768 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21771 Defaults to @samp{"my-server"}.
21775 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21776 Port number the server listens to.
21778 Defaults to @samp{1194}.
21783 @c %end of automatic openvpn-client documentation
21785 @c %automatically generated documentation
21787 Available @code{openvpn-server-configuration} fields are:
21789 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21790 The OpenVPN package.
21794 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21795 The OpenVPN pid file.
21797 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21801 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21802 The protocol (UDP or TCP) used to open a channel between clients and
21805 Defaults to @samp{udp}.
21809 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21810 The device type used to represent the VPN connection.
21812 Defaults to @samp{tun}.
21816 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21817 The certificate authority to check connections against.
21819 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21823 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21824 The certificate of the machine the daemon is running on. It should be
21825 signed by the authority given in @code{ca}.
21827 Defaults to @samp{"/etc/openvpn/client.crt"}.
21831 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21832 The key of the machine the daemon is running on. It must be the key whose
21833 certificate is @code{cert}.
21835 Defaults to @samp{"/etc/openvpn/client.key"}.
21839 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21840 Whether to use the lzo compression algorithm.
21842 Defaults to @samp{#t}.
21846 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21847 Don't re-read key files across SIGUSR1 or --ping-restart.
21849 Defaults to @samp{#t}.
21853 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21854 Don't close and reopen TUN/TAP device or run up/down scripts across
21855 SIGUSR1 or --ping-restart restarts.
21857 Defaults to @samp{#t}.
21861 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21864 Defaults to @samp{3}.
21868 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21869 Add an additional layer of HMAC authentication on top of the TLS control
21870 channel to protect against DoS attacks.
21872 Defaults to @samp{#f}.
21876 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21877 Specifies the port number on which the server listens.
21879 Defaults to @samp{1194}.
21883 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21884 An ip and mask specifying the subnet inside the virtual network.
21886 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21890 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21891 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21893 Defaults to @samp{#f}.
21897 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21898 The Diffie-Hellman parameters file.
21900 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21904 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21905 The file that records client IPs.
21907 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21911 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21912 When true, the server will act as a gateway for its clients.
21914 Defaults to @samp{#f}.
21918 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21919 When true, clients are allowed to talk to each other inside the VPN.
21921 Defaults to @samp{#f}.
21925 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21926 Causes ping-like messages to be sent back and forth over the link so
21927 that each side knows when the other side has gone down. @code{keepalive}
21928 requires a pair. The first element is the period of the ping sending,
21929 and the second element is the timeout before considering the other side
21934 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21935 The maximum number of clients.
21937 Defaults to @samp{100}.
21941 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21942 The status file. This file shows a small report on current connection.
21943 It is truncated and rewritten every minute.
21945 Defaults to @samp{"/var/run/openvpn/status"}.
21949 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21950 The list of configuration for some clients.
21952 Defaults to @samp{()}.
21954 Available @code{openvpn-ccd-configuration} fields are:
21956 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21959 Defaults to @samp{"client"}.
21963 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21966 Defaults to @samp{#f}.
21970 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21973 Defaults to @samp{#f}.
21980 @c %end of automatic openvpn-server documentation
21983 @node Network File System
21984 @subsection Network File System
21987 The @code{(gnu services nfs)} module provides the following services,
21988 which are most commonly used in relation to mounting or exporting
21989 directory trees as @dfn{network file systems} (NFS).
21991 While it is possible to use the individual components that together make
21992 up a Network File System service, we recommended to configure an NFS
21993 server with the @code{nfs-service-type}.
21995 @subsubheading NFS Service
21996 @cindex NFS, server
21998 The NFS service takes care of setting up all NFS component services,
21999 kernel configuration file systems, and installs configuration files in
22000 the locations that NFS expects.
22002 @defvr {Scheme Variable} nfs-service-type
22003 A service type for a complete NFS server.
22006 @deftp {Data Type} nfs-configuration
22007 This data type represents the configuration of the NFS service and all
22010 It has the following parameters:
22012 @item @code{nfs-utils} (default: @code{nfs-utils})
22013 The nfs-utils package to use.
22015 @item @code{nfs-version} (default: @code{#f})
22016 If a string value is provided, the @command{rpc.nfsd} daemon will be
22017 limited to supporting the given version of the NFS protocol.
22019 @item @code{exports} (default: @code{'()})
22020 This is a list of directories the NFS server should export. Each entry
22021 is a list consisting of two elements: a directory name and a string
22022 containing all options. This is an example in which the directory
22023 @file{/export} is served to all NFS clients as a read-only share:
22029 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22032 @item @code{rpcmountd-port} (default: @code{#f})
22033 The network port that the @command{rpc.mountd} daemon should use.
22035 @item @code{rpcstatd-port} (default: @code{#f})
22036 The network port that the @command{rpc.statd} daemon should use.
22038 @item @code{rpcbind} (default: @code{rpcbind})
22039 The rpcbind package to use.
22041 @item @code{idmap-domain} (default: @code{"localdomain"})
22042 The local NFSv4 domain name.
22044 @item @code{nfsd-port} (default: @code{2049})
22045 The network port that the @command{nfsd} daemon should use.
22047 @item @code{nfsd-threads} (default: @code{8})
22048 The number of threads used by the @command{nfsd} daemon.
22050 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22051 The directory where the pipefs file system is mounted.
22053 @item @code{debug} (default: @code{'()"})
22054 A list of subsystems for which debugging output should be enabled. This
22055 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22056 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22060 If you don't need a complete NFS service or prefer to build it yourself
22061 you can use the individual component services that are documented below.
22063 @subsubheading RPC Bind Service
22066 The RPC Bind service provides a facility to map program numbers into
22067 universal addresses.
22068 Many NFS related services use this facility. Hence it is automatically
22069 started when a dependent service starts.
22071 @defvr {Scheme Variable} rpcbind-service-type
22072 A service type for the RPC portmapper daemon.
22076 @deftp {Data Type} rpcbind-configuration
22077 Data type representing the configuration of the RPC Bind Service.
22078 This type has the following parameters:
22080 @item @code{rpcbind} (default: @code{rpcbind})
22081 The rpcbind package to use.
22083 @item @code{warm-start?} (default: @code{#t})
22084 If this parameter is @code{#t}, then the daemon will read a
22085 state file on startup thus reloading state information saved by a previous
22091 @subsubheading Pipefs Pseudo File System
22095 The pipefs file system is used to transfer NFS related data
22096 between the kernel and user space programs.
22098 @defvr {Scheme Variable} pipefs-service-type
22099 A service type for the pipefs pseudo file system.
22102 @deftp {Data Type} pipefs-configuration
22103 Data type representing the configuration of the pipefs pseudo file system service.
22104 This type has the following parameters:
22106 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22107 The directory to which the file system is to be attached.
22112 @subsubheading GSS Daemon Service
22115 @cindex global security system
22117 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22119 Before exchanging RPC requests an RPC client must establish a security
22120 context. Typically this is done using the Kerberos command @command{kinit}
22121 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22123 @defvr {Scheme Variable} gss-service-type
22124 A service type for the Global Security System (GSS) daemon.
22127 @deftp {Data Type} gss-configuration
22128 Data type representing the configuration of the GSS daemon service.
22129 This type has the following parameters:
22131 @item @code{nfs-utils} (default: @code{nfs-utils})
22132 The package in which the @command{rpc.gssd} command is to be found.
22134 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22135 The directory where the pipefs file system is mounted.
22141 @subsubheading IDMAP Daemon Service
22143 @cindex name mapper
22145 The idmap daemon service provides mapping between user IDs and user names.
22146 Typically it is required in order to access file systems mounted via NFSv4.
22148 @defvr {Scheme Variable} idmap-service-type
22149 A service type for the Identity Mapper (IDMAP) daemon.
22152 @deftp {Data Type} idmap-configuration
22153 Data type representing the configuration of the IDMAP daemon service.
22154 This type has the following parameters:
22156 @item @code{nfs-utils} (default: @code{nfs-utils})
22157 The package in which the @command{rpc.idmapd} command is to be found.
22159 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22160 The directory where the pipefs file system is mounted.
22162 @item @code{domain} (default: @code{#f})
22163 The local NFSv4 domain name.
22164 This must be a string or @code{#f}.
22165 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22167 @item @code{verbosity} (default: @code{0})
22168 The verbosity level of the daemon.
22173 @node Continuous Integration
22174 @subsection Continuous Integration
22176 @cindex continuous integration
22177 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22178 continuous integration tool for Guix. It can be used both for development and
22179 for providing substitutes to others (@pxref{Substitutes}).
22181 The @code{(gnu services cuirass)} module provides the following service.
22183 @defvr {Scheme Procedure} cuirass-service-type
22184 The type of the Cuirass service. Its value must be a
22185 @code{cuirass-configuration} object, as described below.
22188 To add build jobs, you have to set the @code{specifications} field of the
22189 configuration. Here is an example of a service that polls the Guix repository
22190 and builds the packages from a manifest. Some of the packages are defined in
22191 the @code{"custom-packages"} input, which is the equivalent of
22192 @code{GUIX_PACKAGE_PATH}.
22195 (define %cuirass-specs
22197 '((#:name . "my-manifest")
22198 (#:load-path-inputs . ("guix"))
22199 (#:package-path-inputs . ("custom-packages"))
22200 (#:proc-input . "guix")
22201 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22202 (#:proc . cuirass-jobs)
22203 (#:proc-args . ((subset . "manifests")
22204 (systems . ("x86_64-linux"))
22205 (manifests . (("config" . "guix/manifest.scm")))))
22206 (#:inputs . (((#:name . "guix")
22207 (#:url . "git://git.savannah.gnu.org/guix.git")
22208 (#:load-path . ".")
22209 (#:branch . "master")
22210 (#:no-compile? . #t))
22211 ((#:name . "config")
22212 (#:url . "https://git.example.org/config.git")
22213 (#:load-path . ".")
22214 (#:branch . "master")
22215 (#:no-compile? . #t))
22216 ((#:name . "custom-packages")
22217 (#:url . "https://git.example.org/custom-packages.git")
22218 (#:load-path . ".")
22219 (#:branch . "master")
22220 (#:no-compile? . #t)))))))
22222 (service cuirass-service-type
22223 (cuirass-configuration
22224 (specifications %cuirass-specs)))
22227 While information related to build jobs is located directly in the
22228 specifications, global settings for the @command{cuirass} process are
22229 accessible in other @code{cuirass-configuration} fields.
22231 @deftp {Data Type} cuirass-configuration
22232 Data type representing the configuration of Cuirass.
22235 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22236 Location of the log file.
22238 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22239 Location of the log file used by the web interface.
22241 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22242 Location of the repository cache.
22244 @item @code{user} (default: @code{"cuirass"})
22245 Owner of the @code{cuirass} process.
22247 @item @code{group} (default: @code{"cuirass"})
22248 Owner's group of the @code{cuirass} process.
22250 @item @code{interval} (default: @code{60})
22251 Number of seconds between the poll of the repositories followed by the
22254 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22255 Location of sqlite database which contains the build results and previously
22256 added specifications.
22258 @item @code{ttl} (default: @code{(* 30 24 3600)})
22259 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22260 are registered for build results. This means that build results are protected
22261 from garbage collection for at least @var{ttl} seconds.
22263 @item @code{port} (default: @code{8081})
22264 Port number used by the HTTP server.
22266 @item @code{host} (default: @code{"localhost"})
22267 Listen on the network interface for @var{host}. The default is to
22268 accept connections from localhost.
22270 @item @code{specifications} (default: @code{#~'()})
22271 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22272 where a specification is an association list
22273 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22274 keys are keywords (@code{#:keyword-example}) as shown in the example
22277 @item @code{use-substitutes?} (default: @code{#f})
22278 This allows using substitutes to avoid building every dependencies of a job
22281 @item @code{one-shot?} (default: @code{#f})
22282 Only evaluate specifications and build derivations once.
22284 @item @code{fallback?} (default: @code{#f})
22285 When substituting a pre-built binary fails, fall back to building
22288 @item @code{cuirass} (default: @code{cuirass})
22289 The Cuirass package to use.
22293 @node Power Management Services
22294 @subsection Power Management Services
22297 @cindex power management with TLP
22298 @subsubheading TLP daemon
22300 The @code{(gnu services pm)} module provides a Guix service definition
22301 for the Linux power management tool TLP.
22303 TLP enables various powersaving modes in userspace and kernel.
22304 Contrary to @code{upower-service}, it is not a passive,
22305 monitoring tool, as it will apply custom settings each time a new power
22306 source is detected. More information can be found at
22307 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22309 @deffn {Scheme Variable} tlp-service-type
22310 The service type for the TLP tool. Its value should be a valid
22311 TLP configuration (see below). To use the default settings, simply
22314 (service tlp-service-type)
22318 By default TLP does not need much configuration but most TLP parameters
22319 can be tweaked using @code{tlp-configuration}.
22321 Each parameter definition is preceded by its type; for example,
22322 @samp{boolean foo} indicates that the @code{foo} parameter
22323 should be specified as a boolean. Types starting with
22324 @code{maybe-} denote parameters that won't show up in TLP config file
22325 when their value is @code{'disabled}.
22327 @c The following documentation was initially generated by
22328 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22329 @c documentation is better, so we shouldn't hesitate to edit below as
22330 @c needed. However if the change you want to make to this documentation
22331 @c can be done in an automated way, it's probably easier to change
22332 @c (generate-documentation) than to make it below and have to deal with
22333 @c the churn as TLP updates.
22335 Available @code{tlp-configuration} fields are:
22337 @deftypevr {@code{tlp-configuration} parameter} package tlp
22342 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22343 Set to true if you wish to enable TLP.
22345 Defaults to @samp{#t}.
22349 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22350 Default mode when no power supply can be detected. Alternatives are AC
22353 Defaults to @samp{"AC"}.
22357 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22358 Number of seconds Linux kernel has to wait after the disk goes idle,
22359 before syncing on AC.
22361 Defaults to @samp{0}.
22365 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22366 Same as @code{disk-idle-ac} but on BAT mode.
22368 Defaults to @samp{2}.
22372 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22373 Dirty pages flushing periodicity, expressed in seconds.
22375 Defaults to @samp{15}.
22379 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22380 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22382 Defaults to @samp{60}.
22386 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22387 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22388 alternatives are powersave and performance. With acpi-cpufreq driver,
22389 alternatives are ondemand, powersave, performance and conservative.
22391 Defaults to @samp{disabled}.
22395 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22396 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22398 Defaults to @samp{disabled}.
22402 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22403 Set the min available frequency for the scaling governor on AC.
22405 Defaults to @samp{disabled}.
22409 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22410 Set the max available frequency for the scaling governor on AC.
22412 Defaults to @samp{disabled}.
22416 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22417 Set the min available frequency for the scaling governor on BAT.
22419 Defaults to @samp{disabled}.
22423 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22424 Set the max available frequency for the scaling governor on BAT.
22426 Defaults to @samp{disabled}.
22430 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22431 Limit the min P-state to control the power dissipation of the CPU, in AC
22432 mode. Values are stated as a percentage of the available performance.
22434 Defaults to @samp{disabled}.
22438 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22439 Limit the max P-state to control the power dissipation of the CPU, in AC
22440 mode. Values are stated as a percentage of the available performance.
22442 Defaults to @samp{disabled}.
22446 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22447 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22449 Defaults to @samp{disabled}.
22453 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22454 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22456 Defaults to @samp{disabled}.
22460 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22461 Enable CPU turbo boost feature on AC mode.
22463 Defaults to @samp{disabled}.
22467 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22468 Same as @code{cpu-boost-on-ac?} on BAT mode.
22470 Defaults to @samp{disabled}.
22474 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22475 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22476 used under light load conditions.
22478 Defaults to @samp{#f}.
22482 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22483 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22485 Defaults to @samp{#t}.
22489 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22490 Enable Linux kernel NMI watchdog.
22492 Defaults to @samp{#f}.
22496 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22497 For Linux kernels with PHC patch applied, change CPU voltages. An
22498 example value would be @samp{"F:V F:V F:V F:V"}.
22500 Defaults to @samp{disabled}.
22504 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22505 Set CPU performance versus energy saving policy on AC. Alternatives are
22506 performance, normal, powersave.
22508 Defaults to @samp{"performance"}.
22512 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22513 Same as @code{energy-perf-policy-ac} but on BAT mode.
22515 Defaults to @samp{"powersave"}.
22519 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22524 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22525 Hard disk advanced power management level.
22529 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22530 Same as @code{disk-apm-bat} but on BAT mode.
22534 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22535 Hard disk spin down timeout. One value has to be specified for each
22536 declared hard disk.
22538 Defaults to @samp{disabled}.
22542 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22543 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22545 Defaults to @samp{disabled}.
22549 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22550 Select IO scheduler for disk devices. One value has to be specified for
22551 each declared hard disk. Example alternatives are cfq, deadline and
22554 Defaults to @samp{disabled}.
22558 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22559 SATA aggressive link power management (ALPM) level. Alternatives are
22560 min_power, medium_power, max_performance.
22562 Defaults to @samp{"max_performance"}.
22566 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22567 Same as @code{sata-linkpwr-ac} but on BAT mode.
22569 Defaults to @samp{"min_power"}.
22573 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22574 Exclude specified SATA host devices for link power management.
22576 Defaults to @samp{disabled}.
22580 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22581 Enable Runtime Power Management for AHCI controller and disks on AC
22584 Defaults to @samp{disabled}.
22588 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22589 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22591 Defaults to @samp{disabled}.
22595 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22596 Seconds of inactivity before disk is suspended.
22598 Defaults to @samp{15}.
22602 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22603 PCI Express Active State Power Management level. Alternatives are
22604 default, performance, powersave.
22606 Defaults to @samp{"performance"}.
22610 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22611 Same as @code{pcie-aspm-ac} but on BAT mode.
22613 Defaults to @samp{"powersave"}.
22617 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22618 Radeon graphics clock speed level. Alternatives are low, mid, high,
22621 Defaults to @samp{"high"}.
22625 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22626 Same as @code{radeon-power-ac} but on BAT mode.
22628 Defaults to @samp{"low"}.
22632 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22633 Radeon dynamic power management method (DPM). Alternatives are battery,
22636 Defaults to @samp{"performance"}.
22640 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22641 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22643 Defaults to @samp{"battery"}.
22647 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22648 Radeon DPM performance level. Alternatives are auto, low, high.
22650 Defaults to @samp{"auto"}.
22654 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22655 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22657 Defaults to @samp{"auto"}.
22661 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22662 Wifi power saving mode.
22664 Defaults to @samp{#f}.
22668 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22669 Same as @code{wifi-power-ac?} but on BAT mode.
22671 Defaults to @samp{#t}.
22675 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22676 Disable wake on LAN.
22678 Defaults to @samp{#t}.
22682 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22683 Timeout duration in seconds before activating audio power saving on
22684 Intel HDA and AC97 devices. A value of 0 disables power saving.
22686 Defaults to @samp{0}.
22690 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22691 Same as @code{sound-powersave-ac} but on BAT mode.
22693 Defaults to @samp{1}.
22697 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22698 Disable controller in powersaving mode on Intel HDA devices.
22700 Defaults to @samp{#t}.
22704 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22705 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22706 powered on again by releasing (and reinserting) the eject lever or by
22707 pressing the disc eject button on newer models.
22709 Defaults to @samp{#f}.
22713 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22714 Name of the optical drive device to power off.
22716 Defaults to @samp{"sr0"}.
22720 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22721 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22724 Defaults to @samp{"on"}.
22728 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22729 Same as @code{runtime-pm-ac} but on BAT mode.
22731 Defaults to @samp{"auto"}.
22735 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22736 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22739 Defaults to @samp{#t}.
22743 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22744 Exclude specified PCI(e) device addresses from Runtime Power Management.
22746 Defaults to @samp{disabled}.
22750 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22751 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22756 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22757 Enable USB autosuspend feature.
22759 Defaults to @samp{#t}.
22763 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22764 Exclude specified devices from USB autosuspend.
22766 Defaults to @samp{disabled}.
22770 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22771 Exclude WWAN devices from USB autosuspend.
22773 Defaults to @samp{#t}.
22777 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22778 Include specified devices into USB autosuspend, even if they are already
22779 excluded by the driver or via @code{usb-blacklist-wwan?}.
22781 Defaults to @samp{disabled}.
22785 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22786 Enable USB autosuspend before shutdown.
22788 Defaults to @samp{disabled}.
22792 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22793 Restore radio device state (bluetooth, wifi, wwan) from previous
22794 shutdown on system startup.
22796 Defaults to @samp{#f}.
22801 @cindex CPU frequency scaling with thermald
22802 @subsubheading Thermald daemon
22804 The @code{(gnu services pm)} module provides an interface to
22805 thermald, a CPU frequency scaling service which helps prevent overheating.
22807 @defvr {Scheme Variable} thermald-service-type
22808 This is the service type for
22809 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
22810 Thermal Daemon, which is responsible for controlling the thermal state
22811 of processors and preventing overheating.
22814 @deftp {Data Type} thermald-configuration
22815 Data type representing the configuration of @code{thermald-service-type}.
22818 @item @code{ignore-cpuid-check?} (default: @code{#f})
22819 Ignore cpuid check for supported CPU models.
22821 @item @code{thermald} (default: @var{thermald})
22822 Package object of thermald.
22827 @node Audio Services
22828 @subsection Audio Services
22830 The @code{(gnu services audio)} module provides a service to start MPD
22831 (the Music Player Daemon).
22834 @subsubheading Music Player Daemon
22836 The Music Player Daemon (MPD) is a service that can play music while
22837 being controlled from the local machine or over the network by a variety
22840 The following example shows how one might run @code{mpd} as user
22841 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
22844 (service mpd-service-type
22850 @defvr {Scheme Variable} mpd-service-type
22851 The service type for @command{mpd}
22854 @deftp {Data Type} mpd-configuration
22855 Data type representing the configuration of @command{mpd}.
22858 @item @code{user} (default: @code{"mpd"})
22859 The user to run mpd as.
22861 @item @code{music-dir} (default: @code{"~/Music"})
22862 The directory to scan for music files.
22864 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22865 The directory to store playlists.
22867 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22868 The location of the music database.
22870 @item @code{state-file} (default: @code{"~/.mpd/state"})
22871 The location of the file that stores current MPD's state.
22873 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22874 The location of the sticker database.
22876 @item @code{port} (default: @code{"6600"})
22877 The port to run mpd on.
22879 @item @code{address} (default: @code{"any"})
22880 The address that mpd will bind to. To use a Unix domain socket,
22881 an absolute path can be specified here.
22883 @item @code{outputs} (default: @code{"(list (mpd-output))"})
22884 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
22889 @deftp {Data Type} mpd-output
22890 Data type representing an @command{mpd} audio output.
22893 @item @code{name} (default: @code{"MPD"})
22894 The name of the audio output.
22896 @item @code{type} (default: @code{"pulse"})
22897 The type of audio output.
22899 @item @code{enabled?} (default: @code{#t})
22900 Specifies whether this audio output is enabled when MPD is started. By
22901 default, all audio outputs are enabled. This is just the default
22902 setting when there is no state file; with a state file, the previous
22905 @item @code{tags?} (default: @code{#t})
22906 If set to @code{#f}, then MPD will not send tags to this output. This
22907 is only useful for output plugins that can receive tags, for example the
22908 @code{httpd} output plugin.
22910 @item @code{always-on?} (default: @code{#f})
22911 If set to @code{#t}, then MPD attempts to keep this audio output always
22912 open. This may be useful for streaming servers, when you don’t want to
22913 disconnect all listeners even when playback is accidentally stopped.
22915 @item @code{mixer-type}
22916 This field accepts a symbol that specifies which mixer should be used
22917 for this audio output: the @code{hardware} mixer, the @code{software}
22918 mixer, the @code{null} mixer (allows setting the volume, but with no
22919 effect; this can be used as a trick to implement an external mixer
22920 External Mixer) or no mixer (@code{none}).
22922 @item @code{extra-options} (default: @code{'()"})
22923 An association list of option symbols to string values to be appended to
22924 the audio output configuration.
22929 The following example shows a configuration of @code{mpd} that provides
22930 an HTTP audio streaming output.
22933 (service mpd-service-type
22941 `((encoder . "vorbis")
22942 (port . "8080"))))))))
22946 @node Virtualization Services
22947 @subsection Virtualization services
22949 The @code{(gnu services virtualization)} module provides services for
22950 the libvirt and virtlog daemons, as well as other virtualization-related
22953 @subsubheading Libvirt daemon
22954 @code{libvirtd} is the server side daemon component of the libvirt
22955 virtualization management system. This daemon runs on host servers
22956 and performs required management tasks for virtualized guests.
22958 @deffn {Scheme Variable} libvirt-service-type
22959 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22960 Its value must be a @code{libvirt-configuration}.
22963 (service libvirt-service-type
22964 (libvirt-configuration
22965 (unix-sock-group "libvirt")
22966 (tls-port "16555")))
22970 @c Auto-generated with (generate-libvirt-documentation)
22971 Available @code{libvirt-configuration} fields are:
22973 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22978 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22979 Flag listening for secure TLS connections on the public TCP/IP port.
22980 must set @code{listen} for this to have any effect.
22982 It is necessary to setup a CA and issue server certificates before using
22985 Defaults to @samp{#t}.
22989 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22990 Listen for unencrypted TCP connections on the public TCP/IP port. must
22991 set @code{listen} for this to have any effect.
22993 Using the TCP socket requires SASL authentication by default. Only SASL
22994 mechanisms which support data encryption are allowed. This is
22995 DIGEST_MD5 and GSSAPI (Kerberos5)
22997 Defaults to @samp{#f}.
23001 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
23002 Port for accepting secure TLS connections This can be a port number, or
23005 Defaults to @samp{"16514"}.
23009 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23010 Port for accepting insecure TCP connections This can be a port number,
23013 Defaults to @samp{"16509"}.
23017 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23018 IP address or hostname used for client connections.
23020 Defaults to @samp{"0.0.0.0"}.
23024 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23025 Flag toggling mDNS advertisement of the libvirt service.
23027 Alternatively can disable for all services on a host by stopping the
23030 Defaults to @samp{#f}.
23034 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23035 Default mDNS advertisement name. This must be unique on the immediate
23038 Defaults to @samp{"Virtualization Host <hostname>"}.
23042 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23043 UNIX domain socket group ownership. This can be used to allow a
23044 'trusted' set of users access to management capabilities without
23047 Defaults to @samp{"root"}.
23051 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23052 UNIX socket permissions for the R/O socket. This is used for monitoring
23055 Defaults to @samp{"0777"}.
23059 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23060 UNIX socket permissions for the R/W socket. Default allows only root.
23061 If PolicyKit is enabled on the socket, the default will change to allow
23062 everyone (eg, 0777)
23064 Defaults to @samp{"0770"}.
23068 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23069 UNIX socket permissions for the admin socket. Default allows only owner
23070 (root), do not change it unless you are sure to whom you are exposing
23073 Defaults to @samp{"0777"}.
23077 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23078 The directory in which sockets will be found/created.
23080 Defaults to @samp{"/var/run/libvirt"}.
23084 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23085 Authentication scheme for UNIX read-only sockets. By default socket
23086 permissions allow anyone to connect
23088 Defaults to @samp{"polkit"}.
23092 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23093 Authentication scheme for UNIX read-write sockets. By default socket
23094 permissions only allow root. If PolicyKit support was compiled into
23095 libvirt, the default will be to use 'polkit' auth.
23097 Defaults to @samp{"polkit"}.
23101 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23102 Authentication scheme for TCP sockets. If you don't enable SASL, then
23103 all TCP traffic is cleartext. Don't do this outside of a dev/test
23106 Defaults to @samp{"sasl"}.
23110 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23111 Authentication scheme for TLS sockets. TLS sockets already have
23112 encryption provided by the TLS layer, and limited authentication is done
23115 It is possible to make use of any SASL authentication mechanism as well,
23116 by using 'sasl' for this option
23118 Defaults to @samp{"none"}.
23122 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23123 API access control scheme.
23125 By default an authenticated user is allowed access to all APIs. Access
23126 drivers can place restrictions on this.
23128 Defaults to @samp{()}.
23132 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23133 Server key file path. If set to an empty string, then no private key is
23136 Defaults to @samp{""}.
23140 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23141 Server key file path. If set to an empty string, then no certificate is
23144 Defaults to @samp{""}.
23148 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23149 Server key file path. If set to an empty string, then no CA certificate
23152 Defaults to @samp{""}.
23156 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23157 Certificate revocation list path. If set to an empty string, then no
23160 Defaults to @samp{""}.
23164 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23165 Disable verification of our own server certificates.
23167 When libvirtd starts it performs some sanity checks against its own
23170 Defaults to @samp{#f}.
23174 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23175 Disable verification of client certificates.
23177 Client certificate verification is the primary authentication mechanism.
23178 Any client which does not present a certificate signed by the CA will be
23181 Defaults to @samp{#f}.
23185 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23186 Whitelist of allowed x509 Distinguished Name.
23188 Defaults to @samp{()}.
23192 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23193 Whitelist of allowed SASL usernames. The format for username depends on
23194 the SASL authentication mechanism.
23196 Defaults to @samp{()}.
23200 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23201 Override the compile time default TLS priority string. The default is
23202 usually "NORMAL" unless overridden at build time. Only set this is it
23203 is desired for libvirt to deviate from the global default settings.
23205 Defaults to @samp{"NORMAL"}.
23209 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23210 Maximum number of concurrent client connections to allow over all
23213 Defaults to @samp{5000}.
23217 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23218 Maximum length of queue of connections waiting to be accepted by the
23219 daemon. Note, that some protocols supporting retransmission may obey
23220 this so that a later reattempt at connection succeeds.
23222 Defaults to @samp{1000}.
23226 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23227 Maximum length of queue of accepted but not yet authenticated clients.
23228 Set this to zero to turn this feature off
23230 Defaults to @samp{20}.
23234 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23235 Number of workers to start up initially.
23237 Defaults to @samp{5}.
23241 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23242 Maximum number of worker threads.
23244 If the number of active clients exceeds @code{min-workers}, then more
23245 threads are spawned, up to max_workers limit. Typically you'd want
23246 max_workers to equal maximum number of clients allowed.
23248 Defaults to @samp{20}.
23252 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23253 Number of priority workers. If all workers from above pool are stuck,
23254 some calls marked as high priority (notably domainDestroy) can be
23255 executed in this pool.
23257 Defaults to @samp{5}.
23261 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23262 Total global limit on concurrent RPC calls.
23264 Defaults to @samp{20}.
23268 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23269 Limit on concurrent requests from a single client connection. To avoid
23270 one client monopolizing the server this should be a small fraction of
23271 the global max_requests and max_workers parameter.
23273 Defaults to @samp{5}.
23277 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23278 Same as @code{min-workers} but for the admin interface.
23280 Defaults to @samp{1}.
23284 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23285 Same as @code{max-workers} but for the admin interface.
23287 Defaults to @samp{5}.
23291 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23292 Same as @code{max-clients} but for the admin interface.
23294 Defaults to @samp{5}.
23298 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23299 Same as @code{max-queued-clients} but for the admin interface.
23301 Defaults to @samp{5}.
23305 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23306 Same as @code{max-client-requests} but for the admin interface.
23308 Defaults to @samp{5}.
23312 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23313 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23315 Defaults to @samp{3}.
23319 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23322 A filter allows to select a different logging level for a given category
23323 of logs The format for a filter is one of:
23334 where @code{name} is a string which is matched against the category
23335 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23336 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23337 be a substring of the full category name, in order to match multiple
23338 similar categories), the optional "+" prefix tells libvirt to log stack
23339 trace for each message matching name, and @code{x} is the minimal level
23340 where matching messages should be logged:
23357 Multiple filters can be defined in a single filters statement, they just
23358 need to be separated by spaces.
23360 Defaults to @samp{"3:remote 4:event"}.
23364 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23367 An output is one of the places to save logging information. The format
23368 for an output can be:
23372 output goes to stderr
23374 @item x:syslog:name
23375 use syslog for the output and use the given name as the ident
23377 @item x:file:file_path
23378 output to a file, with the given filepath
23381 output to journald logging system
23385 In all case the x prefix is the minimal level, acting as a filter
23402 Multiple outputs can be defined, they just need to be separated by
23405 Defaults to @samp{"3:stderr"}.
23409 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23410 Allows usage of the auditing subsystem to be altered
23414 0: disable all auditing
23417 1: enable auditing, only if enabled on host
23420 2: enable auditing, and exit if disabled on host.
23424 Defaults to @samp{1}.
23428 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23429 Send audit messages via libvirt logging infrastructure.
23431 Defaults to @samp{#f}.
23435 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23436 Host UUID. UUID must not have all digits be the same.
23438 Defaults to @samp{""}.
23442 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23443 Source to read host UUID.
23447 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23450 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23454 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23457 Defaults to @samp{"smbios"}.
23461 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23462 A keepalive message is sent to a client after @code{keepalive_interval}
23463 seconds of inactivity to check if the client is still responding. If
23464 set to -1, libvirtd will never send keepalive requests; however clients
23465 can still send them and the daemon will send responses.
23467 Defaults to @samp{5}.
23471 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23472 Maximum number of keepalive messages that are allowed to be sent to the
23473 client without getting any response before the connection is considered
23476 In other words, the connection is automatically closed approximately
23477 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23478 the last message received from the client. When @code{keepalive-count}
23479 is set to 0, connections will be automatically closed after
23480 @code{keepalive-interval} seconds of inactivity without sending any
23481 keepalive messages.
23483 Defaults to @samp{5}.
23487 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23488 Same as above but for admin interface.
23490 Defaults to @samp{5}.
23494 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23495 Same as above but for admin interface.
23497 Defaults to @samp{5}.
23501 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23502 Timeout for Open vSwitch calls.
23504 The @code{ovs-vsctl} utility is used for the configuration and its
23505 timeout option is set by default to 5 seconds to avoid potential
23506 infinite waits blocking libvirt.
23508 Defaults to @samp{5}.
23512 @c %end of autogenerated docs
23514 @subsubheading Virtlog daemon
23515 The virtlogd service is a server side daemon component of libvirt that is
23516 used to manage logs from virtual machine consoles.
23518 This daemon is not used directly by libvirt client applications, rather it
23519 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23520 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23521 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23522 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23524 @deffn {Scheme Variable} virtlog-service-type
23525 This is the type of the virtlog daemon.
23526 Its value must be a @code{virtlog-configuration}.
23529 (service virtlog-service-type
23530 (virtlog-configuration
23531 (max-clients 1000)))
23535 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23536 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23538 Defaults to @samp{3}.
23542 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23545 A filter allows to select a different logging level for a given category
23546 of logs The format for a filter is one of:
23557 where @code{name} is a string which is matched against the category
23558 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23559 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23560 be a substring of the full category name, in order to match multiple
23561 similar categories), the optional "+" prefix tells libvirt to log stack
23562 trace for each message matching name, and @code{x} is the minimal level
23563 where matching messages should be logged:
23580 Multiple filters can be defined in a single filters statement, they just
23581 need to be separated by spaces.
23583 Defaults to @samp{"3:remote 4:event"}.
23587 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23590 An output is one of the places to save logging information The format
23591 for an output can be:
23595 output goes to stderr
23597 @item x:syslog:name
23598 use syslog for the output and use the given name as the ident
23600 @item x:file:file_path
23601 output to a file, with the given filepath
23604 output to journald logging system
23608 In all case the x prefix is the minimal level, acting as a filter
23625 Multiple outputs can be defined, they just need to be separated by
23628 Defaults to @samp{"3:stderr"}.
23632 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23633 Maximum number of concurrent client connections to allow over all
23636 Defaults to @samp{1024}.
23640 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23641 Maximum file size before rolling over.
23643 Defaults to @samp{2MB}
23647 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23648 Maximum number of backup files to keep.
23650 Defaults to @samp{3}
23654 @subsubheading Transparent Emulation with QEMU
23657 @cindex @code{binfmt_misc}
23658 @code{qemu-binfmt-service-type} provides support for transparent
23659 emulation of program binaries built for different architectures---e.g.,
23660 it allows you to transparently execute an ARMv7 program on an x86_64
23661 machine. It achieves this by combining the @uref{https://www.qemu.org,
23662 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23664 @defvr {Scheme Variable} qemu-binfmt-service-type
23665 This is the type of the QEMU/binfmt service for transparent emulation.
23666 Its value must be a @code{qemu-binfmt-configuration} object, which
23667 specifies the QEMU package to use as well as the architecture we want to
23671 (service qemu-binfmt-service-type
23672 (qemu-binfmt-configuration
23673 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23676 In this example, we enable transparent emulation for the ARM and aarch64
23677 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23678 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23679 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23682 @deftp {Data Type} qemu-binfmt-configuration
23683 This is the configuration for the @code{qemu-binfmt} service.
23686 @item @code{platforms} (default: @code{'()})
23687 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23688 object} as returned by @code{lookup-qemu-platforms} (see below).
23690 @item @code{guix-support?} (default: @code{#f})
23691 When it is true, QEMU and all its dependencies are added to the build
23692 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23693 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23694 handlers to be used within the build environment, which in turn means
23695 that you can transparently build programs for another architecture.
23697 For example, let's suppose you're on an x86_64 machine and you have this
23701 (service qemu-binfmt-service-type
23702 (qemu-binfmt-configuration
23703 (platforms (lookup-qemu-platforms "arm"))
23704 (guix-support? #t)))
23710 guix build -s armhf-linux inkscape
23714 and it will build Inkscape for ARMv7 @emph{as if it were a native
23715 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23716 if you'd like to test a package build for an architecture you don't have
23719 @item @code{qemu} (default: @code{qemu})
23720 The QEMU package to use.
23724 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23725 Return the list of QEMU platform objects corresponding to
23726 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23727 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23728 @code{"mips64el"}, and so on.
23731 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23732 Return true if @var{obj} is a platform object.
23735 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23736 Return the name of @var{platform}---a string such as @code{"arm"}.
23739 @node Version Control Services
23740 @subsection Version Control Services
23742 The @code{(gnu services version-control)} module provides a service to
23743 allow remote access to local Git repositories. There are three options:
23744 the @code{git-daemon-service}, which provides access to repositories via
23745 the @code{git://} unsecured TCP-based protocol, extending the
23746 @code{nginx} web server to proxy some requests to
23747 @code{git-http-backend}, or providing a web interface with
23748 @code{cgit-service-type}.
23750 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23752 Return a service that runs @command{git daemon}, a simple TCP server to
23753 expose repositories over the Git protocol for anonymous access.
23755 The optional @var{config} argument should be a
23756 @code{<git-daemon-configuration>} object, by default it allows read-only
23757 access to exported@footnote{By creating the magic file
23758 "git-daemon-export-ok" in the repository directory.} repositories under
23763 @deftp {Data Type} git-daemon-configuration
23764 Data type representing the configuration for @code{git-daemon-service}.
23767 @item @code{package} (default: @var{git})
23768 Package object of the Git distributed version control system.
23770 @item @code{export-all?} (default: @var{#f})
23771 Whether to allow access for all Git repositories, even if they do not
23772 have the @file{git-daemon-export-ok} file.
23774 @item @code{base-path} (default: @file{/srv/git})
23775 Whether to remap all the path requests as relative to the given path.
23776 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23777 then if you later try to pull @code{git://example.com/hello.git}, git
23778 daemon will interpret the path as @code{/srv/git/hello.git}.
23780 @item @code{user-path} (default: @var{#f})
23781 Whether to allow @code{~user} notation to be used in requests. When
23782 specified with empty string, requests to @code{git://host/~alice/foo} is
23783 taken as a request to access @code{foo} repository in the home directory
23784 of user @code{alice}. If @var{(user-path "path")} is specified, the
23785 same request is taken as a request to access @code{path/foo} repository
23786 in the home directory of user @code{alice}.
23788 @item @code{listen} (default: @var{'()})
23789 Whether to listen on specific IP addresses or hostnames, defaults to
23792 @item @code{port} (default: @var{#f})
23793 Whether to listen on an alternative port, which defaults to 9418.
23795 @item @code{whitelist} (default: @var{'()})
23796 If not empty, only allow access to this list of directories.
23798 @item @code{extra-options} (default: @var{'()})
23799 Extra options will be passed to @code{git daemon}, please run
23800 @command{man git-daemon} for more information.
23805 The @code{git://} protocol lacks authentication. When you pull from a
23806 repository fetched via @code{git://}, you don't know whether the data you
23807 receive was modified or is even coming from the specified host, and your
23808 connection is subject to eavesdropping. It's better to use an authenticated
23809 and encrypted transport, such as @code{https}. Although Git allows you
23810 to serve repositories using unsophisticated file-based web servers,
23811 there is a faster protocol implemented by the @code{git-http-backend}
23812 program. This program is the back-end of a proper Git web service. It
23813 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
23814 on running the necessary @code{fcgiwrap} daemon.
23816 Guix has a separate configuration data type for serving Git repositories
23819 @deftp {Data Type} git-http-configuration
23820 Data type representing the configuration for @code{git-http-service}.
23823 @item @code{package} (default: @var{git})
23824 Package object of the Git distributed version control system.
23826 @item @code{git-root} (default: @file{/srv/git})
23827 Directory containing the Git repositories to expose to the world.
23829 @item @code{export-all?} (default: @var{#f})
23830 Whether to expose access for all Git repositories in @var{git-root},
23831 even if they do not have the @file{git-daemon-export-ok} file.
23833 @item @code{uri-path} (default: @file{/git/})
23834 Path prefix for Git access. With the default @code{/git/} prefix, this
23835 will map @code{http://@var{server}/git/@var{repo}.git} to
23836 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
23837 with this prefix are not passed on to this Git instance.
23839 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
23840 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
23845 There is no @code{git-http-service-type}, currently; instead you can
23846 create an @code{nginx-location-configuration} from a
23847 @code{git-http-configuration} and then add that location to a web
23850 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
23851 [config=(git-http-configuration)]
23852 Compute an @code{nginx-location-configuration} that corresponds to the
23853 given Git http configuration. An example nginx service definition to
23854 serve the default @file{/srv/git} over HTTPS might be:
23857 (service nginx-service-type
23858 (nginx-configuration
23861 (nginx-server-configuration
23862 (listen '("443 ssl"))
23863 (server-name "git.my-host.org")
23865 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
23866 (ssl-certificate-key
23867 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
23870 (git-http-nginx-location-configuration
23871 (git-http-configuration (uri-path "/"))))))))))
23874 This example assumes that you are using Let's Encrypt to get your TLS
23875 certificate. @xref{Certificate Services}. The default @code{certbot}
23876 service will redirect all HTTP traffic on @code{git.my-host.org} to
23877 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
23878 system services. @xref{Web Services}.
23881 @subsubheading Cgit Service
23883 @cindex Cgit service
23884 @cindex Git, web interface
23885 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
23886 repositories written in C.
23888 The following example will configure the service with default values.
23889 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
23892 (service cgit-service-type)
23895 The @code{file-object} type designates either a file-like object
23896 (@pxref{G-Expressions, file-like objects}) or a string.
23898 @c %start of fragment
23900 Available @code{cgit-configuration} fields are:
23902 @deftypevr {@code{cgit-configuration} parameter} package package
23907 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
23908 NGINX configuration.
23912 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23913 Specifies a command which will be invoked to format the content of about
23914 pages (both top-level and for each repository).
23916 Defaults to @samp{""}.
23920 @deftypevr {@code{cgit-configuration} parameter} string agefile
23921 Specifies a path, relative to each repository path, which can be used to
23922 specify the date and time of the youngest commit in the repository.
23924 Defaults to @samp{""}.
23928 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23929 Specifies a command that will be invoked for authenticating repository
23932 Defaults to @samp{""}.
23936 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23937 Flag which, when set to @samp{age}, enables date ordering in the branch
23938 ref list, and when set @samp{name} enables ordering by branch name.
23940 Defaults to @samp{"name"}.
23944 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23945 Path used to store the cgit cache entries.
23947 Defaults to @samp{"/var/cache/cgit"}.
23951 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23952 Number which specifies the time-to-live, in minutes, for the cached
23953 version of repository pages accessed with a fixed SHA1.
23955 Defaults to @samp{-1}.
23959 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23960 Number which specifies the time-to-live, in minutes, for the cached
23961 version of repository pages accessed without a fixed SHA1.
23963 Defaults to @samp{5}.
23967 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23968 Number which specifies the time-to-live, in minutes, for the cached
23969 version of the repository summary page.
23971 Defaults to @samp{5}.
23975 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23976 Number which specifies the time-to-live, in minutes, for the cached
23977 version of the repository index page.
23979 Defaults to @samp{5}.
23983 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23984 Number which specifies the time-to-live, in minutes, for the result of
23985 scanning a path for Git repositories.
23987 Defaults to @samp{15}.
23991 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23992 Number which specifies the time-to-live, in minutes, for the cached
23993 version of the repository about page.
23995 Defaults to @samp{15}.
23999 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
24000 Number which specifies the time-to-live, in minutes, for the cached
24001 version of snapshots.
24003 Defaults to @samp{5}.
24007 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
24008 The maximum number of entries in the cgit cache. When set to @samp{0},
24009 caching is disabled.
24011 Defaults to @samp{0}.
24015 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24016 Sort items in the repo list case sensitively.
24018 Defaults to @samp{#t}.
24022 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24023 List of common prefixes which, when combined with a repository URL,
24024 generates valid clone URLs for the repository.
24026 Defaults to @samp{()}.
24030 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24031 List of @code{clone-url} templates.
24033 Defaults to @samp{()}.
24037 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24038 Command which will be invoked to format commit messages.
24040 Defaults to @samp{""}.
24044 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24045 Flag which, when set to @samp{date}, enables strict date ordering in the
24046 commit log, and when set to @samp{topo} enables strict topological
24049 Defaults to @samp{"git log"}.
24053 @deftypevr {@code{cgit-configuration} parameter} file-object css
24054 URL which specifies the css document to include in all cgit pages.
24056 Defaults to @samp{"/share/cgit/cgit.css"}.
24060 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24061 Specifies a command which will be invoked to format names and email
24062 address of committers, authors, and taggers, as represented in various
24063 places throughout the cgit interface.
24065 Defaults to @samp{""}.
24069 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24070 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24071 fragment suitable for embedding in other HTML pages.
24073 Defaults to @samp{#f}.
24077 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24078 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24079 commit history graph to the left of the commit messages in the
24080 repository log page.
24082 Defaults to @samp{#f}.
24086 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24087 Flag which, when set to @samp{#t}, allows all filter settings to be
24088 overridden in repository-specific cgitrc files.
24090 Defaults to @samp{#f}.
24094 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24095 Flag which, when set to @samp{#t}, allows users to follow a file in the
24098 Defaults to @samp{#f}.
24102 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24103 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24106 Defaults to @samp{#t}.
24110 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24111 Flag which, when set to @samp{#t}, will make cgit generate extra links
24112 "summary", "commit", "tree" for each repo in the repository index.
24114 Defaults to @samp{#f}.
24118 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24119 Flag which, when set to @samp{#t}, will make cgit display the owner of
24120 each repo in the repository index.
24122 Defaults to @samp{#t}.
24126 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24127 Flag which, when set to @samp{#t}, will make cgit print the number of
24128 modified files for each commit on the repository log page.
24130 Defaults to @samp{#f}.
24134 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24135 Flag which, when set to @samp{#t}, will make cgit print the number of
24136 added and removed lines for each commit on the repository log page.
24138 Defaults to @samp{#f}.
24142 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24143 Flag which, when set to @code{#t}, will make cgit display remote
24144 branches in the summary and refs views.
24146 Defaults to @samp{#f}.
24150 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24151 Flag which, when set to @code{1}, will make cgit use the subject of the
24152 parent commit as link text when generating links to parent commits in
24155 Defaults to @samp{#f}.
24159 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24160 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24161 parent commit as link text when generating links to parent commits in
24164 Defaults to @samp{#f}.
24168 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24169 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24170 links for plaintext blobs printed in the tree view.
24172 Defaults to @samp{#t}.
24176 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24177 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24178 set any repo specific settings.
24180 Defaults to @samp{#f}.
24184 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24185 URL used as link to a shortcut icon for cgit.
24187 Defaults to @samp{"/favicon.ico"}.
24191 @deftypevr {@code{cgit-configuration} parameter} string footer
24192 The content of the file specified with this option will be included
24193 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24194 "generated by..."@: message).
24196 Defaults to @samp{""}.
24200 @deftypevr {@code{cgit-configuration} parameter} string head-include
24201 The content of the file specified with this option will be included
24202 verbatim in the HTML HEAD section on all pages.
24204 Defaults to @samp{""}.
24208 @deftypevr {@code{cgit-configuration} parameter} string header
24209 The content of the file specified with this option will be included
24210 verbatim at the top of all pages.
24212 Defaults to @samp{""}.
24216 @deftypevr {@code{cgit-configuration} parameter} file-object include
24217 Name of a configfile to include before the rest of the current config-
24220 Defaults to @samp{""}.
24224 @deftypevr {@code{cgit-configuration} parameter} string index-header
24225 The content of the file specified with this option will be included
24226 verbatim above the repository index.
24228 Defaults to @samp{""}.
24232 @deftypevr {@code{cgit-configuration} parameter} string index-info
24233 The content of the file specified with this option will be included
24234 verbatim below the heading on the repository index page.
24236 Defaults to @samp{""}.
24240 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24241 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24242 in the servers timezone.
24244 Defaults to @samp{#f}.
24248 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24249 URL which specifies the source of an image which will be used as a logo
24252 Defaults to @samp{"/share/cgit/cgit.png"}.
24256 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24257 URL loaded when clicking on the cgit logo image.
24259 Defaults to @samp{""}.
24263 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24264 Command which will be invoked to format the Owner column of the main
24267 Defaults to @samp{""}.
24271 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24272 Number of items to display in atom feeds view.
24274 Defaults to @samp{10}.
24278 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24279 Number of entries to list per page in "log" view.
24281 Defaults to @samp{50}.
24285 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24286 Number of commit message characters to display in "log" view.
24288 Defaults to @samp{80}.
24292 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24293 Specifies the number of entries to list per page on the repository index
24296 Defaults to @samp{50}.
24300 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24301 Specifies the maximum number of repo description characters to display
24302 on the repository index page.
24304 Defaults to @samp{80}.
24308 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24309 Specifies the maximum size of a blob to display HTML for in KBytes.
24311 Defaults to @samp{0}.
24315 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24316 Maximum statistics period. Valid values are @samp{week},@samp{month},
24317 @samp{quarter} and @samp{year}.
24319 Defaults to @samp{""}.
24323 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24324 Mimetype for the specified filename extension.
24326 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24327 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24328 "image/png") (svg "image/svg+xml"))}.
24332 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24333 Specifies the file to use for automatic mimetype lookup.
24335 Defaults to @samp{""}.
24339 @deftypevr {@code{cgit-configuration} parameter} string module-link
24340 Text which will be used as the formatstring for a hyperlink when a
24341 submodule is printed in a directory listing.
24343 Defaults to @samp{""}.
24347 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24348 If set to the value @samp{#t} caching will be disabled.
24350 Defaults to @samp{#f}.
24354 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24355 If set to @samp{#t} showing full author email addresses will be
24358 Defaults to @samp{#f}.
24362 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24363 Flag which, when set to @samp{#t}, will make cgit omit the standard
24364 header on all pages.
24366 Defaults to @samp{#f}.
24370 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24371 A list of subdirectories inside of @code{repository-directory}, relative
24372 to it, that should loaded as Git repositories. An empty list means that
24373 all subdirectories will be loaded.
24375 Defaults to @samp{()}.
24379 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24380 Text which will be used as default value for @code{cgit-repo-readme}.
24382 Defaults to @samp{""}.
24386 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24387 If set to @code{#t} and @code{repository-directory} is enabled, if any
24388 repositories are found with a suffix of @code{.git}, this suffix will be
24389 removed for the URL and name.
24391 Defaults to @samp{#f}.
24395 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24396 Maximum number of files to consider when detecting renames.
24398 Defaults to @samp{-1}.
24402 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24403 The way in which repositories in each section are sorted.
24405 Defaults to @samp{""}.
24409 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24410 Text used as content for the @code{robots} meta-tag.
24412 Defaults to @samp{("noindex" "nofollow")}.
24416 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24417 Text printed below the heading on the repository index page.
24419 Defaults to @samp{"a fast webinterface for the git dscm"}.
24423 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24424 The content of the file specified with this option will be included
24425 verbatim below thef "about" link on the repository index page.
24427 Defaults to @samp{""}.
24431 @deftypevr {@code{cgit-configuration} parameter} string root-title
24432 Text printed as heading on the repository index page.
24434 Defaults to @samp{""}.
24438 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24439 If set to @samp{#t} and repository-directory is enabled,
24440 repository-directory will recurse into directories whose name starts
24441 with a period. Otherwise, repository-directory will stay away from such
24442 directories, considered as "hidden". Note that this does not apply to
24443 the ".git" directory in non-bare repos.
24445 Defaults to @samp{#f}.
24449 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24450 Text which specifies the default set of snapshot formats that cgit
24451 generates links for.
24453 Defaults to @samp{()}.
24457 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24458 Name of the directory to scan for repositories (represents
24461 Defaults to @samp{"/srv/git"}.
24465 @deftypevr {@code{cgit-configuration} parameter} string section
24466 The name of the current repository section - all repositories defined
24467 after this option will inherit the current section name.
24469 Defaults to @samp{""}.
24473 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24474 Flag which, when set to @samp{1}, will sort the sections on the
24475 repository listing by name.
24477 Defaults to @samp{""}.
24481 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24482 A number which, if defined prior to repository-directory, specifies how
24483 many path elements from each repo path to use as a default section name.
24485 Defaults to @samp{0}.
24489 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24490 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24493 Defaults to @samp{#f}.
24497 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24498 Specifies a command which will be invoked to format plaintext blobs in
24501 Defaults to @samp{""}.
24505 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24506 Specifies the number of branches to display in the repository "summary"
24509 Defaults to @samp{10}.
24513 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24514 Specifies the number of log entries to display in the repository
24517 Defaults to @samp{10}.
24521 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24522 Specifies the number of tags to display in the repository "summary"
24525 Defaults to @samp{10}.
24529 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24530 Filename which, if specified, needs to be present within the repository
24531 for cgit to allow access to that repository.
24533 Defaults to @samp{""}.
24537 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24538 URL which, if specified, will be used as root for all cgit links.
24540 Defaults to @samp{"/"}.
24544 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24545 A list of @dfn{cgit-repo} records to use with config.
24547 Defaults to @samp{()}.
24549 Available @code{repository-cgit-configuration} fields are:
24551 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24552 A mask of snapshot formats for this repo that cgit generates links for,
24553 restricted by the global @code{snapshots} setting.
24555 Defaults to @samp{()}.
24559 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24560 Override the default @code{source-filter}.
24562 Defaults to @samp{""}.
24566 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24567 The relative URL used to access the repository.
24569 Defaults to @samp{""}.
24573 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24574 Override the default @code{about-filter}.
24576 Defaults to @samp{""}.
24580 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24581 Flag which, when set to @samp{age}, enables date ordering in the branch
24582 ref list, and when set to @samp{name} enables ordering by branch name.
24584 Defaults to @samp{""}.
24588 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24589 A list of URLs which can be used to clone repo.
24591 Defaults to @samp{()}.
24595 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24596 Override the default @code{commit-filter}.
24598 Defaults to @samp{""}.
24602 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24603 Flag which, when set to @samp{date}, enables strict date ordering in the
24604 commit log, and when set to @samp{topo} enables strict topological
24607 Defaults to @samp{""}.
24611 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24612 The name of the default branch for this repository. If no such branch
24613 exists in the repository, the first branch name (when sorted) is used as
24614 default instead. By default branch pointed to by HEAD, or "master" if
24615 there is no suitable HEAD.
24617 Defaults to @samp{""}.
24621 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24622 The value to show as repository description.
24624 Defaults to @samp{""}.
24628 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24629 The value to show as repository homepage.
24631 Defaults to @samp{""}.
24635 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24636 Override the default @code{email-filter}.
24638 Defaults to @samp{""}.
24642 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24643 A flag which can be used to disable the global setting
24644 @code{enable-commit-graph?}.
24646 Defaults to @samp{disabled}.
24650 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24651 A flag which can be used to disable the global setting
24652 @code{enable-log-filecount?}.
24654 Defaults to @samp{disabled}.
24658 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24659 A flag which can be used to disable the global setting
24660 @code{enable-log-linecount?}.
24662 Defaults to @samp{disabled}.
24666 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24667 Flag which, when set to @code{#t}, will make cgit display remote
24668 branches in the summary and refs views.
24670 Defaults to @samp{disabled}.
24674 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24675 A flag which can be used to override the global setting
24676 @code{enable-subject-links?}.
24678 Defaults to @samp{disabled}.
24682 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24683 A flag which can be used to override the global setting
24684 @code{enable-html-serving?}.
24686 Defaults to @samp{disabled}.
24690 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24691 Flag which, when set to @code{#t}, hides the repository from the
24694 Defaults to @samp{#f}.
24698 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24699 Flag which, when set to @samp{#t}, ignores the repository.
24701 Defaults to @samp{#f}.
24705 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24706 URL which specifies the source of an image which will be used as a logo
24707 on this repo’s pages.
24709 Defaults to @samp{""}.
24713 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24714 URL loaded when clicking on the cgit logo image.
24716 Defaults to @samp{""}.
24720 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24721 Override the default @code{owner-filter}.
24723 Defaults to @samp{""}.
24727 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24728 Text which will be used as the formatstring for a hyperlink when a
24729 submodule is printed in a directory listing. The arguments for the
24730 formatstring are the path and SHA1 of the submodule commit.
24732 Defaults to @samp{""}.
24736 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24737 Text which will be used as the formatstring for a hyperlink when a
24738 submodule with the specified subdirectory path is printed in a directory
24741 Defaults to @samp{()}.
24745 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24746 Override the default maximum statistics period.
24748 Defaults to @samp{""}.
24752 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24753 The value to show as repository name.
24755 Defaults to @samp{""}.
24759 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24760 A value used to identify the owner of the repository.
24762 Defaults to @samp{""}.
24766 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24767 An absolute path to the repository directory.
24769 Defaults to @samp{""}.
24773 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24774 A path (relative to repo) which specifies a file to include verbatim as
24775 the "About" page for this repo.
24777 Defaults to @samp{""}.
24781 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24782 The name of the current repository section - all repositories defined
24783 after this option will inherit the current section name.
24785 Defaults to @samp{""}.
24789 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24790 Extra options will be appended to cgitrc file.
24792 Defaults to @samp{()}.
24798 @deftypevr {@code{cgit-configuration} parameter} list extra-options
24799 Extra options will be appended to cgitrc file.
24801 Defaults to @samp{()}.
24806 @c %end of fragment
24808 However, it could be that you just want to get a @code{cgitrc} up and
24809 running. In that case, you can pass an @code{opaque-cgit-configuration}
24810 as a record to @code{cgit-service-type}. As its name indicates, an
24811 opaque configuration does not have easy reflective capabilities.
24813 Available @code{opaque-cgit-configuration} fields are:
24815 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
24819 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
24820 The contents of the @code{cgitrc}, as a string.
24823 For example, if your @code{cgitrc} is just the empty string, you
24824 could instantiate a cgit service like this:
24827 (service cgit-service-type
24828 (opaque-cgit-configuration
24832 @subsubheading Gitolite Service
24834 @cindex Gitolite service
24835 @cindex Git, hosting
24836 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
24837 repositories on a central server.
24839 Gitolite can handle multiple repositories and users, and supports flexible
24840 configuration of the permissions for the users on the repositories.
24842 The following example will configure Gitolite using the default @code{git}
24843 user, and the provided SSH public key.
24846 (service gitolite-service-type
24847 (gitolite-configuration
24848 (admin-pubkey (plain-file
24850 "ssh-rsa AAAA... guix@@example.com"))))
24853 Gitolite is configured through a special admin repository which you can clone,
24854 for example, if you setup Gitolite on @code{example.com}, you would run the
24855 following command to clone the admin repository.
24858 git clone git@@example.com:gitolite-admin
24861 When the Gitolite service is activated, the provided @code{admin-pubkey} will
24862 be inserted in to the @file{keydir} directory in the gitolite-admin
24863 repository. If this results in a change in the repository, it will be
24864 committed using the message ``gitolite setup by GNU Guix''.
24866 @deftp {Data Type} gitolite-configuration
24867 Data type representing the configuration for @code{gitolite-service-type}.
24870 @item @code{package} (default: @var{gitolite})
24871 Gitolite package to use.
24873 @item @code{user} (default: @var{git})
24874 User to use for Gitolite. This will be user that you use when accessing
24877 @item @code{group} (default: @var{git})
24878 Group to use for Gitolite.
24880 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
24881 Directory in which to store the Gitolite configuration and repositories.
24883 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
24884 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
24885 representing the configuration for Gitolite.
24887 @item @code{admin-pubkey} (default: @var{#f})
24888 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
24889 setup Gitolite. This will be inserted in to the @file{keydir} directory
24890 within the gitolite-admin repository.
24892 To specify the SSH key as a string, use the @code{plain-file} function.
24895 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
24901 @deftp {Data Type} gitolite-rc-file
24902 Data type representing the Gitolite RC file.
24905 @item @code{umask} (default: @code{#o0077})
24906 This controls the permissions Gitolite sets on the repositories and their
24909 A value like @code{#o0027} will give read access to the group used by Gitolite
24910 (by default: @code{git}). This is necessary when using Gitolite with software
24911 like cgit or gitweb.
24913 @item @code{git-config-keys} (default: @code{""})
24914 Gitolite allows you to set git config values using the "config" keyword. This
24915 setting allows control over the config keys to accept.
24917 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24918 Set the role names allowed to be used by users running the perms command.
24920 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24921 This setting controls the commands and features to enable within Gitolite.
24927 @node Game Services
24928 @subsection Game Services
24930 @subsubheading The Battle for Wesnoth Service
24932 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24933 based tactical strategy game, with several single player campaigns, and
24934 multiplayer games (both networked and local).
24936 @defvar {Scheme Variable} wesnothd-service-type
24937 Service type for the wesnothd service. Its value must be a
24938 @code{wesnothd-configuration} object. To run wesnothd in the default
24939 configuration, instantiate it as:
24942 (service wesnothd-service-type)
24946 @deftp {Data Type} wesnothd-configuration
24947 Data type representing the configuration of @command{wesnothd}.
24950 @item @code{package} (default: @code{wesnoth-server})
24951 The wesnoth server package to use.
24953 @item @code{port} (default: @code{15000})
24954 The port to bind the server to.
24959 @node PAM Mount Service
24960 @subsection PAM Mount Service
24963 The @code{(gnu services pam-mount)} module provides a service allowing
24964 users to mount volumes when they log in. It should be able to mount any
24965 volume format supported by the system.
24967 @defvar {Scheme Variable} pam-mount-service-type
24968 Service type for PAM Mount support.
24971 @deftp {Data Type} pam-mount-configuration
24972 Data type representing the configuration of PAM Mount.
24974 It takes the following parameters:
24978 The configuration rules that will be used to generate
24979 @file{/etc/security/pam_mount.conf.xml}.
24981 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
24982 Guile Reference Manual}), and the the default ones don't mount anything
24983 for anyone at login:
24986 `((debug (@@ (enable "0")))
24987 (mntoptions (@@ (allow ,(string-join
24988 '("nosuid" "nodev" "loop"
24989 "encryption" "fsck" "nonempty"
24990 "allow_root" "allow_other")
24992 (mntoptions (@@ (require "nosuid,nodev")))
24993 (logout (@@ (wait "0")
24997 (mkmountpoint (@@ (enable "1")
25001 Some @code{volume} elements must be added to automatically mount volumes
25002 at login. Here's an example allowing the user @code{alice} to mount her
25003 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
25004 the partition where he stores his data:
25007 (define pam-mount-rules
25008 `((debug (@@ (enable "0")))
25009 (volume (@@ (user "alice")
25012 (mountpoint "/home/alice")))
25013 (volume (@@ (user "bob")
25016 (mountpoint "/home/bob/data")
25017 (options "defaults,autodefrag,compress")))
25018 (mntoptions (@@ (allow ,(string-join
25019 '("nosuid" "nodev" "loop"
25020 "encryption" "fsck" "nonempty"
25021 "allow_root" "allow_other")
25023 (mntoptions (@@ (require "nosuid,nodev")))
25024 (logout (@@ (wait "0")
25028 (mkmountpoint (@@ (enable "1")
25029 (remove "true")))))
25031 (service pam-mount-service-type
25032 (pam-mount-configuration
25033 (rules pam-mount-rules)))
25036 The complete list of possible options can be found in the man page for
25037 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25042 @node Guix Services
25043 @subsection Guix Services
25045 @subsubheading Guix Data Service
25046 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25047 and provides data about GNU Guix. This includes information about
25048 packages, derivations and lint warnings.
25050 The data is stored in a PostgreSQL database, and available through a web
25053 @defvar {Scheme Variable} guix-data-service-type
25054 Service type for the Guix Data Service. Its value must be a
25055 @code{guix-data-service-configuration} object. The service optionally
25056 extends the getmail service, as the guix-commits mailing list is used to
25057 find out about changes in the Guix git repository.
25060 @deftp {Data Type} guix-data-service-configuration
25061 Data type representing the configuration of the Guix Data Service.
25064 @item @code{package} (default: @code{guix-data-service})
25065 The Guix Data Service package to use.
25067 @item @code{user} (default: @code{"guix-data-service"})
25068 The system user to run the service as.
25070 @item @code{group} (default: @code{"guix-data-service"})
25071 The system group to run the service as.
25073 @item @code{port} (default: @code{8765})
25074 The port to bind the web service to.
25076 @item @code{host} (default: @code{"127.0.0.1"})
25077 The host to bind the web service to.
25079 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25080 If set, this is the list of mailboxes that the getmail service will be
25081 configured to listen to.
25083 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25084 If set, this is the @code{getmail-retriever-configuration} object with
25085 which to configure getmail to fetch mail from the guix-commits mailing
25092 @node Miscellaneous Services
25093 @subsection Miscellaneous Services
25095 @cindex fingerprint
25096 @subsubheading Fingerprint Service
25098 The @code{(gnu services authentication)} module provides a DBus service to
25099 read and identify fingerprints via a fingerprint sensor.
25101 @defvr {Scheme Variable} fprintd-service-type
25102 The service type for @command{fprintd}, which provides the fingerprint
25103 reading capability.
25106 (service fprintd-service-type)
25111 @subsubheading System Control Service
25113 The @code{(gnu services sysctl)} provides a service to configure kernel
25114 parameters at boot.
25116 @defvr {Scheme Variable} sysctl-service-type
25117 The service type for @command{sysctl}, which modifies kernel parameters
25118 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25122 (service sysctl-service-type
25123 (sysctl-configuration
25124 (settings '(("net.ipv4.ip_forward" . "1")))))
25128 @deftp {Data Type} sysctl-configuration
25129 The data type representing the configuration of @command{sysctl}.
25132 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25133 The @command{sysctl} executable to use.
25135 @item @code{settings} (default: @code{'()})
25136 An association list specifies kernel parameters and their values.
25141 @subsubheading PC/SC Smart Card Daemon Service
25143 The @code{(gnu services security-token)} module provides the following service
25144 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25145 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25146 manager that coordinates communications with smart card readers, smart cards
25147 and cryptographic tokens that are connected to the system.
25149 @defvr {Scheme Variable} pcscd-service-type
25150 Service type for the @command{pcscd} service. Its value must be a
25151 @code{pcscd-configuration} object. To run pcscd in the default
25152 configuration, instantiate it as:
25155 (service pcscd-service-type)
25159 @deftp {Data Type} pcscd-configuration
25160 The data type representing the configuration of @command{pcscd}.
25163 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25164 The pcsc-lite package that provides pcscd.
25165 @item @code{usb-drivers} (default: @code{(list ccid)})
25166 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25167 under @file{pcsc/drivers} in the store directory of the package.
25172 @subsubheading Lirc Service
25174 The @code{(gnu services lirc)} module provides the following service.
25176 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25177 [#:device #f] [#:driver #f] [#:config-file #f] @
25178 [#:extra-options '()]
25179 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25180 decodes infrared signals from remote controls.
25182 Optionally, @var{device}, @var{driver} and @var{config-file}
25183 (configuration file name) may be specified. See @command{lircd} manual
25186 Finally, @var{extra-options} is a list of additional command-line options
25187 passed to @command{lircd}.
25191 @subsubheading Spice Service
25193 The @code{(gnu services spice)} module provides the following service.
25195 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25196 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25197 that enables sharing the clipboard with a vm and setting the guest display
25198 resolution when the graphical console window resizes.
25201 @cindex inputattach
25202 @subsubheading inputattach Service
25204 @cindex tablet input, for Xorg
25205 @cindex touchscreen input, for Xorg
25206 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25207 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25208 Xorg display server.
25210 @deffn {Scheme Variable} inputattach-service-type
25211 Type of a service that runs @command{inputattach} on a device and
25212 dispatches events from it.
25215 @deftp {Data Type} inputattach-configuration
25217 @item @code{device-type} (default: @code{"wacom"})
25218 The type of device to connect to. Run @command{inputattach --help}, from the
25219 @code{inputattach} package, to see the list of supported device types.
25221 @item @code{device} (default: @code{"/dev/ttyS0"})
25222 The device file to connect to the device.
25224 @item @code{baud-rate} (default: @code{#f})
25225 Baud rate to use for the serial connection.
25226 Should be a number or @code{#f}.
25228 @item @code{log-file} (default: @code{#f})
25229 If true, this must be the name of a file to log messages to.
25233 @subsection Dictionary Services
25235 The @code{(gnu services dict)} module provides the following service:
25237 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25238 Return a service that runs the @command{dicod} daemon, an implementation
25239 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25241 The optional @var{config} argument specifies the configuration for
25242 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25243 default it serves the GNU Collaborative International Dictonary of English.
25245 You can add @command{open localhost} to your @file{~/.dico} file to make
25246 @code{localhost} the default server for @command{dico} client
25247 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25250 @deftp {Data Type} dicod-configuration
25251 Data type representing the configuration of dicod.
25254 @item @code{dico} (default: @var{dico})
25255 Package object of the GNU Dico dictionary server.
25257 @item @code{interfaces} (default: @var{'("localhost")})
25258 This is the list of IP addresses and ports and possibly socket file
25259 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25260 dico, GNU Dico Manual}).
25262 @item @code{handlers} (default: @var{'()})
25263 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25265 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25266 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25270 @deftp {Data Type} dicod-handler
25271 Data type representing a dictionary handler (module instance).
25275 Name of the handler (module instance).
25277 @item @code{module} (default: @var{#f})
25278 Name of the dicod module of the handler (instance). If it is @code{#f},
25279 the module has the same name as the handler.
25280 (@pxref{Modules,,, dico, GNU Dico Manual}).
25282 @item @code{options}
25283 List of strings or gexps representing the arguments for the module handler
25287 @deftp {Data Type} dicod-database
25288 Data type representing a dictionary database.
25292 Name of the database, will be used in DICT commands.
25294 @item @code{handler}
25295 Name of the dicod handler (module instance) used by this database
25296 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25298 @item @code{complex?} (default: @var{#f})
25299 Whether the database configuration complex. The complex configuration
25300 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25302 @item @code{options}
25303 List of strings or gexps representing the arguments for the database
25304 (@pxref{Databases,,, dico, GNU Dico Manual}).
25308 @defvr {Scheme Variable} %dicod-database:gcide
25309 A @code{<dicod-database>} object serving the GNU Collaborative International
25310 Dictionary of English using the @code{gcide} package.
25313 The following is an example @code{dicod-service} configuration.
25316 (dicod-service #:config
25317 (dicod-configuration
25318 (handlers (list (dicod-handler
25322 (list #~(string-append "dbdir=" #$wordnet))))))
25323 (databases (list (dicod-database
25326 (handler "wordnet")
25327 (options '("database=wn")))
25328 %dicod-database:gcide))))
25332 @subsubheading Docker Service
25334 The @code{(gnu services docker)} module provides the following services.
25336 @defvr {Scheme Variable} docker-service-type
25338 This is the type of the service that runs @url{https://www.docker.com,Docker},
25339 a daemon that can execute application bundles (sometimes referred to as
25340 ``containers'') in isolated environments.
25344 @deftp {Data Type} docker-configuration
25345 This is the data type representing the configuration of Docker and Containerd.
25349 @item @code{package} (default: @code{docker})
25350 The Docker package to use.
25352 @item @code{containerd} (default: @var{containerd})
25353 The Containerd package to use.
25359 @subsubheading Auditd Service
25361 The @code{(gnu services auditd)} module provides the following service.
25363 @defvr {Scheme Variable} auditd-service-type
25365 This is the type of the service that runs
25366 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25367 a daemon that tracks security-relevant information on your system.
25369 Examples of things that can be tracked:
25379 Failed login attempts
25386 @command{auditctl} from the @code{audit} package can be used in order
25387 to add or remove events to be tracked (until the next reboot).
25388 In order to permanently track events, put the command line arguments
25389 of auditctl into @file{/etc/audit/audit.rules}.
25390 @command{aureport} from the @code{audit} package can be used in order
25391 to view a report of all recorded events.
25392 The audit daemon usually logs into the directory @file{/var/log/audit}.
25396 @deftp {Data Type} auditd-configuration
25397 This is the data type representing the configuration of auditd.
25401 @item @code{audit} (default: @code{audit})
25402 The audit package to use.
25407 @defvr {Scheme Variable} singularity-service-type
25408 This is the type of the service that allows you to run
25409 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25410 create and run application bundles (aka. ``containers''). The value for this
25411 service is the Singularity package to use.
25413 The service does not install a daemon; instead, it installs helper programs as
25414 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25415 @command{singularity run} and similar commands.
25419 @subsubheading Nix service
25421 The @code{(gnu services nix)} module provides the following service.
25423 @defvr {Scheme Variable} nix-service-type
25425 This is the type of the service that runs build daemon of the
25426 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25430 (use-modules (gnu))
25431 (use-service-modules nix)
25432 (use-package-modules package-management)
25436 (packages (append (list nix)
25439 (services (append (list (service nix-service-type))
25443 After @command{guix system reconfigure} configure Nix for your user:
25446 @item Add a Nix channel and update it. See
25447 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25449 @item Create a symlink to your profile and activate Nix profile:
25453 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25454 $ source /run/current-system/profile/etc/profile.d/nix.sh
25459 @node Setuid Programs
25460 @section Setuid Programs
25462 @cindex setuid programs
25463 Some programs need to run with ``root'' privileges, even when they are
25464 launched by unprivileged users. A notorious example is the
25465 @command{passwd} program, which users can run to change their
25466 password, and which needs to access the @file{/etc/passwd} and
25467 @file{/etc/shadow} files---something normally restricted to root, for
25468 obvious security reasons. To address that, these executables are
25469 @dfn{setuid-root}, meaning that they always run with root privileges
25470 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25471 for more info about the setuid mechanism.)
25473 The store itself @emph{cannot} contain setuid programs: that would be a
25474 security issue since any user on the system can write derivations that
25475 populate the store (@pxref{The Store}). Thus, a different mechanism is
25476 used: instead of changing the setuid bit directly on files that are in
25477 the store, we let the system administrator @emph{declare} which programs
25478 should be setuid root.
25480 The @code{setuid-programs} field of an @code{operating-system}
25481 declaration contains a list of G-expressions denoting the names of
25482 programs to be setuid-root (@pxref{Using the Configuration System}).
25483 For instance, the @command{passwd} program, which is part of the Shadow
25484 package, can be designated by this G-expression (@pxref{G-Expressions}):
25487 #~(string-append #$shadow "/bin/passwd")
25490 A default set of setuid programs is defined by the
25491 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25493 @defvr {Scheme Variable} %setuid-programs
25494 A list of G-expressions denoting common programs that are setuid-root.
25496 The list includes commands such as @command{passwd}, @command{ping},
25497 @command{su}, and @command{sudo}.
25500 Under the hood, the actual setuid programs are created in the
25501 @file{/run/setuid-programs} directory at system activation time. The
25502 files in this directory refer to the ``real'' binaries, which are in the
25505 @node X.509 Certificates
25506 @section X.509 Certificates
25508 @cindex HTTPS, certificates
25509 @cindex X.509 certificates
25511 Web servers available over HTTPS (that is, HTTP over the transport-layer
25512 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25513 that the client can then use to @emph{authenticate} the server. To do
25514 that, clients verify that the server's certificate is signed by a
25515 so-called @dfn{certificate authority} (CA). But to verify the CA's
25516 signature, clients must have first acquired the CA's certificate.
25518 Web browsers such as GNU@tie{}IceCat include their own set of CA
25519 certificates, such that they are able to verify CA signatures
25522 However, most other programs that can talk HTTPS---@command{wget},
25523 @command{git}, @command{w3m}, etc.---need to be told where CA
25524 certificates can be found.
25526 @cindex @code{nss-certs}
25527 In Guix, this is done by adding a package that provides certificates
25528 to the @code{packages} field of the @code{operating-system} declaration
25529 (@pxref{operating-system Reference}). Guix includes one such package,
25530 @code{nss-certs}, which is a set of CA certificates provided as part of
25531 Mozilla's Network Security Services.
25533 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25534 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25535 most applications and libraries look for certificates by default, points
25536 to the certificates installed globally.
25538 Unprivileged users, including users of Guix on a foreign distro,
25539 can also install their own certificate package in
25540 their profile. A number of environment variables need to be defined so
25541 that applications and libraries know where to find them. Namely, the
25542 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25543 variables. Some applications add their own environment variables; for
25544 instance, the Git version control system honors the certificate bundle
25545 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25546 would typically run something like:
25549 $ guix install nss-certs
25550 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25551 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25552 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25555 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25556 variable to point to a certificate bundle, so you would have to run
25557 something like this:
25560 $ guix install nss-certs
25561 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25564 For other applications you may want to look up the required environment
25565 variable in the relevant documentation.
25568 @node Name Service Switch
25569 @section Name Service Switch
25571 @cindex name service switch
25573 The @code{(gnu system nss)} module provides bindings to the
25574 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25575 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25576 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25577 extended with new ``name'' lookup methods for system databases, which
25578 includes host names, service names, user accounts, and more (@pxref{Name
25579 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25580 C Library Reference Manual}).
25582 The NSS configuration specifies, for each system database, which lookup
25583 method is to be used, and how the various methods are chained
25584 together---for instance, under which circumstances NSS should try the
25585 next method in the list. The NSS configuration is given in the
25586 @code{name-service-switch} field of @code{operating-system} declarations
25587 (@pxref{operating-system Reference, @code{name-service-switch}}).
25590 @cindex .local, host name lookup
25591 As an example, the declaration below configures the NSS to use the
25592 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25593 back-end}, which supports host name lookups over multicast DNS (mDNS)
25594 for host names ending in @code{.local}:
25597 (name-service-switch
25598 (hosts (list %files ;first, check /etc/hosts
25600 ;; If the above did not succeed, try
25601 ;; with 'mdns_minimal'.
25603 (name "mdns_minimal")
25605 ;; 'mdns_minimal' is authoritative for
25606 ;; '.local'. When it returns "not found",
25607 ;; no need to try the next methods.
25608 (reaction (lookup-specification
25609 (not-found => return))))
25611 ;; Then fall back to DNS.
25615 ;; Finally, try with the "full" 'mdns'.
25620 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25621 contains this configuration, so you will not have to type it if all you
25622 want is to have @code{.local} host lookup working.
25624 Note that, in this case, in addition to setting the
25625 @code{name-service-switch} of the @code{operating-system} declaration,
25626 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25627 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25628 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25629 to the name service cache daemon (@pxref{Base Services,
25630 @code{nscd-service}}).
25632 For convenience, the following variables provide typical NSS
25635 @defvr {Scheme Variable} %default-nss
25636 This is the default name service switch configuration, a
25637 @code{name-service-switch} object.
25640 @defvr {Scheme Variable} %mdns-host-lookup-nss
25641 This is the name service switch configuration with support for host name
25642 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25645 The reference for name service switch configuration is given below. It
25646 is a direct mapping of the configuration file format of the C library , so
25647 please refer to the C library manual for more information (@pxref{NSS
25648 Configuration File,,, libc, The GNU C Library Reference Manual}).
25649 Compared to the configuration file format of libc NSS, it has the advantage
25650 not only of adding this warm parenthetic feel that we like, but also
25651 static checks: you will know about syntax errors and typos as soon as you
25652 run @command{guix system}.
25654 @deftp {Data Type} name-service-switch
25656 This is the data type representation the configuration of libc's name
25657 service switch (NSS). Each field below represents one of the supported
25674 The system databases handled by the NSS. Each of these fields must be a
25675 list of @code{<name-service>} objects (see below).
25679 @deftp {Data Type} name-service
25681 This is the data type representing an actual name service and the
25682 associated lookup action.
25686 A string denoting the name service (@pxref{Services in the NSS
25687 configuration,,, libc, The GNU C Library Reference Manual}).
25689 Note that name services listed here must be visible to nscd. This is
25690 achieved by passing the @code{#:name-services} argument to
25691 @code{nscd-service} the list of packages providing the needed name
25692 services (@pxref{Base Services, @code{nscd-service}}).
25695 An action specified using the @code{lookup-specification} macro
25696 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25697 Reference Manual}). For example:
25700 (lookup-specification (unavailable => continue)
25701 (success => return))
25706 @node Initial RAM Disk
25707 @section Initial RAM Disk
25710 @cindex initial RAM disk
25711 For bootstrapping purposes, the Linux-Libre kernel is passed an
25712 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25713 root file system as well as an initialization script. The latter is
25714 responsible for mounting the real root file system, and for loading any
25715 kernel modules that may be needed to achieve that.
25717 The @code{initrd-modules} field of an @code{operating-system}
25718 declaration allows you to specify Linux-libre kernel modules that must
25719 be available in the initrd. In particular, this is where you would list
25720 modules needed to actually drive the hard disk where your root partition
25721 is---although the default value of @code{initrd-modules} should cover
25722 most use cases. For example, assuming you need the @code{megaraid_sas}
25723 module in addition to the default modules to be able to access your root
25724 file system, you would write:
25729 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
25732 @defvr {Scheme Variable} %base-initrd-modules
25733 This is the list of kernel modules included in the initrd by default.
25736 Furthermore, if you need lower-level customization, the @code{initrd}
25737 field of an @code{operating-system} declaration allows
25738 you to specify which initrd you would like to use. The @code{(gnu
25739 system linux-initrd)} module provides three ways to build an initrd: the
25740 high-level @code{base-initrd} procedure and the low-level
25741 @code{raw-initrd} and @code{expression->initrd} procedures.
25743 The @code{base-initrd} procedure is intended to cover most common uses.
25744 For example, if you want to add a bunch of kernel modules to be loaded
25745 at boot time, you can define the @code{initrd} field of the operating
25746 system declaration like this:
25749 (initrd (lambda (file-systems . rest)
25750 ;; Create a standard initrd but set up networking
25751 ;; with the parameters QEMU expects by default.
25752 (apply base-initrd file-systems
25753 #:qemu-networking? #t
25757 The @code{base-initrd} procedure also handles common use cases that
25758 involves using the system as a QEMU guest, or as a ``live'' system with
25759 volatile root file system.
25761 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
25762 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
25763 such as trying to guess which kernel modules and packages should be included
25764 to the initrd. An example use of @code{raw-initrd} is when a user has
25765 a custom Linux kernel configuration and default kernel modules included by
25766 @code{base-initrd} are not available.
25768 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
25769 honors several options passed on the Linux kernel command line
25770 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
25771 @code{-append} option of QEMU), notably:
25774 @item --load=@var{boot}
25775 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
25776 program, once it has mounted the root file system.
25778 Guix uses this option to yield control to a boot program that runs the
25779 service activation programs and then spawns the GNU@tie{}Shepherd, the
25780 initialization system.
25782 @item --root=@var{root}
25783 Mount @var{root} as the root file system. @var{root} can be a
25784 device name like @code{/dev/sda1}, a file system label, or a file system
25787 @item --system=@var{system}
25788 Have @file{/run/booted-system} and @file{/run/current-system} point to
25791 @item modprobe.blacklist=@var{modules}@dots{}
25792 @cindex module, black-listing
25793 @cindex black list, of kernel modules
25794 Instruct the initial RAM disk as well as the @command{modprobe} command
25795 (from the kmod package) to refuse to load @var{modules}. @var{modules}
25796 must be a comma-separated list of module names---e.g.,
25797 @code{usbkbd,9pnet}.
25800 Start a read-eval-print loop (REPL) from the initial RAM disk before it
25801 tries to load kernel modules and to mount the root file system. Our
25802 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
25803 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
25804 Manual}, for more information on Guile's REPL.
25808 Now that you know all the features that initial RAM disks produced by
25809 @code{base-initrd} and @code{raw-initrd} provide,
25810 here is how to use it and customize it further.
25813 @cindex initial RAM disk
25814 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
25815 [#:linux-modules '()] [#:mapped-devices '()] @
25816 [#:keyboard-layout #f] @
25817 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
25818 Return a derivation that builds a raw initrd. @var{file-systems} is
25819 a list of file systems to be mounted by the initrd, possibly in addition to
25820 the root file system specified on the kernel command line via @code{--root}.
25821 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
25822 @var{mapped-devices} is a list of device mappings to realize before
25823 @var{file-systems} are mounted (@pxref{Mapped Devices}).
25824 @var{helper-packages} is a list of packages to be copied in the initrd. It may
25825 include @code{e2fsck/static} or other packages needed by the initrd to check
25826 the root file system.
25828 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25829 the desired console keyboard layout. This is done before @var{mapped-devices}
25830 are set up and before @var{file-systems} are mounted such that, should the
25831 user need to enter a passphrase or use the REPL, this happens using the
25832 intended keyboard layout.
25834 When @var{qemu-networking?} is true, set up networking with the standard QEMU
25835 parameters. When @var{virtio?} is true, load additional modules so that the
25836 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
25838 When @var{volatile-root?} is true, the root file system is writable but any changes
25842 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
25843 [#:mapped-devices '()] [#:keyboard-layout #f] @
25844 [#:qemu-networking? #f] [#:volatile-root? #f] @
25845 [#:linux-modules '()]
25846 Return as a file-like object a generic initrd, with kernel
25847 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
25848 mounted by the initrd, possibly in addition to the root file system specified
25849 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
25850 mappings to realize before @var{file-systems} are mounted.
25852 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25853 the desired console keyboard layout. This is done before @var{mapped-devices}
25854 are set up and before @var{file-systems} are mounted such that, should the
25855 user need to enter a passphrase or use the REPL, this happens using the
25856 intended keyboard layout.
25858 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
25860 The initrd is automatically populated with all the kernel modules necessary
25861 for @var{file-systems} and for the given options. Additional kernel
25862 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
25863 loaded at boot time in the order in which they appear.
25866 Needless to say, the initrds we produce and use embed a
25867 statically-linked Guile, and the initialization program is a Guile
25868 program. That gives a lot of flexibility. The
25869 @code{expression->initrd} procedure builds such an initrd, given the
25870 program to run in that initrd.
25872 @deffn {Scheme Procedure} expression->initrd @var{exp} @
25873 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
25874 Return as a file-like object a Linux initrd (a gzipped cpio archive)
25875 containing @var{guile} and that evaluates @var{exp}, a G-expression,
25876 upon booting. All the derivations referenced by @var{exp} are
25877 automatically copied to the initrd.
25880 @node Bootloader Configuration
25881 @section Bootloader Configuration
25884 @cindex boot loader
25886 The operating system supports multiple bootloaders. The bootloader is
25887 configured using @code{bootloader-configuration} declaration. All the
25888 fields of this structure are bootloader agnostic except for one field,
25889 @code{bootloader} that indicates the bootloader to be configured and
25892 Some of the bootloaders do not honor every field of
25893 @code{bootloader-configuration}. For instance, the extlinux
25894 bootloader does not support themes and thus ignores the @code{theme}
25897 @deftp {Data Type} bootloader-configuration
25898 The type of a bootloader configuration declaration.
25902 @item @code{bootloader}
25903 @cindex EFI, bootloader
25904 @cindex UEFI, bootloader
25905 @cindex BIOS, bootloader
25906 The bootloader to use, as a @code{bootloader} object. For now
25907 @code{grub-bootloader}, @code{grub-efi-bootloader},
25908 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
25910 @vindex grub-efi-bootloader
25911 @code{grub-efi-bootloader} allows to boot on modern systems using the
25912 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
25913 use if the installation image contains a @file{/sys/firmware/efi} directory
25914 when you boot it on your system.
25916 @vindex grub-bootloader
25917 @code{grub-bootloader} allows you to boot in particular Intel-based machines
25918 in ``legacy'' BIOS mode.
25920 @cindex ARM, bootloaders
25921 @cindex AArch64, bootloaders
25922 Available bootloaders are described in @code{(gnu bootloader @dots{})}
25923 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
25924 of bootloaders for a wide range of ARM and AArch64 systems, using the
25925 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
25927 @item @code{target}
25928 This is a string denoting the target onto which to install the
25931 The interpretation depends on the bootloader in question. For
25932 @code{grub-bootloader}, for example, it should be a device name understood by
25933 the bootloader @command{installer} command, such as @code{/dev/sda} or
25934 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
25935 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
25936 system, usually @file{/boot/efi}.
25938 @item @code{menu-entries} (default: @code{()})
25939 A possibly empty list of @code{menu-entry} objects (see below), denoting
25940 entries to appear in the bootloader menu, in addition to the current
25941 system entry and the entry pointing to previous system generations.
25943 @item @code{default-entry} (default: @code{0})
25944 The index of the default boot menu entry. Index 0 is for the entry of the
25947 @item @code{timeout} (default: @code{5})
25948 The number of seconds to wait for keyboard input before booting. Set to
25949 0 to boot immediately, and to -1 to wait indefinitely.
25951 @cindex keyboard layout, for the bootloader
25952 @item @code{keyboard-layout} (default: @code{#f})
25953 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
25954 layout, usually US@tie{}English (``qwerty'').
25956 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
25960 This option is currently ignored by bootloaders other than @code{grub} and
25964 @item @code{theme} (default: @var{#f})
25965 The bootloader theme object describing the theme to use. If no theme
25966 is provided, some bootloaders might use a default theme, that's true
25969 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
25970 The output terminals used for the bootloader boot menu, as a list of
25971 symbols. GRUB accepts the values: @code{console}, @code{serial},
25972 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
25973 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
25974 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
25975 configuration,,, grub,GNU GRUB manual}).
25977 @item @code{terminal-inputs} (default: @code{'()})
25978 The input terminals used for the bootloader boot menu, as a list of
25979 symbols. For GRUB, the default is the native platform terminal as
25980 determined at run-time. GRUB accepts the values: @code{console},
25981 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
25982 @code{usb_keyboard}. This field corresponds to the GRUB variable
25983 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
25986 @item @code{serial-unit} (default: @code{#f})
25987 The serial unit used by the bootloader, as an integer from 0 to 3.
25988 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
25989 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25991 @item @code{serial-speed} (default: @code{#f})
25992 The speed of the serial interface, as an integer. For GRUB, the
25993 default value is chosen at run-time; currently GRUB chooses
25994 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26001 Should you want to list additional boot menu entries @i{via} the
26002 @code{menu-entries} field above, you will need to create them with the
26003 @code{menu-entry} form. For example, imagine you want to be able to
26004 boot another distro (hard to imagine!), you can define a menu entry
26009 (label "The Other Distro")
26010 (linux "/boot/old/vmlinux-2.6.32")
26011 (linux-arguments '("root=/dev/sda2"))
26012 (initrd "/boot/old/initrd"))
26017 @deftp {Data Type} menu-entry
26018 The type of an entry in the bootloader menu.
26023 The label to show in the menu---e.g., @code{"GNU"}.
26026 The Linux kernel image to boot, for example:
26029 (file-append linux-libre "/bzImage")
26032 For GRUB, it is also possible to specify a device explicitly in the
26033 file path using GRUB's device naming convention (@pxref{Naming
26034 convention,,, grub, GNU GRUB manual}), for example:
26037 "(hd0,msdos1)/boot/vmlinuz"
26040 If the device is specified explicitly as above, then the @code{device}
26041 field is ignored entirely.
26043 @item @code{linux-arguments} (default: @code{()})
26044 The list of extra Linux kernel command-line arguments---e.g.,
26045 @code{("console=ttyS0")}.
26047 @item @code{initrd}
26048 A G-Expression or string denoting the file name of the initial RAM disk
26049 to use (@pxref{G-Expressions}).
26050 @item @code{device} (default: @code{#f})
26051 The device where the kernel and initrd are to be found---i.e., for GRUB,
26052 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26054 This may be a file system label (a string), a file system UUID (a
26055 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26056 the bootloader will search the device containing the file specified by
26057 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26058 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26063 @c FIXME: Write documentation once it's stable.
26064 For now only GRUB has theme support. GRUB themes are created using
26065 the @code{grub-theme} form, which is not documented yet.
26067 @defvr {Scheme Variable} %default-theme
26068 This is the default GRUB theme used by the operating system if no
26069 @code{theme} field is specified in @code{bootloader-configuration}
26072 It comes with a fancy background image displaying the GNU and Guix
26077 @node Invoking guix system
26078 @section Invoking @code{guix system}
26080 Once you have written an operating system declaration as seen in the
26081 previous section, it can be @dfn{instantiated} using the @command{guix
26082 system} command. The synopsis is:
26085 guix system @var{options}@dots{} @var{action} @var{file}
26088 @var{file} must be the name of a file containing an
26089 @code{operating-system} declaration. @var{action} specifies how the
26090 operating system is instantiated. Currently the following values are
26095 Display available service type definitions that match the given regular
26096 expressions, sorted by relevance:
26102 $ guix system search console
26103 name: console-fonts
26104 location: gnu/services/base.scm:806:2
26105 extends: shepherd-root
26106 description: Install the given fonts on the specified ttys (fonts are per
26107 + virtual console on GNU/Linux). The value of this service is a list of
26108 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26109 + package or any valid argument to `setfont', as in this example:
26111 + '(("tty1" . "LatGrkCyr-8x16")
26112 + ("tty2" . (file-append
26114 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26115 + ("tty3" . (file-append
26117 + "/share/consolefonts/ter-132n"))) ; for HDPI
26121 location: gnu/services/base.scm:1190:2
26122 extends: shepherd-root
26123 description: Provide console login using the `mingetty' program.
26127 location: gnu/services/base.scm:860:2
26129 description: Provide a console log-in service as specified by its
26130 + configuration value, a `login-configuration' object.
26136 As for @command{guix package --search}, the result is written in
26137 @code{recutils} format, which makes it easy to filter the output
26138 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26141 Build the operating system described in @var{file}, activate it, and
26142 switch to it@footnote{This action (and the related actions
26143 @code{switch-generation} and @code{roll-back}) are usable only on
26144 systems already running Guix System.}.
26147 @c The paragraph below refers to the problem discussed at
26148 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26149 It is highly recommended to run @command{guix pull} once before you run
26150 @command{guix system reconfigure} for the first time (@pxref{Invoking
26151 guix pull}). Failing to do that you would see an older version of Guix
26152 once @command{reconfigure} has completed.
26155 This effects all the configuration specified in @var{file}: user
26156 accounts, system services, global package list, setuid programs, etc.
26157 The command starts system services specified in @var{file} that are not
26158 currently running; if a service is currently running this command will
26159 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26160 @code{herd stop X} or @code{herd restart X}).
26162 This command creates a new generation whose number is one greater than
26163 the current generation (as reported by @command{guix system
26164 list-generations}). If that generation already exists, it will be
26165 overwritten. This behavior mirrors that of @command{guix package}
26166 (@pxref{Invoking guix package}).
26168 It also adds a bootloader menu entry for the new OS configuration,
26169 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26170 entries for older configurations to a submenu, allowing you to choose
26171 an older system generation at boot time should you need it.
26173 @cindex provenance tracking, of the operating system
26174 Upon completion, the new system is deployed under
26175 @file{/run/current-system}. This directory contains @dfn{provenance
26176 meta-data}: the list of channels in use (@pxref{Channels}) and
26177 @var{file} itself, when available. This information is useful should
26178 you later want to inspect how this particular generation was built.
26180 In fact, assuming @var{file} is self-contained, you can later rebuild
26181 generation @var{n} of your operating system with:
26184 guix time-machine \
26185 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26186 system reconfigure \
26187 /var/guix/profiles/system-@var{n}-link/configuration.scm
26190 You can think of it as some sort of built-in version control! Your
26191 system is not just a binary artifact: @emph{it carries its own source}.
26192 @xref{Service Reference, @code{provenance-service-type}}, for more
26193 information on provenance tracking.
26195 @item switch-generation
26196 @cindex generations
26197 Switch to an existing system generation. This action atomically
26198 switches the system profile to the specified system generation. It
26199 also rearranges the system's existing bootloader menu entries. It
26200 makes the menu entry for the specified system generation the default,
26201 and it moves the entries for the other generatiors to a submenu, if
26202 supported by the bootloader being used. The next time the system
26203 boots, it will use the specified system generation.
26205 The bootloader itself is not being reinstalled when using this
26206 command. Thus, the installed bootloader is used with an updated
26207 configuration file.
26209 The target generation can be specified explicitly by its generation
26210 number. For example, the following invocation would switch to system
26214 guix system switch-generation 7
26217 The target generation can also be specified relative to the current
26218 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26219 ``3 generations ahead of the current generation,'' and @code{-1} means
26220 ``1 generation prior to the current generation.'' When specifying a
26221 negative value such as @code{-1}, you must precede it with @code{--} to
26222 prevent it from being parsed as an option. For example:
26225 guix system switch-generation -- -1
26228 Currently, the effect of invoking this action is @emph{only} to switch
26229 the system profile to an existing generation and rearrange the
26230 bootloader menu entries. To actually start using the target system
26231 generation, you must reboot after running this action. In the future,
26232 it will be updated to do the same things as @command{reconfigure},
26233 like activating and deactivating services.
26235 This action will fail if the specified generation does not exist.
26238 @cindex rolling back
26239 Switch to the preceding system generation. The next time the system
26240 boots, it will use the preceding system generation. This is the inverse
26241 of @command{reconfigure}, and it is exactly the same as invoking
26242 @command{switch-generation} with an argument of @code{-1}.
26244 Currently, as with @command{switch-generation}, you must reboot after
26245 running this action to actually start using the preceding system
26248 @item delete-generations
26249 @cindex deleting system generations
26250 @cindex saving space
26251 Delete system generations, making them candidates for garbage collection
26252 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
26255 This works in the same way as @command{guix package --delete-generations}
26256 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
26257 arguments, all system generations but the current one are deleted:
26260 guix system delete-generations
26263 You can also select the generations you want to delete. The example below
26264 deletes all the system generations that are more than two month old:
26267 guix system delete-generations 2m
26270 Running this command automatically reinstalls the bootloader with an updated
26271 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26272 longer lists the generations that have been deleted.
26275 Build the derivation of the operating system, which includes all the
26276 configuration files and programs needed to boot and run the system.
26277 This action does not actually install anything.
26280 Populate the given directory with all the files necessary to run the
26281 operating system specified in @var{file}. This is useful for first-time
26282 installations of Guix System. For instance:
26285 guix system init my-os-config.scm /mnt
26288 copies to @file{/mnt} all the store items required by the configuration
26289 specified in @file{my-os-config.scm}. This includes configuration
26290 files, packages, and so on. It also creates other essential files
26291 needed for the system to operate correctly---e.g., the @file{/etc},
26292 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
26294 This command also installs bootloader on the target specified in
26295 @file{my-os-config}, unless the @option{--no-bootloader} option was
26299 @cindex virtual machine
26301 @anchor{guix system vm}
26302 Build a virtual machine that contains the operating system declared in
26303 @var{file}, and return a script to run that virtual machine (VM).
26306 The @code{vm} action and others below
26307 can use KVM support in the Linux-libre kernel. Specifically, if the
26308 machine has hardware virtualization support, the corresponding
26309 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
26310 must exist and be readable and writable by the user and by the
26311 build users of the daemon (@pxref{Build Environment Setup}).
26314 Arguments given to the script are passed to QEMU as in the example
26315 below, which enables networking and requests 1@tie{}GiB of RAM for the
26319 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
26322 The VM shares its store with the host system.
26324 Additional file systems can be shared between the host and the VM using
26325 the @code{--share} and @code{--expose} command-line options: the former
26326 specifies a directory to be shared with write access, while the latter
26327 provides read-only access to the shared directory.
26329 The example below creates a VM in which the user's home directory is
26330 accessible read-only, and where the @file{/exchange} directory is a
26331 read-write mapping of @file{$HOME/tmp} on the host:
26334 guix system vm my-config.scm \
26335 --expose=$HOME --share=$HOME/tmp=/exchange
26338 On GNU/Linux, the default is to boot directly to the kernel; this has
26339 the advantage of requiring only a very tiny root disk image since the
26340 store of the host can then be mounted.
26342 The @code{--full-boot} option forces a complete boot sequence, starting
26343 with the bootloader. This requires more disk space since a root image
26344 containing at least the kernel, initrd, and bootloader data files must
26345 be created. The @code{--image-size} option can be used to specify the
26348 @cindex System images, creation in various formats
26349 @cindex Creating system images in various formats
26352 @itemx docker-image
26353 Return a virtual machine, disk image, or Docker image of the operating
26354 system declared in @var{file} that stands alone. By default,
26355 @command{guix system} estimates the size of the image needed to store
26356 the system, but you can use the @option{--image-size} option to specify
26357 a value. Docker images are built to contain exactly what they need, so
26358 the @option{--image-size} option is ignored in the case of
26359 @code{docker-image}.
26361 You can specify the root file system type by using the
26362 @option{--file-system-type} option. It defaults to @code{ext4}.
26364 When using @code{vm-image}, the returned image is in qcow2 format, which
26365 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
26366 for more information on how to run the image in a virtual machine.
26368 When using @code{disk-image}, a raw disk image is produced; it can be
26369 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
26370 the device corresponding to a USB stick, one can copy the image to it
26371 using the following command:
26374 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
26377 When using @code{docker-image}, a Docker image is produced. Guix builds
26378 the image from scratch, not from a pre-existing Docker base image. As a
26379 result, it contains @emph{exactly} what you define in the operating
26380 system configuration file. You can then load the image and launch a
26381 Docker container using commands like the following:
26384 image_id="`docker load < guix-system-docker-image.tar.gz`"
26385 container_id="`docker create $image_id`"
26386 docker start $container_id
26389 This command starts a new Docker container from the specified image. It
26390 will boot the Guix system in the usual manner, which means it will
26391 start any services you have defined in the operating system
26392 configuration. You can get an interactive shell running in the container
26393 using @command{docker exec}:
26396 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
26399 Depending on what you run in the Docker container, it
26400 may be necessary to give the container additional permissions. For
26401 example, if you intend to build software using Guix inside of the Docker
26402 container, you may need to pass the @option{--privileged} option to
26403 @code{docker create}.
26406 Return a script to run the operating system declared in @var{file}
26407 within a container. Containers are a set of lightweight isolation
26408 mechanisms provided by the kernel Linux-libre. Containers are
26409 substantially less resource-demanding than full virtual machines since
26410 the kernel, shared objects, and other resources can be shared with the
26411 host system; this also means they provide thinner isolation.
26413 Currently, the script must be run as root in order to support more than
26414 a single user and group. The container shares its store with the host
26417 As with the @code{vm} action (@pxref{guix system vm}), additional file
26418 systems to be shared between the host and container can be specified
26419 using the @option{--share} and @option{--expose} options:
26422 guix system container my-config.scm \
26423 --expose=$HOME --share=$HOME/tmp=/exchange
26427 This option requires Linux-libre 3.19 or newer.
26432 @var{options} can contain any of the common build options (@pxref{Common
26433 Build Options}). In addition, @var{options} can contain one of the
26437 @item --expression=@var{expr}
26438 @itemx -e @var{expr}
26439 Consider the operating-system @var{expr} evaluates to.
26440 This is an alternative to specifying a file which evaluates to an
26442 This is used to generate the Guix system installer @pxref{Building the
26443 Installation Image}).
26445 @item --system=@var{system}
26446 @itemx -s @var{system}
26447 Attempt to build for @var{system} instead of the host system type.
26448 This works as per @command{guix build} (@pxref{Invoking guix build}).
26452 Return the derivation file name of the given operating system without
26455 @cindex provenance tracking, of the operating system
26456 @item --save-provenance
26457 As discussed above, @command{guix system init} and @command{guix system
26458 reconfigure} always save provenance information @i{via} a dedicated
26459 service (@pxref{Service Reference, @code{provenance-service-type}}).
26460 However, other commands don't do that by default. If you wish to, say,
26461 create a virtual machine image that contains provenance information, you
26465 guix system vm-image --save-provenance config.scm
26468 That way, the resulting image will effectively ``embed its own source''
26469 in the form of meta-data in @file{/run/current-system}. With that
26470 information, one can rebuild the image to make sure it really contains
26471 what it pretends to contain; or they could use that to derive a variant
26474 @item --file-system-type=@var{type}
26475 @itemx -t @var{type}
26476 For the @code{disk-image} action, create a file system of the given
26477 @var{type} on the image.
26479 When this option is omitted, @command{guix system} uses @code{ext4}.
26481 @cindex ISO-9660 format
26482 @cindex CD image format
26483 @cindex DVD image format
26484 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26485 for burning on CDs and DVDs.
26487 @item --image-size=@var{size}
26488 For the @code{vm-image} and @code{disk-image} actions, create an image
26489 of the given @var{size}. @var{size} may be a number of bytes, or it may
26490 include a unit as a suffix (@pxref{Block size, size specifications,,
26491 coreutils, GNU Coreutils}).
26493 When this option is omitted, @command{guix system} computes an estimate
26494 of the image size as a function of the size of the system declared in
26499 For the @code{container} action, allow containers to access the host network,
26500 that is, do not create a network namespace.
26502 @item --root=@var{file}
26503 @itemx -r @var{file}
26504 Make @var{file} a symlink to the result, and register it as a garbage
26507 @item --skip-checks
26508 Skip pre-installation safety checks.
26510 By default, @command{guix system init} and @command{guix system
26511 reconfigure} perform safety checks: they make sure the file systems that
26512 appear in the @code{operating-system} declaration actually exist
26513 (@pxref{File Systems}), and that any Linux kernel modules that may be
26514 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26515 RAM Disk}). Passing this option skips these tests altogether.
26518 @cindex on-error strategy
26519 @cindex error strategy
26520 @item --on-error=@var{strategy}
26521 Apply @var{strategy} when an error occurs when reading @var{file}.
26522 @var{strategy} may be one of the following:
26525 @item nothing-special
26526 Report the error concisely and exit. This is the default strategy.
26529 Likewise, but also display a backtrace.
26532 Report the error and enter Guile's debugger. From there, you can run
26533 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26534 display local variable values, and more generally inspect the state of the
26535 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26536 a list of available debugging commands.
26540 Once you have built, configured, re-configured, and re-re-configured
26541 your Guix installation, you may find it useful to list the operating
26542 system generations available on disk---and that you can choose from the
26543 bootloader boot menu:
26548 Describe the current system generation: its file name, the kernel and
26549 bootloader used, etc., as well as provenance information when available.
26551 @item list-generations
26552 List a summary of each generation of the operating system available on
26553 disk, in a human-readable way. This is similar to the
26554 @option{--list-generations} option of @command{guix package}
26555 (@pxref{Invoking guix package}).
26557 Optionally, one can specify a pattern, with the same syntax that is used
26558 in @command{guix package --list-generations}, to restrict the list of
26559 generations displayed. For instance, the following command displays
26560 generations that are up to 10 days old:
26563 $ guix system list-generations 10d
26568 The @command{guix system} command has even more to offer! The following
26569 sub-commands allow you to visualize how your system services relate to
26572 @anchor{system-extension-graph}
26575 @item extension-graph
26576 Emit in Dot/Graphviz format to standard output the @dfn{service
26577 extension graph} of the operating system defined in @var{file}
26578 (@pxref{Service Composition}, for more information on service
26584 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26587 produces a PDF file showing the extension relations among services.
26589 @anchor{system-shepherd-graph}
26590 @item shepherd-graph
26591 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26592 graph} of shepherd services of the operating system defined in
26593 @var{file}. @xref{Shepherd Services}, for more information and for an
26598 @node Invoking guix deploy
26599 @section Invoking @code{guix deploy}
26601 We've already seen @code{operating-system} declarations used to manage a
26602 machine's configuration locally. Suppose you need to configure multiple
26603 machines, though---perhaps you're managing a service on the web that's
26604 comprised of several servers. @command{guix deploy} enables you to use those
26605 same @code{operating-system} declarations to manage multiple remote hosts at
26606 once as a logical ``deployment''.
26609 The functionality described in this section is still under development
26610 and is subject to change. Get in touch with us on
26611 @email{guix-devel@@gnu.org}!
26615 guix deploy @var{file}
26618 Such an invocation will deploy the machines that the code within @var{file}
26619 evaluates to. As an example, @var{file} might contain a definition like this:
26622 ;; This is a Guix deployment of a "bare bones" setup, with
26623 ;; no X11 display server, to a machine with an SSH daemon
26624 ;; listening on localhost:2222. A configuration such as this
26625 ;; may be appropriate for virtual machine with ports
26626 ;; forwarded to the host's loopback interface.
26628 (use-service-modules networking ssh)
26629 (use-package-modules bootloaders)
26633 (host-name "gnu-deployed")
26634 (timezone "Etc/UTC")
26635 (bootloader (bootloader-configuration
26636 (bootloader grub-bootloader)
26637 (target "/dev/vda")
26638 (terminal-outputs '(console))))
26639 (file-systems (cons (file-system
26641 (device "/dev/vda1")
26643 %base-file-systems))
26645 (append (list (service dhcp-client-service-type)
26646 (service openssh-service-type
26647 (openssh-configuration
26648 (permit-root-login #t)
26649 (allow-empty-passwords? #t))))
26653 (operating-system %system)
26654 (environment managed-host-environment-type)
26655 (configuration (machine-ssh-configuration
26656 (host-name "localhost")
26657 (system "x86_64-linux")
26659 (identity "./id_rsa")
26663 The file should evaluate to a list of @var{machine} objects. This example,
26664 upon being deployed, will create a new generation on the remote system
26665 realizing the @code{operating-system} declaration @var{%system}.
26666 @var{environment} and @var{configuration} specify how the machine should be
26667 provisioned---that is, how the computing resources should be created and
26668 managed. The above example does not create any resources, as a
26669 @code{'managed-host} is a machine that is already running the Guix system and
26670 available over the network. This is a particularly simple case; a more
26671 complex deployment may involve, for example, starting virtual machines through
26672 a Virtual Private Server (VPS) provider. In such a case, a different
26673 @var{environment} type would be used.
26675 Do note that you first need to generate a key pair on the coordinator machine
26676 to allow the daemon to export signed archives of files from the store
26677 (@pxref{Invoking guix archive}).
26680 # guix archive --generate-key
26684 Each target machine must authorize the key of the master machine so that it
26685 accepts store items it receives from the coordinator:
26688 # guix archive --authorize < coordinator-public-key.txt
26691 @code{user}, in this example, specifies the name of the user account to log in
26692 as to perform the deployment. Its default value is @code{root}, but root
26693 login over SSH may be forbidden in some cases. To work around this,
26694 @command{guix deploy} can log in as an unprivileged user and employ
26695 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26696 currently installed on the remote and can be invoked non-interactively as
26697 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
26698 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
26700 @deftp {Data Type} machine
26701 This is the data type representing a single machine in a heterogeneous Guix
26705 @item @code{operating-system}
26706 The object of the operating system configuration to deploy.
26708 @item @code{environment}
26709 An @code{environment-type} describing how the machine should be provisioned.
26711 @item @code{configuration} (default: @code{#f})
26712 An object describing the configuration for the machine's @code{environment}.
26713 If the @code{environment} has a default configuration, @code{#f} may be used.
26714 If @code{#f} is used for an environment with no default configuration,
26715 however, an error will be thrown.
26719 @deftp {Data Type} machine-ssh-configuration
26720 This is the data type representing the SSH client parameters for a machine
26721 with an @code{environment} of @code{managed-host-environment-type}.
26724 @item @code{host-name}
26725 @item @code{build-locally?} (default: @code{#t})
26726 If false, system derivations will be built on the machine being deployed to.
26727 @item @code{system}
26728 The system type describing the architecture of the machine being deployed
26729 to---e.g., @code{"x86_64-linux"}.
26730 @item @code{authorize?} (default: @code{#t})
26731 If true, the coordinator's signing key will be added to the remote's ACL
26733 @item @code{port} (default: @code{22})
26734 @item @code{user} (default: @code{"root"})
26735 @item @code{identity} (default: @code{#f})
26736 If specified, the path to the SSH private key to use to authenticate with the
26739 @item @code{host-key} (default: @code{#f})
26740 This should be the SSH host key of the machine, which looks like this:
26743 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
26746 When @code{host-key} is @code{#f}, the server is authenticated against
26747 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
26753 @deftp {Data Type} digital-ocean-configuration
26754 This is the data type describing the Droplet that should be created for a
26755 machine with an @code{environment} of @code{digital-ocean-environment-type}.
26758 @item @code{ssh-key}
26759 The path to the SSH private key to use to authenticate with the remote
26760 host. In the future, this field may not exist.
26762 A list of string ``tags'' that uniquely identify the machine. Must be given
26763 such that no two machines in the deployment have the same set of tags.
26764 @item @code{region}
26765 A Digital Ocean region slug, such as @code{"nyc3"}.
26767 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
26768 @item @code{enable-ipv6?}
26769 Whether or not the droplet should be created with IPv6 networking.
26773 @node Running Guix in a VM
26774 @section Running Guix in a Virtual Machine
26776 @cindex virtual machine
26777 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
26779 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
26780 This image is a compressed image in QCOW format. You will first need to
26781 decompress with @command{xz -d}, and then you can pass it to an emulator such
26782 as QEMU (see below for details).
26784 This image boots the Xfce graphical environment and it contains some
26785 commonly-used tools. You can install more software in the image by running
26786 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
26787 also reconfigure the system based on its initial configuration file available
26788 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
26790 Instead of using this pre-built image, one can also build their own virtual
26791 machine image using @command{guix system vm-image} (@pxref{Invoking guix
26792 system}). The returned image is in qcow2 format, which the
26793 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
26796 If you built your own image, you must copy it out of the store
26797 (@pxref{The Store}) and give yourself permission to write to the copy
26798 before you can use it. When invoking QEMU, you must choose a system
26799 emulator that is suitable for your hardware platform. Here is a minimal
26800 QEMU invocation that will boot the result of @command{guix system
26801 vm-image} on x86_64 hardware:
26804 $ qemu-system-x86_64 \
26805 -nic user,model=virtio-net-pci \
26806 -enable-kvm -m 1024 \
26807 -device virtio-blk,drive=myhd \
26808 -drive if=none,file=/tmp/qemu-image,id=myhd
26811 Here is what each of these options means:
26814 @item qemu-system-x86_64
26815 This specifies the hardware platform to emulate. This should match the
26818 @item -nic user,model=virtio-net-pci
26819 Enable the unprivileged user-mode network stack. The guest OS can
26820 access the host but not vice versa. This is the simplest way to get the
26821 guest OS online. @code{model} specifies which network device to emulate:
26822 @code{virtio-net-pci} is a special device made for virtualized operating
26823 systems and recommended for most uses. Assuming your hardware platform is
26824 x86_64, you can get a list of available NIC models by running
26825 @command{qemu-system-x86_64 -nic model=help}.
26828 If your system has hardware virtualization extensions, enabling the
26829 virtual machine support (KVM) of the Linux kernel will make things run
26832 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
26834 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
26835 which may be insufficient for some operations.
26837 @item -device virtio-blk,drive=myhd
26838 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
26839 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
26840 better performance than if it were emulating a complete disk drive. See the
26841 QEMU and KVM documentation for more info.
26843 @item -drive if=none,file=/tmp/qemu-image,id=myhd
26844 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
26845 the ``myhd'' drive.
26848 The default @command{run-vm.sh} script that is returned by an invocation of
26849 @command{guix system vm} does not add a @command{-nic user} flag by default.
26850 To get network access from within the vm add the @code{(dhcp-client-service)}
26851 to your system definition and start the VM using
26852 @command{`guix system vm config.scm` -nic user}. An important caveat of using
26853 @command{-nic user} for networking is that @command{ping} will not work, because
26854 it uses the ICMP protocol. You'll have to use a different command to check for
26855 network connectivity, for example @command{guix download}.
26857 @subsection Connecting Through SSH
26861 To enable SSH inside a VM you need to add an SSH server like
26862 @code{openssh-service-type} to your VM (@pxref{Networking Services,
26863 @code{openssh-service-type}}). In addition you need to forward the SSH port,
26864 22 by default, to the host. You can do this with
26867 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
26870 To connect to the VM you can run
26873 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
26876 The @command{-p} tells @command{ssh} the port you want to connect to.
26877 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
26878 every time you modify your @command{config.scm} file and the
26879 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
26880 connection to an unknown host every time you connect.
26882 @subsection Using @command{virt-viewer} with Spice
26884 As an alternative to the default @command{qemu} graphical client you can
26885 use the @command{remote-viewer} from the @command{virt-viewer} package. To
26886 connect pass the @command{-spice port=5930,disable-ticketing} flag to
26887 @command{qemu}. See previous section for further information on how to do this.
26889 Spice also allows you to do some nice stuff like share your clipboard with your
26890 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
26893 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
26894 -chardev spicevmc,name=vdagent,id=vdagent
26895 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
26896 name=com.redhat.spice.0
26899 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
26901 @node Defining Services
26902 @section Defining Services
26904 The previous sections show the available services and how one can combine
26905 them in an @code{operating-system} declaration. But how do we define
26906 them in the first place? And what is a service anyway?
26909 * Service Composition:: The model for composing services.
26910 * Service Types and Services:: Types and services.
26911 * Service Reference:: API reference.
26912 * Shepherd Services:: A particular type of service.
26915 @node Service Composition
26916 @subsection Service Composition
26920 Here we define a @dfn{service} as, broadly, something that extends the
26921 functionality of the operating system. Often a service is a process---a
26922 @dfn{daemon}---started when the system boots: a secure shell server, a
26923 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
26924 whose execution can be triggered by another daemon---e.g., an FTP server
26925 started by @command{inetd} or a D-Bus service activated by
26926 @command{dbus-daemon}. Occasionally, a service does not map to a
26927 daemon. For instance, the ``account'' service collects user accounts
26928 and makes sure they exist when the system runs; the ``udev'' service
26929 collects device management rules and makes them available to the eudev
26930 daemon; the @file{/etc} service populates the @file{/etc} directory
26933 @cindex service extensions
26934 Guix system services are connected by @dfn{extensions}. For instance, the
26935 secure shell service @emph{extends} the Shepherd---the
26936 initialization system, running as PID@tie{}1---by giving it the command
26937 lines to start and stop the secure shell daemon (@pxref{Networking
26938 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
26939 service by passing it its @file{.service} specification, and extends the
26940 udev service by passing it device management rules (@pxref{Desktop
26941 Services, @code{upower-service}}); the Guix daemon service extends the
26942 Shepherd by passing it the command lines to start and stop the daemon,
26943 and extends the account service by passing it a list of required build
26944 user accounts (@pxref{Base Services}).
26946 All in all, services and their ``extends'' relations form a directed
26947 acyclic graph (DAG). If we represent services as boxes and extensions
26948 as arrows, a typical system might provide something like this:
26950 @image{images/service-graph,,5in,Typical service extension graph.}
26952 @cindex system service
26953 At the bottom, we see the @dfn{system service}, which produces the
26954 directory containing everything to run and boot the system, as returned
26955 by the @command{guix system build} command. @xref{Service Reference},
26956 to learn about the other service types shown here.
26957 @xref{system-extension-graph, the @command{guix system extension-graph}
26958 command}, for information on how to generate this representation for a
26959 particular operating system definition.
26961 @cindex service types
26962 Technically, developers can define @dfn{service types} to express these
26963 relations. There can be any number of services of a given type on the
26964 system---for instance, a system running two instances of the GNU secure
26965 shell server (lsh) has two instances of @code{lsh-service-type}, with
26966 different parameters.
26968 The following section describes the programming interface for service
26969 types and services.
26971 @node Service Types and Services
26972 @subsection Service Types and Services
26974 A @dfn{service type} is a node in the DAG described above. Let us start
26975 with a simple example, the service type for the Guix build daemon
26976 (@pxref{Invoking guix-daemon}):
26979 (define guix-service-type
26983 (list (service-extension shepherd-root-service-type guix-shepherd-service)
26984 (service-extension account-service-type guix-accounts)
26985 (service-extension activation-service-type guix-activation)))
26986 (default-value (guix-configuration))))
26990 It defines three things:
26994 A name, whose sole purpose is to make inspection and debugging easier.
26997 A list of @dfn{service extensions}, where each extension designates the
26998 target service type and a procedure that, given the parameters of the
26999 service, returns a list of objects to extend the service of that type.
27001 Every service type has at least one service extension. The only
27002 exception is the @dfn{boot service type}, which is the ultimate service.
27005 Optionally, a default value for instances of this type.
27008 In this example, @code{guix-service-type} extends three services:
27011 @item shepherd-root-service-type
27012 The @code{guix-shepherd-service} procedure defines how the Shepherd
27013 service is extended. Namely, it returns a @code{<shepherd-service>}
27014 object that defines how @command{guix-daemon} is started and stopped
27015 (@pxref{Shepherd Services}).
27017 @item account-service-type
27018 This extension for this service is computed by @code{guix-accounts},
27019 which returns a list of @code{user-group} and @code{user-account}
27020 objects representing the build user accounts (@pxref{Invoking
27023 @item activation-service-type
27024 Here @code{guix-activation} is a procedure that returns a gexp, which is
27025 a code snippet to run at ``activation time''---e.g., when the service is
27029 A service of this type is instantiated like this:
27032 (service guix-service-type
27033 (guix-configuration
27035 (use-substitutes? #f)))
27038 The second argument to the @code{service} form is a value representing
27039 the parameters of this specific service instance.
27040 @xref{guix-configuration-type, @code{guix-configuration}}, for
27041 information about the @code{guix-configuration} data type. When the
27042 value is omitted, the default value specified by
27043 @code{guix-service-type} is used:
27046 (service guix-service-type)
27049 @code{guix-service-type} is quite simple because it extends other
27050 services but is not extensible itself.
27052 @c @subsubsubsection Extensible Service Types
27054 The service type for an @emph{extensible} service looks like this:
27057 (define udev-service-type
27058 (service-type (name 'udev)
27060 (list (service-extension shepherd-root-service-type
27061 udev-shepherd-service)))
27063 (compose concatenate) ;concatenate the list of rules
27064 (extend (lambda (config rules)
27066 (($ <udev-configuration> udev initial-rules)
27067 (udev-configuration
27068 (udev udev) ;the udev package to use
27069 (rules (append initial-rules rules)))))))))
27072 This is the service type for the
27073 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27074 management daemon}. Compared to the previous example, in addition to an
27075 extension of @code{shepherd-root-service-type}, we see two new fields:
27079 This is the procedure to @dfn{compose} the list of extensions to
27080 services of this type.
27082 Services can extend the udev service by passing it lists of rules; we
27083 compose those extensions simply by concatenating them.
27086 This procedure defines how the value of the service is @dfn{extended} with
27087 the composition of the extensions.
27089 Udev extensions are composed into a list of rules, but the udev service
27090 value is itself a @code{<udev-configuration>} record. So here, we
27091 extend that record by appending the list of rules it contains to the
27092 list of contributed rules.
27095 This is a string giving an overview of the service type. The string can
27096 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27097 @command{guix system search} command searches these strings and displays
27098 them (@pxref{Invoking guix system}).
27101 There can be only one instance of an extensible service type such as
27102 @code{udev-service-type}. If there were more, the
27103 @code{service-extension} specifications would be ambiguous.
27105 Still here? The next section provides a reference of the programming
27106 interface for services.
27108 @node Service Reference
27109 @subsection Service Reference
27111 We have seen an overview of service types (@pxref{Service Types and
27112 Services}). This section provides a reference on how to manipulate
27113 services and service types. This interface is provided by the
27114 @code{(gnu services)} module.
27116 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27117 Return a new service of @var{type}, a @code{<service-type>} object (see
27118 below.) @var{value} can be any object; it represents the parameters of
27119 this particular service instance.
27121 When @var{value} is omitted, the default value specified by @var{type}
27122 is used; if @var{type} does not specify a default value, an error is
27125 For instance, this:
27128 (service openssh-service-type)
27132 is equivalent to this:
27135 (service openssh-service-type
27136 (openssh-configuration))
27139 In both cases the result is an instance of @code{openssh-service-type}
27140 with the default configuration.
27143 @deffn {Scheme Procedure} service? @var{obj}
27144 Return true if @var{obj} is a service.
27147 @deffn {Scheme Procedure} service-kind @var{service}
27148 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27151 @deffn {Scheme Procedure} service-value @var{service}
27152 Return the value associated with @var{service}. It represents its
27156 Here is an example of how a service is created and manipulated:
27160 (service nginx-service-type
27161 (nginx-configuration
27163 (log-directory log-directory)
27164 (run-directory run-directory)
27165 (file config-file))))
27170 (eq? (service-kind s) nginx-service-type)
27174 The @code{modify-services} form provides a handy way to change the
27175 parameters of some of the services of a list such as
27176 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27177 evaluates to a list of services. Of course, you could always use
27178 standard list combinators such as @code{map} and @code{fold} to do that
27179 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27180 @code{modify-services} simply provides a more concise form for this
27183 @deffn {Scheme Syntax} modify-services @var{services} @
27184 (@var{type} @var{variable} => @var{body}) @dots{}
27186 Modify the services listed in @var{services} according to the given
27187 clauses. Each clause has the form:
27190 (@var{type} @var{variable} => @var{body})
27193 where @var{type} is a service type---e.g.,
27194 @code{guix-service-type}---and @var{variable} is an identifier that is
27195 bound within the @var{body} to the service parameters---e.g., a
27196 @code{guix-configuration} instance---of the original service of that
27199 The @var{body} should evaluate to the new service parameters, which will
27200 be used to configure the new service. This new service will replace the
27201 original in the resulting list. Because a service's service parameters
27202 are created using @code{define-record-type*}, you can write a succinct
27203 @var{body} that evaluates to the new service parameters by using the
27204 @code{inherit} feature that @code{define-record-type*} provides.
27206 @xref{Using the Configuration System}, for example usage.
27210 Next comes the programming interface for service types. This is
27211 something you want to know when writing new service definitions, but not
27212 necessarily when simply looking for ways to customize your
27213 @code{operating-system} declaration.
27215 @deftp {Data Type} service-type
27216 @cindex service type
27217 This is the representation of a @dfn{service type} (@pxref{Service Types
27222 This is a symbol, used only to simplify inspection and debugging.
27224 @item @code{extensions}
27225 A non-empty list of @code{<service-extension>} objects (see below).
27227 @item @code{compose} (default: @code{#f})
27228 If this is @code{#f}, then the service type denotes services that cannot
27229 be extended---i.e., services that do not receive ``values'' from other
27232 Otherwise, it must be a one-argument procedure. The procedure is called
27233 by @code{fold-services} and is passed a list of values collected from
27234 extensions. It may return any single value.
27236 @item @code{extend} (default: @code{#f})
27237 If this is @code{#f}, services of this type cannot be extended.
27239 Otherwise, it must be a two-argument procedure: @code{fold-services}
27240 calls it, passing it the initial value of the service as the first
27241 argument and the result of applying @code{compose} to the extension
27242 values as the second argument. It must return a value that is a valid
27243 parameter value for the service instance.
27246 @xref{Service Types and Services}, for examples.
27249 @deffn {Scheme Procedure} service-extension @var{target-type} @
27251 Return a new extension for services of type @var{target-type}.
27252 @var{compute} must be a one-argument procedure: @code{fold-services}
27253 calls it, passing it the value associated with the service that provides
27254 the extension; it must return a valid value for the target service.
27257 @deffn {Scheme Procedure} service-extension? @var{obj}
27258 Return true if @var{obj} is a service extension.
27261 Occasionally, you might want to simply extend an existing service. This
27262 involves creating a new service type and specifying the extension of
27263 interest, which can be verbose; the @code{simple-service} procedure
27264 provides a shorthand for this.
27266 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
27267 Return a service that extends @var{target} with @var{value}. This works
27268 by creating a singleton service type @var{name}, of which the returned
27269 service is an instance.
27271 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
27275 (simple-service 'my-mcron-job mcron-service-type
27276 #~(job '(next-hour (3)) "guix gc -F 2G"))
27280 At the core of the service abstraction lies the @code{fold-services}
27281 procedure, which is responsible for ``compiling'' a list of services
27282 down to a single directory that contains everything needed to boot and
27283 run the system---the directory shown by the @command{guix system build}
27284 command (@pxref{Invoking guix system}). In essence, it propagates
27285 service extensions down the service graph, updating each node parameters
27286 on the way, until it reaches the root node.
27288 @deffn {Scheme Procedure} fold-services @var{services} @
27289 [#:target-type @var{system-service-type}]
27290 Fold @var{services} by propagating their extensions down to the root of
27291 type @var{target-type}; return the root service adjusted accordingly.
27294 Lastly, the @code{(gnu services)} module also defines several essential
27295 service types, some of which are listed below.
27297 @defvr {Scheme Variable} system-service-type
27298 This is the root of the service graph. It produces the system directory
27299 as returned by the @command{guix system build} command.
27302 @defvr {Scheme Variable} boot-service-type
27303 The type of the ``boot service'', which produces the @dfn{boot script}.
27304 The boot script is what the initial RAM disk runs when booting.
27307 @defvr {Scheme Variable} etc-service-type
27308 The type of the @file{/etc} service. This service is used to create
27309 files under @file{/etc} and can be extended by
27310 passing it name/file tuples such as:
27313 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
27316 In this example, the effect would be to add an @file{/etc/issue} file
27317 pointing to the given file.
27320 @defvr {Scheme Variable} setuid-program-service-type
27321 Type for the ``setuid-program service''. This service collects lists of
27322 executable file names, passed as gexps, and adds them to the set of
27323 setuid-root programs on the system (@pxref{Setuid Programs}).
27326 @defvr {Scheme Variable} profile-service-type
27327 Type of the service that populates the @dfn{system profile}---i.e., the
27328 programs under @file{/run/current-system/profile}. Other services can
27329 extend it by passing it lists of packages to add to the system profile.
27332 @cindex provenance tracking, of the operating system
27333 @defvr {Scheme Variable} provenance-service-type
27334 This is the type of the service that records @dfn{provenance meta-data}
27335 in the system itself. It creates several files under
27336 @file{/run/current-system}:
27340 This is a ``channel file'' that can be passed to @command{guix pull -C}
27341 or @command{guix time-machine -C}, and which describes the channels used
27342 to build the system, if that information was available
27343 (@pxref{Channels}).
27345 @item configuration.scm
27346 This is the file that was passed as the value for this
27347 @code{provenance-service-type} service. By default, @command{guix
27348 system reconfigure} automatically passes the OS configuration file it
27349 received on the command line.
27352 This contains the same information as the two other files but in a
27353 format that is more readily processable.
27356 In general, these two pieces of information (channels and configuration
27357 file) are enough to reproduce the operating system ``from source''.
27360 This information is necessary to rebuild your operating system, but it
27361 is not always sufficient. In particular, @file{configuration.scm}
27362 itself is insufficient if it is not self-contained---if it refers to
27363 external Guile modules or to extra files. If you want
27364 @file{configuration.scm} to be self-contained, we recommend that modules
27365 or files it refers to be part of a channel.
27367 Besides, provenance meta-data is ``silent'' in the sense that it does
27368 not change the bits contained in your system, @emph{except for the
27369 meta-data bits themselves}. Two different OS configurations or sets of
27370 channels can lead to the same system, bit-for-bit; when
27371 @code{provenance-service-type} is used, these two systems will have
27372 different meta-data and thus different store file names, which makes
27373 comparison less trivial.
27376 This service is automatically added to your operating system
27377 configuration when you use @command{guix system reconfigure},
27378 @command{guix system init}, or @command{guix deploy}.
27381 @node Shepherd Services
27382 @subsection Shepherd Services
27384 @cindex shepherd services
27386 @cindex init system
27387 The @code{(gnu services shepherd)} module provides a way to define
27388 services managed by the GNU@tie{}Shepherd, which is the
27389 initialization system---the first process that is started when the
27390 system boots, also known as PID@tie{}1
27391 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
27393 Services in the Shepherd can depend on each other. For instance, the
27394 SSH daemon may need to be started after the syslog daemon has been
27395 started, which in turn can only happen once all the file systems have
27396 been mounted. The simple operating system defined earlier (@pxref{Using
27397 the Configuration System}) results in a service graph like this:
27399 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
27401 You can actually generate such a graph for any operating system
27402 definition using the @command{guix system shepherd-graph} command
27403 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
27405 The @code{%shepherd-root-service} is a service object representing
27406 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
27407 by passing it lists of @code{<shepherd-service>} objects.
27409 @deftp {Data Type} shepherd-service
27410 The data type representing a service managed by the Shepherd.
27413 @item @code{provision}
27414 This is a list of symbols denoting what the service provides.
27416 These are the names that may be passed to @command{herd start},
27417 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
27418 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
27419 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
27421 @item @code{requirement} (default: @code{'()})
27422 List of symbols denoting the Shepherd services this one depends on.
27424 @cindex one-shot services, for the Shepherd
27425 @item @code{one-shot?} (default: @code{#f})
27426 Whether this service is @dfn{one-shot}. One-shot services stop immediately
27427 after their @code{start} action has completed. @xref{Slots of services,,,
27428 shepherd, The GNU Shepherd Manual}, for more info.
27430 @item @code{respawn?} (default: @code{#t})
27431 Whether to restart the service when it stops, for instance when the
27432 underlying process dies.
27435 @itemx @code{stop} (default: @code{#~(const #f)})
27436 The @code{start} and @code{stop} fields refer to the Shepherd's
27437 facilities to start and stop processes (@pxref{Service De- and
27438 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
27439 G-expressions that get expanded in the Shepherd configuration file
27440 (@pxref{G-Expressions}).
27442 @item @code{actions} (default: @code{'()})
27443 @cindex actions, of Shepherd services
27444 This is a list of @code{shepherd-action} objects (see below) defining
27445 @dfn{actions} supported by the service, in addition to the standard
27446 @code{start} and @code{stop} actions. Actions listed here become available as
27447 @command{herd} sub-commands:
27450 herd @var{action} @var{service} [@var{arguments}@dots{}]
27453 @item @code{auto-start?} (default: @code{#t})
27454 Whether this service should be started automatically by the Shepherd. If it
27455 is @code{#f} the service has to be started manually with @code{herd start}.
27457 @item @code{documentation}
27458 A documentation string, as shown when running:
27461 herd doc @var{service-name}
27464 where @var{service-name} is one of the symbols in @code{provision}
27465 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
27467 @item @code{modules} (default: @code{%default-modules})
27468 This is the list of modules that must be in scope when @code{start} and
27469 @code{stop} are evaluated.
27474 @deftp {Data Type} shepherd-action
27475 This is the data type that defines additional actions implemented by a
27476 Shepherd service (see above).
27480 Symbol naming the action.
27482 @item documentation
27483 This is a documentation string for the action. It can be viewed by running:
27486 herd doc @var{service} action @var{action}
27490 This should be a gexp that evaluates to a procedure of at least one argument,
27491 which is the ``running value'' of the service (@pxref{Slots of services,,,
27492 shepherd, The GNU Shepherd Manual}).
27495 The following example defines an action called @code{say-hello} that kindly
27501 (documentation "Say hi!")
27502 (procedure #~(lambda (running . args)
27503 (format #t "Hello, friend! arguments: ~s\n"
27508 Assuming this action is added to the @code{example} service, then you can do:
27511 # herd say-hello example
27512 Hello, friend! arguments: ()
27513 # herd say-hello example a b c
27514 Hello, friend! arguments: ("a" "b" "c")
27517 This, as you can see, is a fairly sophisticated way to say hello.
27518 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27522 @defvr {Scheme Variable} shepherd-root-service-type
27523 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27525 This is the service type that extensions target when they want to create
27526 shepherd services (@pxref{Service Types and Services}, for an example).
27527 Each extension must pass a list of @code{<shepherd-service>}.
27530 @defvr {Scheme Variable} %shepherd-root-service
27531 This service represents PID@tie{}1.
27535 @node Documentation
27536 @chapter Documentation
27538 @cindex documentation, searching for
27539 @cindex searching for documentation
27540 @cindex Info, documentation format
27542 @cindex manual pages
27543 In most cases packages installed with Guix come with documentation.
27544 There are two main documentation formats: ``Info'', a browseable
27545 hypertext format used for GNU software, and ``manual pages'' (or ``man
27546 pages''), the linear documentation format traditionally found on Unix.
27547 Info manuals are accessed with the @command{info} command or with Emacs,
27548 and man pages are accessed using @command{man}.
27550 You can look for documentation of software installed on your system by
27551 keyword. For example, the following command searches for information
27552 about ``TLS'' in Info manuals:
27556 "(emacs)Network Security" -- STARTTLS
27557 "(emacs)Network Security" -- TLS
27558 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27559 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27564 The command below searches for the same keyword in man pages:
27568 SSL (7) - OpenSSL SSL/TLS library
27569 certtool (1) - GnuTLS certificate tool
27573 These searches are purely local to your computer so you have the
27574 guarantee that documentation you find corresponds to what you have
27575 actually installed, you can access it off-line, and your privacy is
27578 Once you have these results, you can view the relevant documentation by
27582 $ info "(gnutls)Core TLS API"
27592 Info manuals contain sections and indices as well as hyperlinks like
27593 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27594 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27595 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27596 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27597 Introduction}, for an introduction to Info navigation.
27599 @node Installing Debugging Files
27600 @chapter Installing Debugging Files
27602 @cindex debugging files
27603 Program binaries, as produced by the GCC compilers for instance, are
27604 typically written in the ELF format, with a section containing
27605 @dfn{debugging information}. Debugging information is what allows the
27606 debugger, GDB, to map binary code to source code; it is required to
27607 debug a compiled program in good conditions.
27609 The problem with debugging information is that is takes up a fair amount
27610 of disk space. For example, debugging information for the GNU C Library
27611 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27612 debugging info of all the installed programs is usually not an option.
27613 Yet, space savings should not come at the cost of an impediment to
27614 debugging---especially in the GNU system, which should make it easier
27615 for users to exert their computing freedom (@pxref{GNU Distribution}).
27617 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27618 mechanism that allows users to get the best of both worlds: debugging
27619 information can be stripped from the binaries and stored in separate
27620 files. GDB is then able to load debugging information from those files,
27621 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27624 The GNU distribution takes advantage of this by storing debugging
27625 information in the @code{lib/debug} sub-directory of a separate package
27626 output unimaginatively called @code{debug} (@pxref{Packages with
27627 Multiple Outputs}). Users can choose to install the @code{debug} output
27628 of a package when they need it. For instance, the following command
27629 installs the debugging information for the GNU C Library and for GNU
27633 guix install glibc:debug guile:debug
27636 GDB must then be told to look for debug files in the user's profile, by
27637 setting the @code{debug-file-directory} variable (consider setting it
27638 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27642 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27645 From there on, GDB will pick up debugging information from the
27646 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27648 In addition, you will most likely want GDB to be able to show the source
27649 code being debugged. To do that, you will have to unpack the source
27650 code of the package of interest (obtained with @code{guix build
27651 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27652 directory using the @code{directory} command (@pxref{Source Path,
27653 @code{directory},, gdb, Debugging with GDB}).
27655 @c XXX: keep me up-to-date
27656 The @code{debug} output mechanism in Guix is implemented by the
27657 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27658 opt-in---debugging information is available only for the packages
27659 with definitions explicitly declaring a @code{debug} output. This may be
27660 changed to opt-out in the future if our build farm servers can handle
27661 the load. To check whether a package has a @code{debug} output, use
27662 @command{guix package --list-available} (@pxref{Invoking guix package}).
27665 @node Security Updates
27666 @chapter Security Updates
27668 @cindex security updates
27669 @cindex security vulnerabilities
27670 Occasionally, important security vulnerabilities are discovered in software
27671 packages and must be patched. Guix developers try hard to keep track of
27672 known vulnerabilities and to apply fixes as soon as possible in the
27673 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27674 containing only security updates.) The @command{guix lint} tool helps
27675 developers find out about vulnerable versions of software packages in the
27680 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
27681 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
27682 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
27686 @xref{Invoking guix lint}, for more information.
27688 Guix follows a functional
27689 package management discipline (@pxref{Introduction}), which implies
27690 that, when a package is changed, @emph{every package that depends on it}
27691 must be rebuilt. This can significantly slow down the deployment of
27692 fixes in core packages such as libc or Bash, since basically the whole
27693 distribution would need to be rebuilt. Using pre-built binaries helps
27694 (@pxref{Substitutes}), but deployment may still take more time than
27698 To address this, Guix implements @dfn{grafts}, a mechanism that allows
27699 for fast deployment of critical updates without the costs associated
27700 with a whole-distribution rebuild. The idea is to rebuild only the
27701 package that needs to be patched, and then to ``graft'' it onto packages
27702 explicitly installed by the user and that were previously referring to
27703 the original package. The cost of grafting is typically very low, and
27704 order of magnitudes lower than a full rebuild of the dependency chain.
27706 @cindex replacements of packages, for grafts
27707 For instance, suppose a security update needs to be applied to Bash.
27708 Guix developers will provide a package definition for the ``fixed''
27709 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
27710 Packages}). Then, the original package definition is augmented with a
27711 @code{replacement} field pointing to the package containing the bug fix:
27718 (replacement bash-fixed)))
27721 From there on, any package depending directly or indirectly on Bash---as
27722 reported by @command{guix gc --requisites} (@pxref{Invoking guix
27723 gc})---that is installed is automatically ``rewritten'' to refer to
27724 @code{bash-fixed} instead of @code{bash}. This grafting process takes
27725 time proportional to the size of the package, usually less than a
27726 minute for an ``average'' package on a recent machine. Grafting is
27727 recursive: when an indirect dependency requires grafting, then grafting
27728 ``propagates'' up to the package that the user is installing.
27730 Currently, the length of the name and version of the graft and that of
27731 the package it replaces (@code{bash-fixed} and @code{bash} in the example
27732 above) must be equal. This restriction mostly comes from the fact that
27733 grafting works by patching files, including binary files, directly.
27734 Other restrictions may apply: for instance, when adding a graft to a
27735 package providing a shared library, the original shared library and its
27736 replacement must have the same @code{SONAME} and be binary-compatible.
27738 The @option{--no-grafts} command-line option allows you to forcefully
27739 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
27743 guix build bash --no-grafts
27747 returns the store file name of the original Bash, whereas:
27754 returns the store file name of the ``fixed'', replacement Bash. This
27755 allows you to distinguish between the two variants of Bash.
27757 To verify which Bash your whole profile refers to, you can run
27758 (@pxref{Invoking guix gc}):
27761 guix gc -R `readlink -f ~/.guix-profile` | grep bash
27765 @dots{} and compare the store file names that you get with those above.
27766 Likewise for a complete Guix system generation:
27769 guix gc -R `guix system build my-config.scm` | grep bash
27772 Lastly, to check which Bash running processes are using, you can use the
27773 @command{lsof} command:
27776 lsof | grep /gnu/store/.*bash
27780 @node Bootstrapping
27781 @chapter Bootstrapping
27783 @c Adapted from the ELS 2013 paper.
27785 @cindex bootstrapping
27787 Bootstrapping in our context refers to how the distribution gets built
27788 ``from nothing''. Remember that the build environment of a derivation
27789 contains nothing but its declared inputs (@pxref{Introduction}). So
27790 there's an obvious chicken-and-egg problem: how does the first package
27791 get built? How does the first compiler get compiled? Note that this is
27792 a question of interest only to the curious hacker, not to the regular
27793 user, so you can shamelessly skip this section if you consider yourself
27794 a ``regular user''.
27796 @cindex bootstrap binaries
27797 The GNU system is primarily made of C code, with libc at its core. The
27798 GNU build system itself assumes the availability of a Bourne shell and
27799 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
27800 `grep'. Furthermore, build programs---programs that run
27801 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
27802 (@pxref{Derivations}). Consequently, to be able to build anything at
27803 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
27804 Binutils, libc, and the other packages mentioned above---the
27805 @dfn{bootstrap binaries}.
27807 These bootstrap binaries are ``taken for granted'', though we can also
27808 re-create them if needed (more on that later).
27810 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
27811 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
27814 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
27815 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
27818 @node Reduced Binary Seed Bootstrap
27819 @section The Reduced Binary Seed Bootstrap
27821 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
27822 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
27823 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
27824 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
27825 ``taken for granted.''
27827 Taking these binaries for granted means that we consider them to be a correct
27828 and trustworthy `seed' for building the complete system. Therein lies a
27829 problem: the current combined size of these bootstrap binaries is about 250MB
27830 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
27831 these is next to impossible.
27833 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
27834 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
27835 Bootstrap'' and while we are working towards that goal it would be hyperbole
27836 to use that term for what we do now.}.
27838 The Reduced Binary Seed bootstrap removes the most critical tools---from a
27839 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
27840 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
27841 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
27842 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
27843 these new binary seeds and a new set of
27845 packages@footnote{@c
27860 gcc-mesboot1-wrapper,
27861 glibc-headers-mesboot,
27865 gcc-mesboot-wrapper.
27868 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
27869 From here on the more traditional bootstrap process resumes. This approach
27870 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
27871 reduce this further. If you are interested, join us on @code{#bootstrappable}
27872 on the Freenode IRC network.
27874 @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
27875 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
27877 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
27878 compiler used to build the rest of GuixSD.
27880 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
27882 @node Preparing to Use the Bootstrap Binaries
27883 @section Preparing to Use the Bootstrap Binaries
27885 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
27886 @c large image, it's hard to scroll. Oh well.
27887 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
27889 The figure above shows the very beginning of the dependency graph of the
27890 distribution, corresponding to the package definitions of the @code{(gnu
27891 packages bootstrap)} module. A similar figure can be generated with
27892 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
27895 guix graph -t derivation \
27896 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
27897 | dot -Tps > gcc.ps
27900 or, for the Reduced Binary Seed bootstrap
27903 guix graph -t derivation \
27904 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
27905 | dot -Tps > mes.ps
27908 At this level of detail, things are
27909 slightly complex. First, Guile itself consists of an ELF executable,
27910 along with many source and compiled Scheme files that are dynamically
27911 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
27912 tarball shown in this graph. This tarball is part of Guix's ``source''
27913 distribution, and gets inserted into the store with @code{add-to-store}
27914 (@pxref{The Store}).
27916 But how do we write a derivation that unpacks this tarball and adds it
27917 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
27918 derivation---the first one that gets built---uses @code{bash} as its
27919 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
27920 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
27921 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
27922 the Guix source distribution, whose sole purpose is to allow the Guile
27923 tarball to be unpacked.
27925 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
27926 Guile that can be used to run subsequent build programs. Its first task
27927 is to download tarballs containing the other pre-built binaries---this
27928 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
27929 @code{ftp-client.scm} are used for this purpose. The
27930 @code{module-import.drv} derivations import those modules in a directory
27931 in the store, using the original layout. The
27932 @code{module-import-compiled.drv} derivations compile those modules, and
27933 write them in an output directory with the right layout. This
27934 corresponds to the @code{#:modules} argument of
27935 @code{build-expression->derivation} (@pxref{Derivations}).
27937 Finally, the various tarballs are unpacked by the derivations
27938 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
27939 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
27940 point we have a working C tool chain.
27942 @unnumberedsec Building the Build Tools
27944 Bootstrapping is complete when we have a full tool chain that does not
27945 depend on the pre-built bootstrap tools discussed above. This
27946 no-dependency requirement is verified by checking whether the files of
27947 the final tool chain contain references to the @file{/gnu/store}
27948 directories of the bootstrap inputs. The process that leads to this
27949 ``final'' tool chain is described by the package definitions found in
27950 the @code{(gnu packages commencement)} module.
27952 The @command{guix graph} command allows us to ``zoom out'' compared to
27953 the graph above, by looking at the level of package objects instead of
27954 individual derivations---remember that a package may translate to
27955 several derivations, typically one derivation to download its source,
27956 one to build the Guile modules it needs, and one to actually build the
27957 package from source. The command:
27960 guix graph -t bag \
27961 -e '(@@@@ (gnu packages commencement)
27962 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
27966 produces the dependency graph leading to the ``final'' C
27967 library@footnote{You may notice the @code{glibc-intermediate} label,
27968 suggesting that it is not @emph{quite} final, but as a good
27969 approximation, we will consider it final.}, depicted below.
27971 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
27973 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
27974 The first tool that gets built with the bootstrap binaries is
27975 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
27976 for all the following packages. From there Findutils and Diffutils get
27979 Then come the first-stage Binutils and GCC, built as pseudo cross
27980 tools---i.e., with @code{--target} equal to @code{--host}. They are
27981 used to build libc. Thanks to this cross-build trick, this libc is
27982 guaranteed not to hold any reference to the initial tool chain.
27984 From there the final Binutils and GCC (not shown above) are built.
27986 from the final Binutils, and links programs against the just-built libc.
27987 This tool chain is used to build the other packages used by Guix and by
27988 the GNU Build System: Guile, Bash, Coreutils, etc.
27990 And voilà! At this point we have the complete set of build tools that
27991 the GNU Build System expects. These are in the @code{%final-inputs}
27992 variable of the @code{(gnu packages commencement)} module, and are
27993 implicitly used by any package that uses @code{gnu-build-system}
27994 (@pxref{Build Systems, @code{gnu-build-system}}).
27997 @unnumberedsec Building the Bootstrap Binaries
27999 @cindex bootstrap binaries
28000 Because the final tool chain does not depend on the bootstrap binaries,
28001 those rarely need to be updated. Nevertheless, it is useful to have an
28002 automated way to produce them, should an update occur, and this is what
28003 the @code{(gnu packages make-bootstrap)} module provides.
28005 The following command builds the tarballs containing the bootstrap binaries
28006 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
28007 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
28008 and Guile, and a tarball containing a mixture of Coreutils and other basic
28009 command-line tools):
28012 guix build bootstrap-tarballs
28015 The generated tarballs are those that should be referred to in the
28016 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28019 Still here? Then perhaps by now you've started to wonder: when do we
28020 reach a fixed point? That is an interesting question! The answer is
28021 unknown, but if you would like to investigate further (and have
28022 significant computational and storage resources to do so), then let us
28025 @unnumberedsec Reducing the Set of Bootstrap Binaries
28027 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28028 binary code! Why is that a problem? It's a problem because these big chunks
28029 of binary code are practically non-auditable, which makes it hard to establish
28030 what source code produced them. Every unauditable binary also leaves us
28031 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28032 paper @emph{Reflections on Trusting Trust}.
28034 This is mitigated by the fact that our bootstrap binaries were generated
28035 from an earlier Guix revision. Nevertheless it lacks the level of
28036 transparency that we get in the rest of the package dependency graph,
28037 where Guix always gives us a source-to-binary mapping. Thus, our goal
28038 is to reduce the set of bootstrap binaries to the bare minimum.
28040 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
28041 on-going projects to do that. One of these is about replacing the
28042 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28043 of increasing complexity, which could be built from source starting from
28044 a simple and auditable assembler.
28046 Our first major achievement is the replacement of of GCC, the GNU C Library
28047 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28048 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28049 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28050 bootstrapped yet and thus we inject them as binary seeds. We call this the
28051 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28052 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28053 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28055 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28056 also looking at any other bootstrap binaries. Your help is welcome!
28059 @chapter Porting to a New Platform
28061 As discussed above, the GNU distribution is self-contained, and
28062 self-containment is achieved by relying on pre-built ``bootstrap
28063 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28064 operating system kernel, CPU architecture, and application binary
28065 interface (ABI). Thus, to port the distribution to a platform that is
28066 not yet supported, one must build those bootstrap binaries, and update
28067 the @code{(gnu packages bootstrap)} module to use them on that platform.
28069 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28070 When everything goes well, and assuming the GNU tool chain supports the
28071 target platform, this can be as simple as running a command like this
28075 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28078 For this to work, the @code{glibc-dynamic-linker} procedure in
28079 @code{(gnu packages bootstrap)} must be augmented to return the right
28080 file name for libc's dynamic linker on that platform; likewise,
28081 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28082 taught about the new platform.
28084 Once these are built, the @code{(gnu packages bootstrap)} module needs
28085 to be updated to refer to these binaries on the target platform. That
28086 is, the hashes and URLs of the bootstrap tarballs for the new platform
28087 must be added alongside those of the currently supported platforms. The
28088 bootstrap Guile tarball is treated specially: it is expected to be
28089 available locally, and @file{gnu/local.mk} has rules to download it for
28090 the supported architectures; a rule for the new platform must be added
28093 In practice, there may be some complications. First, it may be that the
28094 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28095 above) is not recognized by all the GNU tools. Typically, glibc
28096 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
28097 configure flag (see @code{gcc.scm} for examples of how to handle this).
28098 Second, some of the required packages could fail to build for that
28099 platform. Lastly, the generated binaries could be broken for some
28102 @c *********************************************************************
28103 @include contributing.texi
28105 @c *********************************************************************
28106 @node Acknowledgments
28107 @chapter Acknowledgments
28109 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28110 which was designed and
28111 implemented by Eelco Dolstra, with contributions from other people (see
28112 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28113 management, and promoted unprecedented features, such as transactional
28114 package upgrades and rollbacks, per-user profiles, and referentially
28115 transparent build processes. Without this work, Guix would not exist.
28117 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28118 an inspiration for Guix.
28120 GNU@tie{}Guix itself is a collective work with contributions from a
28121 number of people. See the @file{AUTHORS} file in Guix for more
28122 information on these fine people. The @file{THANKS} file lists people
28123 who have helped by reporting bugs, taking care of the infrastructure,
28124 providing artwork and themes, making suggestions, and more---thank you!
28127 @c *********************************************************************
28128 @node GNU Free Documentation License
28129 @appendix GNU Free Documentation License
28130 @cindex license, GNU Free Documentation License
28131 @include fdl-1.3.texi
28133 @c *********************************************************************
28134 @node Concept Index
28135 @unnumbered Concept Index
28138 @node Programming Index
28139 @unnumbered Programming Index
28140 @syncodeindex tp fn
28141 @syncodeindex vr fn
28146 @c Local Variables:
28147 @c ispell-local-dictionary: "american";