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, 2020 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, 2020 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, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 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, 2020 Simon Tournier@*
74 Copyright @copyright{} 2020 Wiktor Żelazny@*
75 Copyright @copyright{} 2020 Damien Cassou@*
76 Copyright @copyright{} 2020 Jakub Kądziołka@*
77 Copyright @copyright{} 2020 Jack Hill@*
79 Permission is granted to copy, distribute and/or modify this document
80 under the terms of the GNU Free Documentation License, Version 1.3 or
81 any later version published by the Free Software Foundation; with no
82 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
83 copy of the license is included in the section entitled ``GNU Free
84 Documentation License''.
87 @dircategory System administration
89 * Guix: (guix). Manage installed software and system configuration.
90 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
91 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
92 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
93 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
94 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
97 @dircategory Software development
99 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
100 * guix build: (guix)Invoking guix build. Building packages.
101 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
105 @title GNU Guix Reference Manual
106 @subtitle Using the GNU Guix Functional Package Manager
107 @author The GNU Guix Developers
110 @vskip 0pt plus 1filll
111 Edition @value{EDITION} @*
119 @c *********************************************************************
123 This document describes GNU Guix version @value{VERSION}, a functional
124 package management tool written for the GNU system.
126 @c TRANSLATORS: You can replace the following paragraph with information on
127 @c how to join your own translation team and how to report issues with the
129 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
130 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
131 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
132 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
133 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
134 would like to translate it in your native language, consider joining the
135 @uref{https://translationproject.org/domain/guix-manual.html, Translation
139 * Introduction:: What is Guix about?
140 * Installation:: Installing Guix.
141 * System Installation:: Installing the whole operating system.
142 * Package Management:: Package installation, upgrade, etc.
143 * Development:: Guix-aided software development.
144 * Programming Interface:: Using Guix in Scheme.
145 * Utilities:: Package management commands.
146 * System Configuration:: Configuring the operating system.
147 * Documentation:: Browsing software user manuals.
148 * Installing Debugging Files:: Feeding the debugger.
149 * Security Updates:: Deploying security fixes quickly.
150 * Bootstrapping:: GNU/Linux built from scratch.
151 * Porting:: Targeting another platform or kernel.
152 * Contributing:: Your help needed!
154 * Acknowledgments:: Thanks!
155 * GNU Free Documentation License:: The license of this manual.
156 * Concept Index:: Concepts.
157 * Programming Index:: Data types, functions, and variables.
160 --- The Detailed Node Listing ---
164 * Managing Software the Guix Way:: What's special.
165 * GNU Distribution:: The packages and tools.
169 * Binary Installation:: Getting Guix running in no time!
170 * Requirements:: Software needed to build and run Guix.
171 * Running the Test Suite:: Testing Guix.
172 * Setting Up the Daemon:: Preparing the build daemon's environment.
173 * Invoking guix-daemon:: Running the build daemon.
174 * Application Setup:: Application-specific setup.
176 Setting Up the Daemon
178 * Build Environment Setup:: Preparing the isolated build environment.
179 * Daemon Offload Setup:: Offloading builds to remote machines.
180 * SELinux Support:: Using an SELinux policy for the daemon.
184 * Limitations:: What you can expect.
185 * Hardware Considerations:: Supported hardware.
186 * USB Stick and DVD Installation:: Preparing the installation medium.
187 * Preparing for Installation:: Networking, partitioning, etc.
188 * Guided Graphical Installation:: Easy graphical installation.
189 * Manual Installation:: Manual installation for wizards.
190 * After System Installation:: When installation succeeded.
191 * Installing Guix in a VM:: Guix System playground.
192 * Building the Installation Image:: How this comes to be.
196 * Keyboard Layout and Networking and Partitioning:: Initial setup.
197 * Proceeding with the Installation:: Installing.
201 * Features:: How Guix will make your life brighter.
202 * Invoking guix package:: Package installation, removal, etc.
203 * Substitutes:: Downloading pre-built binaries.
204 * Packages with Multiple Outputs:: Single source package, multiple outputs.
205 * Invoking guix gc:: Running the garbage collector.
206 * Invoking guix pull:: Fetching the latest Guix and distribution.
207 * Channels:: Customizing the package collection.
208 * Invoking guix time-machine:: Running an older revision of Guix.
209 * Inferiors:: Interacting with another revision of Guix.
210 * Invoking guix describe:: Display information about your Guix revision.
211 * Invoking guix archive:: Exporting and importing store files.
215 * Official Substitute Server:: One particular source of substitutes.
216 * Substitute Server Authorization:: How to enable or disable substitutes.
217 * Substitute Authentication:: How Guix verifies substitutes.
218 * Proxy Settings:: How to get substitutes via proxy.
219 * Substitution Failure:: What happens when substitution fails.
220 * On Trusting Binaries:: How can you trust that binary blob?
224 * Invoking guix environment:: Setting up development environments.
225 * Invoking guix pack:: Creating software bundles.
227 Programming Interface
229 * Package Modules:: Packages from the programmer's viewpoint.
230 * Defining Packages:: Defining new packages.
231 * Build Systems:: Specifying how packages are built.
232 * The Store:: Manipulating the package store.
233 * Derivations:: Low-level interface to package derivations.
234 * The Store Monad:: Purely functional interface to the store.
235 * G-Expressions:: Manipulating build expressions.
236 * Invoking guix repl:: Fiddling with Guix interactively.
240 * package Reference:: The package data type.
241 * origin Reference:: The origin data type.
245 * Invoking guix build:: Building packages from the command line.
246 * Invoking guix edit:: Editing package definitions.
247 * Invoking guix download:: Downloading a file and printing its hash.
248 * Invoking guix hash:: Computing the cryptographic hash of a file.
249 * Invoking guix import:: Importing package definitions.
250 * Invoking guix refresh:: Updating package definitions.
251 * Invoking guix lint:: Finding errors in package definitions.
252 * Invoking guix size:: Profiling disk usage.
253 * Invoking guix graph:: Visualizing the graph of packages.
254 * Invoking guix publish:: Sharing substitutes.
255 * Invoking guix challenge:: Challenging substitute servers.
256 * Invoking guix copy:: Copying to and from a remote store.
257 * Invoking guix container:: Process isolation.
258 * Invoking guix weather:: Assessing substitute availability.
259 * Invoking guix processes:: Listing client processes.
261 Invoking @command{guix build}
263 * Common Build Options:: Build options for most commands.
264 * Package Transformation Options:: Creating variants of packages.
265 * Additional Build Options:: Options specific to 'guix build'.
266 * Debugging Build Failures:: Real life packaging experience.
270 * Using the Configuration System:: Customizing your GNU system.
271 * operating-system Reference:: Detail of operating-system declarations.
272 * File Systems:: Configuring file system mounts.
273 * Mapped Devices:: Block device extra processing.
274 * User Accounts:: Specifying user accounts.
275 * Keyboard Layout:: How the system interprets key strokes.
276 * Locales:: Language and cultural convention settings.
277 * Services:: Specifying system services.
278 * Setuid Programs:: Programs running with root privileges.
279 * X.509 Certificates:: Authenticating HTTPS servers.
280 * Name Service Switch:: Configuring libc's name service switch.
281 * Initial RAM Disk:: Linux-Libre bootstrapping.
282 * Bootloader Configuration:: Configuring the boot loader.
283 * Invoking guix system:: Instantiating a system configuration.
284 * Invoking guix deploy:: Deploying a system configuration to a remote host.
285 * Running Guix in a VM:: How to run Guix System in a virtual machine.
286 * Defining Services:: Adding new service definitions.
290 * Base Services:: Essential system services.
291 * Scheduled Job Execution:: The mcron service.
292 * Log Rotation:: The rottlog service.
293 * Networking Services:: Network setup, SSH daemon, etc.
294 * X Window:: Graphical display.
295 * Printing Services:: Local and remote printer support.
296 * Desktop Services:: D-Bus and desktop services.
297 * Sound Services:: ALSA and Pulseaudio services.
298 * Database Services:: SQL databases, key-value stores, etc.
299 * Mail Services:: IMAP, POP3, SMTP, and all that.
300 * Messaging Services:: Messaging services.
301 * Telephony Services:: Telephony services.
302 * Monitoring Services:: Monitoring services.
303 * Kerberos Services:: Kerberos services.
304 * Web Services:: Web servers.
305 * Certificate Services:: TLS certificates via Let's Encrypt.
306 * DNS Services:: DNS daemons.
307 * VPN Services:: VPN daemons.
308 * Network File System:: NFS related services.
309 * Continuous Integration:: The Cuirass service.
310 * Power Management Services:: Extending battery life.
311 * Audio Services:: The MPD.
312 * Virtualization Services:: Virtualization services.
313 * Version Control Services:: Providing remote access to Git repositories.
314 * Game Services:: Game servers.
315 * PAM Mount Service:: Service to mount volumes when logging in.
316 * Linux Services:: Services tied to the Linux kernel.
317 * Miscellaneous Services:: Other services.
321 * Service Composition:: The model for composing services.
322 * Service Types and Services:: Types and services.
323 * Service Reference:: API reference.
324 * Shepherd Services:: A particular type of service.
329 @c *********************************************************************
331 @chapter Introduction
334 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
335 using the international phonetic alphabet (IPA).} is a package
336 management tool for and distribution of the GNU system.
337 Guix makes it easy for unprivileged
338 users to install, upgrade, or remove software packages, to roll back to a
339 previous package set, to build packages from source, and generally
340 assists with the creation and maintenance of software environments.
343 @cindex GuixSD, now Guix System
344 @cindex Guix System Distribution, now Guix System
345 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
346 complements the available tools without interference (@pxref{Installation}),
347 or you can use it as a standalone operating system distribution,
348 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
349 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
350 group everything under the ``Guix'' banner since, after all, Guix System is
351 readily available through the @command{guix system} command, even if you're
352 using a different distro underneath!}. @xref{GNU Distribution}.
355 * Managing Software the Guix Way:: What's special.
356 * GNU Distribution:: The packages and tools.
359 @node Managing Software the Guix Way
360 @section Managing Software the Guix Way
362 @cindex user interfaces
363 Guix provides a command-line package management interface
364 (@pxref{Package Management}), tools to help with software development
365 (@pxref{Development}), command-line utilities for more advanced usage,
366 (@pxref{Utilities}), as well as Scheme programming interfaces
367 (@pxref{Programming Interface}).
369 Its @dfn{build daemon} is responsible for building packages on behalf of
370 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
371 binaries from authorized sources (@pxref{Substitutes}).
373 @cindex extensibility of the distribution
374 @cindex customization, of packages
375 Guix includes package definitions for many GNU and non-GNU packages, all
376 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
377 user's computing freedom}. It is @emph{extensible}: users can write
378 their own package definitions (@pxref{Defining Packages}) and make them
379 available as independent package modules (@pxref{Package Modules}). It
380 is also @emph{customizable}: users can @emph{derive} specialized package
381 definitions from existing ones, including from the command line
382 (@pxref{Package Transformation Options}).
384 @cindex functional package management
386 Under the hood, Guix implements the @dfn{functional package management}
387 discipline pioneered by Nix (@pxref{Acknowledgments}).
388 In Guix, the package build and installation process is seen
389 as a @emph{function}, in the mathematical sense. That function takes inputs,
390 such as build scripts, a compiler, and libraries, and
391 returns an installed package. As a pure function, its result depends
392 solely on its inputs---for instance, it cannot refer to software or
393 scripts that were not explicitly passed as inputs. A build function
394 always produces the same result when passed a given set of inputs. It
395 cannot alter the environment of the running system in
396 any way; for instance, it cannot create, modify, or delete files outside
397 of its build and installation directories. This is achieved by running
398 build processes in isolated environments (or @dfn{containers}), where only their
399 explicit inputs are visible.
402 The result of package build functions is @dfn{cached} in the file
403 system, in a special directory called @dfn{the store} (@pxref{The
404 Store}). Each package is installed in a directory of its own in the
405 store---by default under @file{/gnu/store}. The directory name contains
406 a hash of all the inputs used to build that package; thus, changing an
407 input yields a different directory name.
409 This approach is the foundation for the salient features of Guix: support
410 for transactional package upgrade and rollback, per-user installation, and
411 garbage collection of packages (@pxref{Features}).
414 @node GNU Distribution
415 @section GNU Distribution
418 Guix comes with a distribution of the GNU system consisting entirely of
419 free software@footnote{The term ``free'' here refers to the
420 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
421 users of that software}.}. The
422 distribution can be installed on its own (@pxref{System Installation}),
423 but it is also possible to install Guix as a package manager on top of
424 an installed GNU/Linux system (@pxref{Installation}). When we need to
425 distinguish between the two, we refer to the standalone distribution as
428 The distribution provides core GNU packages such as GNU libc, GCC, and
429 Binutils, as well as many GNU and non-GNU applications. The complete
430 list of available packages can be browsed
431 @url{https://www.gnu.org/software/guix/packages,on-line} or by
432 running @command{guix package} (@pxref{Invoking guix package}):
435 guix package --list-available
438 Our goal is to provide a practical 100% free software distribution of
439 Linux-based and other variants of GNU, with a focus on the promotion and
440 tight integration of GNU components, and an emphasis on programs and
441 tools that help users exert that freedom.
443 Packages are currently available on the following platforms:
448 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
451 Intel 32-bit architecture (IA32), Linux-Libre kernel;
454 ARMv7-A architecture with hard float, Thumb-2 and NEON,
455 using the EABI hard-float application binary interface (ABI),
456 and Linux-Libre kernel.
459 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
462 little-endian 64-bit MIPS processors, specifically the Loongson series,
463 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
464 supported; in particular, the project's build farms no longer provide
465 substitutes for this architecture.
469 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
470 configuration and Guix takes care of instantiating the configuration in a
471 transactional, reproducible, and stateless fashion (@pxref{System
472 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
473 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
474 Manual}), the well-known GNU utilities and tool chain, as well as the
475 graphical environment or system services of your choice.
477 Guix System is available on all the above platforms except
478 @code{mips64el-linux}.
481 For information on porting to other architectures or kernels,
484 Building this distribution is a cooperative effort, and you are invited
485 to join! @xref{Contributing}, for information about how you can help.
488 @c *********************************************************************
490 @chapter Installation
492 @cindex installing Guix
495 We recommend the use of this
496 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
497 shell installer script} to install Guix on top of a running GNU/Linux system,
498 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
499 with the installation of the package manager, which can be done on top of a
500 running GNU/Linux system. If, instead, you want to install the complete GNU
501 operating system, @pxref{System Installation}.} The script automates the
502 download, installation, and initial configuration of Guix. It should be run
506 @cindex foreign distro
507 @cindex directories related to foreign distro
508 When installed on a foreign distro, GNU@tie{}Guix complements the available
509 tools without interference. Its data lives exclusively in two directories,
510 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
511 such as @file{/etc}, are left untouched.
513 Once installed, Guix can be updated by running @command{guix pull}
514 (@pxref{Invoking guix pull}).
516 If you prefer to perform the installation steps manually or want to tweak
517 them, you may find the following subsections useful. They describe the
518 software requirements of Guix, as well as how to install it manually and get
522 * Binary Installation:: Getting Guix running in no time!
523 * Requirements:: Software needed to build and run Guix.
524 * Running the Test Suite:: Testing Guix.
525 * Setting Up the Daemon:: Preparing the build daemon's environment.
526 * Invoking guix-daemon:: Running the build daemon.
527 * Application Setup:: Application-specific setup.
528 * Upgrading Guix:: Upgrading Guix and its build daemon.
531 @node Binary Installation
532 @section Binary Installation
534 @cindex installing Guix from binaries
535 @cindex installer script
536 This section describes how to install Guix on an arbitrary system from a
537 self-contained tarball providing binaries for Guix and for all its
538 dependencies. This is often quicker than installing from source, which
539 is described in the next sections. The only requirement is to have
542 @c Note duplicated from the ``Installation'' node.
544 We recommend the use of this
545 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
546 shell installer script}. The script automates the download, installation, and
547 initial configuration steps described below. It should be run as the root
551 Installing goes along these lines:
555 @cindex downloading Guix binary
556 Download the binary tarball from
557 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
558 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
559 already running the kernel Linux, and so on.
561 @c The following is somewhat duplicated in ``System Installation''.
562 Make sure to download the associated @file{.sig} file and to verify the
563 authenticity of the tarball against it, along these lines:
566 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
567 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
570 If that command fails because you do not have the required public key,
571 then run this command to import it:
574 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
575 -qO - | gpg --import -
579 and rerun the @code{gpg --verify} command.
581 Take note that a warning like ``This key is not certified with a trusted
582 signature!'' is normal.
584 @c end authentication part
587 Now, you need to become the @code{root} user. Depending on your distribution,
588 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
592 # tar --warning=no-timestamp -xf \
593 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
594 # mv var/guix /var/ && mv gnu /
597 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
598 The latter contains a ready-to-use profile for @code{root} (see next
601 Do @emph{not} unpack the tarball on a working Guix system since that
602 would overwrite its own essential files.
604 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
605 not emit warnings about ``implausibly old time stamps'' (such
606 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
608 They stem from the fact that all the
609 files in the archive have their modification time set to zero (which
610 means January 1st, 1970.) This is done on purpose to make sure the
611 archive content is independent of its creation time, thus making it
615 Make the profile available under @file{~root/.config/guix/current}, which is
616 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
619 # mkdir -p ~root/.config/guix
620 # ln -sf /var/guix/profiles/per-user/root/current-guix \
621 ~root/.config/guix/current
624 Source @file{etc/profile} to augment @code{PATH} and other relevant
625 environment variables:
628 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
629 source $GUIX_PROFILE/etc/profile
633 Create the group and user accounts for build users as explained below
634 (@pxref{Build Environment Setup}).
637 Run the daemon, and set it to automatically start on boot.
639 If your host distro uses the systemd init system, this can be achieved
642 @c Versions of systemd that supported symlinked service files are not
643 @c yet widely deployed, so we should suggest that users copy the service
646 @c See this thread for more information:
647 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
650 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
652 # systemctl start guix-daemon && systemctl enable guix-daemon
655 If your host distro uses the Upstart init system:
658 # initctl reload-configuration
659 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
664 Otherwise, you can still start the daemon manually with:
667 # ~root/.config/guix/current/bin/guix-daemon \
668 --build-users-group=guixbuild
672 Make the @command{guix} command available to other users on the machine,
676 # mkdir -p /usr/local/bin
678 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
681 It is also a good idea to make the Info version of this manual available
685 # mkdir -p /usr/local/share/info
686 # cd /usr/local/share/info
687 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
691 That way, assuming @file{/usr/local/share/info} is in the search path,
692 running @command{info guix} will open this manual (@pxref{Other Info
693 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
697 @cindex substitutes, authorization thereof
698 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
699 (@pxref{Substitutes}), authorize them:
702 # guix archive --authorize < \
703 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
707 Each user may need to perform a few additional steps to make their Guix
708 environment ready for use, @pxref{Application Setup}.
711 Voilà, the installation is complete!
713 You can confirm that Guix is working by installing a sample package into
720 The binary installation tarball can be (re)produced and verified simply
721 by running the following command in the Guix source tree:
724 make guix-binary.@var{system}.tar.xz
728 ...@: which, in turn, runs:
731 guix pack -s @var{system} --localstatedir \
732 --profile-name=current-guix guix
735 @xref{Invoking guix pack}, for more info on this handy tool.
738 @section Requirements
740 This section lists requirements when building Guix from source. The
741 build procedure for Guix is the same as for other GNU software, and is
742 not covered here. Please see the files @file{README} and @file{INSTALL}
743 in the Guix source tree for additional details.
745 @cindex official website
746 GNU Guix is available for download from its website at
747 @url{https://www.gnu.org/software/guix/}.
749 GNU Guix depends on the following packages:
752 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
754 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
757 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
758 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
759 Guile,, gnutls-guile, GnuTLS-Guile});
761 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
764 @c FIXME: Specify a version number once a release has been made.
765 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
767 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
768 @item @url{https://zlib.net, zlib};
769 @item @url{https://www.gnu.org/software/make/, GNU Make}.
772 The following dependencies are optional:
776 @c Note: We need at least 0.12.0 for 'userauth-gssapi!'.
777 Support for build offloading (@pxref{Daemon Offload Setup}) and
778 @command{guix copy} (@pxref{Invoking guix copy}) depends on
779 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
780 version 0.12.0 or later.
783 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
784 substitutes can be used and @command{guix publish} can compress substitutes
788 When @url{http://www.bzip.org, libbz2} is available,
789 @command{guix-daemon} can use it to compress build logs.
792 Unless @code{--disable-daemon} was passed to @command{configure}, the
793 following packages are also needed:
796 @item @url{https://gnupg.org/, GNU libgcrypt};
797 @item @url{https://sqlite.org, SQLite 3};
798 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
802 @cindex state directory
803 When configuring Guix on a system that already has a Guix installation,
804 be sure to specify the same state directory as the existing installation
805 using the @code{--localstatedir} option of the @command{configure}
806 script (@pxref{Directory Variables, @code{localstatedir},, standards,
807 GNU Coding Standards}). Usually, this @var{localstatedir} option is
808 set to the value @file{/var}. The @command{configure} script protects
809 against unintended misconfiguration of @var{localstatedir} so you do not
810 inadvertently corrupt your store (@pxref{The Store}).
812 @node Running the Test Suite
813 @section Running the Test Suite
816 After a successful @command{configure} and @code{make} run, it is a good
817 idea to run the test suite. It can help catch issues with the setup or
818 environment, or bugs in Guix itself---and really, reporting test
819 failures is a good way to help improve the software. To run the test
826 Test cases can run in parallel: you can use the @code{-j} option of
827 GNU@tie{}make to speed things up. The first run may take a few minutes
828 on a recent machine; subsequent runs will be faster because the store
829 that is created for test purposes will already have various things in
832 It is also possible to run a subset of the tests by defining the
833 @code{TESTS} makefile variable as in this example:
836 make check TESTS="tests/store.scm tests/cpio.scm"
839 By default, tests results are displayed at a file level. In order to
840 see the details of every individual test cases, it is possible to define
841 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
844 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
847 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
848 @file{test-suite.log} file. Please specify the Guix version being used
849 as well as version numbers of the dependencies (@pxref{Requirements}) in
852 Guix also comes with a whole-system test suite that tests complete
853 Guix System instances. It can only run on systems where
854 Guix is already installed, using:
861 or, again, by defining @code{TESTS} to select a subset of tests to run:
864 make check-system TESTS="basic mcron"
867 These system tests are defined in the @code{(gnu tests @dots{})}
868 modules. They work by running the operating systems under test with
869 lightweight instrumentation in a virtual machine (VM). They can be
870 computationally intensive or rather cheap, depending on whether
871 substitutes are available for their dependencies (@pxref{Substitutes}).
872 Some of them require a lot of storage space to hold VM images.
874 Again in case of test failures, please send @email{bug-guix@@gnu.org}
877 @node Setting Up the Daemon
878 @section Setting Up the Daemon
881 Operations such as building a package or running the garbage collector
882 are all performed by a specialized process, the @dfn{build daemon}, on
883 behalf of clients. Only the daemon may access the store and its
884 associated database. Thus, any operation that manipulates the store
885 goes through the daemon. For instance, command-line tools such as
886 @command{guix package} and @command{guix build} communicate with the
887 daemon (@i{via} remote procedure calls) to instruct it what to do.
889 The following sections explain how to prepare the build daemon's
890 environment. See also @ref{Substitutes}, for information on how to allow
891 the daemon to download pre-built binaries.
894 * Build Environment Setup:: Preparing the isolated build environment.
895 * Daemon Offload Setup:: Offloading builds to remote machines.
896 * SELinux Support:: Using an SELinux policy for the daemon.
899 @node Build Environment Setup
900 @subsection Build Environment Setup
902 @cindex build environment
903 In a standard multi-user setup, Guix and its daemon---the
904 @command{guix-daemon} program---are installed by the system
905 administrator; @file{/gnu/store} is owned by @code{root} and
906 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
907 Guix tools to build packages or otherwise access the store, and the
908 daemon will do it on their behalf, ensuring that the store is kept in a
909 consistent state, and allowing built packages to be shared among users.
912 When @command{guix-daemon} runs as @code{root}, you may not want package
913 build processes themselves to run as @code{root} too, for obvious
914 security reasons. To avoid that, a special pool of @dfn{build users}
915 should be created for use by build processes started by the daemon.
916 These build users need not have a shell and a home directory: they will
917 just be used when the daemon drops @code{root} privileges in build
918 processes. Having several such users allows the daemon to launch
919 distinct build processes under separate UIDs, which guarantees that they
920 do not interfere with each other---an essential feature since builds are
921 regarded as pure functions (@pxref{Introduction}).
923 On a GNU/Linux system, a build user pool may be created like this (using
924 Bash syntax and the @code{shadow} commands):
926 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
927 @c for why `-G' is needed.
929 # groupadd --system guixbuild
930 # for i in `seq -w 1 10`;
932 useradd -g guixbuild -G guixbuild \
933 -d /var/empty -s `which nologin` \
934 -c "Guix build user $i" --system \
940 The number of build users determines how many build jobs may run in
941 parallel, as specified by the @option{--max-jobs} option
942 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
943 @command{guix system vm} and related commands, you may need to add the
944 build users to the @code{kvm} group so they can access @file{/dev/kvm},
945 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
946 (@pxref{Invoking guix system}).
948 The @code{guix-daemon} program may then be run as @code{root} with the
949 following command@footnote{If your machine uses the systemd init system,
950 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
951 file in @file{/etc/systemd/system} will ensure that
952 @command{guix-daemon} is automatically started. Similarly, if your
953 machine uses the Upstart init system, drop the
954 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
955 file in @file{/etc/init}.}:
958 # guix-daemon --build-users-group=guixbuild
963 This way, the daemon starts build processes in a chroot, under one of
964 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
965 environment contains nothing but:
967 @c Keep this list in sync with libstore/build.cc! -----------------------
970 a minimal @code{/dev} directory, created mostly independently from the
971 host @code{/dev}@footnote{``Mostly'', because while the set of files
972 that appear in the chroot's @code{/dev} is fixed, most of these files
973 can only be created if the host has them.};
976 the @code{/proc} directory; it only shows the processes of the container
977 since a separate PID name space is used;
980 @file{/etc/passwd} with an entry for the current user and an entry for
984 @file{/etc/group} with an entry for the user's group;
987 @file{/etc/hosts} with an entry that maps @code{localhost} to
991 a writable @file{/tmp} directory.
994 You can influence the directory where the daemon stores build trees
995 @i{via} the @code{TMPDIR} environment variable. However, the build tree
996 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
997 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
998 This way, the value of @code{TMPDIR} does not leak inside build
999 environments, which avoids discrepancies in cases where build processes
1000 capture the name of their build tree.
1003 The daemon also honors the @code{http_proxy} environment variable for
1004 HTTP downloads it performs, be it for fixed-output derivations
1005 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1007 If you are installing Guix as an unprivileged user, it is still possible
1008 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1009 However, build processes will not be isolated from one another, and not
1010 from the rest of the system. Thus, build processes may interfere with
1011 each other, and may access programs, libraries, and other files
1012 available on the system---making it much harder to view them as
1013 @emph{pure} functions.
1016 @node Daemon Offload Setup
1017 @subsection Using the Offload Facility
1021 When desired, the build daemon can @dfn{offload} derivation builds to
1022 other machines running Guix, using the @code{offload} @dfn{build
1023 hook}@footnote{This feature is available only when
1024 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1025 present.}. When that
1026 feature is enabled, a list of user-specified build machines is read from
1027 @file{/etc/guix/machines.scm}; every time a build is requested, for
1028 instance via @code{guix build}, the daemon attempts to offload it to one
1029 of the machines that satisfy the constraints of the derivation, in
1030 particular its system type---e.g., @file{x86_64-linux}. Missing
1031 prerequisites for the build are copied over SSH to the target machine,
1032 which then proceeds with the build; upon success the output(s) of the
1033 build are copied back to the initial machine.
1035 The @file{/etc/guix/machines.scm} file typically looks like this:
1038 (list (build-machine
1039 (name "eightysix.example.org")
1040 (system "x86_64-linux")
1041 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1043 (speed 2.)) ;incredibly fast!
1046 (name "meeps.example.org")
1047 (system "mips64el-linux")
1048 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1051 (string-append (getenv "HOME")
1052 "/.ssh/identity-for-guix"))))
1056 In the example above we specify a list of two build machines, one for
1057 the @code{x86_64} architecture and one for the @code{mips64el}
1060 In fact, this file is---not surprisingly!---a Scheme file that is
1061 evaluated when the @code{offload} hook is started. Its return value
1062 must be a list of @code{build-machine} objects. While this example
1063 shows a fixed list of build machines, one could imagine, say, using
1064 DNS-SD to return a list of potential build machines discovered in the
1065 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1066 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1069 @deftp {Data Type} build-machine
1070 This data type represents build machines to which the daemon may offload
1071 builds. The important fields are:
1076 The host name of the remote machine.
1079 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1082 The user account to use when connecting to the remote machine over SSH.
1083 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1084 allow non-interactive logins.
1087 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1088 This is used to authenticate the machine when we connect to it. It is a
1089 long string that looks like this:
1092 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1095 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1096 key can be found in a file such as
1097 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1099 If the machine is running the SSH daemon of GNU@tie{}lsh,
1100 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1101 similar file. It can be converted to the OpenSSH format using
1102 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1105 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1106 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1111 A number of optional fields may be specified:
1115 @item @code{port} (default: @code{22})
1116 Port number of SSH server on the machine.
1118 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1119 The SSH private key file to use when connecting to the machine, in
1120 OpenSSH format. This key must not be protected with a passphrase.
1122 Note that the default value is the private key @emph{of the root
1123 account}. Make sure it exists if you use the default.
1125 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1126 @itemx @code{compression-level} (default: @code{3})
1127 The SSH-level compression methods and compression level requested.
1129 Note that offloading relies on SSH compression to reduce bandwidth usage
1130 when transferring files to and from build machines.
1132 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1133 File name of the Unix-domain socket @command{guix-daemon} is listening
1136 @item @code{parallel-builds} (default: @code{1})
1137 The number of builds that may run in parallel on the machine.
1139 @item @code{speed} (default: @code{1.0})
1140 A ``relative speed factor''. The offload scheduler will tend to prefer
1141 machines with a higher speed factor.
1143 @item @code{features} (default: @code{'()})
1144 A list of strings denoting specific features supported by the machine.
1145 An example is @code{"kvm"} for machines that have the KVM Linux modules
1146 and corresponding hardware support. Derivations can request features by
1147 name, and they will be scheduled on matching build machines.
1152 The @command{guix} command must be in the search path on the build
1153 machines. You can check whether this is the case by running:
1156 ssh build-machine guix repl --version
1159 There is one last thing to do once @file{machines.scm} is in place. As
1160 explained above, when offloading, files are transferred back and forth
1161 between the machine stores. For this to work, you first need to
1162 generate a key pair on each machine to allow the daemon to export signed
1163 archives of files from the store (@pxref{Invoking guix archive}):
1166 # guix archive --generate-key
1170 Each build machine must authorize the key of the master machine so that
1171 it accepts store items it receives from the master:
1174 # guix archive --authorize < master-public-key.txt
1178 Likewise, the master machine must authorize the key of each build machine.
1180 All the fuss with keys is here to express pairwise mutual trust
1181 relations between the master and the build machines. Concretely, when
1182 the master receives files from a build machine (and @i{vice versa}), its
1183 build daemon can make sure they are genuine, have not been tampered
1184 with, and that they are signed by an authorized key.
1186 @cindex offload test
1187 To test whether your setup is operational, run this command on the
1194 This will attempt to connect to each of the build machines specified in
1195 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1196 available on each machine, attempt to export to the machine and import
1197 from it, and report any error in the process.
1199 If you want to test a different machine file, just specify it on the
1203 # guix offload test machines-qualif.scm
1206 Last, you can test the subset of the machines whose name matches a
1207 regular expression like this:
1210 # guix offload test machines.scm '\.gnu\.org$'
1213 @cindex offload status
1214 To display the current load of all build hosts, run this command on the
1218 # guix offload status
1222 @node SELinux Support
1223 @subsection SELinux Support
1225 @cindex SELinux, daemon policy
1226 @cindex mandatory access control, SELinux
1227 @cindex security, guix-daemon
1228 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1229 can be installed on a system where SELinux is enabled, in order to label
1230 Guix files and to specify the expected behavior of the daemon. Since
1231 Guix System does not provide an SELinux base policy, the daemon policy cannot
1232 be used on Guix System.
1234 @subsubsection Installing the SELinux policy
1235 @cindex SELinux, policy installation
1236 To install the policy run this command as root:
1239 semodule -i etc/guix-daemon.cil
1242 Then relabel the file system with @code{restorecon} or by a different
1243 mechanism provided by your system.
1245 Once the policy is installed, the file system has been relabeled, and
1246 the daemon has been restarted, it should be running in the
1247 @code{guix_daemon_t} context. You can confirm this with the following
1251 ps -Zax | grep guix-daemon
1254 Monitor the SELinux log files as you run a command like @code{guix build
1255 hello} to convince yourself that SELinux permits all necessary
1258 @subsubsection Limitations
1259 @cindex SELinux, limitations
1261 This policy is not perfect. Here is a list of limitations or quirks
1262 that should be considered when deploying the provided SELinux policy for
1267 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1268 operations involve contexts that have anything to do with
1269 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1270 but it would be preferrable to define socket rules for only this label.
1273 @code{guix gc} cannot access arbitrary links to profiles. By design,
1274 the file label of the destination of a symlink is independent of the
1275 file label of the link itself. Although all profiles under
1276 $localstatedir are labelled, the links to these profiles inherit the
1277 label of the directory they are in. For links in the user’s home
1278 directory this will be @code{user_home_t}. But for links from the root
1279 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1280 directory, etc, this won’t work. @code{guix gc} would be prevented from
1281 reading and following these links.
1284 The daemon’s feature to listen for TCP connections might no longer work.
1285 This might require extra rules, because SELinux treats network sockets
1286 differently from files.
1289 Currently all files with a name matching the regular expression
1290 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1291 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1292 that name in any profile would be permitted to run in the
1293 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1294 build a package that provides this executable and convince a user to
1295 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1296 At that point SELinux could not prevent it from accessing files that are
1297 allowed for processes in that domain.
1299 We could generate a much more restrictive policy at installation time,
1300 so that only the @emph{exact} file name of the currently installed
1301 @code{guix-daemon} executable would be labelled with
1302 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1303 The downside is that root would have to install or upgrade the policy at
1304 installation time whenever the Guix package that provides the
1305 effectively running @code{guix-daemon} executable is upgraded.
1308 @node Invoking guix-daemon
1309 @section Invoking @command{guix-daemon}
1311 The @command{guix-daemon} program implements all the functionality to
1312 access the store. This includes launching build processes, running the
1313 garbage collector, querying the availability of a build result, etc. It
1314 is normally run as @code{root} like this:
1317 # guix-daemon --build-users-group=guixbuild
1321 For details on how to set it up, @pxref{Setting Up the Daemon}.
1324 @cindex container, build environment
1325 @cindex build environment
1326 @cindex reproducible builds
1327 By default, @command{guix-daemon} launches build processes under
1328 different UIDs, taken from the build group specified with
1329 @code{--build-users-group}. In addition, each build process is run in a
1330 chroot environment that only contains the subset of the store that the
1331 build process depends on, as specified by its derivation
1332 (@pxref{Programming Interface, derivation}), plus a set of specific
1333 system directories. By default, the latter contains @file{/dev} and
1334 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1335 @dfn{container}: in addition to having its own file system tree, it has
1336 a separate mount name space, its own PID name space, network name space,
1337 etc. This helps achieve reproducible builds (@pxref{Features}).
1339 When the daemon performs a build on behalf of the user, it creates a
1340 build directory under @file{/tmp} or under the directory specified by
1341 its @code{TMPDIR} environment variable. This directory is shared with
1342 the container for the duration of the build, though within the container,
1343 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1345 The build directory is automatically deleted upon completion, unless the
1346 build failed and the client specified @option{--keep-failed}
1347 (@pxref{Invoking guix build, @option{--keep-failed}}).
1349 The daemon listens for connections and spawns one sub-process for each session
1350 started by a client (one of the @command{guix} sub-commands.) The
1351 @command{guix processes} command allows you to get an overview of the activity
1352 on your system by viewing each of the active sessions and clients.
1353 @xref{Invoking guix processes}, for more information.
1355 The following command-line options are supported:
1358 @item --build-users-group=@var{group}
1359 Take users from @var{group} to run build processes (@pxref{Setting Up
1360 the Daemon, build users}).
1362 @item --no-substitutes
1364 Do not use substitutes for build products. That is, always build things
1365 locally instead of allowing downloads of pre-built binaries
1366 (@pxref{Substitutes}).
1368 When the daemon runs with @code{--no-substitutes}, clients can still
1369 explicitly enable substitution @i{via} the @code{set-build-options}
1370 remote procedure call (@pxref{The Store}).
1372 @item --substitute-urls=@var{urls}
1373 @anchor{daemon-substitute-urls}
1374 Consider @var{urls} the default whitespace-separated list of substitute
1375 source URLs. When this option is omitted,
1376 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1378 This means that substitutes may be downloaded from @var{urls}, as long
1379 as they are signed by a trusted signature (@pxref{Substitutes}).
1383 Do not use offload builds to other machines (@pxref{Daemon Offload
1384 Setup}). That is, always build things locally instead of offloading
1385 builds to remote machines.
1387 @item --cache-failures
1388 Cache build failures. By default, only successful builds are cached.
1390 When this option is used, @command{guix gc --list-failures} can be used
1391 to query the set of store items marked as failed; @command{guix gc
1392 --clear-failures} removes store items from the set of cached failures.
1393 @xref{Invoking guix gc}.
1395 @item --cores=@var{n}
1397 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1400 The default value is @code{0}, but it may be overridden by clients, such
1401 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1404 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1405 in the build process, which can then use it to exploit internal
1406 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1408 @item --max-jobs=@var{n}
1410 Allow at most @var{n} build jobs in parallel. The default value is
1411 @code{1}. Setting it to @code{0} means that no builds will be performed
1412 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1413 Setup}), or simply fail.
1415 @item --max-silent-time=@var{seconds}
1416 When the build or substitution process remains silent for more than
1417 @var{seconds}, terminate it and report a build failure.
1419 The default value is @code{0}, which disables the timeout.
1421 The value specified here can be overridden by clients (@pxref{Common
1422 Build Options, @code{--max-silent-time}}).
1424 @item --timeout=@var{seconds}
1425 Likewise, when the build or substitution process lasts for more than
1426 @var{seconds}, terminate it and report a build failure.
1428 The default value is @code{0}, which disables the timeout.
1430 The value specified here can be overridden by clients (@pxref{Common
1431 Build Options, @code{--timeout}}).
1433 @item --rounds=@var{N}
1434 Build each derivation @var{n} times in a row, and raise an error if
1435 consecutive build results are not bit-for-bit identical. Note that this
1436 setting can be overridden by clients such as @command{guix build}
1437 (@pxref{Invoking guix build}).
1439 When used in conjunction with @option{--keep-failed}, the differing
1440 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1441 This makes it easy to look for differences between the two results.
1444 Produce debugging output.
1446 This is useful to debug daemon start-up issues, but then it may be
1447 overridden by clients, for example the @code{--verbosity} option of
1448 @command{guix build} (@pxref{Invoking guix build}).
1450 @item --chroot-directory=@var{dir}
1451 Add @var{dir} to the build chroot.
1453 Doing this may change the result of build processes---for instance if
1454 they use optional dependencies found in @var{dir} when it is available,
1455 and not otherwise. For that reason, it is not recommended to do so.
1456 Instead, make sure that each derivation declares all the inputs that it
1459 @item --disable-chroot
1460 Disable chroot builds.
1462 Using this option is not recommended since, again, it would allow build
1463 processes to gain access to undeclared dependencies. It is necessary,
1464 though, when @command{guix-daemon} is running under an unprivileged user
1467 @item --log-compression=@var{type}
1468 Compress build logs according to @var{type}, one of @code{gzip},
1469 @code{bzip2}, or @code{none}.
1471 Unless @code{--lose-logs} is used, all the build logs are kept in the
1472 @var{localstatedir}. To save space, the daemon automatically compresses
1473 them with bzip2 by default.
1475 @item --disable-deduplication
1476 @cindex deduplication
1477 Disable automatic file ``deduplication'' in the store.
1479 By default, files added to the store are automatically ``deduplicated'':
1480 if a newly added file is identical to another one found in the store,
1481 the daemon makes the new file a hard link to the other file. This can
1482 noticeably reduce disk usage, at the expense of slightly increased
1483 input/output load at the end of a build process. This option disables
1486 @item --gc-keep-outputs[=yes|no]
1487 Tell whether the garbage collector (GC) must keep outputs of live
1491 @cindex garbage collector roots
1492 When set to ``yes'', the GC will keep the outputs of any live derivation
1493 available in the store---the @code{.drv} files. The default is ``no'',
1494 meaning that derivation outputs are kept only if they are reachable from a GC
1495 root. @xref{Invoking guix gc}, for more on GC roots.
1497 @item --gc-keep-derivations[=yes|no]
1498 Tell whether the garbage collector (GC) must keep derivations
1499 corresponding to live outputs.
1501 When set to ``yes'', as is the case by default, the GC keeps
1502 derivations---i.e., @code{.drv} files---as long as at least one of their
1503 outputs is live. This allows users to keep track of the origins of
1504 items in their store. Setting it to ``no'' saves a bit of disk space.
1506 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1507 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1508 ``yes'' causes liveness to flow from derivations to outputs. When both are
1509 set to ``yes'', the effect is to keep all the build prerequisites (the
1510 sources, compiler, libraries, and other build-time tools) of live objects in
1511 the store, regardless of whether these prerequisites are reachable from a GC
1512 root. This is convenient for developers since it saves rebuilds or downloads.
1514 @item --impersonate-linux-2.6
1515 On Linux-based systems, impersonate Linux 2.6. This means that the
1516 kernel's @code{uname} system call will report 2.6 as the release number.
1518 This might be helpful to build programs that (usually wrongfully) depend
1519 on the kernel version number.
1522 Do not keep build logs. By default they are kept under
1523 @code{@var{localstatedir}/guix/log}.
1525 @item --system=@var{system}
1526 Assume @var{system} as the current system type. By default it is the
1527 architecture/kernel pair found at configure time, such as
1528 @code{x86_64-linux}.
1530 @item --listen=@var{endpoint}
1531 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1532 as the file name of a Unix-domain socket if it starts with
1533 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1534 host name or host name and port to listen to. Here are a few examples:
1537 @item --listen=/gnu/var/daemon
1538 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1539 creating it if needed.
1541 @item --listen=localhost
1542 @cindex daemon, remote access
1543 @cindex remote access to the daemon
1544 @cindex daemon, cluster setup
1545 @cindex clusters, daemon setup
1546 Listen for TCP connections on the network interface corresponding to
1547 @code{localhost}, on port 44146.
1549 @item --listen=128.0.0.42:1234
1550 Listen for TCP connections on the network interface corresponding to
1551 @code{128.0.0.42}, on port 1234.
1554 This option can be repeated multiple times, in which case
1555 @command{guix-daemon} accepts connections on all the specified
1556 endpoints. Users can tell client commands what endpoint to connect to
1557 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1558 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1561 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1562 @code{--listen=@var{host}} is suitable on local networks, such as
1563 clusters, where only trusted nodes may connect to the build daemon. In
1564 other cases where remote access to the daemon is needed, we recommend
1565 using Unix-domain sockets along with SSH.
1568 When @code{--listen} is omitted, @command{guix-daemon} listens for
1569 connections on the Unix-domain socket located at
1570 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1574 @node Application Setup
1575 @section Application Setup
1577 @cindex foreign distro
1578 When using Guix on top of GNU/Linux distribution other than Guix System---a
1579 so-called @dfn{foreign distro}---a few additional steps are needed to
1580 get everything in place. Here are some of them.
1584 @anchor{locales-and-locpath}
1585 @cindex locales, when not on Guix System
1587 @vindex GUIX_LOCPATH
1588 Packages installed @i{via} Guix will not use the locale data of the
1589 host system. Instead, you must first install one of the locale packages
1590 available with Guix and then define the @code{GUIX_LOCPATH} environment
1594 $ guix install glibc-locales
1595 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1598 Note that the @code{glibc-locales} package contains data for all the
1599 locales supported by the GNU@tie{}libc and weighs in at around
1600 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1601 limited to a few UTF-8 locales.
1603 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1604 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1605 Manual}). There are two important differences though:
1609 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1610 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1611 to make sure the programs of the foreign distro will not end up loading
1612 incompatible locale data.
1615 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1616 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1617 should your Guix profile contain a mixture of programs linked against
1618 different libc version, each libc version will only try to load locale
1619 data in the right format.
1622 This is important because the locale data format used by different libc
1623 versions may be incompatible.
1625 @subsection Name Service Switch
1627 @cindex name service switch, glibc
1628 @cindex NSS (name service switch), glibc
1629 @cindex nscd (name service caching daemon)
1630 @cindex name service caching daemon (nscd)
1631 When using Guix on a foreign distro, we @emph{strongly recommend} that
1632 the system run the GNU C library's @dfn{name service cache daemon},
1633 @command{nscd}, which should be listening on the
1634 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1635 installed with Guix may fail to look up host names or user accounts, or
1636 may even crash. The next paragraphs explain why.
1638 @cindex @file{nsswitch.conf}
1639 The GNU C library implements a @dfn{name service switch} (NSS), which is
1640 an extensible mechanism for ``name lookups'' in general: host name
1641 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1642 The GNU C Library Reference Manual}).
1644 @cindex Network information service (NIS)
1645 @cindex NIS (Network information service)
1646 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1647 lookup implementations: for example, the @code{nss-mdns} plugin allow
1648 resolution of @code{.local} host names, the @code{nis} plugin allows
1649 user account lookup using the Network information service (NIS), and so
1650 on. These extra ``lookup services'' are configured system-wide in
1651 @file{/etc/nsswitch.conf}, and all the programs running on the system
1652 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1655 When they perform a name lookup---for instance by calling the
1656 @code{getaddrinfo} function in C---applications first try to connect to
1657 the nscd; on success, nscd performs name lookups on their behalf. If
1658 the nscd is not running, then they perform the name lookup by
1659 themselves, by loading the name lookup services into their own address
1660 space and running it. These name lookup services---the
1661 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1662 the host system's C library, rather than from the C library the
1663 application is linked against (the C library coming from Guix).
1665 And this is where the problem is: if your application is linked against
1666 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1667 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1668 likely crash or have its name lookups fail unexpectedly.
1670 Running @command{nscd} on the system, among other advantages, eliminates
1671 this binary incompatibility problem because those @code{libnss_*.so}
1672 files are loaded in the @command{nscd} process, not in applications
1675 @subsection X11 Fonts
1678 The majority of graphical applications use Fontconfig to locate and
1679 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1680 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1681 by default. Thus, to allow graphical applications installed with Guix
1682 to display fonts, you have to install fonts with Guix as well.
1683 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1684 @code{font-gnu-freefont-ttf}.
1686 To display text written in Chinese languages, Japanese, or Korean in
1687 graphical applications, consider installing
1688 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1689 has multiple outputs, one per language family (@pxref{Packages with
1690 Multiple Outputs}). For instance, the following command installs fonts
1691 for Chinese languages:
1694 guix install font-adobe-source-han-sans:cn
1697 @cindex @code{xterm}
1698 Older programs such as @command{xterm} do not use Fontconfig and instead
1699 rely on server-side font rendering. Such programs require to specify a
1700 full name of a font using XLFD (X Logical Font Description), like this:
1703 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1706 To be able to use such full names for the TrueType fonts installed in
1707 your Guix profile, you need to extend the font path of the X server:
1709 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1710 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1712 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1715 @cindex @code{xlsfonts}
1716 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1717 to make sure your TrueType fonts are listed there.
1719 @cindex @code{fc-cache}
1721 After installing fonts you may have to refresh the font cache to use
1722 them in applications. The same applies when applications installed via
1723 Guix do not seem to find fonts. To force rebuilding of the font cache
1724 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1725 the @code{fontconfig} package.
1727 @subsection X.509 Certificates
1729 @cindex @code{nss-certs}
1730 The @code{nss-certs} package provides X.509 certificates, which allow
1731 programs to authenticate Web servers accessed over HTTPS.
1733 When using Guix on a foreign distro, you can install this package and
1734 define the relevant environment variables so that packages know where to
1735 look for certificates. @xref{X.509 Certificates}, for detailed
1738 @subsection Emacs Packages
1740 @cindex @code{emacs}
1741 When you install Emacs packages with Guix, the Elisp files are placed
1742 under the @file{share/emacs/site-lisp/} directory of the profile in
1743 which they are installed. The Elisp libraries are made available to
1744 Emacs through the @code{EMACSLOADPATH} environment variable, which is
1745 set when installing Emacs itself.
1747 Additionally, autoload definitions are automatically evaluated at the
1748 initialization of Emacs, by the Guix-specific
1749 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1750 want to avoid auto-loading the Emacs packages installed with Guix, you
1751 can do so by running Emacs with the @code{--no-site-file} option
1752 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1754 @subsection The GCC toolchain
1759 Guix offers individual compiler packages such as @code{gcc} but if you
1760 are in need of a complete toolchain for compiling and linking source
1761 code what you really want is the @code{gcc-toolchain} package. This
1762 package provides a complete GCC toolchain for C/C++ development,
1763 including GCC itself, the GNU C Library (headers and binaries, plus
1764 debugging symbols in the @code{debug} output), Binutils, and a linker
1767 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1768 passed to the linker, add corresponding @code{-rpath} arguments, and
1769 invoke the actual linker with this new set of arguments. You can instruct the
1770 wrapper to refuse to link against libraries not in the store by setting the
1771 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1773 @node Upgrading Guix
1774 @section Upgrading Guix
1776 @cindex Upgrading Guix, on a foreign distro
1778 To upgrade Guix, run:
1784 @xref{Invoking guix pull}, for more information.
1786 @cindex upgrading Guix for the root user, on a foreign distro
1787 @cindex upgrading the Guix daemon, on a foreign distro
1788 @cindex @command{guix pull} for the root user, on a foreign distro
1790 On a foreign distro, you can upgrade the build daemon by running:
1797 followed by (assuming your distro uses the systemd service management
1801 systemctl restart guix-daemon.service
1804 On Guix System, upgrading the daemon is achieved by reconfiguring the
1805 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1809 @c *********************************************************************
1810 @node System Installation
1811 @chapter System Installation
1813 @cindex installing Guix System
1814 @cindex Guix System, installation
1815 This section explains how to install Guix System
1816 on a machine. Guix, as a package manager, can
1817 also be installed on top of a running GNU/Linux system,
1818 @pxref{Installation}.
1822 @c This paragraph is for people reading this from tty2 of the
1823 @c installation image.
1824 You are reading this documentation with an Info reader. For details on
1825 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1826 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1827 Info}. Hit @kbd{l} afterwards to come back here.
1829 Alternately, run @command{info info} in another tty to keep the manual
1835 * Limitations:: What you can expect.
1836 * Hardware Considerations:: Supported hardware.
1837 * USB Stick and DVD Installation:: Preparing the installation medium.
1838 * Preparing for Installation:: Networking, partitioning, etc.
1839 * Guided Graphical Installation:: Easy graphical installation.
1840 * Manual Installation:: Manual installation for wizards.
1841 * After System Installation:: When installation succeeded.
1842 * Installing Guix in a VM:: Guix System playground.
1843 * Building the Installation Image:: How this comes to be.
1847 @section Limitations
1849 We consider Guix System to be ready for a wide range of ``desktop'' and server
1850 use cases. The reliability guarantees it provides---transactional upgrades
1851 and rollbacks, reproducibility---make it a solid foundation.
1853 Nevertheless, before you proceed with the installation, be aware of the
1854 following noteworthy limitations applicable to version @value{VERSION}:
1858 Support for the Logical Volume Manager (LVM) is missing.
1861 More and more system services are provided (@pxref{Services}), but some
1865 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1866 as well as a number of X11 window managers. However, KDE is currently
1870 More than a disclaimer, this is an invitation to report issues (and success
1871 stories!), and to join us in improving it. @xref{Contributing}, for more
1875 @node Hardware Considerations
1876 @section Hardware Considerations
1878 @cindex hardware support on Guix System
1879 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1880 builds around the kernel Linux-libre, which means that only hardware for
1881 which free software drivers and firmware exist is supported. Nowadays,
1882 a wide range of off-the-shelf hardware is supported on
1883 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1884 Ethernet controllers. Unfortunately, there are still areas where
1885 hardware vendors deny users control over their own computing, and such
1886 hardware is not supported on Guix System.
1888 @cindex WiFi, hardware support
1889 One of the main areas where free drivers or firmware are lacking is WiFi
1890 devices. WiFi devices known to work include those using Atheros chips
1891 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1892 driver, and those using Broadcom/AirForce chips (BCM43xx with
1893 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1894 Linux-libre driver. Free firmware exists for both and is available
1895 out-of-the-box on Guix System, as part of @code{%base-firmware}
1896 (@pxref{operating-system Reference, @code{firmware}}).
1898 @cindex RYF, Respects Your Freedom
1899 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1900 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1901 certification program for hardware products that respect your freedom
1902 and your privacy and ensure that you have control over your device. We
1903 encourage you to check the list of RYF-certified devices.
1905 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1906 web site. It contains a catalog of hardware devices with information
1907 about their support in GNU/Linux.
1910 @node USB Stick and DVD Installation
1911 @section USB Stick and DVD Installation
1913 An ISO-9660 installation image that can be written to a USB stick or
1914 burnt to a DVD can be downloaded from
1915 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1916 where @var{system} is one of:
1920 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1923 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1926 @c start duplication of authentication part from ``Binary Installation''
1927 Make sure to download the associated @file{.sig} file and to verify the
1928 authenticity of the image against it, along these lines:
1931 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1932 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1935 If that command fails because you do not have the required public key,
1936 then run this command to import it:
1939 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1940 -qO - | gpg --import -
1944 and rerun the @code{gpg --verify} command.
1946 Take note that a warning like ``This key is not certified with a trusted
1947 signature!'' is normal.
1951 This image contains the tools necessary for an installation.
1952 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1954 @unnumberedsubsec Copying to a USB Stick
1956 To copy the image to a USB stick, follow these steps:
1960 Decompress the image using the @command{xz} command:
1963 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1967 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1968 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1969 copy the image with:
1972 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1976 Access to @file{/dev/sdX} usually requires root privileges.
1979 @unnumberedsubsec Burning on a DVD
1981 To copy the image to a DVD, follow these steps:
1985 Decompress the image using the @command{xz} command:
1988 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1992 Insert a blank DVD into your machine, and determine
1993 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1994 copy the image with:
1997 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
2000 Access to @file{/dev/srX} usually requires root privileges.
2003 @unnumberedsubsec Booting
2005 Once this is done, you should be able to reboot the system and boot from
2006 the USB stick or DVD. The latter usually requires you to get in the
2007 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2008 In order to boot from Libreboot, switch to the command mode by pressing
2009 the @kbd{c} key and type @command{search_grub usb}.
2011 @xref{Installing Guix in a VM}, if, instead, you would like to install
2012 Guix System in a virtual machine (VM).
2015 @node Preparing for Installation
2016 @section Preparing for Installation
2018 Once you have booted, you can use the guided graphical installer, which makes
2019 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2020 if you are already familiar with GNU/Linux and if you want more control than
2021 what the graphical installer provides, you can choose the ``manual''
2022 installation process (@pxref{Manual Installation}).
2024 The graphical installer is available on TTY1. You can obtain root shells on
2025 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2026 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2027 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2028 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2029 which allows you to select text with the left mouse button and to paste it
2030 with the middle button.
2033 Installation requires access to the Internet so that any missing
2034 dependencies of your system configuration can be downloaded. See the
2035 ``Networking'' section below.
2038 @node Guided Graphical Installation
2039 @section Guided Graphical Installation
2041 The graphical installer is a text-based user interface. It will guide you,
2042 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2044 The first dialog boxes allow you to set up the system as you use it during the
2045 installation: you can choose the language, keyboard layout, and set up
2046 networking, which will be used during the installation. The image below shows
2047 the networking dialog.
2049 @image{images/installer-network,5in,, networking setup with the graphical installer}
2051 Later steps allow you to partition your hard disk, as shown in the image
2052 below, to choose whether or not to use encrypted file systems, to enter the
2053 host name and root password, and to create an additional account, among other
2056 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2058 Note that, at any time, the installer allows you to exit the current
2059 installation step and resume at a previous step, as show in the image below.
2061 @image{images/installer-resume,5in,, resuming the installation process}
2063 Once you're done, the installer produces an operating system configuration and
2064 displays it (@pxref{Using the Configuration System}). At that point you can
2065 hit ``OK'' and installation will proceed. On success, you can reboot into the
2066 new system and enjoy. @xref{After System Installation}, for what's next!
2069 @node Manual Installation
2070 @section Manual Installation
2072 This section describes how you would ``manually'' install GNU@tie{}Guix System
2073 on your machine. This option requires familiarity with GNU/Linux, with the
2074 shell, and with common administration tools. If you think this is not for
2075 you, consider using the guided graphical installer (@pxref{Guided Graphical
2078 The installation system provides root shells on TTYs 3 to 6; press
2079 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2080 many common tools needed to install the system. But it is also a full-blown
2081 Guix System, which means that you can install additional packages, should you
2082 need it, using @command{guix package} (@pxref{Invoking guix package}).
2085 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2086 * Proceeding with the Installation:: Installing.
2089 @node Keyboard Layout and Networking and Partitioning
2090 @subsection Keyboard Layout, Networking, and Partitioning
2092 Before you can install the system, you may want to adjust the keyboard layout,
2093 set up networking, and partition your target hard disk. This section will
2094 guide you through this.
2096 @subsubsection Keyboard Layout
2098 @cindex keyboard layout
2099 The installation image uses the US qwerty keyboard layout. If you want
2100 to change it, you can use the @command{loadkeys} command. For example,
2101 the following command selects the Dvorak keyboard layout:
2107 See the files under @file{/run/current-system/profile/share/keymaps} for
2108 a list of available keyboard layouts. Run @command{man loadkeys} for
2111 @subsubsection Networking
2113 Run the following command to see what your network interfaces are called:
2120 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2126 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2127 Wired interfaces have a name starting with @samp{e}; for example, the
2128 interface corresponding to the first on-board Ethernet controller is
2129 called @samp{eno1}. Wireless interfaces have a name starting with
2130 @samp{w}, like @samp{w1p2s0}.
2133 @item Wired connection
2134 To configure a wired network run the following command, substituting
2135 @var{interface} with the name of the wired interface you want to use.
2138 ifconfig @var{interface} up
2142 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2145 ip link set @var{interface} up
2148 @item Wireless connection
2151 To configure wireless networking, you can create a configuration file
2152 for the @command{wpa_supplicant} configuration tool (its location is not
2153 important) using one of the available text editors such as
2157 nano wpa_supplicant.conf
2160 As an example, the following stanza can go to this file and will work
2161 for many wireless networks, provided you give the actual SSID and
2162 passphrase for the network you are connecting to:
2166 ssid="@var{my-ssid}"
2168 psk="the network's secret passphrase"
2172 Start the wireless service and run it in the background with the
2173 following command (substitute @var{interface} with the name of the
2174 network interface you want to use):
2177 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2180 Run @command{man wpa_supplicant} for more information.
2184 At this point, you need to acquire an IP address. On a network where IP
2185 addresses are automatically assigned @i{via} DHCP, you can run:
2188 dhclient -v @var{interface}
2191 Try to ping a server to see if networking is up and running:
2197 Setting up network access is almost always a requirement because the
2198 image does not contain all the software and tools that may be needed.
2200 @cindex installing over SSH
2201 If you want to, you can continue the installation remotely by starting
2205 herd start ssh-daemon
2208 Make sure to either set a password with @command{passwd}, or configure
2209 OpenSSH public key authentication before logging in.
2211 @subsubsection Disk Partitioning
2213 Unless this has already been done, the next step is to partition, and
2214 then format the target partition(s).
2216 The installation image includes several partitioning tools, including
2217 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2218 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2219 the partition layout you want:
2225 If your disk uses the GUID Partition Table (GPT) format and you plan to
2226 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2227 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2230 @cindex EFI, installation
2231 @cindex UEFI, installation
2232 @cindex ESP, EFI system partition
2233 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2234 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2235 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2238 parted /dev/sda set 1 esp on
2242 @vindex grub-bootloader
2243 @vindex grub-efi-bootloader
2244 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2245 @file{/sys/firmware/efi} exists in the installation image, then you should
2246 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2247 Otherwise you should use the BIOS-based GRUB, known as
2248 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2252 Once you are done partitioning the target hard disk drive, you have to
2253 create a file system on the relevant partition(s)@footnote{Currently
2254 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2255 code that reads file system UUIDs and labels only works for these file system
2256 types.}. For the ESP, if you have one and assuming it is
2257 @file{/dev/sda1}, run:
2260 mkfs.fat -F32 /dev/sda1
2263 Preferably, assign file systems a label so that you can easily and
2264 reliably refer to them in @code{file-system} declarations (@pxref{File
2265 Systems}). This is typically done using the @code{-L} option of
2266 @command{mkfs.ext4} and related commands. So, assuming the target root
2267 partition lives at @file{/dev/sda2}, a file system with the label
2268 @code{my-root} can be created with:
2271 mkfs.ext4 -L my-root /dev/sda2
2274 @cindex encrypted disk
2275 If you are instead planning to encrypt the root partition, you can use
2276 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2277 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2278 @code{man cryptsetup}} for more information.) Assuming you want to
2279 store the root partition on @file{/dev/sda2}, the command sequence would
2280 be along these lines:
2283 cryptsetup luksFormat /dev/sda2
2284 cryptsetup open --type luks /dev/sda2 my-partition
2285 mkfs.ext4 -L my-root /dev/mapper/my-partition
2288 Once that is done, mount the target file system under @file{/mnt}
2289 with a command like (again, assuming @code{my-root} is the label of the
2293 mount LABEL=my-root /mnt
2296 Also mount any other file systems you would like to use on the target
2297 system relative to this path. If you have opted for @file{/boot/efi} as an
2298 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2299 found by @code{guix system init} afterwards.
2301 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2302 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2303 sure to initialize them with @command{mkswap}. Assuming you have one
2304 swap partition on @file{/dev/sda3}, you would run:
2311 Alternatively, you may use a swap file. For example, assuming that in
2312 the new system you want to use the file @file{/swapfile} as a swap file,
2313 you would run@footnote{This example will work for many types of file
2314 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2315 btrfs), the required steps may be different. For details, see the
2316 manual pages for @command{mkswap} and @command{swapon}.}:
2319 # This is 10 GiB of swap space. Adjust "count" to change the size.
2320 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2321 # For security, make the file readable and writable only by root.
2322 chmod 600 /mnt/swapfile
2323 mkswap /mnt/swapfile
2324 swapon /mnt/swapfile
2327 Note that if you have encrypted the root partition and created a swap
2328 file in its file system as described above, then the encryption also
2329 protects the swap file, just like any other file in that file system.
2331 @node Proceeding with the Installation
2332 @subsection Proceeding with the Installation
2334 With the target partitions ready and the target root mounted on
2335 @file{/mnt}, we're ready to go. First, run:
2338 herd start cow-store /mnt
2341 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2342 during the installation phase are written to the target disk on @file{/mnt}
2343 rather than kept in memory. This is necessary because the first phase of
2344 the @command{guix system init} command (see below) entails downloads or
2345 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2347 Next, you have to edit a file and
2348 provide the declaration of the operating system to be installed. To
2349 that end, the installation system comes with three text editors. We
2350 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2351 supports syntax highlighting and parentheses matching; other editors
2352 include GNU Zile (an Emacs clone), and
2353 nvi (a clone of the original BSD @command{vi} editor).
2354 We strongly recommend storing that file on the target root file system, say,
2355 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2356 configuration file once you have rebooted into the newly-installed system.
2358 @xref{Using the Configuration System}, for an overview of the
2359 configuration file. The example configurations discussed in that
2360 section are available under @file{/etc/configuration} in the
2361 installation image. Thus, to get started with a system configuration
2362 providing a graphical display server (a ``desktop'' system), you can run
2363 something along these lines:
2367 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2368 # nano /mnt/etc/config.scm
2371 You should pay attention to what your configuration file contains, and
2376 Make sure the @code{bootloader-configuration} form refers to the target
2377 you want to install GRUB on. It should mention @code{grub-bootloader} if
2378 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2379 for newer UEFI systems. For legacy systems, the @code{target} field
2380 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2381 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2382 currently mounted and a @code{file-system} entry is specified in your
2386 Be sure that your file system labels match the value of their respective
2387 @code{device} fields in your @code{file-system} configuration, assuming
2388 your @code{file-system} configuration uses the @code{file-system-label}
2389 procedure in its @code{device} field.
2392 If there are encrypted or RAID partitions, make sure to add a
2393 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2396 Once you are done preparing the configuration file, the new system must
2397 be initialized (remember that the target root file system is mounted
2401 guix system init /mnt/etc/config.scm /mnt
2405 This copies all the necessary files and installs GRUB on
2406 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2407 more information, @pxref{Invoking guix system}. This command may trigger
2408 downloads or builds of missing packages, which can take some time.
2410 Once that command has completed---and hopefully succeeded!---you can run
2411 @command{reboot} and boot into the new system. The @code{root} password
2412 in the new system is initially empty; other users' passwords need to be
2413 initialized by running the @command{passwd} command as @code{root},
2414 unless your configuration specifies otherwise
2415 (@pxref{user-account-password, user account passwords}).
2416 @xref{After System Installation}, for what's next!
2419 @node After System Installation
2420 @section After System Installation
2422 Success, you've now booted into Guix System! From then on, you can update the
2423 system whenever you want by running, say:
2427 sudo guix system reconfigure /etc/config.scm
2431 This builds a new system generation with the latest packages and services
2432 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2433 your system includes the latest security updates (@pxref{Security Updates}).
2435 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2437 @cindex sudo vs. @command{guix pull}
2438 Note that @command{sudo guix} runs your user's @command{guix} command and
2439 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2440 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2442 The difference matters here, because @command{guix pull} updates
2443 the @command{guix} command and package definitions only for the user it is ran
2444 as. This means that if you choose to use @command{guix system reconfigure} in
2445 root's login shell, you'll need to @command{guix pull} separately.
2448 Join us on @code{#guix} on the Freenode IRC network or on
2449 @email{guix-devel@@gnu.org} to share your experience!
2452 @node Installing Guix in a VM
2453 @section Installing Guix in a Virtual Machine
2455 @cindex virtual machine, Guix System installation
2456 @cindex virtual private server (VPS)
2457 @cindex VPS (virtual private server)
2458 If you'd like to install Guix System in a virtual machine (VM) or on a
2459 virtual private server (VPS) rather than on your beloved machine, this
2462 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2463 disk image, follow these steps:
2467 First, retrieve and decompress the Guix system installation image as
2468 described previously (@pxref{USB Stick and DVD Installation}).
2471 Create a disk image that will hold the installed system. To make a
2472 qcow2-formatted disk image, use the @command{qemu-img} command:
2475 qemu-img create -f qcow2 guix-system.img 50G
2478 The resulting file will be much smaller than 50 GB (typically less than
2479 1 MB), but it will grow as the virtualized storage device is filled up.
2482 Boot the USB installation image in an VM:
2485 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2486 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2487 -drive file=guix-system.img \
2488 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2491 @code{-enable-kvm} is optional, but significantly improves performance,
2492 @pxref{Running Guix in a VM}.
2495 You're now root in the VM, proceed with the installation process.
2496 @xref{Preparing for Installation}, and follow the instructions.
2499 Once installation is complete, you can boot the system that's on your
2500 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2503 @node Building the Installation Image
2504 @section Building the Installation Image
2506 @cindex installation image
2507 The installation image described above was built using the @command{guix
2508 system} command, specifically:
2511 guix system disk-image --file-system-type=iso9660 \
2512 gnu/system/install.scm
2515 Have a look at @file{gnu/system/install.scm} in the source tree,
2516 and see also @ref{Invoking guix system} for more information
2517 about the installation image.
2519 @section Building the Installation Image for ARM Boards
2521 Many ARM boards require a specific variant of the
2522 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2524 If you build a disk image and the bootloader is not available otherwise
2525 (on another boot drive etc), it's advisable to build an image that
2526 includes the bootloader, specifically:
2529 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2532 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2533 board, a list of possible boards will be printed.
2535 @c *********************************************************************
2536 @node Package Management
2537 @chapter Package Management
2540 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2541 remove software packages, without having to know about their build
2542 procedures or dependencies. Guix also goes beyond this obvious set of
2545 This chapter describes the main features of Guix, as well as the
2546 package management tools it provides. Along with the command-line
2547 interface described below (@pxref{Invoking guix package, @code{guix
2548 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2549 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2550 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2554 guix install emacs-guix
2558 * Features:: How Guix will make your life brighter.
2559 * Invoking guix package:: Package installation, removal, etc.
2560 * Substitutes:: Downloading pre-built binaries.
2561 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2562 * Invoking guix gc:: Running the garbage collector.
2563 * Invoking guix pull:: Fetching the latest Guix and distribution.
2564 * Channels:: Customizing the package collection.
2565 * Invoking guix time-machine:: Running an older revision of Guix.
2566 * Inferiors:: Interacting with another revision of Guix.
2567 * Invoking guix describe:: Display information about your Guix revision.
2568 * Invoking guix archive:: Exporting and importing store files.
2574 When using Guix, each package ends up in the @dfn{package store}, in its
2575 own directory---something that resembles
2576 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2578 Instead of referring to these directories, users have their own
2579 @dfn{profile}, which points to the packages that they actually want to
2580 use. These profiles are stored within each user's home directory, at
2581 @code{$HOME/.guix-profile}.
2583 For example, @code{alice} installs GCC 4.7.2. As a result,
2584 @file{/home/alice/.guix-profile/bin/gcc} points to
2585 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2586 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2587 simply continues to point to
2588 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2589 coexist on the same system without any interference.
2591 The @command{guix package} command is the central tool to manage
2592 packages (@pxref{Invoking guix package}). It operates on the per-user
2593 profiles, and can be used @emph{with normal user privileges}.
2595 @cindex transactions
2596 The command provides the obvious install, remove, and upgrade
2597 operations. Each invocation is actually a @emph{transaction}: either
2598 the specified operation succeeds, or nothing happens. Thus, if the
2599 @command{guix package} process is terminated during the transaction,
2600 or if a power outage occurs during the transaction, then the user's
2601 profile remains in its previous state, and remains usable.
2603 In addition, any package transaction may be @emph{rolled back}. So, if,
2604 for example, an upgrade installs a new version of a package that turns
2605 out to have a serious bug, users may roll back to the previous instance
2606 of their profile, which was known to work well. Similarly, the global
2607 system configuration on Guix is subject to
2608 transactional upgrades and roll-back
2609 (@pxref{Using the Configuration System}).
2611 All packages in the package store may be @emph{garbage-collected}.
2612 Guix can determine which packages are still referenced by user
2613 profiles, and remove those that are provably no longer referenced
2614 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2615 generations of their profile so that the packages they refer to can be
2618 @cindex reproducibility
2619 @cindex reproducible builds
2620 Guix takes a @dfn{purely functional} approach to package
2621 management, as described in the introduction (@pxref{Introduction}).
2622 Each @file{/gnu/store} package directory name contains a hash of all the
2623 inputs that were used to build that package---compiler, libraries, build
2624 scripts, etc. This direct correspondence allows users to make sure a
2625 given package installation matches the current state of their
2626 distribution. It also helps maximize @dfn{build reproducibility}:
2627 thanks to the isolated build environments that are used, a given build
2628 is likely to yield bit-identical files when performed on different
2629 machines (@pxref{Invoking guix-daemon, container}).
2632 This foundation allows Guix to support @dfn{transparent binary/source
2633 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2634 available from an external source---a @dfn{substitute}, Guix just
2635 downloads it and unpacks it;
2636 otherwise, it builds the package from source, locally
2637 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2638 reproducible, users do not have to trust servers that provide
2639 substitutes: they can force a local build and @emph{challenge} providers
2640 (@pxref{Invoking guix challenge}).
2642 Control over the build environment is a feature that is also useful for
2643 developers. The @command{guix environment} command allows developers of
2644 a package to quickly set up the right development environment for their
2645 package, without having to manually install the dependencies of the
2646 package into their profile (@pxref{Invoking guix environment}).
2648 @cindex replication, of software environments
2649 @cindex provenance tracking, of software artifacts
2650 All of Guix and its package definitions is version-controlled, and
2651 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2652 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2653 Guix instance on a different machine or at a later point in time, which in
2654 turn allows you to @emph{replicate complete software environments}, while
2655 retaining precise @dfn{provenance tracking} of the software.
2657 @node Invoking guix package
2658 @section Invoking @command{guix package}
2660 @cindex installing packages
2661 @cindex removing packages
2662 @cindex package installation
2663 @cindex package removal
2664 The @command{guix package} command is the tool that allows users to
2665 install, upgrade, and remove packages, as well as rolling back to
2666 previous configurations. It operates only on the user's own profile,
2667 and works with normal user privileges (@pxref{Features}). Its syntax
2671 guix package @var{options}
2674 @cindex transactions
2675 Primarily, @var{options} specifies the operations to be performed during
2676 the transaction. Upon completion, a new profile is created, but
2677 previous @dfn{generations} of the profile remain available, should the user
2680 For example, to remove @code{lua} and install @code{guile} and
2681 @code{guile-cairo} in a single transaction:
2684 guix package -r lua -i guile guile-cairo
2687 @cindex aliases, for @command{guix package}
2688 For your convenience, we also provide the following aliases:
2692 @command{guix search} is an alias for @command{guix package -s},
2694 @command{guix install} is an alias for @command{guix package -i},
2696 @command{guix remove} is an alias for @command{guix package -r},
2698 @command{guix upgrade} is an alias for @command{guix package -u},
2700 and @command{guix show} is an alias for @command{guix package --show=}.
2703 These aliases are less expressive than @command{guix package} and provide
2704 fewer options, so in some cases you'll probably want to use @command{guix
2707 @command{guix package} also supports a @dfn{declarative approach}
2708 whereby the user specifies the exact set of packages to be available and
2709 passes it @i{via} the @option{--manifest} option
2710 (@pxref{profile-manifest, @option{--manifest}}).
2713 For each user, a symlink to the user's default profile is automatically
2714 created in @file{$HOME/.guix-profile}. This symlink always points to the
2715 current generation of the user's default profile. Thus, users can add
2716 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2717 variable, and so on.
2718 @cindex search paths
2719 If you are not using Guix System, consider adding the
2720 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2721 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2722 shells get all the right environment variable definitions:
2725 GUIX_PROFILE="$HOME/.guix-profile" ; \
2726 source "$HOME/.guix-profile/etc/profile"
2729 In a multi-user setup, user profiles are stored in a place registered as
2730 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2731 to (@pxref{Invoking guix gc}). That directory is normally
2732 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2733 @var{localstatedir} is the value passed to @code{configure} as
2734 @code{--localstatedir}, and @var{user} is the user name. The
2735 @file{per-user} directory is created when @command{guix-daemon} is
2736 started, and the @var{user} sub-directory is created by @command{guix
2739 The @var{options} can be among the following:
2743 @item --install=@var{package} @dots{}
2744 @itemx -i @var{package} @dots{}
2745 Install the specified @var{package}s.
2747 Each @var{package} may specify either a simple package name, such as
2748 @code{guile}, or a package name followed by an at-sign and version number,
2749 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2750 case, the newest version prefixed by @code{1.8} is selected.)
2752 If no version number is specified, the
2753 newest available version will be selected. In addition, @var{package}
2754 may contain a colon, followed by the name of one of the outputs of the
2755 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2756 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2757 name (and optionally version) are searched for among the GNU
2758 distribution modules (@pxref{Package Modules}).
2760 @cindex propagated inputs
2761 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2762 that automatically get installed along with the required package
2763 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2764 @code{package} objects}, for information about propagated inputs in
2765 package definitions).
2767 @anchor{package-cmd-propagated-inputs}
2768 An example is the GNU MPC library: its C header files refer to those of
2769 the GNU MPFR library, which in turn refer to those of the GMP library.
2770 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2771 in the profile; removing MPC also removes MPFR and GMP---unless they had
2772 also been explicitly installed by the user.
2774 Besides, packages sometimes rely on the definition of environment
2775 variables for their search paths (see explanation of
2776 @code{--search-paths} below). Any missing or possibly incorrect
2777 environment variable definitions are reported here.
2779 @item --install-from-expression=@var{exp}
2781 Install the package @var{exp} evaluates to.
2783 @var{exp} must be a Scheme expression that evaluates to a
2784 @code{<package>} object. This option is notably useful to disambiguate
2785 between same-named variants of a package, with expressions such as
2786 @code{(@@ (gnu packages base) guile-final)}.
2788 Note that this option installs the first output of the specified
2789 package, which may be insufficient when needing a specific output of a
2790 multiple-output package.
2792 @item --install-from-file=@var{file}
2793 @itemx -f @var{file}
2794 Install the package that the code within @var{file} evaluates to.
2796 As an example, @var{file} might contain a definition like this
2797 (@pxref{Defining Packages}):
2800 @include package-hello.scm
2803 Developers may find it useful to include such a @file{guix.scm} file
2804 in the root of their project source tree that can be used to test
2805 development snapshots and create reproducible development environments
2806 (@pxref{Invoking guix environment}).
2808 @item --remove=@var{package} @dots{}
2809 @itemx -r @var{package} @dots{}
2810 Remove the specified @var{package}s.
2812 As for @code{--install}, each @var{package} may specify a version number
2813 and/or output name in addition to the package name. For instance,
2814 @code{-r glibc:debug} would remove the @code{debug} output of
2817 @item --upgrade[=@var{regexp} @dots{}]
2818 @itemx -u [@var{regexp} @dots{}]
2819 @cindex upgrading packages
2820 Upgrade all the installed packages. If one or more @var{regexp}s are
2821 specified, upgrade only installed packages whose name matches a
2822 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2824 Note that this upgrades package to the latest version of packages found
2825 in the distribution currently installed. To update your distribution,
2826 you should regularly run @command{guix pull} (@pxref{Invoking guix
2829 @item --do-not-upgrade[=@var{regexp} @dots{}]
2830 When used together with the @code{--upgrade} option, do @emph{not}
2831 upgrade any packages whose name matches a @var{regexp}. For example, to
2832 upgrade all packages in the current profile except those containing the
2833 substring ``emacs'':
2836 $ guix package --upgrade . --do-not-upgrade emacs
2839 @item @anchor{profile-manifest}--manifest=@var{file}
2840 @itemx -m @var{file}
2841 @cindex profile declaration
2842 @cindex profile manifest
2843 Create a new generation of the profile from the manifest object
2844 returned by the Scheme code in @var{file}. This option can be repeated
2845 several times, in which case the manifests are concatenated.
2847 This allows you to @emph{declare} the profile's contents rather than
2848 constructing it through a sequence of @code{--install} and similar
2849 commands. The advantage is that @var{file} can be put under version
2850 control, copied to different machines to reproduce the same profile, and
2853 @c FIXME: Add reference to (guix profile) documentation when available.
2854 @var{file} must return a @dfn{manifest} object, which is roughly a list
2857 @findex packages->manifest
2859 (use-package-modules guile emacs)
2864 ;; Use a specific package output.
2865 (list guile-2.0 "debug")))
2868 @findex specifications->manifest
2869 In this example we have to know which modules define the @code{emacs}
2870 and @code{guile-2.0} variables to provide the right
2871 @code{use-package-modules} line, which can be cumbersome. We can
2872 instead provide regular package specifications and let
2873 @code{specifications->manifest} look up the corresponding package
2877 (specifications->manifest
2878 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2882 @cindex rolling back
2883 @cindex undoing transactions
2884 @cindex transactions, undoing
2885 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2886 the last transaction.
2888 When combined with options such as @code{--install}, roll back occurs
2889 before any other actions.
2891 When rolling back from the first generation that actually contains
2892 installed packages, the profile is made to point to the @dfn{zeroth
2893 generation}, which contains no files apart from its own metadata.
2895 After having rolled back, installing, removing, or upgrading packages
2896 overwrites previous future generations. Thus, the history of the
2897 generations in a profile is always linear.
2899 @item --switch-generation=@var{pattern}
2900 @itemx -S @var{pattern}
2902 Switch to a particular generation defined by @var{pattern}.
2904 @var{pattern} may be either a generation number or a number prefixed
2905 with ``+'' or ``-''. The latter means: move forward/backward by a
2906 specified number of generations. For example, if you want to return to
2907 the latest generation after @code{--roll-back}, use
2908 @code{--switch-generation=+1}.
2910 The difference between @code{--roll-back} and
2911 @code{--switch-generation=-1} is that @code{--switch-generation} will
2912 not make a zeroth generation, so if a specified generation does not
2913 exist, the current generation will not be changed.
2915 @item --search-paths[=@var{kind}]
2916 @cindex search paths
2917 Report environment variable definitions, in Bash syntax, that may be
2918 needed in order to use the set of installed packages. These environment
2919 variables are used to specify @dfn{search paths} for files used by some
2920 of the installed packages.
2922 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2923 environment variables to be defined so it can look for headers and
2924 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2925 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2926 library are installed in the profile, then @code{--search-paths} will
2927 suggest setting these variables to @code{@var{profile}/include} and
2928 @code{@var{profile}/lib}, respectively.
2930 The typical use case is to define these environment variables in the
2934 $ eval `guix package --search-paths`
2937 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2938 meaning that the returned environment variable definitions will either
2939 be exact settings, or prefixes or suffixes of the current value of these
2940 variables. When omitted, @var{kind} defaults to @code{exact}.
2942 This option can also be used to compute the @emph{combined} search paths
2943 of several profiles. Consider this example:
2946 $ guix package -p foo -i guile
2947 $ guix package -p bar -i guile-json
2948 $ guix package -p foo -p bar --search-paths
2951 The last command above reports about the @code{GUILE_LOAD_PATH}
2952 variable, even though, taken individually, neither @file{foo} nor
2953 @file{bar} would lead to that recommendation.
2956 @item --profile=@var{profile}
2957 @itemx -p @var{profile}
2958 Use @var{profile} instead of the user's default profile.
2960 @var{profile} must be the name of a file that will be created upon
2961 completion. Concretely, @var{profile} will be a mere symbolic link
2962 (``symlink'') pointing to the actual profile where packages are
2966 $ guix install hello -p ~/code/my-profile
2968 $ ~/code/my-profile/bin/hello
2972 All it takes to get rid of the profile is to remove this symlink and its
2973 siblings that point to specific generations:
2976 $ rm ~/code/my-profile ~/code/my-profile-*-link
2979 @item --list-profiles
2980 List all the user's profiles:
2983 $ guix package --list-profiles
2984 /home/charlie/.guix-profile
2985 /home/charlie/code/my-profile
2986 /home/charlie/code/devel-profile
2987 /home/charlie/tmp/test
2990 When running as root, list all the profiles of all the users.
2992 @cindex collisions, in a profile
2993 @cindex colliding packages in profiles
2994 @cindex profile collisions
2995 @item --allow-collisions
2996 Allow colliding packages in the new profile. Use at your own risk!
2998 By default, @command{guix package} reports as an error @dfn{collisions}
2999 in the profile. Collisions happen when two or more different versions
3000 or variants of a given package end up in the profile.
3003 Use the bootstrap Guile to build the profile. This option is only
3004 useful to distribution developers.
3008 In addition to these actions, @command{guix package} supports the
3009 following options to query the current state of a profile, or the
3010 availability of packages:
3014 @item --search=@var{regexp}
3015 @itemx -s @var{regexp}
3016 @cindex searching for packages
3017 List the available packages whose name, synopsis, or description matches
3018 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3019 Print all the metadata of matching packages in
3020 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3021 GNU recutils manual}).
3023 This allows specific fields to be extracted using the @command{recsel}
3024 command, for instance:
3027 $ guix package -s malloc | recsel -p name,version,relevance
3041 Similarly, to show the name of all the packages available under the
3042 terms of the GNU@tie{}LGPL version 3:
3045 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3052 It is also possible to refine search results using several @code{-s} flags to
3053 @command{guix package}, or several arguments to @command{guix search}. For
3054 example, the following command returns a list of board games (this time using
3055 the @command{guix search} alias):
3058 $ guix search '\<board\>' game | recsel -p name
3063 If we were to omit @code{-s game}, we would also get software packages
3064 that deal with printed circuit boards; removing the angle brackets
3065 around @code{board} would further add packages that have to do with
3068 And now for a more elaborate example. The following command searches
3069 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3070 libraries, and prints the name and synopsis of the matching packages:
3073 $ guix search crypto library | \
3074 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3078 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3079 information on @dfn{selection expressions} for @code{recsel -e}.
3081 @item --show=@var{package}
3082 Show details about @var{package}, taken from the list of available packages, in
3083 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3087 $ guix package --show=python | recsel -p name,version
3095 You may also specify the full name of a package to only get details about a
3096 specific version of it (this time using the @command{guix show} alias):
3098 $ guix show python@@3.4 | recsel -p name,version
3105 @item --list-installed[=@var{regexp}]
3106 @itemx -I [@var{regexp}]
3107 List the currently installed packages in the specified profile, with the
3108 most recently installed packages shown last. When @var{regexp} is
3109 specified, list only installed packages whose name matches @var{regexp}.
3111 For each installed package, print the following items, separated by
3112 tabs: the package name, its version string, the part of the package that
3113 is installed (for instance, @code{out} for the default output,
3114 @code{include} for its headers, etc.), and the path of this package in
3117 @item --list-available[=@var{regexp}]
3118 @itemx -A [@var{regexp}]
3119 List packages currently available in the distribution for this system
3120 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3121 available packages whose name matches @var{regexp}.
3123 For each package, print the following items separated by tabs: its name,
3124 its version string, the parts of the package (@pxref{Packages with
3125 Multiple Outputs}), and the source location of its definition.
3127 @item --list-generations[=@var{pattern}]
3128 @itemx -l [@var{pattern}]
3130 Return a list of generations along with their creation dates; for each
3131 generation, show the installed packages, with the most recently
3132 installed packages shown last. Note that the zeroth generation is never
3135 For each installed package, print the following items, separated by
3136 tabs: the name of a package, its version string, the part of the package
3137 that is installed (@pxref{Packages with Multiple Outputs}), and the
3138 location of this package in the store.
3140 When @var{pattern} is used, the command returns only matching
3141 generations. Valid patterns include:
3144 @item @emph{Integers and comma-separated integers}. Both patterns denote
3145 generation numbers. For instance, @code{--list-generations=1} returns
3148 And @code{--list-generations=1,8,2} outputs three generations in the
3149 specified order. Neither spaces nor trailing commas are allowed.
3151 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3152 specified generations and everything in between. Note that the start of
3153 a range must be smaller than its end.
3155 It is also possible to omit the endpoint. For example,
3156 @code{--list-generations=2..}, returns all generations starting from the
3159 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3160 or months by passing an integer along with the first letter of the
3161 duration. For example, @code{--list-generations=20d} lists generations
3162 that are up to 20 days old.
3165 @item --delete-generations[=@var{pattern}]
3166 @itemx -d [@var{pattern}]
3167 When @var{pattern} is omitted, delete all generations except the current
3170 This command accepts the same patterns as @option{--list-generations}.
3171 When @var{pattern} is specified, delete the matching generations. When
3172 @var{pattern} specifies a duration, generations @emph{older} than the
3173 specified duration match. For instance, @code{--delete-generations=1m}
3174 deletes generations that are more than one month old.
3176 If the current generation matches, it is @emph{not} deleted. Also, the
3177 zeroth generation is never deleted.
3179 Note that deleting generations prevents rolling back to them.
3180 Consequently, this command must be used with care.
3184 Finally, since @command{guix package} may actually start build
3185 processes, it supports all the common build options (@pxref{Common Build
3186 Options}). It also supports package transformation options, such as
3187 @option{--with-source} (@pxref{Package Transformation Options}).
3188 However, note that package transformations are lost when upgrading; to
3189 preserve transformations across upgrades, you should define your own
3190 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3191 (@pxref{Defining Packages}).
3194 @section Substitutes
3197 @cindex pre-built binaries
3198 Guix supports transparent source/binary deployment, which means that it
3199 can either build things locally, or download pre-built items from a
3200 server, or both. We call these pre-built items @dfn{substitutes}---they
3201 are substitutes for local build results. In many cases, downloading a
3202 substitute is much faster than building things locally.
3204 Substitutes can be anything resulting from a derivation build
3205 (@pxref{Derivations}). Of course, in the common case, they are
3206 pre-built package binaries, but source tarballs, for instance, which
3207 also result from derivation builds, can be available as substitutes.
3210 * Official Substitute Server:: One particular source of substitutes.
3211 * Substitute Server Authorization:: How to enable or disable substitutes.
3212 * Substitute Authentication:: How Guix verifies substitutes.
3213 * Proxy Settings:: How to get substitutes via proxy.
3214 * Substitution Failure:: What happens when substitution fails.
3215 * On Trusting Binaries:: How can you trust that binary blob?
3218 @node Official Substitute Server
3219 @subsection Official Substitute Server
3222 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3223 that builds packages from Guix continuously for some
3224 architectures, and makes them available as substitutes. This is the
3225 default source of substitutes; it can be overridden by passing the
3226 @option{--substitute-urls} option either to @command{guix-daemon}
3227 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3228 or to client tools such as @command{guix package}
3229 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3232 Substitute URLs can be either HTTP or HTTPS.
3233 HTTPS is recommended because communications are encrypted; conversely,
3234 using HTTP makes all communications visible to an eavesdropper, who
3235 could use the information gathered to determine, for instance, whether
3236 your system has unpatched security vulnerabilities.
3238 Substitutes from the official build farm are enabled by default when
3239 using Guix System (@pxref{GNU Distribution}). However,
3240 they are disabled by default when using Guix on a foreign distribution,
3241 unless you have explicitly enabled them via one of the recommended
3242 installation steps (@pxref{Installation}). The following paragraphs
3243 describe how to enable or disable substitutes for the official build
3244 farm; the same procedure can also be used to enable substitutes for any
3245 other substitute server.
3247 @node Substitute Server Authorization
3248 @subsection Substitute Server Authorization
3251 @cindex substitutes, authorization thereof
3252 @cindex access control list (ACL), for substitutes
3253 @cindex ACL (access control list), for substitutes
3254 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3256 must add its public key to the access control list (ACL) of archive
3257 imports, using the @command{guix archive} command (@pxref{Invoking guix
3258 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3259 be compromised and to serve genuine substitutes.
3261 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3262 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3263 the installation prefix of Guix. If you installed Guix from source,
3264 make sure you checked the GPG signature of
3265 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3266 Then, you can run something like this:
3269 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3272 Once this is in place, the output of a command like @code{guix build}
3273 should change from something like:
3276 $ guix build emacs --dry-run
3277 The following derivations would be built:
3278 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3279 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3280 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3281 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3289 $ guix build emacs --dry-run
3290 112.3 MB would be downloaded:
3291 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3292 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3293 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3294 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3299 The text changed from ``The following derivations would be built'' to
3300 ``112.3 MB would be downloaded''. This indicates that substitutes from
3301 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3302 possible, for future builds.
3304 @cindex substitutes, how to disable
3305 The substitute mechanism can be disabled globally by running
3306 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3307 guix-daemon}). It can also be disabled temporarily by passing the
3308 @code{--no-substitutes} option to @command{guix package}, @command{guix
3309 build}, and other command-line tools.
3311 @node Substitute Authentication
3312 @subsection Substitute Authentication
3314 @cindex digital signatures
3315 Guix detects and raises an error when attempting to use a substitute
3316 that has been tampered with. Likewise, it ignores substitutes that are
3317 not signed, or that are not signed by one of the keys listed in the ACL.
3319 There is one exception though: if an unauthorized server provides
3320 substitutes that are @emph{bit-for-bit identical} to those provided by
3321 an authorized server, then the unauthorized server becomes eligible for
3322 downloads. For example, assume we have chosen two substitute servers
3326 --substitute-urls="https://a.example.org https://b.example.org"
3330 @cindex reproducible builds
3331 If the ACL contains only the key for @code{b.example.org}, and if
3332 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3333 then Guix will download substitutes from @code{a.example.org} because it
3334 comes first in the list and can be considered a mirror of
3335 @code{b.example.org}. In practice, independent build machines usually
3336 produce the same binaries, thanks to bit-reproducible builds (see
3339 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3340 (in other words, the server is not authenticated), contrary to what
3341 HTTPS clients such as Web browsers usually do. This is because Guix
3342 authenticates substitute information itself, as explained above, which
3343 is what we care about (whereas X.509 certificates are about
3344 authenticating bindings between domain names and public keys.)
3346 @node Proxy Settings
3347 @subsection Proxy Settings
3350 Substitutes are downloaded over HTTP or HTTPS.
3351 The @code{http_proxy} environment
3352 variable can be set in the environment of @command{guix-daemon} and is
3353 honored for downloads of substitutes. Note that the value of
3354 @code{http_proxy} in the environment where @command{guix build},
3355 @command{guix package}, and other client commands are run has
3356 @emph{absolutely no effect}.
3358 @node Substitution Failure
3359 @subsection Substitution Failure
3361 Even when a substitute for a derivation is available, sometimes the
3362 substitution attempt will fail. This can happen for a variety of
3363 reasons: the substitute server might be offline, the substitute may
3364 recently have been deleted, the connection might have been interrupted,
3367 When substitutes are enabled and a substitute for a derivation is
3368 available, but the substitution attempt fails, Guix will attempt to
3369 build the derivation locally depending on whether or not
3370 @code{--fallback} was given (@pxref{fallback-option,, common build
3371 option @code{--fallback}}). Specifically, if @code{--fallback} was
3372 omitted, then no local build will be performed, and the derivation is
3373 considered to have failed. However, if @code{--fallback} was given,
3374 then Guix will attempt to build the derivation locally, and the success
3375 or failure of the derivation depends on the success or failure of the
3376 local build. Note that when substitutes are disabled or no substitute
3377 is available for the derivation in question, a local build will
3378 @emph{always} be performed, regardless of whether or not
3379 @code{--fallback} was given.
3381 To get an idea of how many substitutes are available right now, you can
3382 try running the @command{guix weather} command (@pxref{Invoking guix
3383 weather}). This command provides statistics on the substitutes provided
3386 @node On Trusting Binaries
3387 @subsection On Trusting Binaries
3389 @cindex trust, of pre-built binaries
3390 Today, each individual's control over their own computing is at the
3391 mercy of institutions, corporations, and groups with enough power and
3392 determination to subvert the computing infrastructure and exploit its
3393 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3394 convenient, we encourage users to also build on their own, or even run
3395 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3396 interesting target. One way to help is by publishing the software you
3397 build using @command{guix publish} so that others have one more choice
3398 of server to download substitutes from (@pxref{Invoking guix publish}).
3400 Guix has the foundations to maximize build reproducibility
3401 (@pxref{Features}). In most cases, independent builds of a given
3402 package or derivation should yield bit-identical results. Thus, through
3403 a diverse set of independent package builds, we can strengthen the
3404 integrity of our systems. The @command{guix challenge} command aims to
3405 help users assess substitute servers, and to assist developers in
3406 finding out about non-deterministic package builds (@pxref{Invoking guix
3407 challenge}). Similarly, the @option{--check} option of @command{guix
3408 build} allows users to check whether previously-installed substitutes
3409 are genuine by rebuilding them locally (@pxref{build-check,
3410 @command{guix build --check}}).
3412 In the future, we want Guix to have support to publish and retrieve
3413 binaries to/from other users, in a peer-to-peer fashion. If you would
3414 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3416 @node Packages with Multiple Outputs
3417 @section Packages with Multiple Outputs
3419 @cindex multiple-output packages
3420 @cindex package outputs
3423 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3424 source package leads to exactly one directory in the store. When running
3425 @command{guix install glibc}, one installs the default output of the
3426 GNU libc package; the default output is called @code{out}, but its name
3427 can be omitted as shown in this command. In this particular case, the
3428 default output of @code{glibc} contains all the C header files, shared
3429 libraries, static libraries, Info documentation, and other supporting
3432 Sometimes it is more appropriate to separate the various types of files
3433 produced from a single source package into separate outputs. For
3434 instance, the GLib C library (used by GTK+ and related packages)
3435 installs more than 20 MiB of reference documentation as HTML pages.
3436 To save space for users who do not need it, the documentation goes to a
3437 separate output, called @code{doc}. To install the main GLib output,
3438 which contains everything but the documentation, one would run:
3444 @cindex documentation
3445 The command to install its documentation is:
3448 guix install glib:doc
3451 Some packages install programs with different ``dependency footprints''.
3452 For instance, the WordNet package installs both command-line tools and
3453 graphical user interfaces (GUIs). The former depend solely on the C
3454 library, whereas the latter depend on Tcl/Tk and the underlying X
3455 libraries. In this case, we leave the command-line tools in the default
3456 output, whereas the GUIs are in a separate output. This allows users
3457 who do not need the GUIs to save space. The @command{guix size} command
3458 can help find out about such situations (@pxref{Invoking guix size}).
3459 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3461 There are several such multiple-output packages in the GNU distribution.
3462 Other conventional output names include @code{lib} for libraries and
3463 possibly header files, @code{bin} for stand-alone programs, and
3464 @code{debug} for debugging information (@pxref{Installing Debugging
3465 Files}). The outputs of a packages are listed in the third column of
3466 the output of @command{guix package --list-available} (@pxref{Invoking
3470 @node Invoking guix gc
3471 @section Invoking @command{guix gc}
3473 @cindex garbage collector
3475 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3476 The @command{guix gc} command allows users to explicitly run the garbage
3477 collector to reclaim space from the @file{/gnu/store} directory. It is
3478 the @emph{only} way to remove files from @file{/gnu/store}---removing
3479 files or directories manually may break it beyond repair!
3482 @cindex garbage collector roots
3483 The garbage collector has a set of known @dfn{roots}: any file under
3484 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3485 cannot be deleted; any other file is considered @dfn{dead} and may be
3486 deleted. The set of garbage collector roots (``GC roots'' for short)
3487 includes default user profiles; by default, the symlinks under
3488 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3489 added with @command{guix build --root}, for example (@pxref{Invoking
3490 guix build}). The @command{guix gc --list-roots} command lists them.
3492 Prior to running @code{guix gc --collect-garbage} to make space, it is
3493 often useful to remove old generations from user profiles; that way, old
3494 package builds referenced by those generations can be reclaimed. This
3495 is achieved by running @code{guix package --delete-generations}
3496 (@pxref{Invoking guix package}).
3498 Our recommendation is to run a garbage collection periodically, or when
3499 you are short on disk space. For instance, to guarantee that at least
3500 5@tie{}GB are available on your disk, simply run:
3506 It is perfectly safe to run as a non-interactive periodic job
3507 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3508 Running @command{guix gc} with no arguments will collect as
3509 much garbage as it can, but that is often inconvenient: you may find
3510 yourself having to rebuild or re-download software that is ``dead'' from
3511 the GC viewpoint but that is necessary to build other pieces of
3512 software---e.g., the compiler tool chain.
3514 The @command{guix gc} command has three modes of operation: it can be
3515 used to garbage-collect any dead files (the default), to delete specific
3516 files (the @code{--delete} option), to print garbage-collector
3517 information, or for more advanced queries. The garbage collection
3518 options are as follows:
3521 @item --collect-garbage[=@var{min}]
3522 @itemx -C [@var{min}]
3523 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3524 sub-directories. This is the default operation when no option is
3527 When @var{min} is given, stop once @var{min} bytes have been collected.
3528 @var{min} may be a number of bytes, or it may include a unit as a
3529 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3530 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3532 When @var{min} is omitted, collect all the garbage.
3534 @item --free-space=@var{free}
3535 @itemx -F @var{free}
3536 Collect garbage until @var{free} space is available under
3537 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3538 as @code{500MiB}, as described above.
3540 When @var{free} or more is already available in @file{/gnu/store}, do
3541 nothing and exit immediately.
3543 @item --delete-generations[=@var{duration}]
3544 @itemx -d [@var{duration}]
3545 Before starting the garbage collection process, delete all the generations
3546 older than @var{duration}, for all the user profiles; when run as root, this
3547 applies to all the profiles @emph{of all the users}.
3549 For example, this command deletes all the generations of all your profiles
3550 that are older than 2 months (except generations that are current), and then
3551 proceeds to free space until at least 10 GiB are available:
3554 guix gc -d 2m -F 10G
3559 Attempt to delete all the store files and directories specified as
3560 arguments. This fails if some of the files are not in the store, or if
3561 they are still live.
3563 @item --list-failures
3564 List store items corresponding to cached build failures.
3566 This prints nothing unless the daemon was started with
3567 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3568 @option{--cache-failures}}).
3571 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3575 List store items in use by currently running processes. These store
3576 items are effectively considered GC roots: they cannot be deleted.
3578 @item --clear-failures
3579 Remove the specified store items from the failed-build cache.
3581 Again, this option only makes sense when the daemon is started with
3582 @option{--cache-failures}. Otherwise, it does nothing.
3585 Show the list of dead files and directories still present in the
3586 store---i.e., files and directories no longer reachable from any root.
3589 Show the list of live store files and directories.
3593 In addition, the references among existing store files can be queried:
3599 @cindex package dependencies
3600 List the references (respectively, the referrers) of store files given
3606 List the requisites of the store files passed as arguments. Requisites
3607 include the store files themselves, their references, and the references
3608 of these, recursively. In other words, the returned list is the
3609 @dfn{transitive closure} of the store files.
3611 @xref{Invoking guix size}, for a tool to profile the size of the closure
3612 of an element. @xref{Invoking guix graph}, for a tool to visualize
3613 the graph of references.
3617 Return the derivation(s) leading to the given store items
3618 (@pxref{Derivations}).
3620 For example, this command:
3623 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3627 returns the @file{.drv} file(s) leading to the @code{emacs} package
3628 installed in your profile.
3630 Note that there may be zero matching @file{.drv} files, for instance
3631 because these files have been garbage-collected. There can also be more
3632 than one matching @file{.drv} due to fixed-output derivations.
3635 Lastly, the following options allow you to check the integrity of the
3636 store and to control disk usage.
3640 @item --verify[=@var{options}]
3641 @cindex integrity, of the store
3642 @cindex integrity checking
3643 Verify the integrity of the store.
3645 By default, make sure that all the store items marked as valid in the
3646 database of the daemon actually exist in @file{/gnu/store}.
3648 When provided, @var{options} must be a comma-separated list containing one
3649 or more of @code{contents} and @code{repair}.
3651 When passing @option{--verify=contents}, the daemon computes the
3652 content hash of each store item and compares it against its hash in the
3653 database. Hash mismatches are reported as data corruptions. Because it
3654 traverses @emph{all the files in the store}, this command can take a
3655 long time, especially on systems with a slow disk drive.
3657 @cindex repairing the store
3658 @cindex corruption, recovering from
3659 Using @option{--verify=repair} or @option{--verify=contents,repair}
3660 causes the daemon to try to repair corrupt store items by fetching
3661 substitutes for them (@pxref{Substitutes}). Because repairing is not
3662 atomic, and thus potentially dangerous, it is available only to the
3663 system administrator. A lightweight alternative, when you know exactly
3664 which items in the store are corrupt, is @command{guix build --repair}
3665 (@pxref{Invoking guix build}).
3668 @cindex deduplication
3669 Optimize the store by hard-linking identical files---this is
3670 @dfn{deduplication}.
3672 The daemon performs deduplication after each successful build or archive
3673 import, unless it was started with @code{--disable-deduplication}
3674 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3675 this option is primarily useful when the daemon was running with
3676 @code{--disable-deduplication}.
3680 @node Invoking guix pull
3681 @section Invoking @command{guix pull}
3683 @cindex upgrading Guix
3684 @cindex updating Guix
3685 @cindex @command{guix pull}
3687 Packages are installed or upgraded to the latest version available in
3688 the distribution currently available on your local machine. To update
3689 that distribution, along with the Guix tools, you must run @command{guix
3690 pull}: the command downloads the latest Guix source code and package
3691 descriptions, and deploys it. Source code is downloaded from a
3692 @uref{https://git-scm.com, Git} repository, by default the official
3693 GNU@tie{}Guix repository, though this can be customized.
3695 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3696 (@pxref{Channels}) specified by one of the followings, in this order:
3700 the @option{--channels} option;
3702 the user's @file{~/.config/guix/channels.scm} file;
3704 the system-wide @file{/etc/guix/channels.scm} file;
3706 the built-in default channels specified in the @code{%default-channels}
3710 On completion, @command{guix package} will use packages and package
3711 versions from this just-retrieved copy of Guix. Not only that, but all
3712 the Guix commands and Scheme modules will also be taken from that latest
3713 version. New @command{guix} sub-commands added by the update also
3716 Any user can update their Guix copy using @command{guix pull}, and the
3717 effect is limited to the user who ran @command{guix pull}. For
3718 instance, when user @code{root} runs @command{guix pull}, this has no
3719 effect on the version of Guix that user @code{alice} sees, and vice
3722 The result of running @command{guix pull} is a @dfn{profile} available
3723 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3724 make sure to add it to the beginning of your search path so that you use
3725 the latest version, and similarly for the Info manual
3726 (@pxref{Documentation}):
3729 export PATH="$HOME/.config/guix/current/bin:$PATH"
3730 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3733 The @code{--list-generations} or @code{-l} option lists past generations
3734 produced by @command{guix pull}, along with details about their provenance:
3738 Generation 1 Jun 10 2018 00:18:18
3740 repository URL: https://git.savannah.gnu.org/git/guix.git
3741 branch: origin/master
3742 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3744 Generation 2 Jun 11 2018 11:02:49
3746 repository URL: https://git.savannah.gnu.org/git/guix.git
3747 branch: origin/master
3748 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3749 2 new packages: keepalived, libnfnetlink
3750 6 packages upgraded: emacs-nix-mode@@2.0.4,
3751 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3752 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3754 Generation 3 Jun 13 2018 23:31:07 (current)
3756 repository URL: https://git.savannah.gnu.org/git/guix.git
3757 branch: origin/master
3758 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3759 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3760 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3763 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3764 describe the current status of Guix.
3766 This @code{~/.config/guix/current} profile works exactly like the profiles
3767 created by @command{guix package} (@pxref{Invoking guix package}). That
3768 is, you can list generations, roll back to the previous
3769 generation---i.e., the previous Guix---and so on:
3772 $ guix pull --roll-back
3773 switched from generation 3 to 2
3774 $ guix pull --delete-generations=1
3775 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3778 You can also use @command{guix package} (@pxref{Invoking guix package})
3779 to manage the profile by naming it explicitly:
3781 $ guix package -p ~/.config/guix/current --roll-back
3782 switched from generation 3 to 2
3783 $ guix package -p ~/.config/guix/current --delete-generations=1
3784 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3787 The @command{guix pull} command is usually invoked with no arguments,
3788 but it supports the following options:
3791 @item --url=@var{url}
3792 @itemx --commit=@var{commit}
3793 @itemx --branch=@var{branch}
3794 Download code for the @code{guix} channel from the specified @var{url}, at the
3795 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3796 string), or @var{branch}.
3798 @cindex @file{channels.scm}, configuration file
3799 @cindex configuration file for channels
3800 These options are provided for convenience, but you can also specify your
3801 configuration in the @file{~/.config/guix/channels.scm} file or using the
3802 @option{--channels} option (see below).
3804 @item --channels=@var{file}
3805 @itemx -C @var{file}
3806 Read the list of channels from @var{file} instead of
3807 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3808 @var{file} must contain Scheme code that
3809 evaluates to a list of channel objects. @xref{Channels}, for more
3812 @cindex channel news
3815 Display the list of packages added or upgraded since the previous
3816 generation, as well as, occasionally, news written by channel authors
3817 for their users (@pxref{Channels, Writing Channel News}).
3819 The package information is the same as displayed upon @command{guix
3820 pull} completion, but without ellipses; it is also similar to the output
3821 of @command{guix pull -l} for the last generation (see below).
3823 @item --list-generations[=@var{pattern}]
3824 @itemx -l [@var{pattern}]
3825 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3826 is provided, the subset of generations that match @var{pattern}.
3827 The syntax of @var{pattern} is the same as with @code{guix package
3828 --list-generations} (@pxref{Invoking guix package}).
3831 @cindex rolling back
3832 @cindex undoing transactions
3833 @cindex transactions, undoing
3834 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3835 undo the last transaction.
3837 @item --switch-generation=@var{pattern}
3838 @itemx -S @var{pattern}
3840 Switch to a particular generation defined by @var{pattern}.
3842 @var{pattern} may be either a generation number or a number prefixed
3843 with ``+'' or ``-''. The latter means: move forward/backward by a
3844 specified number of generations. For example, if you want to return to
3845 the latest generation after @code{--roll-back}, use
3846 @code{--switch-generation=+1}.
3848 @item --delete-generations[=@var{pattern}]
3849 @itemx -d [@var{pattern}]
3850 When @var{pattern} is omitted, delete all generations except the current
3853 This command accepts the same patterns as @option{--list-generations}.
3854 When @var{pattern} is specified, delete the matching generations. When
3855 @var{pattern} specifies a duration, generations @emph{older} than the
3856 specified duration match. For instance, @code{--delete-generations=1m}
3857 deletes generations that are more than one month old.
3859 If the current generation matches, it is @emph{not} deleted.
3861 Note that deleting generations prevents rolling back to them.
3862 Consequently, this command must be used with care.
3864 @xref{Invoking guix describe}, for a way to display information about the
3865 current generation only.
3867 @item --profile=@var{profile}
3868 @itemx -p @var{profile}
3869 Use @var{profile} instead of @file{~/.config/guix/current}.
3873 Show which channel commit(s) would be used and what would be built or
3874 substituted but do not actually do it.
3876 @item --system=@var{system}
3877 @itemx -s @var{system}
3878 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3879 the system type of the build host.
3882 Produce verbose output, writing build logs to the standard error output.
3885 Use the bootstrap Guile to build the latest Guix. This option is only
3886 useful to Guix developers.
3889 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3890 repository and branch to pull from, as well as @emph{additional} repositories
3891 containing package modules that should be deployed. @xref{Channels}, for more
3894 In addition, @command{guix pull} supports all the common build options
3895 (@pxref{Common Build Options}).
3901 @cindex @file{channels.scm}, configuration file
3902 @cindex configuration file for channels
3903 @cindex @command{guix pull}, configuration file
3904 @cindex configuration of @command{guix pull}
3905 Guix and its package collection are updated by running @command{guix pull}
3906 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3907 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3908 customized by defining @dfn{channels} in the
3909 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3910 of a Git repository to be deployed, and @command{guix pull} can be instructed
3911 to pull from one or more channels. In other words, channels can be used to
3912 @emph{customize} and to @emph{extend} Guix, as we will see below.
3914 @subsection Using a Custom Guix Channel
3916 The channel called @code{guix} specifies where Guix itself---its command-line
3917 tools as well as its package collection---should be downloaded. For instance,
3918 suppose you want to update from your own copy of the Guix repository at
3919 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3920 write in @code{~/.config/guix/channels.scm} this specification:
3923 ;; Tell 'guix pull' to use my own repo.
3926 (url "https://example.org/my-guix.git")
3927 (branch "super-hacks")))
3931 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3932 branch of the repository at @code{example.org}.
3934 @subsection Specifying Additional Channels
3936 @cindex extending the package collection (channels)
3937 @cindex personal packages (channels)
3938 @cindex channels, for personal packages
3939 You can also specify @emph{additional channels} to pull from. Let's say you
3940 have a bunch of custom package variants or personal packages that you think
3941 would make little sense to contribute to the Guix project, but would like to
3942 have these packages transparently available to you at the command line. You
3943 would first write modules containing those package definitions (@pxref{Package
3944 Modules}), maintain them in a Git repository, and then you and anyone else can
3945 use it as an additional channel to get packages from. Neat, no?
3947 @c What follows stems from discussions at
3948 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3949 @c earlier discussions on guix-devel@gnu.org.
3951 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3952 publish your personal channel to the world, we would like to share a few words
3957 Before publishing a channel, please consider contributing your package
3958 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3959 to free software of all sorts, and packages in Guix proper are readily
3960 available to all Guix users and benefit from the project's quality assurance
3964 When you maintain package definitions outside Guix, we, Guix developers,
3965 consider that @emph{the compatibility burden is on you}. Remember that
3966 package modules and package definitions are just Scheme code that uses various
3967 programming interfaces (APIs). We want to remain free to change these APIs to
3968 keep improving Guix, possibly in ways that break your channel. We never
3969 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3973 Corollary: if you're using an external channel and that channel breaks, please
3974 @emph{report the issue to the channel authors}, not to the Guix project.
3977 You've been warned! Having said this, we believe external channels are a
3978 practical way to exert your freedom to augment Guix' package collection and to
3979 share your improvements, which are basic tenets of
3980 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3981 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3984 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3985 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3988 @vindex %default-channels
3990 ;; Add my personal packages to those Guix provides.
3992 (name 'my-personal-packages)
3993 (url "https://example.org/personal-packages.git"))
3998 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3999 add a channel the list of channels that the variable @code{%default-channels}
4000 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4001 Manual}). With this file in place, @command{guix pull} builds not only Guix
4002 but also the package modules from your own repository. The result in
4003 @file{~/.config/guix/current} is the union of Guix with your own package
4007 $ guix pull --list-generations
4009 Generation 19 Aug 27 2018 16:20:48
4011 repository URL: https://git.savannah.gnu.org/git/guix.git
4013 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4014 my-personal-packages dd3df5e
4015 repository URL: https://example.org/personal-packages.git
4017 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4018 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4019 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4023 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4024 both Guix and packages from the @code{my-personal-packages} channel. Among
4025 the new and upgraded packages that are listed, some like @code{my-gimp} and
4026 @code{my-emacs-with-cool-features} might come from
4027 @code{my-personal-packages}, while others come from the Guix default channel.
4029 To create a channel, create a Git repository containing your own package
4030 modules and make it available. The repository can contain anything, but a
4031 useful channel will contain Guile modules that export packages. Once you
4032 start using a channel, Guix will behave as if the root directory of that
4033 channel's Git repository has been added to the Guile load path (@pxref{Load
4034 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4035 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4036 module, then the module will be available under the name @code{(my-packages
4037 my-tools)}, and you will be able to use it like any other module
4038 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4040 @cindex dependencies, channels
4041 @cindex meta-data, channels
4042 @subsection Declaring Channel Dependencies
4044 Channel authors may decide to augment a package collection provided by other
4045 channels. They can declare their channel to be dependent on other channels in
4046 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4047 the channel repository.
4049 The meta-data file should contain a simple S-expression like this:
4056 (name some-collection)
4057 (url "https://example.org/first-collection.git"))
4059 (name some-other-collection)
4060 (url "https://example.org/second-collection.git")
4061 (branch "testing"))))
4064 In the above example this channel is declared to depend on two other channels,
4065 which will both be fetched automatically. The modules provided by the channel
4066 will be compiled in an environment where the modules of all these declared
4067 channels are available.
4069 For the sake of reliability and maintainability, you should avoid dependencies
4070 on channels that you don't control, and you should aim to keep the number of
4071 dependencies to a minimum.
4073 @cindex subdirectory, channels
4074 @subsection Package Modules in a Sub-directory
4076 As a channel author, you may want to keep your channel modules in a
4077 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4078 add a meta-data file @file{.guix-channel} that contains:
4086 @cindex news, for channels
4087 @subsection Writing Channel News
4089 Channel authors may occasionally want to communicate to their users
4090 information about important changes in the channel. You'd send them all
4091 an email, but that's not convenient.
4093 Instead, channels can provide a @dfn{news file}; when the channel users
4094 run @command{guix pull}, that news file is automatically read and
4095 @command{guix pull --news} can display the announcements that correspond
4096 to the new commits that have been pulled, if any.
4098 To do that, channel authors must first declare the name of the news file
4099 in their @file{.guix-channel} file:
4104 (news-file "etc/news.txt"))
4107 The news file itself, @file{etc/news.txt} in this example, must look
4108 something like this:
4113 (entry (tag "the-bug-fix")
4114 (title (en "Fixed terrible bug")
4116 (body (en "@@emph@{Good news@}! It's fixed!")
4117 (eo "Certe ĝi pli bone funkcias nun!")))
4118 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4119 (title (en "Added a great package")
4120 (ca "Què vol dir guix?"))
4121 (body (en "Don't miss the @@code@{hello@} package!"))))
4124 The file consists of a list of @dfn{news entries}. Each entry is
4125 associated with a commit or tag: it describes changes made in this
4126 commit, possibly in preceding commits as well. Users see entries only
4127 the first time they obtain the commit the entry refers to.
4129 The @code{title} field should be a one-line summary while @code{body}
4130 can be arbitrarily long, and both can contain Texinfo markup
4131 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4132 a list of language tag/message tuples, which allows @command{guix pull}
4133 to display news in the language that corresponds to the user's locale.
4135 If you want to translate news using a gettext-based workflow, you can
4136 extract translatable strings with @command{xgettext} (@pxref{xgettext
4137 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4138 you write news entries in English first, the command below creates a PO
4139 file containing the strings to translate:
4142 xgettext -o news.po -l scheme -ken etc/news.scm
4145 To sum up, yes, you could use your channel as a blog. But beware, this
4146 is @emph{not quite} what your users might expect.
4148 @subsection Replicating Guix
4150 @cindex pinning, channels
4151 @cindex replicating Guix
4152 @cindex reproducibility, of Guix
4153 The @command{guix pull --list-generations} output above shows precisely which
4154 commits were used to build this instance of Guix. We can thus replicate it,
4155 say, on another machine, by providing a channel specification in
4156 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4159 ;; Deploy specific commits of my channels of interest.
4162 (url "https://git.savannah.gnu.org/git/guix.git")
4163 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4165 (name 'my-personal-packages)
4166 (url "https://example.org/personal-packages.git")
4167 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4170 The @command{guix describe --format=channels} command can even generate this
4171 list of channels directly (@pxref{Invoking guix describe}). The resulting
4172 file can be used with the -C options of @command{guix pull}
4173 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4174 (@pxref{Invoking guix time-machine}).
4176 At this point the two machines run the @emph{exact same Guix}, with access to
4177 the @emph{exact same packages}. The output of @command{guix build gimp} on
4178 one machine will be exactly the same, bit for bit, as the output of the same
4179 command on the other machine. It also means both machines have access to all
4180 the source code of Guix and, transitively, to all the source code of every
4183 This gives you super powers, allowing you to track the provenance of binary
4184 artifacts with very fine grain, and to reproduce software environments at
4185 will---some sort of ``meta reproducibility'' capabilities, if you will.
4186 @xref{Inferiors}, for another way to take advantage of these super powers.
4188 @node Invoking guix time-machine
4189 @section Invoking @command{guix time-machine}
4191 @cindex @command{guix time-machine}
4192 @cindex pinning, channels
4193 @cindex replicating Guix
4194 @cindex reproducibility, of Guix
4196 The @command{guix time-machine} command provides access to other
4197 revisions of Guix, for example to install older versions of packages,
4198 or to reproduce a computation in an identical environment. The revision
4199 of Guix to be used is defined by a commit or by a channel
4200 description file created by @command{guix describe}
4201 (@pxref{Invoking guix describe}).
4203 The general syntax is:
4206 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4209 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4210 @command{guix} command if the specified revision. The @var{options} that define
4211 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4214 @item --url=@var{url}
4215 @itemx --commit=@var{commit}
4216 @itemx --branch=@var{branch}
4217 Use the @code{guix} channel from the specified @var{url}, at the
4218 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4219 string), or @var{branch}.
4221 @item --channels=@var{file}
4222 @itemx -C @var{file}
4223 Read the list of channels from @var{file}. @var{file} must contain
4224 Scheme code that evaluates to a list of channel objects.
4225 @xref{Channels} for more information.
4228 As for @command{guix pull}, the absence of any options means that the
4229 the latest commit on the master branch will be used. The command
4232 guix time-machine -- build hello
4235 will thus build the package @code{hello} as defined in the master branch,
4236 which is in general a newer revision of Guix than you have installed.
4237 Time travel works in both directions!
4239 Note that @command{guix time-machine} can trigger builds of channels and
4240 their dependencies, and these are controlled by the standard build
4241 options (@pxref{Common Build Options}).
4246 @c TODO: Remove this once we're more confident about API stability.
4248 The functionality described here is a ``technology preview'' as of version
4249 @value{VERSION}. As such, the interface is subject to change.
4253 @cindex composition of Guix revisions
4254 Sometimes you might need to mix packages from the revision of Guix you're
4255 currently running with packages available in a different revision of Guix.
4256 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4257 revisions in arbitrary ways.
4259 @cindex inferior packages
4260 Technically, an ``inferior'' is essentially a separate Guix process connected
4261 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4262 @code{(guix inferior)} module allows you to create inferiors and to
4263 communicate with them. It also provides a high-level interface to browse and
4264 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4266 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4267 to interact with a separate revision of Guix. For example, let's assume you
4268 want to install in your profile the current @code{guile} package, along with
4269 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4270 because the newer @code{guile-json} has an incompatible API and you want to
4271 run your code against the old API@. To do that, you could write a manifest for
4272 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4273 manifest, you would create an inferior for that old Guix revision you care
4274 about, and you would look up the @code{guile-json} package in the inferior:
4277 (use-modules (guix inferior) (guix channels)
4278 (srfi srfi-1)) ;for 'first'
4281 ;; This is the old revision from which we want to
4282 ;; extract guile-json.
4285 (url "https://git.savannah.gnu.org/git/guix.git")
4287 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4290 ;; An inferior representing the above revision.
4291 (inferior-for-channels channels))
4293 ;; Now create a manifest with the current "guile" package
4294 ;; and the old "guile-json" package.
4296 (list (first (lookup-inferior-packages inferior "guile-json"))
4297 (specification->package "guile")))
4300 On its first run, @command{guix package --manifest} might have to build the
4301 channel you specified before it can create the inferior; subsequent runs will
4302 be much faster because the Guix revision will be cached.
4304 The @code{(guix inferior)} module provides the following procedures to open an
4307 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4308 [#:cache-directory] [#:ttl]
4309 Return an inferior for @var{channels}, a list of channels. Use the cache at
4310 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4311 This procedure opens a new connection to the build daemon.
4313 As a side effect, this procedure may build or substitute binaries for
4314 @var{channels}, which can take time.
4317 @deffn {Scheme Procedure} open-inferior @var{directory} @
4318 [#:command "bin/guix"]
4319 Open the inferior Guix in @var{directory}, running
4320 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4321 the inferior could not be launched.
4324 @cindex inferior packages
4325 The procedures listed below allow you to obtain and manipulate inferior
4328 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4329 Return the list of packages known to @var{inferior}.
4332 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4334 Return the sorted list of inferior packages matching @var{name} in
4335 @var{inferior}, with highest version numbers first. If @var{version} is true,
4336 return only packages with a version number prefixed by @var{version}.
4339 @deffn {Scheme Procedure} inferior-package? @var{obj}
4340 Return true if @var{obj} is an inferior package.
4343 @deffn {Scheme Procedure} inferior-package-name @var{package}
4344 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4345 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4346 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4347 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4348 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4349 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4350 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4351 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4352 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4353 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4354 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4355 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4356 These procedures are the counterpart of package record accessors
4357 (@pxref{package Reference}). Most of them work by querying the inferior
4358 @var{package} comes from, so the inferior must still be live when you call
4362 Inferior packages can be used transparently like any other package or
4363 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4364 transparently handled by the @code{packages->manifest} procedure, which is
4365 commonly use in manifests (@pxref{Invoking guix package, the
4366 @option{--manifest} option of @command{guix package}}). Thus you can insert
4367 an inferior package pretty much anywhere you would insert a regular package:
4368 in manifests, in the @code{packages} field of your @code{operating-system}
4369 declaration, and so on.
4371 @node Invoking guix describe
4372 @section Invoking @command{guix describe}
4374 @cindex reproducibility
4375 @cindex replicating Guix
4376 Often you may want to answer questions like: ``Which revision of Guix am I
4377 using?'' or ``Which channels am I using?'' This is useful information in many
4378 situations: if you want to @emph{replicate} an environment on a different
4379 machine or user account, if you want to report a bug or to determine what
4380 change in the channels you are using caused it, or if you want to record your
4381 system state for reproducibility purposes. The @command{guix describe}
4382 command answers these questions.
4384 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4385 displays the channel(s) that it was built from, including their repository URL
4386 and commit IDs (@pxref{Channels}):
4390 Generation 10 Sep 03 2018 17:32:44 (current)
4392 repository URL: https://git.savannah.gnu.org/git/guix.git
4394 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4397 If you're familiar with the Git version control system, this is similar in
4398 spirit to @command{git describe}; the output is also similar to that of
4399 @command{guix pull --list-generations}, but limited to the current generation
4400 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4401 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4402 information is all it takes to describe the revision of Guix you're using, and
4403 also to replicate it.
4405 To make it easier to replicate Guix, @command{guix describe} can also be asked
4406 to return a list of channels instead of the human-readable description above:
4409 $ guix describe -f channels
4412 (url "https://git.savannah.gnu.org/git/guix.git")
4414 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4418 You can save this to a file and feed it to @command{guix pull -C} on some
4419 other machine or at a later point in time, which will instantiate @emph{this
4420 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4421 From there on, since you're able to deploy the same revision of Guix, you can
4422 just as well @emph{replicate a complete software environment}. We humbly
4423 think that this is @emph{awesome}, and we hope you'll like it too!
4425 The details of the options supported by @command{guix describe} are as
4429 @item --format=@var{format}
4430 @itemx -f @var{format}
4431 Produce output in the specified @var{format}, one of:
4435 produce human-readable output;
4437 produce a list of channel specifications that can be passed to @command{guix
4438 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4442 produce a list of channel specifications in JSON format;
4444 produce a list of channel specifications in Recutils format.
4447 @item --profile=@var{profile}
4448 @itemx -p @var{profile}
4449 Display information about @var{profile}.
4452 @node Invoking guix archive
4453 @section Invoking @command{guix archive}
4455 @cindex @command{guix archive}
4457 The @command{guix archive} command allows users to @dfn{export} files
4458 from the store into a single archive, and to later @dfn{import} them on
4459 a machine that runs Guix.
4460 In particular, it allows store files to be transferred from one machine
4461 to the store on another machine.
4464 If you're looking for a way to produce archives in a format suitable for
4465 tools other than Guix, @pxref{Invoking guix pack}.
4468 @cindex exporting store items
4469 To export store files as an archive to standard output, run:
4472 guix archive --export @var{options} @var{specifications}...
4475 @var{specifications} may be either store file names or package
4476 specifications, as for @command{guix package} (@pxref{Invoking guix
4477 package}). For instance, the following command creates an archive
4478 containing the @code{gui} output of the @code{git} package and the main
4479 output of @code{emacs}:
4482 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4485 If the specified packages are not built yet, @command{guix archive}
4486 automatically builds them. The build process may be controlled with the
4487 common build options (@pxref{Common Build Options}).
4489 To transfer the @code{emacs} package to a machine connected over SSH,
4493 guix archive --export -r emacs | ssh the-machine guix archive --import
4497 Similarly, a complete user profile may be transferred from one machine
4498 to another like this:
4501 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4502 ssh the-machine guix archive --import
4506 However, note that, in both examples, all of @code{emacs} and the
4507 profile as well as all of their dependencies are transferred (due to
4508 @code{-r}), regardless of what is already available in the store on the
4509 target machine. The @code{--missing} option can help figure out which
4510 items are missing from the target store. The @command{guix copy}
4511 command simplifies and optimizes this whole process, so this is probably
4512 what you should use in this case (@pxref{Invoking guix copy}).
4514 @cindex nar, archive format
4515 @cindex normalized archive (nar)
4516 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4517 comparable in spirit to `tar', but with differences
4518 that make it more appropriate for our purposes. First, rather than
4519 recording all Unix metadata for each file, the nar format only mentions
4520 the file type (regular, directory, or symbolic link); Unix permissions
4521 and owner/group are dismissed. Second, the order in which directory
4522 entries are stored always follows the order of file names according to
4523 the C locale collation order. This makes archive production fully
4526 When exporting, the daemon digitally signs the contents of the archive,
4527 and that digital signature is appended. When importing, the daemon
4528 verifies the signature and rejects the import in case of an invalid
4529 signature or if the signing key is not authorized.
4530 @c FIXME: Add xref to daemon doc about signatures.
4532 The main options are:
4536 Export the specified store files or packages (see below.) Write the
4537 resulting archive to the standard output.
4539 Dependencies are @emph{not} included in the output, unless
4540 @code{--recursive} is passed.
4544 When combined with @code{--export}, this instructs @command{guix
4545 archive} to include dependencies of the given items in the archive.
4546 Thus, the resulting archive is self-contained: it contains the closure
4547 of the exported store items.
4550 Read an archive from the standard input, and import the files listed
4551 therein into the store. Abort if the archive has an invalid digital
4552 signature, or if it is signed by a public key not among the authorized
4553 keys (see @code{--authorize} below.)
4556 Read a list of store file names from the standard input, one per line,
4557 and write on the standard output the subset of these files missing from
4560 @item --generate-key[=@var{parameters}]
4561 @cindex signing, archives
4562 Generate a new key pair for the daemon. This is a prerequisite before
4563 archives can be exported with @code{--export}. Note that this operation
4564 usually takes time, because it needs to gather enough entropy to
4565 generate the key pair.
4567 The generated key pair is typically stored under @file{/etc/guix}, in
4568 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4569 key, which must be kept secret.) When @var{parameters} is omitted,
4570 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4571 versions before 1.6.0, it is a 4096-bit RSA key.
4572 Alternatively, @var{parameters} can specify
4573 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4574 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4575 Libgcrypt Reference Manual}).
4578 @cindex authorizing, archives
4579 Authorize imports signed by the public key passed on standard input.
4580 The public key must be in ``s-expression advanced format''---i.e., the
4581 same format as the @file{signing-key.pub} file.
4583 The list of authorized keys is kept in the human-editable file
4584 @file{/etc/guix/acl}. The file contains
4585 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4586 s-expressions''} and is structured as an access-control list in the
4587 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4590 @item --extract=@var{directory}
4591 @itemx -x @var{directory}
4592 Read a single-item archive as served by substitute servers
4593 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4594 low-level operation needed in only very narrow use cases; see below.
4596 For example, the following command extracts the substitute for Emacs
4597 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4601 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4602 | bunzip2 | guix archive -x /tmp/emacs
4605 Single-item archives are different from multiple-item archives produced
4606 by @command{guix archive --export}; they contain a single store item,
4607 and they do @emph{not} embed a signature. Thus this operation does
4608 @emph{no} signature verification and its output should be considered
4611 The primary purpose of this operation is to facilitate inspection of
4612 archive contents coming from possibly untrusted substitute servers.
4616 Read a single-item archive as served by substitute servers
4617 (@pxref{Substitutes}) and print the list of files it contains, as in
4622 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4623 | lzip -d | guix archive -t
4629 @c *********************************************************************
4631 @chapter Development
4633 @cindex software development
4634 If you are a software developer, Guix provides tools that you should find
4635 helpful---independently of the language you're developing in. This is what
4636 this chapter is about.
4638 The @command{guix environment} command provides a convenient way to set up
4639 @dfn{development environments} containing all the dependencies and tools
4640 necessary to work on the software package of your choice. The @command{guix
4641 pack} command allows you to create @dfn{application bundles} that can be
4642 easily distributed to users who do not run Guix.
4645 * Invoking guix environment:: Setting up development environments.
4646 * Invoking guix pack:: Creating software bundles.
4649 @node Invoking guix environment
4650 @section Invoking @command{guix environment}
4652 @cindex reproducible build environments
4653 @cindex development environments
4654 @cindex @command{guix environment}
4655 @cindex environment, package build environment
4656 The purpose of @command{guix environment} is to assist hackers in
4657 creating reproducible development environments without polluting their
4658 package profile. The @command{guix environment} tool takes one or more
4659 packages, builds all of their inputs, and creates a shell
4660 environment to use them.
4662 The general syntax is:
4665 guix environment @var{options} @var{package}@dots{}
4668 The following example spawns a new shell set up for the development of
4672 guix environment guile
4675 If the needed dependencies are not built yet, @command{guix environment}
4676 automatically builds them. The environment of the new shell is an augmented
4677 version of the environment that @command{guix environment} was run in.
4678 It contains the necessary search paths for building the given package
4679 added to the existing environment variables. To create a ``pure''
4680 environment, in which the original environment variables have been unset,
4681 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4682 environment variables such as @code{PATH} in their @file{~/.bashrc}
4683 file. As a consequence, when @code{guix environment} launches it, Bash
4684 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4685 environment variables. It is an error to define such environment
4686 variables in @file{.bashrc}; instead, they should be defined in
4687 @file{.bash_profile}, which is sourced only by log-in shells.
4688 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4689 details on Bash start-up files.}.
4691 @vindex GUIX_ENVIRONMENT
4692 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4693 variable in the shell it spawns; its value is the file name of the
4694 profile of this environment. This allows users to, say, define a
4695 specific prompt for development environments in their @file{.bashrc}
4696 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4699 if [ -n "$GUIX_ENVIRONMENT" ]
4701 export PS1="\u@@\h \w [dev]\$ "
4706 ...@: or to browse the profile:
4709 $ ls "$GUIX_ENVIRONMENT/bin"
4712 Additionally, more than one package may be specified, in which case the
4713 union of the inputs for the given packages are used. For example, the
4714 command below spawns a shell where all of the dependencies of both Guile
4715 and Emacs are available:
4718 guix environment guile emacs
4721 Sometimes an interactive shell session is not desired. An arbitrary
4722 command may be invoked by placing the @code{--} token to separate the
4723 command from the rest of the arguments:
4726 guix environment guile -- make -j4
4729 In other situations, it is more convenient to specify the list of
4730 packages needed in the environment. For example, the following command
4731 runs @command{python} from an environment containing Python@tie{}2.7 and
4735 guix environment --ad-hoc python2-numpy python-2.7 -- python
4738 Furthermore, one might want the dependencies of a package and also some
4739 additional packages that are not build-time or runtime dependencies, but
4740 are useful when developing nonetheless. Because of this, the
4741 @code{--ad-hoc} flag is positional. Packages appearing before
4742 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4743 added to the environment. Packages appearing after are interpreted as
4744 packages that will be added to the environment directly. For example,
4745 the following command creates a Guix development environment that
4746 additionally includes Git and strace:
4749 guix environment guix --ad-hoc git strace
4752 Sometimes it is desirable to isolate the environment as much as
4753 possible, for maximal purity and reproducibility. In particular, when
4754 using Guix on a host distro that is not Guix System, it is desirable to
4755 prevent access to @file{/usr/bin} and other system-wide resources from
4756 the development environment. For example, the following command spawns
4757 a Guile REPL in a ``container'' where only the store and the current
4758 working directory are mounted:
4761 guix environment --ad-hoc --container guile -- guile
4765 The @code{--container} option requires Linux-libre 3.19 or newer.
4768 The available options are summarized below.
4771 @item --root=@var{file}
4772 @itemx -r @var{file}
4773 @cindex persistent environment
4774 @cindex garbage collector root, for environments
4775 Make @var{file} a symlink to the profile for this environment, and
4776 register it as a garbage collector root.
4778 This is useful if you want to protect your environment from garbage
4779 collection, to make it ``persistent''.
4781 When this option is omitted, the environment is protected from garbage
4782 collection only for the duration of the @command{guix environment}
4783 session. This means that next time you recreate the same environment,
4784 you could have to rebuild or re-download packages. @xref{Invoking guix
4785 gc}, for more on GC roots.
4787 @item --expression=@var{expr}
4788 @itemx -e @var{expr}
4789 Create an environment for the package or list of packages that
4790 @var{expr} evaluates to.
4792 For example, running:
4795 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4798 starts a shell with the environment for this specific variant of the
4804 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4807 starts a shell with all the base system packages available.
4809 The above commands only use the default output of the given packages.
4810 To select other outputs, two element tuples can be specified:
4813 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4816 @item --load=@var{file}
4817 @itemx -l @var{file}
4818 Create an environment for the package or list of packages that the code
4819 within @var{file} evaluates to.
4821 As an example, @var{file} might contain a definition like this
4822 (@pxref{Defining Packages}):
4825 @verbatiminclude environment-gdb.scm
4828 @item --manifest=@var{file}
4829 @itemx -m @var{file}
4830 Create an environment for the packages contained in the manifest object
4831 returned by the Scheme code in @var{file}. This option can be repeated
4832 several times, in which case the manifests are concatenated.
4834 This is similar to the same-named option in @command{guix package}
4835 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4839 Include all specified packages in the resulting environment, as if an
4840 @i{ad hoc} package were defined with them as inputs. This option is
4841 useful for quickly creating an environment without having to write a
4842 package expression to contain the desired inputs.
4844 For instance, the command:
4847 guix environment --ad-hoc guile guile-sdl -- guile
4850 runs @command{guile} in an environment where Guile and Guile-SDL are
4853 Note that this example implicitly asks for the default output of
4854 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4855 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4856 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4858 This option may be composed with the default behavior of @command{guix
4859 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4860 as packages whose dependencies will be added to the environment, the
4861 default behavior. Packages appearing after are interpreted as packages
4862 that will be added to the environment directly.
4865 Unset existing environment variables when building the new environment, except
4866 those specified with @option{--preserve} (see below.) This has the effect of
4867 creating an environment in which search paths only contain package inputs.
4869 @item --preserve=@var{regexp}
4870 @itemx -E @var{regexp}
4871 When used alongside @option{--pure}, preserve the environment variables
4872 matching @var{regexp}---in other words, put them on a ``white list'' of
4873 environment variables that must be preserved. This option can be repeated
4877 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4881 This example runs @command{mpirun} in a context where the only environment
4882 variables defined are @code{PATH}, environment variables whose name starts
4883 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4886 @item --search-paths
4887 Display the environment variable definitions that make up the
4890 @item --system=@var{system}
4891 @itemx -s @var{system}
4892 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4897 Run @var{command} within an isolated container. The current working
4898 directory outside the container is mapped inside the container.
4899 Additionally, unless overridden with @code{--user}, a dummy home
4900 directory is created that matches the current user's home directory, and
4901 @file{/etc/passwd} is configured accordingly.
4903 The spawned process runs as the current user outside the container. Inside
4904 the container, it has the same UID and GID as the current user, unless
4905 @option{--user} is passed (see below.)
4909 For containers, share the network namespace with the host system.
4910 Containers created without this flag only have access to the loopback
4913 @item --link-profile
4915 For containers, link the environment profile to
4916 @file{~/.guix-profile} within the container. This is equivalent to
4917 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4918 within the container. Linking will fail and abort the environment if
4919 the directory already exists, which will certainly be the case if
4920 @command{guix environment} was invoked in the user's home directory.
4922 Certain packages are configured to look in
4923 @code{~/.guix-profile} for configuration files and data;@footnote{For
4924 example, the @code{fontconfig} package inspects
4925 @file{~/.guix-profile/share/fonts} for additional fonts.}
4926 @code{--link-profile} allows these programs to behave as expected within
4929 @item --user=@var{user}
4930 @itemx -u @var{user}
4931 For containers, use the username @var{user} in place of the current
4932 user. The generated @file{/etc/passwd} entry within the container will
4933 contain the name @var{user}, the home directory will be
4934 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4935 the UID and GID inside the container are 1000. @var{user}
4936 need not exist on the system.
4938 Additionally, any shared or exposed path (see @code{--share} and
4939 @code{--expose} respectively) whose target is within the current user's
4940 home directory will be remapped relative to @file{/home/USER}; this
4941 includes the automatic mapping of the current working directory.
4944 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4946 guix environment --container --user=foo \
4947 --expose=$HOME/test \
4948 --expose=/tmp/target=$HOME/target
4951 While this will limit the leaking of user identity through home paths
4952 and each of the user fields, this is only one useful component of a
4953 broader privacy/anonymity solution---not one in and of itself.
4956 For containers, the default behavior is to share the current working
4957 directory with the isolated container and immediately change to that
4958 directory within the container. If this is undesirable, @code{--no-cwd}
4959 will cause the current working directory to @emph{not} be automatically
4960 shared and will change to the user's home directory within the container
4961 instead. See also @code{--user}.
4963 @item --expose=@var{source}[=@var{target}]
4964 @itemx --share=@var{source}[=@var{target}]
4965 For containers, @code{--expose} (resp. @code{--share}) exposes the file
4966 system @var{source} from the host system as the read-only
4967 (resp. writable) file system @var{target} within the container. If
4968 @var{target} is not specified, @var{source} is used as the target mount
4969 point in the container.
4971 The example below spawns a Guile REPL in a container in which the user's
4972 home directory is accessible read-only via the @file{/exchange}
4976 guix environment --container --expose=$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 -S /bin=bin guile guile-readline
5059 The result is a tarball that can be passed to the @command{docker load}
5060 command, followed by @code{docker run}:
5063 docker load < @var{file}
5064 docker run -ti guile-guile-readline /bin/guile
5068 where @var{file} is the image returned by @var{guix pack}, and
5069 @code{guile-guile-readline} is its ``image tag''. See the
5070 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5071 documentation} for more information.
5073 @cindex Singularity, build an image with guix pack
5074 @cindex SquashFS, build an image with guix pack
5075 Yet another option is to produce a SquashFS image with the following
5079 guix pack -f squashfs bash guile emacs geiser
5083 The result is a SquashFS file system image that can either be mounted or
5084 directly be used as a file system container image with the
5085 @uref{https://singularity.lbl.gov, Singularity container execution
5086 environment}, using commands like @command{singularity shell} or
5087 @command{singularity exec}.
5089 Several command-line options allow you to customize your pack:
5092 @item --format=@var{format}
5093 @itemx -f @var{format}
5094 Produce a pack in the given @var{format}.
5096 The available formats are:
5100 This is the default format. It produces a tarball containing all the
5101 specified binaries and symlinks.
5104 This produces a tarball that follows the
5105 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5106 Docker Image Specification}. The ``repository name'' as it appears in
5107 the output of the @command{docker images} command is computed from
5108 package names passed on the command line or in the manifest file.
5111 This produces a SquashFS image containing all the specified binaries and
5112 symlinks, as well as empty mount points for virtual file systems like
5116 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5117 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5118 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5119 with something like:
5122 guix pack -f squashfs bash @dots{}
5125 If you forget the @code{bash} (or similar) package, @command{singularity
5126 run} and @command{singularity exec} will fail with an unhelpful ``no
5127 such file or directory'' message.
5131 @cindex relocatable binaries
5134 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5135 anywhere in the file system hierarchy and run from there.
5137 When this option is passed once, the resulting binaries require support for
5138 @dfn{user namespaces} in the kernel Linux; when passed
5139 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5140 PRoot support, can be thought of as the abbreviation of ``Really
5141 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5142 if user namespaces are unavailable, and essentially work anywhere---see below
5143 for the implications.
5145 For example, if you create a pack containing Bash with:
5148 guix pack -RR -S /mybin=bin bash
5152 ...@: you can copy that pack to a machine that lacks Guix, and from your
5153 home directory as a normal user, run:
5161 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5162 @file{/gnu/store} shows up and contains all the dependencies of
5163 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5164 altogether! That is probably the simplest way to deploy Guix-built
5165 software on a non-Guix machine.
5168 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5169 the kernel Linux, which allows unprivileged users to mount or change root.
5170 Old versions of Linux did not support it, and some GNU/Linux distributions
5173 To produce relocatable binaries that work even in the absence of user
5174 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5175 case, binaries will try user namespace support and fall back to PRoot if user
5176 namespaces are not supported.
5178 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5179 support for file system virtualization. It achieves that by using the
5180 @code{ptrace} system call on the running program. This approach has the
5181 advantage to work without requiring special kernel support, but it incurs
5182 run-time overhead every time a system call is made.
5185 @cindex entry point, for Docker images
5186 @item --entry-point=@var{command}
5187 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5188 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5189 support it. @var{command} must be relative to the profile contained in the
5192 The entry point specifies the command that tools like @code{docker run} or
5193 @code{singularity run} automatically start by default. For example, you can
5197 guix pack -f docker --entry-point=bin/guile guile
5200 The resulting pack can easily be loaded and @code{docker run} with no extra
5201 arguments will spawn @code{bin/guile}:
5204 docker load -i pack.tar.gz
5205 docker run @var{image-id}
5208 @item --expression=@var{expr}
5209 @itemx -e @var{expr}
5210 Consider the package @var{expr} evaluates to.
5212 This has the same purpose as the same-named option in @command{guix
5213 build} (@pxref{Additional Build Options, @code{--expression} in
5214 @command{guix build}}).
5216 @item --manifest=@var{file}
5217 @itemx -m @var{file}
5218 Use the packages contained in the manifest object returned by the Scheme
5219 code in @var{file}. This option can be repeated several times, in which
5220 case the manifests are concatenated.
5222 This has a similar purpose as the same-named option in @command{guix
5223 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5224 same manifest files. It allows you to define a collection of packages
5225 once and use it both for creating profiles and for creating archives
5226 for use on machines that do not have Guix installed. Note that you can
5227 specify @emph{either} a manifest file @emph{or} a list of packages,
5230 @item --system=@var{system}
5231 @itemx -s @var{system}
5232 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5233 the system type of the build host.
5235 @item --target=@var{triplet}
5236 @cindex cross-compilation
5237 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5238 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5239 configuration triplets,, autoconf, Autoconf}).
5241 @item --compression=@var{tool}
5242 @itemx -C @var{tool}
5243 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5244 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5246 @item --symlink=@var{spec}
5247 @itemx -S @var{spec}
5248 Add the symlinks specified by @var{spec} to the pack. This option can
5249 appear several times.
5251 @var{spec} has the form @code{@var{source}=@var{target}}, where
5252 @var{source} is the symlink that will be created and @var{target} is the
5255 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5256 symlink pointing to the @file{bin} sub-directory of the profile.
5258 @item --save-provenance
5259 Save provenance information for the packages passed on the command line.
5260 Provenance information includes the URL and commit of the channels in use
5263 Provenance information is saved in the
5264 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5265 usual package metadata---the name and version of each package, their
5266 propagated inputs, and so on. It is useful information to the recipient of
5267 the pack, who then knows how the pack was (supposedly) obtained.
5269 This option is not enabled by default because, like timestamps, provenance
5270 information contributes nothing to the build process. In other words, there
5271 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5272 Recording such ``silent'' metadata in the output thus potentially breaks the
5273 source-to-binary bitwise reproducibility property.
5275 @item --root=@var{file}
5276 @itemx -r @var{file}
5277 @cindex garbage collector root, for packs
5278 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5281 @item --localstatedir
5282 @itemx --profile-name=@var{name}
5283 Include the ``local state directory'', @file{/var/guix}, in the resulting
5284 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5285 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5286 @file{~root/.guix-profile}.
5288 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5289 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5290 the pack means that the store is ``complete'' and manageable by Guix;
5291 not providing it pack means that the store is ``dead'': items cannot be
5292 added to it or removed from it after extraction of the pack.
5294 One use case for this is the Guix self-contained binary tarball
5295 (@pxref{Binary Installation}).
5299 Print the name of the derivation that builds the pack.
5302 Use the bootstrap binaries to build the pack. This option is only
5303 useful to Guix developers.
5306 In addition, @command{guix pack} supports all the common build options
5307 (@pxref{Common Build Options}) and all the package transformation
5308 options (@pxref{Package Transformation Options}).
5311 @c *********************************************************************
5312 @node Programming Interface
5313 @chapter Programming Interface
5315 GNU Guix provides several Scheme programming interfaces (APIs) to
5316 define, build, and query packages. The first interface allows users to
5317 write high-level package definitions. These definitions refer to
5318 familiar packaging concepts, such as the name and version of a package,
5319 its build system, and its dependencies. These definitions can then be
5320 turned into concrete build actions.
5322 Build actions are performed by the Guix daemon, on behalf of users. In a
5323 standard setup, the daemon has write access to the store---the
5324 @file{/gnu/store} directory---whereas users do not. The recommended
5325 setup also has the daemon perform builds in chroots, under a specific
5326 build users, to minimize interference with the rest of the system.
5329 Lower-level APIs are available to interact with the daemon and the
5330 store. To instruct the daemon to perform a build action, users actually
5331 provide it with a @dfn{derivation}. A derivation is a low-level
5332 representation of the build actions to be taken, and the environment in
5333 which they should occur---derivations are to package definitions what
5334 assembly is to C programs. The term ``derivation'' comes from the fact
5335 that build results @emph{derive} from them.
5337 This chapter describes all these APIs in turn, starting from high-level
5338 package definitions.
5341 * Package Modules:: Packages from the programmer's viewpoint.
5342 * Defining Packages:: Defining new packages.
5343 * Build Systems:: Specifying how packages are built.
5344 * The Store:: Manipulating the package store.
5345 * Derivations:: Low-level interface to package derivations.
5346 * The Store Monad:: Purely functional interface to the store.
5347 * G-Expressions:: Manipulating build expressions.
5348 * Invoking guix repl:: Fiddling with Guix interactively.
5351 @node Package Modules
5352 @section Package Modules
5354 From a programming viewpoint, the package definitions of the
5355 GNU distribution are provided by Guile modules in the @code{(gnu packages
5356 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5357 packages @dots{})} module name space are not necessarily ``GNU
5358 packages''. This module naming scheme follows the usual Guile module
5359 naming convention: @code{gnu} means that these modules are distributed
5360 as part of the GNU system, and @code{packages} identifies modules that
5361 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5362 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5363 module exports a variable named @code{emacs}, which is bound to a
5364 @code{<package>} object (@pxref{Defining Packages}).
5366 The @code{(gnu packages @dots{})} module name space is
5367 automatically scanned for packages by the command-line tools. For
5368 instance, when running @code{guix install emacs}, all the @code{(gnu
5369 packages @dots{})} modules are scanned until one that exports a package
5370 object whose name is @code{emacs} is found. This package search
5371 facility is implemented in the @code{(gnu packages)} module.
5373 @cindex customization, of packages
5374 @cindex package module search path
5375 Users can store package definitions in modules with different
5376 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5377 name and module name must match. For instance, the @code{(my-packages
5378 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5379 relative to the load path specified with @option{--load-path} or
5380 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5381 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5382 these package definitions visible to the user interfaces:
5386 By adding the directory containing your package modules to the search path
5387 with the @code{-L} flag of @command{guix package} and other commands
5388 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5389 environment variable described below.
5392 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5393 pulls from it. A channel is essentially a Git repository containing package
5394 modules. @xref{Channels}, for more information on how to define and use
5398 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5400 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5401 This is a colon-separated list of directories to search for additional
5402 package modules. Directories listed in this variable take precedence
5403 over the own modules of the distribution.
5406 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5407 each package is built based solely on other packages in the
5408 distribution. The root of this dependency graph is a small set of
5409 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5410 bootstrap)} module. For more information on bootstrapping,
5411 @pxref{Bootstrapping}.
5413 @node Defining Packages
5414 @section Defining Packages
5416 The high-level interface to package definitions is implemented in the
5417 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5418 example, the package definition, or @dfn{recipe}, for the GNU Hello
5419 package looks like this:
5422 (define-module (gnu packages hello)
5423 #:use-module (guix packages)
5424 #:use-module (guix download)
5425 #:use-module (guix build-system gnu)
5426 #:use-module (guix licenses)
5427 #:use-module (gnu packages gawk))
5429 (define-public hello
5435 (uri (string-append "mirror://gnu/hello/hello-" version
5439 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5440 (build-system gnu-build-system)
5441 (arguments '(#:configure-flags '("--enable-silent-rules")))
5442 (inputs `(("gawk" ,gawk)))
5443 (synopsis "Hello, GNU world: An example GNU package")
5444 (description "Guess what GNU Hello prints!")
5445 (home-page "https://www.gnu.org/software/hello/")
5450 Without being a Scheme expert, the reader may have guessed the meaning
5451 of the various fields here. This expression binds the variable
5452 @code{hello} to a @code{<package>} object, which is essentially a record
5453 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5454 This package object can be inspected using procedures found in the
5455 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5456 returns---surprise!---@code{"hello"}.
5458 With luck, you may be able to import part or all of the definition of
5459 the package you are interested in from another repository, using the
5460 @code{guix import} command (@pxref{Invoking guix import}).
5462 In the example above, @var{hello} is defined in a module of its own,
5463 @code{(gnu packages hello)}. Technically, this is not strictly
5464 necessary, but it is convenient to do so: all the packages defined in
5465 modules under @code{(gnu packages @dots{})} are automatically known to
5466 the command-line tools (@pxref{Package Modules}).
5468 There are a few points worth noting in the above package definition:
5472 The @code{source} field of the package is an @code{<origin>} object
5473 (@pxref{origin Reference}, for the complete reference).
5474 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5475 meaning that the source is a file to be downloaded over FTP or HTTP.
5477 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5478 the GNU mirrors defined in @code{(guix download)}.
5480 The @code{sha256} field specifies the expected SHA256 hash of the file
5481 being downloaded. It is mandatory, and allows Guix to check the
5482 integrity of the file. The @code{(base32 @dots{})} form introduces the
5483 base32 representation of the hash. You can obtain this information with
5484 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5485 hash} (@pxref{Invoking guix hash}).
5488 When needed, the @code{origin} form can also have a @code{patches} field
5489 listing patches to be applied, and a @code{snippet} field giving a
5490 Scheme expression to modify the source code.
5493 @cindex GNU Build System
5494 The @code{build-system} field specifies the procedure to build the
5495 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5496 represents the familiar GNU Build System, where packages may be
5497 configured, built, and installed with the usual @code{./configure &&
5498 make && make check && make install} command sequence.
5501 The @code{arguments} field specifies options for the build system
5502 (@pxref{Build Systems}). Here it is interpreted by
5503 @var{gnu-build-system} as a request run @file{configure} with the
5504 @code{--enable-silent-rules} flag.
5510 What about these quote (@code{'}) characters? They are Scheme syntax to
5511 introduce a literal list; @code{'} is synonymous with @code{quote}.
5512 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5513 for details. Here the value of the @code{arguments} field is a list of
5514 arguments passed to the build system down the road, as with @code{apply}
5515 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5518 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5519 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5520 @code{#:configure-flags} is a keyword used to pass a keyword argument
5521 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5525 The @code{inputs} field specifies inputs to the build process---i.e.,
5526 build-time or run-time dependencies of the package. Here, we define an
5527 input called @code{"gawk"} whose value is that of the @var{gawk}
5528 variable; @var{gawk} is itself bound to a @code{<package>} object.
5530 @cindex backquote (quasiquote)
5533 @cindex comma (unquote)
5537 @findex unquote-splicing
5538 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5539 us to introduce a literal list in the @code{inputs} field, while
5540 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5541 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5544 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5545 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5546 of ensuring that they are present (@pxref{Build Systems}).
5548 However, any other dependencies need to be specified in the
5549 @code{inputs} field. Any dependency not specified here will simply be
5550 unavailable to the build process, possibly leading to a build failure.
5553 @xref{package Reference}, for a full description of possible fields.
5555 Once a package definition is in place, the
5556 package may actually be built using the @code{guix build} command-line
5557 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5558 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5559 package definition using the @command{guix edit} command
5560 (@pxref{Invoking guix edit}).
5561 @xref{Packaging Guidelines}, for
5562 more information on how to test package definitions, and
5563 @ref{Invoking guix lint}, for information on how to check a definition
5564 for style conformance.
5565 @vindex GUIX_PACKAGE_PATH
5566 Lastly, @pxref{Channels}, for information
5567 on how to extend the distribution by adding your own package definitions
5570 Finally, updating the package definition to a new upstream version
5571 can be partly automated by the @command{guix refresh} command
5572 (@pxref{Invoking guix refresh}).
5574 Behind the scenes, a derivation corresponding to the @code{<package>}
5575 object is first computed by the @code{package-derivation} procedure.
5576 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5577 The build actions it prescribes may then be realized by using the
5578 @code{build-derivations} procedure (@pxref{The Store}).
5580 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5581 Return the @code{<derivation>} object of @var{package} for @var{system}
5582 (@pxref{Derivations}).
5584 @var{package} must be a valid @code{<package>} object, and @var{system}
5585 must be a string denoting the target system type---e.g.,
5586 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5587 must be a connection to the daemon, which operates on the store
5588 (@pxref{The Store}).
5592 @cindex cross-compilation
5593 Similarly, it is possible to compute a derivation that cross-builds a
5594 package for some other system:
5596 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5597 @var{package} @var{target} [@var{system}]
5598 Return the @code{<derivation>} object of @var{package} cross-built from
5599 @var{system} to @var{target}.
5601 @var{target} must be a valid GNU triplet denoting the target hardware
5602 and operating system, such as @code{"mips64el-linux-gnu"}
5603 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5606 @cindex package transformations
5607 @cindex input rewriting
5608 @cindex dependency tree rewriting
5609 Packages can be manipulated in arbitrary ways. An example of a useful
5610 transformation is @dfn{input rewriting}, whereby the dependency tree of
5611 a package is rewritten by replacing specific inputs by others:
5613 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5614 [@var{rewrite-name}]
5615 Return a procedure that, when passed a package, replaces its direct and
5616 indirect dependencies (but not its implicit inputs) according to
5617 @var{replacements}. @var{replacements} is a list of package pairs; the
5618 first element of each pair is the package to replace, and the second one
5621 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5622 the name of a package and returns its new name after rewrite.
5626 Consider this example:
5629 (define libressl-instead-of-openssl
5630 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5632 (package-input-rewriting `((,openssl . ,libressl))))
5634 (define git-with-libressl
5635 (libressl-instead-of-openssl git))
5639 Here we first define a rewriting procedure that replaces @var{openssl}
5640 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5641 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5642 This is exactly what the @option{--with-input} command-line option does
5643 (@pxref{Package Transformation Options, @option{--with-input}}).
5645 The following variant of @code{package-input-rewriting} can match packages to
5646 be replaced by name rather than by identity.
5648 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5649 Return a procedure that, given a package, applies the given @var{replacements} to
5650 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5651 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5652 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5653 replacement for that package.
5656 The example above could be rewritten this way:
5659 (define libressl-instead-of-openssl
5660 ;; Replace all the packages called "openssl" with LibreSSL.
5661 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5664 The key difference here is that, this time, packages are matched by spec and
5665 not by identity. In other words, any package in the graph that is called
5666 @code{openssl} will be replaced.
5668 A more generic procedure to rewrite a package dependency graph is
5669 @code{package-mapping}: it supports arbitrary changes to nodes in the
5672 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5673 Return a procedure that, given a package, applies @var{proc} to all the packages
5674 depended on and returns the resulting package. The procedure stops recursion
5675 when @var{cut?} returns true for a given package.
5679 * package Reference:: The package data type.
5680 * origin Reference:: The origin data type.
5684 @node package Reference
5685 @subsection @code{package} Reference
5687 This section summarizes all the options available in @code{package}
5688 declarations (@pxref{Defining Packages}).
5690 @deftp {Data Type} package
5691 This is the data type representing a package recipe.
5695 The name of the package, as a string.
5697 @item @code{version}
5698 The version of the package, as a string.
5701 An object telling how the source code for the package should be
5702 acquired. Most of the time, this is an @code{origin} object, which
5703 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5704 can also be any other ``file-like'' object such as a @code{local-file},
5705 which denotes a file from the local file system (@pxref{G-Expressions,
5706 @code{local-file}}).
5708 @item @code{build-system}
5709 The build system that should be used to build the package (@pxref{Build
5712 @item @code{arguments} (default: @code{'()})
5713 The arguments that should be passed to the build system. This is a
5714 list, typically containing sequential keyword-value pairs.
5716 @item @code{inputs} (default: @code{'()})
5717 @itemx @code{native-inputs} (default: @code{'()})
5718 @itemx @code{propagated-inputs} (default: @code{'()})
5719 @cindex inputs, of packages
5720 These fields list dependencies of the package. Each one is a list of
5721 tuples, where each tuple has a label for the input (a string) as its
5722 first element, a package, origin, or derivation as its second element,
5723 and optionally the name of the output thereof that should be used, which
5724 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5725 more on package outputs). For example, the list below specifies three
5729 `(("libffi" ,libffi)
5730 ("libunistring" ,libunistring)
5731 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5734 @cindex cross compilation, package dependencies
5735 The distinction between @code{native-inputs} and @code{inputs} is
5736 necessary when considering cross-compilation. When cross-compiling,
5737 dependencies listed in @code{inputs} are built for the @emph{target}
5738 architecture; conversely, dependencies listed in @code{native-inputs}
5739 are built for the architecture of the @emph{build} machine.
5741 @code{native-inputs} is typically used to list tools needed at
5742 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5743 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5744 this area (@pxref{Invoking guix lint}).
5746 @anchor{package-propagated-inputs}
5747 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5748 specified packages will be automatically installed alongside the package
5749 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5750 package}}, for information on how @command{guix package} deals with
5753 For example this is necessary when a C/C++ library needs headers of
5754 another library to compile, or when a pkg-config file refers to another
5755 one @i{via} its @code{Requires} field.
5757 Another example where @code{propagated-inputs} is useful is for languages
5758 that lack a facility to record the run-time search path akin to the
5759 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5760 more. To ensure that libraries written in those languages can find
5761 library code they depend on at run time, run-time dependencies must be
5762 listed in @code{propagated-inputs} rather than @code{inputs}.
5764 @item @code{outputs} (default: @code{'("out")})
5765 The list of output names of the package. @xref{Packages with Multiple
5766 Outputs}, for typical uses of additional outputs.
5768 @item @code{native-search-paths} (default: @code{'()})
5769 @itemx @code{search-paths} (default: @code{'()})
5770 A list of @code{search-path-specification} objects describing
5771 search-path environment variables honored by the package.
5773 @item @code{replacement} (default: @code{#f})
5774 This must be either @code{#f} or a package object that will be used as a
5775 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5778 @item @code{synopsis}
5779 A one-line description of the package.
5781 @item @code{description}
5782 A more elaborate description of the package.
5784 @item @code{license}
5785 @cindex license, of packages
5786 The license of the package; a value from @code{(guix licenses)},
5787 or a list of such values.
5789 @item @code{home-page}
5790 The URL to the home-page of the package, as a string.
5792 @item @code{supported-systems} (default: @var{%supported-systems})
5793 The list of systems supported by the package, as strings of the form
5794 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5796 @item @code{location} (default: source location of the @code{package} form)
5797 The source location of the package. It is useful to override this when
5798 inheriting from another package, in which case this field is not
5799 automatically corrected.
5803 @deffn {Scheme Syntax} this-package
5804 When used in the @emph{lexical scope} of a package field definition, this
5805 identifier resolves to the package being defined.
5807 The example below shows how to add a package as a native input of itself when
5815 ;; When cross-compiled, Guile, for example, depends on
5816 ;; a native version of itself. Add it here.
5817 (native-inputs (if (%current-target-system)
5818 `(("self" ,this-package))
5822 It is an error to refer to @code{this-package} outside a package definition.
5825 @node origin Reference
5826 @subsection @code{origin} Reference
5828 This section summarizes all the options available in @code{origin}
5829 declarations (@pxref{Defining Packages}).
5831 @deftp {Data Type} origin
5832 This is the data type representing a source code origin.
5836 An object containing the URI of the source. The object type depends on
5837 the @code{method} (see below). For example, when using the
5838 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5839 values are: a URL represented as a string, or a list thereof.
5842 A procedure that handles the URI.
5847 @item @var{url-fetch} from @code{(guix download)}
5848 download a file from the HTTP, HTTPS, or FTP URL specified in the
5852 @item @var{git-fetch} from @code{(guix git-download)}
5853 clone the Git version control repository, and check out the revision
5854 specified in the @code{uri} field as a @code{git-reference} object; a
5855 @code{git-reference} looks like this:
5859 (url "https://git.savannah.gnu.org/git/hello.git")
5865 A bytevector containing the SHA-256 hash of the source. Typically the
5866 @code{base32} form is used here to generate the bytevector from a
5869 You can obtain this information using @code{guix download}
5870 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5873 @item @code{file-name} (default: @code{#f})
5874 The file name under which the source code should be saved. When this is
5875 @code{#f}, a sensible default value will be used in most cases. In case
5876 the source is fetched from a URL, the file name from the URL will be
5877 used. For version control checkouts, it is recommended to provide the
5878 file name explicitly because the default is not very descriptive.
5880 @item @code{patches} (default: @code{'()})
5881 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5882 file-like objects}) pointing to patches to be applied to the source.
5884 This list of patches must be unconditional. In particular, it cannot
5885 depend on the value of @code{%current-system} or
5886 @code{%current-target-system}.
5888 @item @code{snippet} (default: @code{#f})
5889 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5890 in the source directory. This is a convenient way to modify the source,
5891 sometimes more convenient than a patch.
5893 @item @code{patch-flags} (default: @code{'("-p1")})
5894 A list of command-line flags that should be passed to the @code{patch}
5897 @item @code{patch-inputs} (default: @code{#f})
5898 Input packages or derivations to the patching process. When this is
5899 @code{#f}, the usual set of inputs necessary for patching are provided,
5900 such as GNU@tie{}Patch.
5902 @item @code{modules} (default: @code{'()})
5903 A list of Guile modules that should be loaded during the patching
5904 process and while running the code in the @code{snippet} field.
5906 @item @code{patch-guile} (default: @code{#f})
5907 The Guile package that should be used in the patching process. When
5908 this is @code{#f}, a sensible default is used.
5914 @section Build Systems
5916 @cindex build system
5917 Each package definition specifies a @dfn{build system} and arguments for
5918 that build system (@pxref{Defining Packages}). This @code{build-system}
5919 field represents the build procedure of the package, as well as implicit
5920 dependencies of that build procedure.
5922 Build systems are @code{<build-system>} objects. The interface to
5923 create and manipulate them is provided by the @code{(guix build-system)}
5924 module, and actual build systems are exported by specific modules.
5926 @cindex bag (low-level package representation)
5927 Under the hood, build systems first compile package objects to
5928 @dfn{bags}. A @dfn{bag} is like a package, but with less
5929 ornamentation---in other words, a bag is a lower-level representation of
5930 a package, which includes all the inputs of that package, including some
5931 that were implicitly added by the build system. This intermediate
5932 representation is then compiled to a derivation (@pxref{Derivations}).
5934 Build systems accept an optional list of @dfn{arguments}. In package
5935 definitions, these are passed @i{via} the @code{arguments} field
5936 (@pxref{Defining Packages}). They are typically keyword arguments
5937 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5938 Guile Reference Manual}). The value of these arguments is usually
5939 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5940 by the daemon (@pxref{Derivations}).
5942 The main build system is @code{gnu-build-system}, which implements the
5943 standard build procedure for GNU and many other packages. It
5944 is provided by the @code{(guix build-system gnu)} module.
5946 @defvr {Scheme Variable} gnu-build-system
5947 @code{gnu-build-system} represents the GNU Build System, and variants
5948 thereof (@pxref{Configuration, configuration and makefile conventions,,
5949 standards, GNU Coding Standards}).
5951 @cindex build phases
5952 In a nutshell, packages using it are configured, built, and installed with
5953 the usual @code{./configure && make && make check && make install}
5954 command sequence. In practice, a few additional steps are often needed.
5955 All these steps are split up in separate @dfn{phases},
5956 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5957 modules for more details about the build phases.}:
5961 Unpack the source tarball, and change the current directory to the
5962 extracted source tree. If the source is actually a directory, copy it
5963 to the build tree, and enter that directory.
5965 @item patch-source-shebangs
5966 Patch shebangs encountered in source files so they refer to the right
5967 store file names. For instance, this changes @code{#!/bin/sh} to
5968 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5971 Run the @file{configure} script with a number of default options, such
5972 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5973 by the @code{#:configure-flags} argument.
5976 Run @code{make} with the list of flags specified with
5977 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5978 (the default), build with @code{make -j}.
5981 Run @code{make check}, or some other target specified with
5982 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5983 @code{#:parallel-tests?} argument is true (the default), run @code{make
5987 Run @code{make install} with the flags listed in @code{#:make-flags}.
5989 @item patch-shebangs
5990 Patch shebangs on the installed executable files.
5993 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5994 is false), copying them to the @code{debug} output when available
5995 (@pxref{Installing Debugging Files}).
5998 @vindex %standard-phases
5999 The build-side module @code{(guix build gnu-build-system)} defines
6000 @code{%standard-phases} as the default list of build phases.
6001 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6002 procedure implements the actual phase.
6004 The list of phases used for a particular package can be changed with the
6005 @code{#:phases} parameter. For instance, passing:
6008 #:phases (modify-phases %standard-phases (delete 'configure))
6011 means that all the phases described above will be used, except the
6012 @code{configure} phase.
6014 In addition, this build system ensures that the ``standard'' environment
6015 for GNU packages is available. This includes tools such as GCC, libc,
6016 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6017 build-system gnu)} module for a complete list). We call these the
6018 @dfn{implicit inputs} of a package, because package definitions do not
6019 have to mention them.
6022 Other @code{<build-system>} objects are defined to support other
6023 conventions and tools used by free software packages. They inherit most
6024 of @code{gnu-build-system}, and differ mainly in the set of inputs
6025 implicitly added to the build process, and in the list of phases
6026 executed. Some of these build systems are listed below.
6028 @defvr {Scheme Variable} ant-build-system
6029 This variable is exported by @code{(guix build-system ant)}. It
6030 implements the build procedure for Java packages that can be built with
6031 @url{https://ant.apache.org/, Ant build tool}.
6033 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6034 provided by the @code{icedtea} package to the set of inputs. Different
6035 packages can be specified with the @code{#:ant} and @code{#:jdk}
6036 parameters, respectively.
6038 When the original package does not provide a suitable Ant build file,
6039 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6040 build file @file{build.xml} with tasks to build the specified jar
6041 archive. In this case the parameter @code{#:source-dir} can be used to
6042 specify the source sub-directory, defaulting to ``src''.
6044 The @code{#:main-class} parameter can be used with the minimal ant
6045 buildfile to specify the main class of the resulting jar. This makes the
6046 jar file executable. The @code{#:test-include} parameter can be used to
6047 specify the list of junit tests to run. It defaults to
6048 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6049 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6050 because abstract classes cannot be run as tests.
6052 The parameter @code{#:build-target} can be used to specify the Ant task
6053 that should be run during the @code{build} phase. By default the
6054 ``jar'' task will be run.
6058 @defvr {Scheme Variable} android-ndk-build-system
6059 @cindex Android distribution
6060 @cindex Android NDK build system
6061 This variable is exported by @code{(guix build-system android-ndk)}. It
6062 implements a build procedure for Android NDK (native development kit)
6063 packages using a Guix-specific build process.
6065 The build system assumes that packages install their public interface
6066 (header) files to the subdirectory "include" of the "out" output and
6067 their libraries to the subdirectory "lib" of the "out" output.
6069 It's also assumed that the union of all the dependencies of a package
6070 has no conflicting files.
6072 For the time being, cross-compilation is not supported - so right now
6073 the libraries and header files are assumed to be host tools.
6077 @defvr {Scheme Variable} asdf-build-system/source
6078 @defvrx {Scheme Variable} asdf-build-system/sbcl
6079 @defvrx {Scheme Variable} asdf-build-system/ecl
6081 These variables, exported by @code{(guix build-system asdf)}, implement
6082 build procedures for Common Lisp packages using
6083 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6084 definition facility for Common Lisp programs and libraries.
6086 The @code{asdf-build-system/source} system installs the packages in
6087 source form, and can be loaded using any common lisp implementation, via
6088 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6089 systems in the format which a particular implementation understands.
6090 These build systems can also be used to produce executable programs, or
6091 lisp images which contain a set of packages pre-loaded.
6093 The build system uses naming conventions. For binary packages, the
6094 package name should be prefixed with the lisp implementation, such as
6095 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6097 Additionally, the corresponding source package should be labeled using
6098 the same convention as python packages (see @ref{Python Modules}), using
6099 the @code{cl-} prefix.
6101 For binary packages, each system should be defined as a Guix package.
6102 If one package @code{origin} contains several systems, package variants
6103 can be created in order to build all the systems. Source packages,
6104 which use @code{asdf-build-system/source}, may contain several systems.
6106 In order to create executable programs and images, the build-side
6107 procedures @code{build-program} and @code{build-image} can be used.
6108 They should be called in a build phase after the @code{create-symlinks}
6109 phase, so that the system which was just built can be used within the
6110 resulting image. @code{build-program} requires a list of Common Lisp
6111 expressions to be passed as the @code{#:entry-program} argument.
6113 If the system is not defined within its own @code{.asd} file of the same
6114 name, then the @code{#:asd-file} parameter should be used to specify
6115 which file the system is defined in. Furthermore, if the package
6116 defines a system for its tests in a separate file, it will be loaded
6117 before the tests are run if it is specified by the
6118 @code{#:test-asd-file} parameter. If it is not set, the files
6119 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6120 and @code{test.asd} will be tried if they exist.
6122 If for some reason the package must be named in a different way than the
6123 naming conventions suggest, the @code{#:asd-system-name} parameter can
6124 be used to specify the name of the system.
6128 @defvr {Scheme Variable} cargo-build-system
6129 @cindex Rust programming language
6130 @cindex Cargo (Rust build system)
6131 This variable is exported by @code{(guix build-system cargo)}. It
6132 supports builds of packages using Cargo, the build tool of the
6133 @uref{https://www.rust-lang.org, Rust programming language}.
6135 It adds @code{rustc} and @code{cargo} to the set of inputs.
6136 A different Rust package can be specified with the @code{#:rust} parameter.
6138 Regular cargo dependencies should be added to the package definition via the
6139 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6140 spec can be a package or a source definition. Note that the spec must
6141 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6142 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6143 should be added to the package definition via the
6144 @code{#:cargo-development-inputs} parameter.
6146 In its @code{configure} phase, this build system will make any source inputs
6147 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6148 parameters available to cargo. It will also remove an included
6149 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6150 @code{build} phase. The @code{install} phase installs any crate the binaries
6151 if they are defined by the crate.
6155 @defvr {Scheme Variable} copy-build-system
6156 @cindex (copy build system)
6157 This variable is exported by @code{(guix build-system copy)}. It
6158 supports builds of simple packages that don't require much compiling,
6159 mostly just moving files around.
6161 It adds much of the @code{gnu-build-system} packages to the set of
6162 inputs. Because of this, the @code{copy-build-system} does not require
6163 all the boilerplate code often needed for the
6164 @code{trivial-build-system}.
6166 To further simplify the file installation process, an
6167 @code{#:install-plan} argument is exposed to let the packager specify
6168 which files go where. The install plan is a list of @code{(@var{source}
6169 @var{target} [@var{filters}])}. @var{filters} are optional.
6172 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6174 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6175 @item Otherwise install @var{source} as @var{target}.
6178 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6179 the trailing slash of @var{target} is implied with the same meaning
6182 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6183 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6184 @code{#:exclude-regexp}, only select files are installed depending on
6185 the filters. Each filters is specified by a list of strings.
6187 @item With @code{#:include}, install all the files which the path suffix matches
6188 at least one of the elements in the given list.
6189 @item With @code{#:include-regexp}, install all the files which the
6190 subpaths match at least one of the regular expressions in the given
6192 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6193 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6194 install all files but those matching the exclusion filters.
6195 If both inclusions and exclusions are specified, the exclusions are done
6196 on top of the inclusions.
6199 In all cases, the paths relative to @var{source} are preserved within
6206 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6207 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6208 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6209 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6210 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6211 @file{share/my-app/sub/file}.
6212 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6213 @file{share/my-app/file}.
6218 @cindex Clojure (programming language)
6219 @cindex simple Clojure build system
6220 @defvr {Scheme Variable} clojure-build-system
6221 This variable is exported by @code{(guix build-system clojure)}. It implements
6222 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6223 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6226 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6227 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6228 @code{#:zip} parameters, respectively.
6230 A list of source directories, test directories and jar names can be specified
6231 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6232 parameters, respectively. Compile directory and main class can be specified
6233 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6234 Other parameters are documented below.
6236 This build system is an extension of @code{ant-build-system}, but with the
6237 following phases changed:
6242 This phase calls @code{compile} in Clojure to compile source files and runs
6243 @command{jar} to create jars from both source files and compiled files
6244 according to the include list and exclude list specified in
6245 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6246 has priority over the include list. These lists consist of symbols
6247 representing Clojure libraries or the special keyword @code{#:all} representing
6248 all Clojure libraries found under the source directories. The parameter
6249 @code{#:omit-source?} decides if source should be included into the jars.
6252 This phase runs tests according to the include list and exclude list specified
6253 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6254 meanings are analogous to that of @code{#:aot-include} and
6255 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6256 stands for all Clojure libraries found under the test directories. The
6257 parameter @code{#:tests?} decides if tests should be run.
6260 This phase installs all jars built previously.
6263 Apart from the above, this build system also contains an additional phase:
6268 This phase installs all top-level files with base name matching
6269 @code{%doc-regex}. A different regex can be specified with the
6270 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6271 directories specified in @code{#:doc-dirs} are installed as well.
6275 @defvr {Scheme Variable} cmake-build-system
6276 This variable is exported by @code{(guix build-system cmake)}. It
6277 implements the build procedure for packages using the
6278 @url{https://www.cmake.org, CMake build tool}.
6280 It automatically adds the @code{cmake} package to the set of inputs.
6281 Which package is used can be specified with the @code{#:cmake}
6284 The @code{#:configure-flags} parameter is taken as a list of flags
6285 passed to the @command{cmake} command. The @code{#:build-type}
6286 parameter specifies in abstract terms the flags passed to the compiler;
6287 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6288 debugging information''), which roughly means that code is compiled with
6289 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6292 @defvr {Scheme Variable} dune-build-system
6293 This variable is exported by @code{(guix build-system dune)}. It
6294 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6295 tool for the OCaml programming language. It is implemented as an extension
6296 of the @code{ocaml-build-system} which is described below. As such, the
6297 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6300 It automatically adds the @code{dune} package to the set of inputs.
6301 Which package is used can be specified with the @code{#:dune}
6304 There is no @code{configure} phase because dune packages typically don't
6305 need to be configured. The @code{#:build-flags} parameter is taken as a
6306 list of flags passed to the @code{dune} command during the build.
6308 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6309 command instead of the more recent @code{dune} command while building
6310 a package. Its default value is @code{#f}.
6312 The @code{#:package} parameter can be passed to specify a package name, which
6313 is useful when a package contains multiple packages and you want to build
6314 only one of them. This is equivalent to passing the @code{-p} argument to
6318 @defvr {Scheme Variable} go-build-system
6319 This variable is exported by @code{(guix build-system go)}. It
6320 implements a build procedure for Go packages using the standard
6321 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6322 Go build mechanisms}.
6324 The user is expected to provide a value for the key @code{#:import-path}
6325 and, in some cases, @code{#:unpack-path}. The
6326 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6327 corresponds to the file system path expected by the package's build
6328 scripts and any referring packages, and provides a unique way to
6329 refer to a Go package. It is typically based on a combination of the
6330 package source code's remote URI and file system hierarchy structure. In
6331 some cases, you will need to unpack the package's source code to a
6332 different directory structure than the one indicated by the import path,
6333 and @code{#:unpack-path} should be used in such cases.
6335 Packages that provide Go libraries should install their source code into
6336 the built output. The key @code{#:install-source?}, which defaults to
6337 @code{#t}, controls whether or not the source code is installed. It can
6338 be set to @code{#f} for packages that only provide executable files.
6341 @defvr {Scheme Variable} glib-or-gtk-build-system
6342 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6343 is intended for use with packages making use of GLib or GTK+.
6345 This build system adds the following two phases to the ones defined by
6346 @code{gnu-build-system}:
6349 @item glib-or-gtk-wrap
6350 The phase @code{glib-or-gtk-wrap} ensures that programs in
6351 @file{bin/} are able to find GLib ``schemas'' and
6352 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6353 modules}. This is achieved by wrapping the programs in launch scripts
6354 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6355 environment variables.
6357 It is possible to exclude specific package outputs from that wrapping
6358 process by listing their names in the
6359 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6360 when an output is known not to contain any GLib or GTK+ binaries, and
6361 where wrapping would gratuitously add a dependency of that output on
6364 @item glib-or-gtk-compile-schemas
6365 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6366 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6367 GSettings schemas} of GLib are compiled. Compilation is performed by the
6368 @command{glib-compile-schemas} program. It is provided by the package
6369 @code{glib:bin} which is automatically imported by the build system.
6370 The @code{glib} package providing @command{glib-compile-schemas} can be
6371 specified with the @code{#:glib} parameter.
6374 Both phases are executed after the @code{install} phase.
6377 @defvr {Scheme Variable} guile-build-system
6378 This build system is for Guile packages that consist exclusively of Scheme
6379 code and that are so lean that they don't even have a makefile, let alone a
6380 @file{configure} script. It compiles Scheme code using @command{guild
6381 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6382 installs the @file{.scm} and @file{.go} files in the right place. It also
6383 installs documentation.
6385 This build system supports cross-compilation by using the @code{--target}
6386 option of @command{guild compile}.
6388 Packages built with @code{guile-build-system} must provide a Guile package in
6389 their @code{native-inputs} field.
6392 @defvr {Scheme Variable} julia-build-system
6393 This variable is exported by @code{(guix build-system julia)}. It implements
6394 the build procedure used by @uref{https://julialang.org/, julia} packages,
6395 which essentially is similar to running @command{julia -e 'using Pkg;
6396 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6397 paths to all Julia package inputs. Tests are run not run.
6399 Julia packages require the source @code{file-name} to be the real name of the
6400 package, correctly capitalized.
6402 For packages requiring shared library dependencies, you may need to write the
6403 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6404 variable = /gnu/store/library.so} for each dependency, plus a void function
6405 @code{check_deps() = nothing}.
6407 Some older packages that aren't using @file{Package.toml} yet, will require
6408 this file to be created, too. The function @code{julia-create-package-toml}
6409 helps creating the file. You need to pass the outputs and the source of the
6410 package, it's name (the same as the @code{file-name} parameter), the package
6411 uuid, the package version, and a list of dependencies specified by their name
6415 @defvr {Scheme Variable} minify-build-system
6416 This variable is exported by @code{(guix build-system minify)}. It
6417 implements a minification procedure for simple JavaScript packages.
6419 It adds @code{uglify-js} to the set of inputs and uses it to compress
6420 all JavaScript files in the @file{src} directory. A different minifier
6421 package can be specified with the @code{#:uglify-js} parameter, but it
6422 is expected that the package writes the minified code to the standard
6425 When the input JavaScript files are not all located in the @file{src}
6426 directory, the parameter @code{#:javascript-files} can be used to
6427 specify a list of file names to feed to the minifier.
6430 @defvr {Scheme Variable} ocaml-build-system
6431 This variable is exported by @code{(guix build-system ocaml)}. It implements
6432 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6433 of choosing the correct set of commands to run for each package. OCaml
6434 packages can expect many different commands to be run. This build system will
6437 When the package has a @file{setup.ml} file present at the top-level, it will
6438 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6439 @code{ocaml setup.ml -install}. The build system will assume that this file
6440 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6441 care of setting the prefix and enabling tests if they are not disabled. You
6442 can pass configure and build flags with the @code{#:configure-flags} and
6443 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6444 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6445 bypass this system in the build and install phases.
6447 When the package has a @file{configure} file, it is assumed that it is a
6448 hand-made configure script that requires a different argument format than
6449 in the @code{gnu-build-system}. You can add more flags with the
6450 @code{#:configure-flags} key.
6452 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6453 @code{#t}), it will be used and more flags can be passed to the build and
6454 install phases with the @code{#:make-flags} key.
6456 Finally, some packages do not have these files and use a somewhat standard
6457 location for its build system. In that case, the build system will run
6458 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6459 providing the path to the required findlib module. Additional flags can
6460 be passed via the @code{#:build-flags} key. Install is taken care of by
6461 @command{opam-installer}. In this case, the @code{opam} package must
6462 be added to the @code{native-inputs} field of the package definition.
6464 Note that most OCaml packages assume they will be installed in the same
6465 directory as OCaml, which is not what we want in guix. In particular, they
6466 will install @file{.so} files in their module's directory, which is usually
6467 fine because it is in the OCaml compiler directory. In guix though, these
6468 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6469 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6470 @file{.so} libraries should be installed.
6473 @defvr {Scheme Variable} python-build-system
6474 This variable is exported by @code{(guix build-system python)}. It
6475 implements the more or less standard build procedure used by Python
6476 packages, which consists in running @code{python setup.py build} and
6477 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6479 For packages that install stand-alone Python programs under @code{bin/},
6480 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6481 environment variable points to all the Python libraries they depend on.
6483 Which Python package is used to perform the build can be specified with
6484 the @code{#:python} parameter. This is a useful way to force a package
6485 to be built for a specific version of the Python interpreter, which
6486 might be necessary if the package is only compatible with a single
6487 interpreter version.
6489 By default guix calls @code{setup.py} under control of
6490 @code{setuptools}, much like @command{pip} does. Some packages are not
6491 compatible with setuptools (and pip), thus you can disable this by
6492 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6495 @defvr {Scheme Variable} perl-build-system
6496 This variable is exported by @code{(guix build-system perl)}. It
6497 implements the standard build procedure for Perl packages, which either
6498 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6499 followed by @code{Build} and @code{Build install}; or in running
6500 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6501 @code{make} and @code{make install}, depending on which of
6502 @code{Build.PL} or @code{Makefile.PL} is present in the package
6503 distribution. Preference is given to the former if both @code{Build.PL}
6504 and @code{Makefile.PL} exist in the package distribution. This
6505 preference can be reversed by specifying @code{#t} for the
6506 @code{#:make-maker?} parameter.
6508 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6509 passes flags specified by the @code{#:make-maker-flags} or
6510 @code{#:module-build-flags} parameter, respectively.
6512 Which Perl package is used can be specified with @code{#:perl}.
6515 @defvr {Scheme Variable} qt-build-system
6516 This variable is exported by @code{(guix build-system qt)}. It
6517 is intended for use with applications using Qt or KDE.
6519 This build system adds the following two phases to the ones defined by
6520 @code{cmake-build-system}:
6524 The phase @code{check-setup} prepares the environment for running
6525 the checks as commonly used by Qt test programs.
6526 For now this only sets some environment variables:
6527 @code{QT_QPA_PLATFORM=offscreen},
6528 @code{DBUS_FATAL_WARNINGS=0} and
6529 @code{CTEST_OUTPUT_ON_FAILURE=1}.
6531 This phase is added before the @code{check} phase.
6532 It's a separate phase to ease adjusting if necessary.
6535 The phase @code{qt-wrap}
6536 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6537 and output. In case some path is found, all programs in the output's
6538 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6539 are wrapped in scripts defining the necessary environment variables.
6541 It is possible to exclude specific package outputs from that wrapping process
6542 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6543 This is useful when an output is known not to contain any Qt binaries, and
6544 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6547 This phase is added after the @code{install} phase.
6551 @defvr {Scheme Variable} r-build-system
6552 This variable is exported by @code{(guix build-system r)}. It
6553 implements the build procedure used by @uref{https://r-project.org, R}
6554 packages, which essentially is little more than running @code{R CMD
6555 INSTALL --library=/gnu/store/@dots{}} in an environment where
6556 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6557 are run after installation using the R function
6558 @code{tools::testInstalledPackage}.
6561 @defvr {Scheme Variable} rakudo-build-system
6562 This variable is exported by @code{(guix build-system rakudo)}. It
6563 implements the build procedure used by @uref{https://rakudo.org/,
6564 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6565 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6566 installs the binaries, library files and the resources, as well as wrap
6567 the files under the @code{bin/} directory. Tests can be skipped by
6568 passing @code{#f} to the @code{tests?} parameter.
6570 Which rakudo package is used can be specified with @code{rakudo}.
6571 Which perl6-tap-harness package used for the tests can be specified with
6572 @code{#:prove6} or removed by passing @code{#f} to the
6573 @code{with-prove6?} parameter.
6574 Which perl6-zef package used for tests and installing can be specified
6575 with @code{#:zef} or removed by passing @code{#f} to the
6576 @code{with-zef?} parameter.
6579 @defvr {Scheme Variable} texlive-build-system
6580 This variable is exported by @code{(guix build-system texlive)}. It is
6581 used to build TeX packages in batch mode with a specified engine. The
6582 build system sets the @code{TEXINPUTS} variable to find all TeX source
6583 files in the inputs.
6585 By default it runs @code{luatex} on all files ending on @code{ins}. A
6586 different engine and format can be specified with the
6587 @code{#:tex-format} argument. Different build targets can be specified
6588 with the @code{#:build-targets} argument, which expects a list of file
6589 names. The build system adds only @code{texlive-bin} and
6590 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6591 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6592 and @code{#:texlive-latex-base}, respectively.
6594 The @code{#:tex-directory} parameter tells the build system where to
6595 install the built files under the texmf tree.
6598 @defvr {Scheme Variable} ruby-build-system
6599 This variable is exported by @code{(guix build-system ruby)}. It
6600 implements the RubyGems build procedure used by Ruby packages, which
6601 involves running @code{gem build} followed by @code{gem install}.
6603 The @code{source} field of a package that uses this build system
6604 typically references a gem archive, since this is the format that Ruby
6605 developers use when releasing their software. The build system unpacks
6606 the gem archive, potentially patches the source, runs the test suite,
6607 repackages the gem, and installs it. Additionally, directories and
6608 tarballs may be referenced to allow building unreleased gems from Git or
6609 a traditional source release tarball.
6611 Which Ruby package is used can be specified with the @code{#:ruby}
6612 parameter. A list of additional flags to be passed to the @command{gem}
6613 command can be specified with the @code{#:gem-flags} parameter.
6616 @defvr {Scheme Variable} waf-build-system
6617 This variable is exported by @code{(guix build-system waf)}. It
6618 implements a build procedure around the @code{waf} script. The common
6619 phases---@code{configure}, @code{build}, and @code{install}---are
6620 implemented by passing their names as arguments to the @code{waf}
6623 The @code{waf} script is executed by the Python interpreter. Which
6624 Python package is used to run the script can be specified with the
6625 @code{#:python} parameter.
6628 @defvr {Scheme Variable} scons-build-system
6629 This variable is exported by @code{(guix build-system scons)}. It
6630 implements the build procedure used by the SCons software construction
6631 tool. This build system runs @code{scons} to build the package,
6632 @code{scons test} to run tests, and then @code{scons install} to install
6635 Additional flags to be passed to @code{scons} can be specified with the
6636 @code{#:scons-flags} parameter. The default build and install targets
6637 can be overridden with @code{#:build-targets} and
6638 @code{#:install-targets} respectively. The version of Python used to
6639 run SCons can be specified by selecting the appropriate SCons package
6640 with the @code{#:scons} parameter.
6643 @defvr {Scheme Variable} haskell-build-system
6644 This variable is exported by @code{(guix build-system haskell)}. It
6645 implements the Cabal build procedure used by Haskell packages, which
6646 involves running @code{runhaskell Setup.hs configure
6647 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6648 Instead of installing the package by running @code{runhaskell Setup.hs
6649 install}, to avoid trying to register libraries in the read-only
6650 compiler store directory, the build system uses @code{runhaskell
6651 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6652 addition, the build system generates the package documentation by
6653 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6654 is passed. Optional Haddock parameters can be passed with the help of
6655 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6656 not found, the build system looks for @code{Setup.lhs} instead.
6658 Which Haskell compiler is used can be specified with the @code{#:haskell}
6659 parameter which defaults to @code{ghc}.
6662 @defvr {Scheme Variable} dub-build-system
6663 This variable is exported by @code{(guix build-system dub)}. It
6664 implements the Dub build procedure used by D packages, which
6665 involves running @code{dub build} and @code{dub run}.
6666 Installation is done by copying the files manually.
6668 Which D compiler is used can be specified with the @code{#:ldc}
6669 parameter which defaults to @code{ldc}.
6672 @defvr {Scheme Variable} emacs-build-system
6673 This variable is exported by @code{(guix build-system emacs)}. It
6674 implements an installation procedure similar to the packaging system
6675 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6677 It first creates the @code{@code{package}-autoloads.el} file, then it
6678 byte compiles all Emacs Lisp files. Differently from the Emacs
6679 packaging system, the Info documentation files are moved to the standard
6680 documentation directory and the @file{dir} file is deleted. The Elisp
6681 package files are installed directly under @file{share/emacs/site-lisp}.
6684 @defvr {Scheme Variable} font-build-system
6685 This variable is exported by @code{(guix build-system font)}. It
6686 implements an installation procedure for font packages where upstream
6687 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6688 need to be copied into place. It copies font files to standard
6689 locations in the output directory.
6692 @defvr {Scheme Variable} meson-build-system
6693 This variable is exported by @code{(guix build-system meson)}. It
6694 implements the build procedure for packages that use
6695 @url{https://mesonbuild.com, Meson} as their build system.
6697 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6698 of inputs, and they can be changed with the parameters @code{#:meson}
6699 and @code{#:ninja} if needed. The default Meson is
6700 @code{meson-for-build}, which is special because it doesn't clear the
6701 @code{RUNPATH} of binaries and libraries when they are installed.
6703 This build system is an extension of @code{gnu-build-system}, but with the
6704 following phases changed to some specific for Meson:
6709 The phase runs @code{meson} with the flags specified in
6710 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6711 @code{plain} unless something else is specified in @code{#:build-type}.
6714 The phase runs @code{ninja} to build the package in parallel by default, but
6715 this can be changed with @code{#:parallel-build?}.
6718 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6719 which is @code{"test"} by default.
6722 The phase runs @code{ninja install} and can not be changed.
6725 Apart from that, the build system also adds the following phases:
6730 This phase ensures that all binaries can find the libraries they need.
6731 It searches for required libraries in subdirectories of the package being
6732 built, and adds those to @code{RUNPATH} where needed. It also removes
6733 references to libraries left over from the build phase by
6734 @code{meson-for-build}, such as test dependencies, that aren't actually
6735 required for the program to run.
6737 @item glib-or-gtk-wrap
6738 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6739 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6741 @item glib-or-gtk-compile-schemas
6742 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6743 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6747 @defvr {Scheme Variable} linux-module-build-system
6748 @code{linux-module-build-system} allows building Linux kernel modules.
6750 @cindex build phases
6751 This build system is an extension of @code{gnu-build-system}, but with the
6752 following phases changed:
6757 This phase configures the environment so that the Linux kernel's Makefile
6758 can be used to build the external kernel module.
6761 This phase uses the Linux kernel's Makefile in order to build the external
6765 This phase uses the Linux kernel's Makefile in order to install the external
6769 It is possible and useful to specify the Linux kernel to use for building
6770 the module (in the "arguments" form of a package using the
6771 linux-module-build-system, use the key #:linux to specify it).
6774 @defvr {Scheme Variable} node-build-system
6775 This variable is exported by @code{(guix build-system node)}. It
6776 implements the build procedure used by @uref{https://nodejs.org,
6777 Node.js}, which implements an approximation of the @code{npm install}
6778 command, followed by an @code{npm test} command.
6780 Which Node.js package is used to interpret the @code{npm} commands can
6781 be specified with the @code{#:node} parameter which defaults to
6785 Lastly, for packages that do not need anything as sophisticated, a
6786 ``trivial'' build system is provided. It is trivial in the sense that
6787 it provides basically no support: it does not pull any implicit inputs,
6788 and does not have a notion of build phases.
6790 @defvr {Scheme Variable} trivial-build-system
6791 This variable is exported by @code{(guix build-system trivial)}.
6793 This build system requires a @code{#:builder} argument. This argument
6794 must be a Scheme expression that builds the package output(s)---as
6795 with @code{build-expression->derivation} (@pxref{Derivations,
6796 @code{build-expression->derivation}}).
6806 Conceptually, the @dfn{store} is the place where derivations that have
6807 been built successfully are stored---by default, @file{/gnu/store}.
6808 Sub-directories in the store are referred to as @dfn{store items} or
6809 sometimes @dfn{store paths}. The store has an associated database that
6810 contains information such as the store paths referred to by each store
6811 path, and the list of @emph{valid} store items---results of successful
6812 builds. This database resides in @file{@var{localstatedir}/guix/db},
6813 where @var{localstatedir} is the state directory specified @i{via}
6814 @option{--localstatedir} at configure time, usually @file{/var}.
6816 The store is @emph{always} accessed by the daemon on behalf of its clients
6817 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6818 connect to the daemon over a Unix-domain socket, send requests to it,
6819 and read the result---these are remote procedure calls, or RPCs.
6822 Users must @emph{never} modify files under @file{/gnu/store} directly.
6823 This would lead to inconsistencies and break the immutability
6824 assumptions of Guix's functional model (@pxref{Introduction}).
6826 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6827 how to check the integrity of the store and attempt recovery from
6828 accidental modifications.
6831 The @code{(guix store)} module provides procedures to connect to the
6832 daemon, and to perform RPCs. These are described below. By default,
6833 @code{open-connection}, and thus all the @command{guix} commands,
6834 connect to the local daemon or to the URI specified by the
6835 @code{GUIX_DAEMON_SOCKET} environment variable.
6837 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6838 When set, the value of this variable should be a file name or a URI
6839 designating the daemon endpoint. When it is a file name, it denotes a
6840 Unix-domain socket to connect to. In addition to file names, the
6841 supported URI schemes are:
6846 These are for Unix-domain sockets.
6847 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6848 @file{/var/guix/daemon-socket/socket}.
6851 @cindex daemon, remote access
6852 @cindex remote access to the daemon
6853 @cindex daemon, cluster setup
6854 @cindex clusters, daemon setup
6855 These URIs denote connections over TCP/IP, without encryption nor
6856 authentication of the remote host. The URI must specify the host name
6857 and optionally a port number (by default port 44146 is used):
6860 guix://master.guix.example.org:1234
6863 This setup is suitable on local networks, such as clusters, where only
6864 trusted nodes may connect to the build daemon at
6865 @code{master.guix.example.org}.
6867 The @code{--listen} option of @command{guix-daemon} can be used to
6868 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6872 @cindex SSH access to build daemons
6873 These URIs allow you to connect to a remote daemon over SSH. This
6874 feature requires Guile-SSH (@pxref{Requirements}) and a working
6875 @code{guile} binary in @code{PATH} on the destination machine. It
6876 supports public key and GSSAPI authentication. A typical URL might look
6880 ssh://charlie@@guix.example.org:22
6883 As for @command{guix copy}, the usual OpenSSH client configuration files
6884 are honored (@pxref{Invoking guix copy}).
6887 Additional URI schemes may be supported in the future.
6889 @c XXX: Remove this note when the protocol incurs fewer round trips
6890 @c and when (guix derivations) no longer relies on file system access.
6892 The ability to connect to remote build daemons is considered
6893 experimental as of @value{VERSION}. Please get in touch with us to
6894 share any problems or suggestions you may have (@pxref{Contributing}).
6898 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6899 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6900 @var{reserve-space?} is true, instruct it to reserve a little bit of
6901 extra space on the file system so that the garbage collector can still
6902 operate should the disk become full. Return a server object.
6904 @var{file} defaults to @code{%default-socket-path}, which is the normal
6905 location given the options that were passed to @command{configure}.
6908 @deffn {Scheme Procedure} close-connection @var{server}
6909 Close the connection to @var{server}.
6912 @defvr {Scheme Variable} current-build-output-port
6913 This variable is bound to a SRFI-39 parameter, which refers to the port
6914 where build and error logs sent by the daemon should be written.
6917 Procedures that make RPCs all take a server object as their first
6920 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6921 @cindex invalid store items
6922 Return @code{#t} when @var{path} designates a valid store item and
6923 @code{#f} otherwise (an invalid item may exist on disk but still be
6924 invalid, for instance because it is the result of an aborted or failed
6927 A @code{&store-protocol-error} condition is raised if @var{path} is not
6928 prefixed by the store directory (@file{/gnu/store}).
6931 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6932 Add @var{text} under file @var{name} in the store, and return its store
6933 path. @var{references} is the list of store paths referred to by the
6934 resulting store path.
6937 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6939 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6940 file names, or derivation/output pairs, using the specified
6941 @var{mode}---@code{(build-mode normal)} by default.
6944 Note that the @code{(guix monads)} module provides a monad as well as
6945 monadic versions of the above procedures, with the goal of making it
6946 more convenient to work with code that accesses the store (@pxref{The
6950 @i{This section is currently incomplete.}
6953 @section Derivations
6956 Low-level build actions and the environment in which they are performed
6957 are represented by @dfn{derivations}. A derivation contains the
6958 following pieces of information:
6962 The outputs of the derivation---derivations produce at least one file or
6963 directory in the store, but may produce more.
6966 @cindex build-time dependencies
6967 @cindex dependencies, build-time
6968 The inputs of the derivations---i.e., its build-time dependencies---which may
6969 be other derivations or plain files in the store (patches, build scripts,
6973 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6976 The file name of a build script in the store, along with the arguments
6980 A list of environment variables to be defined.
6984 @cindex derivation path
6985 Derivations allow clients of the daemon to communicate build actions to
6986 the store. They exist in two forms: as an in-memory representation,
6987 both on the client- and daemon-side, and as files in the store whose
6988 name end in @code{.drv}---these files are referred to as @dfn{derivation
6989 paths}. Derivations paths can be passed to the @code{build-derivations}
6990 procedure to perform the build actions they prescribe (@pxref{The
6993 @cindex fixed-output derivations
6994 Operations such as file downloads and version-control checkouts for
6995 which the expected content hash is known in advance are modeled as
6996 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6997 of a fixed-output derivation are independent of its inputs---e.g., a
6998 source code download produces the same result regardless of the download
6999 method and tools being used.
7002 @cindex run-time dependencies
7003 @cindex dependencies, run-time
7004 The outputs of derivations---i.e., the build results---have a set of
7005 @dfn{references}, as reported by the @code{references} RPC or the
7006 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7007 are the set of run-time dependencies of the build results. References are a
7008 subset of the inputs of the derivation; this subset is automatically computed
7009 by the build daemon by scanning all the files in the outputs.
7011 The @code{(guix derivations)} module provides a representation of
7012 derivations as Scheme objects, along with procedures to create and
7013 otherwise manipulate derivations. The lowest-level primitive to create
7014 a derivation is the @code{derivation} procedure:
7016 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7017 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7018 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7019 [#:system (%current-system)] [#:references-graphs #f] @
7020 [#:allowed-references #f] [#:disallowed-references #f] @
7021 [#:leaked-env-vars #f] [#:local-build? #f] @
7022 [#:substitutable? #t] [#:properties '()]
7023 Build a derivation with the given arguments, and return the resulting
7024 @code{<derivation>} object.
7026 When @var{hash} and @var{hash-algo} are given, a
7027 @dfn{fixed-output derivation} is created---i.e., one whose result is
7028 known in advance, such as a file download. If, in addition,
7029 @var{recursive?} is true, then that fixed output may be an executable
7030 file or a directory and @var{hash} must be the hash of an archive
7031 containing this output.
7033 When @var{references-graphs} is true, it must be a list of file
7034 name/store path pairs. In that case, the reference graph of each store
7035 path is exported in the build environment in the corresponding file, in
7036 a simple text format.
7038 When @var{allowed-references} is true, it must be a list of store items
7039 or outputs that the derivation's output may refer to. Likewise,
7040 @var{disallowed-references}, if true, must be a list of things the
7041 outputs may @emph{not} refer to.
7043 When @var{leaked-env-vars} is true, it must be a list of strings
7044 denoting environment variables that are allowed to ``leak'' from the
7045 daemon's environment to the build environment. This is only applicable
7046 to fixed-output derivations---i.e., when @var{hash} is true. The main
7047 use is to allow variables such as @code{http_proxy} to be passed to
7048 derivations that download files.
7050 When @var{local-build?} is true, declare that the derivation is not a
7051 good candidate for offloading and should rather be built locally
7052 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7053 where the costs of data transfers would outweigh the benefits.
7055 When @var{substitutable?} is false, declare that substitutes of the
7056 derivation's output should not be used (@pxref{Substitutes}). This is
7057 useful, for instance, when building packages that capture details of the
7058 host CPU instruction set.
7060 @var{properties} must be an association list describing ``properties'' of the
7061 derivation. It is kept as-is, uninterpreted, in the derivation.
7065 Here's an example with a shell script as its builder, assuming
7066 @var{store} is an open connection to the daemon, and @var{bash} points
7067 to a Bash executable in the store:
7070 (use-modules (guix utils)
7074 (let ((builder ; add the Bash script to the store
7075 (add-text-to-store store "my-builder.sh"
7076 "echo hello world > $out\n" '())))
7077 (derivation store "foo"
7078 bash `("-e" ,builder)
7079 #:inputs `((,bash) (,builder))
7080 #:env-vars '(("HOME" . "/homeless"))))
7081 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7084 As can be guessed, this primitive is cumbersome to use directly. A
7085 better approach is to write build scripts in Scheme, of course! The
7086 best course of action for that is to write the build code as a
7087 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7088 information, @pxref{G-Expressions}.
7090 Once upon a time, @code{gexp->derivation} did not exist and constructing
7091 derivations with build code written in Scheme was achieved with
7092 @code{build-expression->derivation}, documented below. This procedure
7093 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7095 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7096 @var{name} @var{exp} @
7097 [#:system (%current-system)] [#:inputs '()] @
7098 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7099 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7100 [#:references-graphs #f] [#:allowed-references #f] @
7101 [#:disallowed-references #f] @
7102 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7103 Return a derivation that executes Scheme expression @var{exp} as a
7104 builder for derivation @var{name}. @var{inputs} must be a list of
7105 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7106 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7107 modules from the current search path to be copied in the store,
7108 compiled, and made available in the load path during the execution of
7109 @var{exp}---e.g., @code{((guix build utils) (guix build
7110 gnu-build-system))}.
7112 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7113 to a list of output/path pairs, and where @code{%build-inputs} is bound
7114 to a list of string/output-path pairs made from @var{inputs}.
7115 Optionally, @var{env-vars} is a list of string pairs specifying the name
7116 and value of environment variables visible to the builder. The builder
7117 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7118 @var{exp} returns @code{#f}, the build is considered to have failed.
7120 @var{exp} is built using @var{guile-for-build} (a derivation). When
7121 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7122 @code{%guile-for-build} fluid is used instead.
7124 See the @code{derivation} procedure for the meaning of
7125 @var{references-graphs}, @var{allowed-references},
7126 @var{disallowed-references}, @var{local-build?}, and
7127 @var{substitutable?}.
7131 Here's an example of a single-output derivation that creates a directory
7132 containing one file:
7135 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7136 (mkdir out) ; create /gnu/store/@dots{}-goo
7137 (call-with-output-file (string-append out "/test")
7139 (display '(hello guix) p))))))
7140 (build-expression->derivation store "goo" builder))
7142 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7146 @node The Store Monad
7147 @section The Store Monad
7151 The procedures that operate on the store described in the previous
7152 sections all take an open connection to the build daemon as their first
7153 argument. Although the underlying model is functional, they either have
7154 side effects or depend on the current state of the store.
7156 The former is inconvenient: the connection to the build daemon has to be
7157 carried around in all those functions, making it impossible to compose
7158 functions that do not take that parameter with functions that do. The
7159 latter can be problematic: since store operations have side effects
7160 and/or depend on external state, they have to be properly sequenced.
7162 @cindex monadic values
7163 @cindex monadic functions
7164 This is where the @code{(guix monads)} module comes in. This module
7165 provides a framework for working with @dfn{monads}, and a particularly
7166 useful monad for our uses, the @dfn{store monad}. Monads are a
7167 construct that allows two things: associating ``context'' with values
7168 (in our case, the context is the store), and building sequences of
7169 computations (here computations include accesses to the store). Values
7170 in a monad---values that carry this additional context---are called
7171 @dfn{monadic values}; procedures that return such values are called
7172 @dfn{monadic procedures}.
7174 Consider this ``normal'' procedure:
7177 (define (sh-symlink store)
7178 ;; Return a derivation that symlinks the 'bash' executable.
7179 (let* ((drv (package-derivation store bash))
7180 (out (derivation->output-path drv))
7181 (sh (string-append out "/bin/bash")))
7182 (build-expression->derivation store "sh"
7183 `(symlink ,sh %output))))
7186 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7187 as a monadic function:
7190 (define (sh-symlink)
7191 ;; Same, but return a monadic value.
7192 (mlet %store-monad ((drv (package->derivation bash)))
7193 (gexp->derivation "sh"
7194 #~(symlink (string-append #$drv "/bin/bash")
7198 There are several things to note in the second version: the @code{store}
7199 parameter is now implicit and is ``threaded'' in the calls to the
7200 @code{package->derivation} and @code{gexp->derivation} monadic
7201 procedures, and the monadic value returned by @code{package->derivation}
7202 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7204 As it turns out, the call to @code{package->derivation} can even be
7205 omitted since it will take place implicitly, as we will see later
7206 (@pxref{G-Expressions}):
7209 (define (sh-symlink)
7210 (gexp->derivation "sh"
7211 #~(symlink (string-append #$bash "/bin/bash")
7216 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7217 @c for the funny quote.
7218 Calling the monadic @code{sh-symlink} has no effect. As someone once
7219 said, ``you exit a monad like you exit a building on fire: by running''.
7220 So, to exit the monad and get the desired effect, one must use
7221 @code{run-with-store}:
7224 (run-with-store (open-connection) (sh-symlink))
7225 @result{} /gnu/store/...-sh-symlink
7228 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7229 new ``meta-commands'' to make it easier to deal with monadic procedures:
7230 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7231 to ``run'' a single monadic value through the store:
7234 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7235 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7238 The latter enters a recursive REPL, where all the return values are
7239 automatically run through the store:
7242 scheme@@(guile-user)> ,enter-store-monad
7243 store-monad@@(guile-user) [1]> (package->derivation hello)
7244 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7245 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7246 $3 = "/gnu/store/@dots{}-foo"
7247 store-monad@@(guile-user) [1]> ,q
7248 scheme@@(guile-user)>
7252 Note that non-monadic values cannot be returned in the
7253 @code{store-monad} REPL.
7255 The main syntactic forms to deal with monads in general are provided by
7256 the @code{(guix monads)} module and are described below.
7258 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7259 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7263 @deffn {Scheme Syntax} return @var{val}
7264 Return a monadic value that encapsulates @var{val}.
7267 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7268 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7269 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7270 referred to as ``bind'', but that name denotes an unrelated procedure in
7271 Guile. Thus we use this somewhat cryptic symbol inherited from the
7272 Haskell language.}. There can be one @var{mproc} or several of them, as
7277 (with-monad %state-monad
7279 (lambda (x) (return (+ 1 x)))
7280 (lambda (x) (return (* 2 x)))))
7284 @result{} some-state
7288 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7290 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7292 Bind the variables @var{var} to the monadic values @var{mval} in
7293 @var{body}, which is a sequence of expressions. As with the bind
7294 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7295 value ``contained'' in @var{mval} and making @var{var} refer to that
7296 raw, non-monadic value within the scope of the @var{body}. The form
7297 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7298 @var{val}, as per @code{let}. The binding operations occur in sequence
7299 from left to right. The last expression of @var{body} must be a monadic
7300 expression, and its result will become the result of the @code{mlet} or
7301 @code{mlet*} when run in the @var{monad}.
7303 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7304 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7307 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7308 Bind @var{mexp} and the following monadic expressions in sequence,
7309 returning the result of the last expression. Every expression in the
7310 sequence must be a monadic expression.
7312 This is akin to @code{mlet}, except that the return values of the
7313 monadic expressions are ignored. In that sense, it is analogous to
7314 @code{begin}, but applied to monadic expressions.
7317 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7318 When @var{condition} is true, evaluate the sequence of monadic
7319 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7320 @var{condition} is false, return @code{*unspecified*} in the current
7321 monad. Every expression in the sequence must be a monadic expression.
7324 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7325 When @var{condition} is false, evaluate the sequence of monadic
7326 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7327 @var{condition} is true, return @code{*unspecified*} in the current
7328 monad. Every expression in the sequence must be a monadic expression.
7332 The @code{(guix monads)} module provides the @dfn{state monad}, which
7333 allows an additional value---the state---to be @emph{threaded} through
7334 monadic procedure calls.
7336 @defvr {Scheme Variable} %state-monad
7337 The state monad. Procedures in the state monad can access and change
7338 the state that is threaded.
7340 Consider the example below. The @code{square} procedure returns a value
7341 in the state monad. It returns the square of its argument, but also
7342 increments the current state value:
7346 (mlet %state-monad ((count (current-state)))
7347 (mbegin %state-monad
7348 (set-current-state (+ 1 count))
7351 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7356 When ``run'' through @var{%state-monad}, we obtain that additional state
7357 value, which is the number of @code{square} calls.
7360 @deffn {Monadic Procedure} current-state
7361 Return the current state as a monadic value.
7364 @deffn {Monadic Procedure} set-current-state @var{value}
7365 Set the current state to @var{value} and return the previous state as a
7369 @deffn {Monadic Procedure} state-push @var{value}
7370 Push @var{value} to the current state, which is assumed to be a list,
7371 and return the previous state as a monadic value.
7374 @deffn {Monadic Procedure} state-pop
7375 Pop a value from the current state and return it as a monadic value.
7376 The state is assumed to be a list.
7379 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7380 Run monadic value @var{mval} starting with @var{state} as the initial
7381 state. Return two values: the resulting value, and the resulting state.
7384 The main interface to the store monad, provided by the @code{(guix
7385 store)} module, is as follows.
7387 @defvr {Scheme Variable} %store-monad
7388 The store monad---an alias for @var{%state-monad}.
7390 Values in the store monad encapsulate accesses to the store. When its
7391 effect is needed, a value of the store monad must be ``evaluated'' by
7392 passing it to the @code{run-with-store} procedure (see below.)
7395 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7396 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7397 open store connection.
7400 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7401 Return as a monadic value the absolute file name in the store of the file
7402 containing @var{text}, a string. @var{references} is a list of store items that the
7403 resulting text file refers to; it defaults to the empty list.
7406 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7407 Return as a monadic value the absolute file name in the store of the file
7408 containing @var{data}, a bytevector. @var{references} is a list of store
7409 items that the resulting binary file refers to; it defaults to the empty list.
7412 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7413 [#:recursive? #t] [#:select? (const #t)]
7414 Return the name of @var{file} once interned in the store. Use
7415 @var{name} as its store name, or the basename of @var{file} if
7416 @var{name} is omitted.
7418 When @var{recursive?} is true, the contents of @var{file} are added
7419 recursively; if @var{file} designates a flat file and @var{recursive?}
7420 is true, its contents are added, and its permission bits are kept.
7422 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7423 @var{stat})} for each directory entry, where @var{file} is the entry's
7424 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7425 entries for which @var{select?} does not return true.
7427 The example below adds a file to the store, under two different names:
7430 (run-with-store (open-connection)
7431 (mlet %store-monad ((a (interned-file "README"))
7432 (b (interned-file "README" "LEGU-MIN")))
7433 (return (list a b))))
7435 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7440 The @code{(guix packages)} module exports the following package-related
7443 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7444 [#:system (%current-system)] [#:target #f] @
7447 value in the absolute file name of @var{file} within the @var{output}
7448 directory of @var{package}. When @var{file} is omitted, return the name
7449 of the @var{output} directory of @var{package}. When @var{target} is
7450 true, use it as a cross-compilation target triplet.
7453 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7454 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7455 @var{target} [@var{system}]
7456 Monadic version of @code{package-derivation} and
7457 @code{package-cross-derivation} (@pxref{Defining Packages}).
7462 @section G-Expressions
7464 @cindex G-expression
7465 @cindex build code quoting
7466 So we have ``derivations'', which represent a sequence of build actions
7467 to be performed to produce an item in the store (@pxref{Derivations}).
7468 These build actions are performed when asking the daemon to actually
7469 build the derivations; they are run by the daemon in a container
7470 (@pxref{Invoking guix-daemon}).
7472 @cindex strata of code
7473 It should come as no surprise that we like to write these build actions
7474 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7475 code@footnote{The term @dfn{stratum} in this context was coined by
7476 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7477 Kiselyov, who has written insightful
7478 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7479 on this topic}, refers to this kind of code generation as
7480 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7481 to the daemon, etc.---and the ``build code''---code that actually
7482 performs build actions, such as making directories, invoking
7483 @command{make}, etc.
7485 To describe a derivation and its build actions, one typically needs to
7486 embed build code inside host code. It boils down to manipulating build
7487 code as data, and the homoiconicity of Scheme---code has a direct
7488 representation as data---comes in handy for that. But we need more than
7489 the normal @code{quasiquote} mechanism in Scheme to construct build
7492 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7493 S-expressions adapted to build expressions. G-expressions, or
7494 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7495 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7496 @code{#$}, and @code{#$@@}), which are comparable to
7497 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7498 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7499 GNU Guile Reference Manual}). However, there are major differences:
7503 Gexps are meant to be written to a file and run or manipulated by other
7507 When a high-level object such as a package or derivation is unquoted
7508 inside a gexp, the result is as if its output file name had been
7512 Gexps carry information about the packages or derivations they refer to,
7513 and these dependencies are automatically added as inputs to the build
7514 processes that use them.
7517 @cindex lowering, of high-level objects in gexps
7518 This mechanism is not limited to package and derivation
7519 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7520 derivations or files in the store can be defined,
7521 such that these objects can also be inserted
7522 into gexps. For example, a useful type of high-level objects that can be
7523 inserted in a gexp is ``file-like objects'', which make it easy to
7524 add files to the store and to refer to them in
7525 derivations and such (see @code{local-file} and @code{plain-file}
7528 To illustrate the idea, here is an example of a gexp:
7535 (symlink (string-append #$coreutils "/bin/ls")
7539 This gexp can be passed to @code{gexp->derivation}; we obtain a
7540 derivation that builds a directory containing exactly one symlink to
7541 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7544 (gexp->derivation "the-thing" build-exp)
7547 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7548 substituted to the reference to the @var{coreutils} package in the
7549 actual build code, and @var{coreutils} is automatically made an input to
7550 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7551 output)}) is replaced by a string containing the directory name of the
7552 output of the derivation.
7554 @cindex cross compilation
7555 In a cross-compilation context, it is useful to distinguish between
7556 references to the @emph{native} build of a package---that can run on the
7557 host---versus references to cross builds of a package. To that end, the
7558 @code{#+} plays the same role as @code{#$}, but is a reference to a
7559 native package build:
7562 (gexp->derivation "vi"
7565 (mkdir (string-append #$output "/bin"))
7566 (system* (string-append #+coreutils "/bin/ln")
7568 (string-append #$emacs "/bin/emacs")
7569 (string-append #$output "/bin/vi")))
7570 #:target "mips64el-linux-gnu")
7574 In the example above, the native build of @var{coreutils} is used, so
7575 that @command{ln} can actually run on the host; but then the
7576 cross-compiled build of @var{emacs} is referenced.
7578 @cindex imported modules, for gexps
7579 @findex with-imported-modules
7580 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7581 able to use certain Guile modules from the ``host environment'' in the
7582 gexp, so those modules should be imported in the ``build environment''.
7583 The @code{with-imported-modules} form allows you to express that:
7586 (let ((build (with-imported-modules '((guix build utils))
7588 (use-modules (guix build utils))
7589 (mkdir-p (string-append #$output "/bin"))))))
7590 (gexp->derivation "empty-dir"
7593 (display "success!\n")
7598 In this example, the @code{(guix build utils)} module is automatically
7599 pulled into the isolated build environment of our gexp, such that
7600 @code{(use-modules (guix build utils))} works as expected.
7602 @cindex module closure
7603 @findex source-module-closure
7604 Usually you want the @emph{closure} of the module to be imported---i.e.,
7605 the module itself and all the modules it depends on---rather than just
7606 the module; failing to do that, attempts to use the module will fail
7607 because of missing dependent modules. The @code{source-module-closure}
7608 procedure computes the closure of a module by looking at its source file
7609 headers, which comes in handy in this case:
7612 (use-modules (guix modules)) ;for 'source-module-closure'
7614 (with-imported-modules (source-module-closure
7615 '((guix build utils)
7617 (gexp->derivation "something-with-vms"
7619 (use-modules (guix build utils)
7624 @cindex extensions, for gexps
7625 @findex with-extensions
7626 In the same vein, sometimes you want to import not just pure-Scheme
7627 modules, but also ``extensions'' such as Guile bindings to C libraries
7628 or other ``full-blown'' packages. Say you need the @code{guile-json}
7629 package available on the build side, here's how you would do it:
7632 (use-modules (gnu packages guile)) ;for 'guile-json'
7634 (with-extensions (list guile-json)
7635 (gexp->derivation "something-with-json"
7637 (use-modules (json))
7641 The syntactic form to construct gexps is summarized below.
7643 @deffn {Scheme Syntax} #~@var{exp}
7644 @deffnx {Scheme Syntax} (gexp @var{exp})
7645 Return a G-expression containing @var{exp}. @var{exp} may contain one
7646 or more of the following forms:
7650 @itemx (ungexp @var{obj})
7651 Introduce a reference to @var{obj}. @var{obj} may have one of the
7652 supported types, for example a package or a
7653 derivation, in which case the @code{ungexp} form is replaced by its
7654 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7656 If @var{obj} is a list, it is traversed and references to supported
7657 objects are substituted similarly.
7659 If @var{obj} is another gexp, its contents are inserted and its
7660 dependencies are added to those of the containing gexp.
7662 If @var{obj} is another kind of object, it is inserted as is.
7664 @item #$@var{obj}:@var{output}
7665 @itemx (ungexp @var{obj} @var{output})
7666 This is like the form above, but referring explicitly to the
7667 @var{output} of @var{obj}---this is useful when @var{obj} produces
7668 multiple outputs (@pxref{Packages with Multiple Outputs}).
7671 @itemx #+@var{obj}:output
7672 @itemx (ungexp-native @var{obj})
7673 @itemx (ungexp-native @var{obj} @var{output})
7674 Same as @code{ungexp}, but produces a reference to the @emph{native}
7675 build of @var{obj} when used in a cross compilation context.
7677 @item #$output[:@var{output}]
7678 @itemx (ungexp output [@var{output}])
7679 Insert a reference to derivation output @var{output}, or to the main
7680 output when @var{output} is omitted.
7682 This only makes sense for gexps passed to @code{gexp->derivation}.
7685 @itemx (ungexp-splicing @var{lst})
7686 Like the above, but splices the contents of @var{lst} inside the
7690 @itemx (ungexp-native-splicing @var{lst})
7691 Like the above, but refers to native builds of the objects listed in
7696 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7697 of the @code{gexp?} type (see below.)
7700 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7701 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7702 in their execution environment.
7704 Each item in @var{modules} can be the name of a module, such as
7705 @code{(guix build utils)}, or it can be a module name, followed by an
7706 arrow, followed by a file-like object:
7709 `((guix build utils)
7711 ((guix config) => ,(scheme-file "config.scm"
7712 #~(define-module @dots{}))))
7716 In the example above, the first two modules are taken from the search
7717 path, and the last one is created from the given file-like object.
7719 This form has @emph{lexical} scope: it has an effect on the gexps
7720 directly defined in @var{body}@dots{}, but not on those defined, say, in
7721 procedures called from @var{body}@dots{}.
7724 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7725 Mark the gexps defined in @var{body}@dots{} as requiring
7726 @var{extensions} in their build and execution environment.
7727 @var{extensions} is typically a list of package objects such as those
7728 defined in the @code{(gnu packages guile)} module.
7730 Concretely, the packages listed in @var{extensions} are added to the
7731 load path while compiling imported modules in @var{body}@dots{}; they
7732 are also added to the load path of the gexp returned by
7736 @deffn {Scheme Procedure} gexp? @var{obj}
7737 Return @code{#t} if @var{obj} is a G-expression.
7740 G-expressions are meant to be written to disk, either as code building
7741 some derivation, or as plain files in the store. The monadic procedures
7742 below allow you to do that (@pxref{The Store Monad}, for more
7743 information about monads.)
7745 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7746 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7747 [#:hash #f] [#:hash-algo #f] @
7748 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7749 [#:module-path @var{%load-path}] @
7750 [#:effective-version "2.2"] @
7751 [#:references-graphs #f] [#:allowed-references #f] @
7752 [#:disallowed-references #f] @
7753 [#:leaked-env-vars #f] @
7754 [#:script-name (string-append @var{name} "-builder")] @
7755 [#:deprecation-warnings #f] @
7756 [#:local-build? #f] [#:substitutable? #t] @
7757 [#:properties '()] [#:guile-for-build #f]
7758 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7759 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7760 stored in a file called @var{script-name}. When @var{target} is true,
7761 it is used as the cross-compilation target triplet for packages referred
7764 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7766 make @var{modules} available in the evaluation context of @var{exp};
7767 @var{modules} is a list of names of Guile modules searched in
7768 @var{module-path} to be copied in the store, compiled, and made available in
7769 the load path during the execution of @var{exp}---e.g., @code{((guix
7770 build utils) (guix build gnu-build-system))}.
7772 @var{effective-version} determines the string to use when adding extensions of
7773 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7775 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7778 When @var{references-graphs} is true, it must be a list of tuples of one of the
7782 (@var{file-name} @var{package})
7783 (@var{file-name} @var{package} @var{output})
7784 (@var{file-name} @var{derivation})
7785 (@var{file-name} @var{derivation} @var{output})
7786 (@var{file-name} @var{store-item})
7789 The right-hand-side of each element of @var{references-graphs} is automatically made
7790 an input of the build process of @var{exp}. In the build environment, each
7791 @var{file-name} contains the reference graph of the corresponding item, in a simple
7794 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7795 In the latter case, the list denotes store items that the result is allowed to
7796 refer to. Any reference to another store item will lead to a build error.
7797 Similarly for @var{disallowed-references}, which can list items that must not be
7798 referenced by the outputs.
7800 @var{deprecation-warnings} determines whether to show deprecation warnings while
7801 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7803 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7806 @cindex file-like objects
7807 The @code{local-file}, @code{plain-file}, @code{computed-file},
7808 @code{program-file}, and @code{scheme-file} procedures below return
7809 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7810 these objects lead to a file in the store. Consider this G-expression:
7813 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7814 #$(local-file "/tmp/my-nscd.conf"))
7817 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7818 to the store. Once expanded, for instance @i{via}
7819 @code{gexp->derivation}, the G-expression refers to that copy under
7820 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7821 does not have any effect on what the G-expression does.
7822 @code{plain-file} can be used similarly; it differs in that the file
7823 content is directly passed as a string.
7825 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7826 [#:recursive? #f] [#:select? (const #t)]
7827 Return an object representing local file @var{file} to add to the store;
7828 this object can be used in a gexp. If @var{file} is a literal string
7829 denoting a relative file name, it is looked up relative to the source
7830 file where it appears; if @var{file} is not a literal string, it is
7831 looked up relative to the current working directory at run time.
7832 @var{file} will be added to the store under @var{name}--by default the
7833 base name of @var{file}.
7835 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7836 designates a flat file and @var{recursive?} is true, its contents are added, and its
7837 permission bits are kept.
7839 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7840 @var{stat})} for each directory entry, where @var{file} is the entry's
7841 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7842 entries for which @var{select?} does not return true.
7844 This is the declarative counterpart of the @code{interned-file} monadic
7845 procedure (@pxref{The Store Monad, @code{interned-file}}).
7848 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7849 Return an object representing a text file called @var{name} with the given
7850 @var{content} (a string or a bytevector) to be added to the store.
7852 This is the declarative counterpart of @code{text-file}.
7855 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7856 [#:options '(#:local-build? #t)]
7857 Return an object representing the store item @var{name}, a file or
7858 directory computed by @var{gexp}. @var{options}
7859 is a list of additional arguments to pass to @code{gexp->derivation}.
7861 This is the declarative counterpart of @code{gexp->derivation}.
7864 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7865 [#:guile (default-guile)] [#:module-path %load-path] @
7866 [#:system (%current-system)] [#:target #f]
7867 Return an executable script @var{name} that runs @var{exp} using
7868 @var{guile}, with @var{exp}'s imported modules in its search path.
7869 Look up @var{exp}'s modules in @var{module-path}.
7871 The example below builds a script that simply invokes the @command{ls}
7875 (use-modules (guix gexp) (gnu packages base))
7877 (gexp->script "list-files"
7878 #~(execl #$(file-append coreutils "/bin/ls")
7882 When ``running'' it through the store (@pxref{The Store Monad,
7883 @code{run-with-store}}), we obtain a derivation that produces an
7884 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7887 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7889 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7893 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7894 [#:guile #f] [#:module-path %load-path]
7895 Return an object representing the executable store item @var{name} that
7896 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7897 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7899 This is the declarative counterpart of @code{gexp->script}.
7902 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7903 [#:set-load-path? #t] [#:module-path %load-path] @
7905 [#:guile (default-guile)]
7906 Return a derivation that builds a file @var{name} containing @var{exp}.
7907 When @var{splice?} is true, @var{exp} is considered to be a list of
7908 expressions that will be spliced in the resulting file.
7910 When @var{set-load-path?} is true, emit code in the resulting file to
7911 set @code{%load-path} and @code{%load-compiled-path} to honor
7912 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7915 The resulting file holds references to all the dependencies of @var{exp}
7916 or a subset thereof.
7919 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7920 Return an object representing the Scheme file @var{name} that contains
7923 This is the declarative counterpart of @code{gexp->file}.
7926 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7927 Return as a monadic value a derivation that builds a text file
7928 containing all of @var{text}. @var{text} may list, in addition to
7929 strings, objects of any type that can be used in a gexp: packages,
7930 derivations, local file objects, etc. The resulting store file holds
7931 references to all these.
7933 This variant should be preferred over @code{text-file} anytime the file
7934 to create will reference items from the store. This is typically the
7935 case when building a configuration file that embeds store file names,
7939 (define (profile.sh)
7940 ;; Return the name of a shell script in the store that
7941 ;; initializes the 'PATH' environment variable.
7942 (text-file* "profile.sh"
7943 "export PATH=" coreutils "/bin:"
7944 grep "/bin:" sed "/bin\n"))
7947 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7948 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7949 preventing them from being garbage-collected during its lifetime.
7952 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7953 Return an object representing store file @var{name} containing
7954 @var{text}. @var{text} is a sequence of strings and file-like objects,
7958 (mixed-text-file "profile"
7959 "export PATH=" coreutils "/bin:" grep "/bin")
7962 This is the declarative counterpart of @code{text-file*}.
7965 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7966 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7967 Each item in @var{files} must be a two-element list where the first element is the
7968 file name to use in the new directory, and the second element is a gexp
7969 denoting the target file. Here's an example:
7973 `(("hosts" ,(plain-file "hosts"
7974 "127.0.0.1 localhost"))
7975 ("bashrc" ,(plain-file "bashrc"
7976 "alias ls='ls --color=auto'"))))
7979 This yields an @code{etc} directory containing these two files.
7982 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7983 Return a directory that is the union of @var{things}, where @var{things} is a list of
7984 file-like objects denoting directories. For example:
7987 (directory-union "guile+emacs" (list guile emacs))
7990 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7993 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7994 Return a file-like object that expands to the concatenation of @var{obj}
7995 and @var{suffix}, where @var{obj} is a lowerable object and each
7996 @var{suffix} is a string.
7998 As an example, consider this gexp:
8001 (gexp->script "run-uname"
8002 #~(system* #$(file-append coreutils
8006 The same effect could be achieved with:
8009 (gexp->script "run-uname"
8010 #~(system* (string-append #$coreutils
8014 There is one difference though: in the @code{file-append} case, the
8015 resulting script contains the absolute file name as a string, whereas in
8016 the second case, the resulting script contains a @code{(string-append
8017 @dots{})} expression to construct the file name @emph{at run time}.
8020 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8021 This macro is similar to the @code{parameterize} form for
8022 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8023 Guile Reference Manual}). The key difference is that it takes effect
8024 when the file-like object returned by @var{exp} is lowered to a
8025 derivation or store item.
8027 A typical use of @code{with-parameters} is to force the system in effect
8031 (with-parameters ((%current-system "i686-linux"))
8035 The example above returns an object that corresponds to the i686 build
8036 of Coreutils, regardless of the current value of @code{%current-system}.
8040 Of course, in addition to gexps embedded in ``host'' code, there are
8041 also modules containing build tools. To make it clear that they are
8042 meant to be used in the build stratum, these modules are kept in the
8043 @code{(guix build @dots{})} name space.
8045 @cindex lowering, of high-level objects in gexps
8046 Internally, high-level objects are @dfn{lowered}, using their compiler,
8047 to either derivations or store items. For instance, lowering a package
8048 yields a derivation, and lowering a @code{plain-file} yields a store
8049 item. This is achieved using the @code{lower-object} monadic procedure.
8051 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8053 Return as a value in @var{%store-monad} the derivation or store item
8054 corresponding to @var{obj} for @var{system}, cross-compiling for
8055 @var{target} if @var{target} is true. @var{obj} must be an object that
8056 has an associated gexp compiler, such as a @code{<package>}.
8059 @node Invoking guix repl
8060 @section Invoking @command{guix repl}
8062 @cindex REPL, read-eval-print loop
8063 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
8064 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
8065 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
8066 command, @command{guix repl} guarantees that all the Guix modules and all its
8067 dependencies are available in the search path. You can use it this way:
8071 scheme@@(guile-user)> ,use (gnu packages base)
8072 scheme@@(guile-user)> coreutils
8073 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8077 In addition, @command{guix repl} implements a simple machine-readable REPL
8078 protocol for use by @code{(guix inferior)}, a facility to interact with
8079 @dfn{inferiors}, separate processes running a potentially different revision
8082 The available options are as follows:
8085 @item --type=@var{type}
8086 @itemx -t @var{type}
8087 Start a REPL of the given @var{TYPE}, which can be one of the following:
8091 This is default, and it spawns a standard full-featured Guile REPL.
8093 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8094 that the @code{(guix inferior)} module speaks.
8097 @item --listen=@var{endpoint}
8098 By default, @command{guix repl} reads from standard input and writes to
8099 standard output. When this option is passed, it will instead listen for
8100 connections on @var{endpoint}. Here are examples of valid options:
8103 @item --listen=tcp:37146
8104 Accept connections on localhost on port 37146.
8106 @item --listen=unix:/tmp/socket
8107 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8110 @item --load-path=@var{directory}
8111 @itemx -L @var{directory}
8112 Add @var{directory} to the front of the package module search path
8113 (@pxref{Package Modules}).
8115 This allows users to define their own packages and make them visible to
8116 the command-line tool.
8119 Inhibit loading of the @file{~/.guile} file. By default, that
8120 configuration file is loaded when spawning a @code{guile} REPL.
8123 @c *********************************************************************
8127 This section describes Guix command-line utilities. Some of them are
8128 primarily targeted at developers and users who write new package
8129 definitions, while others are more generally useful. They complement
8130 the Scheme programming interface of Guix in a convenient way.
8133 * Invoking guix build:: Building packages from the command line.
8134 * Invoking guix edit:: Editing package definitions.
8135 * Invoking guix download:: Downloading a file and printing its hash.
8136 * Invoking guix hash:: Computing the cryptographic hash of a file.
8137 * Invoking guix import:: Importing package definitions.
8138 * Invoking guix refresh:: Updating package definitions.
8139 * Invoking guix lint:: Finding errors in package definitions.
8140 * Invoking guix size:: Profiling disk usage.
8141 * Invoking guix graph:: Visualizing the graph of packages.
8142 * Invoking guix publish:: Sharing substitutes.
8143 * Invoking guix challenge:: Challenging substitute servers.
8144 * Invoking guix copy:: Copying to and from a remote store.
8145 * Invoking guix container:: Process isolation.
8146 * Invoking guix weather:: Assessing substitute availability.
8147 * Invoking guix processes:: Listing client processes.
8150 @node Invoking guix build
8151 @section Invoking @command{guix build}
8153 @cindex package building
8154 @cindex @command{guix build}
8155 The @command{guix build} command builds packages or derivations and
8156 their dependencies, and prints the resulting store paths. Note that it
8157 does not modify the user's profile---this is the job of the
8158 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8159 it is mainly useful for distribution developers.
8161 The general syntax is:
8164 guix build @var{options} @var{package-or-derivation}@dots{}
8167 As an example, the following command builds the latest versions of Emacs
8168 and of Guile, displays their build logs, and finally displays the
8169 resulting directories:
8172 guix build emacs guile
8175 Similarly, the following command builds all the available packages:
8178 guix build --quiet --keep-going \
8179 `guix package -A | cut -f1,2 --output-delimiter=@@`
8182 @var{package-or-derivation} may be either the name of a package found in
8183 the software distribution such as @code{coreutils} or
8184 @code{coreutils@@8.20}, or a derivation such as
8185 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8186 package with the corresponding name (and optionally version) is searched
8187 for among the GNU distribution modules (@pxref{Package Modules}).
8189 Alternatively, the @code{--expression} option may be used to specify a
8190 Scheme expression that evaluates to a package; this is useful when
8191 disambiguating among several same-named packages or package variants is
8194 There may be zero or more @var{options}. The available options are
8195 described in the subsections below.
8198 * Common Build Options:: Build options for most commands.
8199 * Package Transformation Options:: Creating variants of packages.
8200 * Additional Build Options:: Options specific to 'guix build'.
8201 * Debugging Build Failures:: Real life packaging experience.
8204 @node Common Build Options
8205 @subsection Common Build Options
8207 A number of options that control the build process are common to
8208 @command{guix build} and other commands that can spawn builds, such as
8209 @command{guix package} or @command{guix archive}. These are the
8214 @item --load-path=@var{directory}
8215 @itemx -L @var{directory}
8216 Add @var{directory} to the front of the package module search path
8217 (@pxref{Package Modules}).
8219 This allows users to define their own packages and make them visible to
8220 the command-line tools.
8224 Keep the build tree of failed builds. Thus, if a build fails, its build
8225 tree is kept under @file{/tmp}, in a directory whose name is shown at
8226 the end of the build log. This is useful when debugging build issues.
8227 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8230 This option implies @option{--no-offload}, and it has no effect when
8231 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8232 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8236 Keep going when some of the derivations fail to build; return only once
8237 all the builds have either completed or failed.
8239 The default behavior is to stop as soon as one of the specified
8240 derivations has failed.
8244 Do not build the derivations.
8246 @anchor{fallback-option}
8248 When substituting a pre-built binary fails, fall back to building
8249 packages locally (@pxref{Substitution Failure}).
8251 @item --substitute-urls=@var{urls}
8252 @anchor{client-substitute-urls}
8253 Consider @var{urls} the whitespace-separated list of substitute source
8254 URLs, overriding the default list of URLs of @command{guix-daemon}
8255 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8257 This means that substitutes may be downloaded from @var{urls}, provided
8258 they are signed by a key authorized by the system administrator
8259 (@pxref{Substitutes}).
8261 When @var{urls} is the empty string, substitutes are effectively
8264 @item --no-substitutes
8265 Do not use substitutes for build products. That is, always build things
8266 locally instead of allowing downloads of pre-built binaries
8267 (@pxref{Substitutes}).
8270 Do not ``graft'' packages. In practice, this means that package updates
8271 available as grafts are not applied. @xref{Security Updates}, for more
8272 information on grafts.
8274 @item --rounds=@var{n}
8275 Build each derivation @var{n} times in a row, and raise an error if
8276 consecutive build results are not bit-for-bit identical.
8278 This is a useful way to detect non-deterministic builds processes.
8279 Non-deterministic build processes are a problem because they make it
8280 practically impossible for users to @emph{verify} whether third-party
8281 binaries are genuine. @xref{Invoking guix challenge}, for more.
8283 Note that, currently, the differing build results are not kept around,
8284 so you will have to manually investigate in case of an error---e.g., by
8285 stashing one of the build results with @code{guix archive --export}
8286 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8290 Do not use offload builds to other machines (@pxref{Daemon Offload
8291 Setup}). That is, always build things locally instead of offloading
8292 builds to remote machines.
8294 @item --max-silent-time=@var{seconds}
8295 When the build or substitution process remains silent for more than
8296 @var{seconds}, terminate it and report a build failure.
8298 By default, the daemon's setting is honored (@pxref{Invoking
8299 guix-daemon, @code{--max-silent-time}}).
8301 @item --timeout=@var{seconds}
8302 Likewise, when the build or substitution process lasts for more than
8303 @var{seconds}, terminate it and report a build failure.
8305 By default, the daemon's setting is honored (@pxref{Invoking
8306 guix-daemon, @code{--timeout}}).
8308 @c Note: This option is actually not part of %standard-build-options but
8309 @c most programs honor it.
8310 @cindex verbosity, of the command-line tools
8311 @cindex build logs, verbosity
8312 @item -v @var{level}
8313 @itemx --verbosity=@var{level}
8314 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8315 output is produced, 1 is for quiet output, and 2 shows all the build log
8316 output on standard error.
8318 @item --cores=@var{n}
8320 Allow the use of up to @var{n} CPU cores for the build. The special
8321 value @code{0} means to use as many CPU cores as available.
8323 @item --max-jobs=@var{n}
8325 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8326 guix-daemon, @code{--max-jobs}}, for details about this option and the
8327 equivalent @command{guix-daemon} option.
8329 @item --debug=@var{level}
8330 Produce debugging output coming from the build daemon. @var{level} must be an
8331 integer between 0 and 5; higher means more verbose output. Setting a level of
8332 4 or more may be helpful when debugging setup issues with the build daemon.
8336 Behind the scenes, @command{guix build} is essentially an interface to
8337 the @code{package-derivation} procedure of the @code{(guix packages)}
8338 module, and to the @code{build-derivations} procedure of the @code{(guix
8339 derivations)} module.
8341 In addition to options explicitly passed on the command line,
8342 @command{guix build} and other @command{guix} commands that support
8343 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8345 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8346 Users can define this variable to a list of command line options that
8347 will automatically be used by @command{guix build} and other
8348 @command{guix} commands that can perform builds, as in the example
8352 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8355 These options are parsed independently, and the result is appended to
8356 the parsed command-line options.
8360 @node Package Transformation Options
8361 @subsection Package Transformation Options
8363 @cindex package variants
8364 Another set of command-line options supported by @command{guix build}
8365 and also @command{guix package} are @dfn{package transformation
8366 options}. These are options that make it possible to define @dfn{package
8367 variants}---for instance, packages built from different source code.
8368 This is a convenient way to create customized packages on the fly
8369 without having to type in the definitions of package variants
8370 (@pxref{Defining Packages}).
8374 @item --with-source=@var{source}
8375 @itemx --with-source=@var{package}=@var{source}
8376 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8377 Use @var{source} as the source of @var{package}, and @var{version} as
8379 @var{source} must be a file name or a URL, as for @command{guix
8380 download} (@pxref{Invoking guix download}).
8382 When @var{package} is omitted,
8383 it is taken to be the package name specified on the
8384 command line that matches the base of @var{source}---e.g.,
8385 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8386 package is @code{guile}.
8388 Likewise, when @var{version} is omitted, the version string is inferred from
8389 @var{source}; in the previous example, it is @code{2.0.10}.
8391 This option allows users to try out versions of packages other than the
8392 one provided by the distribution. The example below downloads
8393 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8394 the @code{ed} package:
8397 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8400 As a developer, @code{--with-source} makes it easy to test release
8404 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8407 @dots{} or to build from a checkout in a pristine environment:
8410 $ git clone git://git.sv.gnu.org/guix.git
8411 $ guix build guix --with-source=guix@@1.0=./guix
8414 @item --with-input=@var{package}=@var{replacement}
8415 Replace dependency on @var{package} by a dependency on
8416 @var{replacement}. @var{package} must be a package name, and
8417 @var{replacement} must be a package specification such as @code{guile}
8418 or @code{guile@@1.8}.
8420 For instance, the following command builds Guix, but replaces its
8421 dependency on the current stable version of Guile with a dependency on
8422 the legacy version of Guile, @code{guile@@2.0}:
8425 guix build --with-input=guile=guile@@2.0 guix
8428 This is a recursive, deep replacement. So in this example, both
8429 @code{guix} and its dependency @code{guile-json} (which also depends on
8430 @code{guile}) get rebuilt against @code{guile@@2.0}.
8432 This is implemented using the @code{package-input-rewriting} Scheme
8433 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8435 @item --with-graft=@var{package}=@var{replacement}
8436 This is similar to @code{--with-input} but with an important difference:
8437 instead of rebuilding the whole dependency chain, @var{replacement} is
8438 built and then @dfn{grafted} onto the binaries that were initially
8439 referring to @var{package}. @xref{Security Updates}, for more
8440 information on grafts.
8442 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8443 and all its dependencies, replacing references to the version of GnuTLS
8444 they currently refer to:
8447 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8450 This has the advantage of being much faster than rebuilding everything.
8451 But there is a caveat: it works if and only if @var{package} and
8452 @var{replacement} are strictly compatible---for example, if they provide
8453 a library, the application binary interface (ABI) of those libraries
8454 must be compatible. If @var{replacement} is somehow incompatible with
8455 @var{package}, then the resulting package may be unusable. Use with
8458 @item --with-git-url=@var{package}=@var{url}
8459 @cindex Git, using the latest commit
8460 @cindex latest commit, building
8461 Build @var{package} from the latest commit of the @code{master} branch of the
8462 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8465 For example, the following command builds the NumPy Python library against the
8466 latest commit of the master branch of Python itself:
8469 guix build python-numpy \
8470 --with-git-url=python=https://github.com/python/cpython
8473 This option can also be combined with @code{--with-branch} or
8474 @code{--with-commit} (see below).
8476 @cindex continuous integration
8477 Obviously, since it uses the latest commit of the given branch, the result of
8478 such a command varies over time. Nevertheless it is a convenient way to
8479 rebuild entire software stacks against the latest commit of one or more
8480 packages. This is particularly useful in the context of continuous
8483 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8484 consecutive accesses to the same repository. You may want to clean it up once
8485 in a while to save disk space.
8487 @item --with-branch=@var{package}=@var{branch}
8488 Build @var{package} from the latest commit of @var{branch}. If the
8489 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8490 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8491 repository URL is taken from that @code{source}. Otherwise you have to use
8492 @code{--with-git-url} to specify the URL of the Git repository.
8494 For instance, the following command builds @code{guile-sqlite3} from the
8495 latest commit of its @code{master} branch, and then builds @code{guix} (which
8496 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8497 specific @code{guile-sqlite3} build:
8500 guix build --with-branch=guile-sqlite3=master cuirass
8503 @item --with-commit=@var{package}=@var{commit}
8504 This is similar to @code{--with-branch}, except that it builds from
8505 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8506 Git commit SHA1 identifier or a tag.
8509 @node Additional Build Options
8510 @subsection Additional Build Options
8512 The command-line options presented below are specific to @command{guix
8519 Build quietly, without displaying the build log; this is equivalent to
8520 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8521 (or similar) and can always be retrieved using the @option{--log-file} option.
8523 @item --file=@var{file}
8524 @itemx -f @var{file}
8525 Build the package, derivation, or other file-like object that the code within
8526 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8528 As an example, @var{file} might contain a package definition like this
8529 (@pxref{Defining Packages}):
8532 @include package-hello.scm
8535 @item --manifest=@var{manifest}
8536 @itemx -m @var{manifest}
8537 Build all packages listed in the given @var{manifest}
8538 (@pxref{profile-manifest, @option{--manifest}}).
8540 @item --expression=@var{expr}
8541 @itemx -e @var{expr}
8542 Build the package or derivation @var{expr} evaluates to.
8544 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8545 guile-1.8)}, which unambiguously designates this specific variant of
8546 version 1.8 of Guile.
8548 Alternatively, @var{expr} may be a G-expression, in which case it is used
8549 as a build program passed to @code{gexp->derivation}
8550 (@pxref{G-Expressions}).
8552 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8553 (@pxref{The Store Monad}). The procedure must return a derivation as a
8554 monadic value, which is then passed through @code{run-with-store}.
8558 Build the source derivations of the packages, rather than the packages
8561 For instance, @code{guix build -S gcc} returns something like
8562 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8565 The returned source tarball is the result of applying any patches and
8566 code snippets specified in the package @code{origin} (@pxref{Defining
8569 Note that @command{guix build -S} compiles the sources only of the
8570 specified packages. They do not include the sources of statically
8571 linked dependencies and by themselves are insufficient for reproducing
8575 Fetch and return the source of @var{package-or-derivation} and all their
8576 dependencies, recursively. This is a handy way to obtain a local copy
8577 of all the source code needed to build @var{packages}, allowing you to
8578 eventually build them even without network access. It is an extension
8579 of the @code{--source} option and can accept one of the following
8580 optional argument values:
8584 This value causes the @code{--sources} option to behave in the same way
8585 as the @code{--source} option.
8588 Build the source derivations of all packages, including any source that
8589 might be listed as @code{inputs}. This is the default value.
8592 $ guix build --sources tzdata
8593 The following derivations will be built:
8594 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8595 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8599 Build the source derivations of all packages, as well of all transitive
8600 inputs to the packages. This can be used e.g.@: to
8601 prefetch package source for later offline building.
8604 $ guix build --sources=transitive tzdata
8605 The following derivations will be built:
8606 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8607 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8608 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8609 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8610 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8611 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8617 @item --system=@var{system}
8618 @itemx -s @var{system}
8619 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8620 the system type of the build host. The @command{guix build} command allows
8621 you to repeat this option several times, in which case it builds for all the
8622 specified systems; other commands ignore extraneous @option{-s} options.
8625 The @code{--system} flag is for @emph{native} compilation and must not
8626 be confused with cross-compilation. See @code{--target} below for
8627 information on cross-compilation.
8630 An example use of this is on Linux-based systems, which can emulate
8631 different personalities. For instance, passing
8632 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8633 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8634 to build packages in a complete 32-bit environment.
8637 Building for an @code{armhf-linux} system is unconditionally enabled on
8638 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8639 allow for this functionality, notably the ThunderX.
8642 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8643 is enabled (@pxref{Virtualization Services,
8644 @code{qemu-binfmt-service-type}}), you can build for any system for
8645 which a QEMU @code{binfmt_misc} handler is installed.
8647 Builds for a system other than that of the machine you are using can
8648 also be offloaded to a remote machine of the right architecture.
8649 @xref{Daemon Offload Setup}, for more information on offloading.
8651 @item --target=@var{triplet}
8652 @cindex cross-compilation
8653 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8654 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8655 configuration triplets,, autoconf, Autoconf}).
8657 @anchor{build-check}
8659 @cindex determinism, checking
8660 @cindex reproducibility, checking
8661 Rebuild @var{package-or-derivation}, which are already available in the
8662 store, and raise an error if the build results are not bit-for-bit
8665 This mechanism allows you to check whether previously installed
8666 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8667 of a package is deterministic. @xref{Invoking guix challenge}, for more
8668 background information and tools.
8670 When used in conjunction with @option{--keep-failed}, the differing
8671 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8672 This makes it easy to look for differences between the two results.
8675 @cindex repairing store items
8676 @cindex corruption, recovering from
8677 Attempt to repair the specified store items, if they are corrupt, by
8678 re-downloading or rebuilding them.
8680 This operation is not atomic and thus restricted to @code{root}.
8684 Return the derivation paths, not the output paths, of the given
8687 @item --root=@var{file}
8688 @itemx -r @var{file}
8689 @cindex GC roots, adding
8690 @cindex garbage collector roots, adding
8691 Make @var{file} a symlink to the result, and register it as a garbage
8694 Consequently, the results of this @command{guix build} invocation are
8695 protected from garbage collection until @var{file} is removed. When
8696 that option is omitted, build results are eligible for garbage
8697 collection as soon as the build completes. @xref{Invoking guix gc}, for
8701 @cindex build logs, access
8702 Return the build log file names or URLs for the given
8703 @var{package-or-derivation}, or raise an error if build logs are
8706 This works regardless of how packages or derivations are specified. For
8707 instance, the following invocations are equivalent:
8710 guix build --log-file `guix build -d guile`
8711 guix build --log-file `guix build guile`
8712 guix build --log-file guile
8713 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8716 If a log is unavailable locally, and unless @code{--no-substitutes} is
8717 passed, the command looks for a corresponding log on one of the
8718 substitute servers (as specified with @code{--substitute-urls}.)
8720 So for instance, imagine you want to see the build log of GDB on MIPS,
8721 but you are actually on an @code{x86_64} machine:
8724 $ guix build --log-file gdb -s mips64el-linux
8725 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8728 You can freely access a huge library of build logs!
8731 @node Debugging Build Failures
8732 @subsection Debugging Build Failures
8734 @cindex build failures, debugging
8735 When defining a new package (@pxref{Defining Packages}), you will
8736 probably find yourself spending some time debugging and tweaking the
8737 build until it succeeds. To do that, you need to operate the build
8738 commands yourself in an environment as close as possible to the one the
8741 To that end, the first thing to do is to use the @option{--keep-failed}
8742 or @option{-K} option of @command{guix build}, which will keep the
8743 failed build tree in @file{/tmp} or whatever directory you specified as
8744 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8746 From there on, you can @command{cd} to the failed build tree and source
8747 the @file{environment-variables} file, which contains all the
8748 environment variable definitions that were in place when the build
8749 failed. So let's say you're debugging a build failure in package
8750 @code{foo}; a typical session would look like this:
8754 @dots{} @i{build fails}
8755 $ cd /tmp/guix-build-foo.drv-0
8756 $ source ./environment-variables
8760 Now, you can invoke commands as if you were the daemon (almost) and
8761 troubleshoot your build process.
8763 Sometimes it happens that, for example, a package's tests pass when you
8764 run them manually but they fail when the daemon runs them. This can
8765 happen because the daemon runs builds in containers where, unlike in our
8766 environment above, network access is missing, @file{/bin/sh} does not
8767 exist, etc. (@pxref{Build Environment Setup}).
8769 In such cases, you may need to run inspect the build process from within
8770 a container similar to the one the build daemon creates:
8775 $ cd /tmp/guix-build-foo.drv-0
8776 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8777 [env]# source ./environment-variables
8781 Here, @command{guix environment -C} creates a container and spawns a new
8782 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8783 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8784 the container, which would may find handy while debugging. The
8785 @option{--no-grafts} option makes sure we get the exact same
8786 environment, with ungrafted packages (@pxref{Security Updates}, for more
8789 To get closer to a container like that used by the build daemon, we can
8790 remove @file{/bin/sh}:
8796 (Don't worry, this is harmless: this is all happening in the throw-away
8797 container created by @command{guix environment}.)
8799 The @command{strace} command is probably not in the search path, but we
8803 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8806 In this way, not only you will have reproduced the environment variables
8807 the daemon uses, you will also be running the build process in a container
8808 similar to the one the daemon uses.
8811 @node Invoking guix edit
8812 @section Invoking @command{guix edit}
8814 @cindex @command{guix edit}
8815 @cindex package definition, editing
8816 So many packages, so many source files! The @command{guix edit} command
8817 facilitates the life of users and packagers by pointing their editor at
8818 the source file containing the definition of the specified packages.
8822 guix edit gcc@@4.9 vim
8826 launches the program specified in the @code{VISUAL} or in the
8827 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8830 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8831 have created your own packages on @code{GUIX_PACKAGE_PATH}
8832 (@pxref{Package Modules}), you will be able to edit the package
8833 recipes. In other cases, you will be able to examine the read-only recipes
8834 for packages currently in the store.
8836 Instead of @code{GUIX_PACKAGE_PATH}, the command-line option
8837 @code{--load-path=@var{directory}} (or in short @code{-L
8838 @var{directory}}) allows you to add @var{directory} to the front of the
8839 package module search path and so make your own packages visible.
8841 @node Invoking guix download
8842 @section Invoking @command{guix download}
8844 @cindex @command{guix download}
8845 @cindex downloading package sources
8846 When writing a package definition, developers typically need to download
8847 a source tarball, compute its SHA256 hash, and write that
8848 hash in the package definition (@pxref{Defining Packages}). The
8849 @command{guix download} tool helps with this task: it downloads a file
8850 from the given URI, adds it to the store, and prints both its file name
8851 in the store and its SHA256 hash.
8853 The fact that the downloaded file is added to the store saves bandwidth:
8854 when the developer eventually tries to build the newly defined package
8855 with @command{guix build}, the source tarball will not have to be
8856 downloaded again because it is already in the store. It is also a
8857 convenient way to temporarily stash files, which may be deleted
8858 eventually (@pxref{Invoking guix gc}).
8860 The @command{guix download} command supports the same URIs as used in
8861 package definitions. In particular, it supports @code{mirror://} URIs.
8862 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8863 Guile bindings for GnuTLS are available in the user's environment; when
8864 they are not available, an error is raised. @xref{Guile Preparations,
8865 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8866 GnuTLS-Guile}, for more information.
8868 @command{guix download} verifies HTTPS server certificates by loading
8869 the certificates of X.509 authorities from the directory pointed to by
8870 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8871 Certificates}), unless @option{--no-check-certificate} is used.
8873 The following options are available:
8876 @item --format=@var{fmt}
8878 Write the hash in the format specified by @var{fmt}. For more
8879 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8881 @item --no-check-certificate
8882 Do not validate the X.509 certificates of HTTPS servers.
8884 When using this option, you have @emph{absolutely no guarantee} that you
8885 are communicating with the authentic server responsible for the given
8886 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8888 @item --output=@var{file}
8889 @itemx -o @var{file}
8890 Save the downloaded file to @var{file} instead of adding it to the
8894 @node Invoking guix hash
8895 @section Invoking @command{guix hash}
8897 @cindex @command{guix hash}
8898 The @command{guix hash} command computes the SHA256 hash of a file.
8899 It is primarily a convenience tool for anyone contributing to the
8900 distribution: it computes the cryptographic hash of a file, which can be
8901 used in the definition of a package (@pxref{Defining Packages}).
8903 The general syntax is:
8906 guix hash @var{option} @var{file}
8909 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8910 hash of data read from standard input. @command{guix hash} has the
8915 @item --format=@var{fmt}
8917 Write the hash in the format specified by @var{fmt}.
8919 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8920 (@code{hex} and @code{hexadecimal} can be used as well).
8922 If the @option{--format} option is not specified, @command{guix hash}
8923 will output the hash in @code{nix-base32}. This representation is used
8924 in the definitions of packages.
8928 Compute the hash on @var{file} recursively.
8930 In this case, the hash is computed on an archive containing @var{file},
8931 including its children if it is a directory. Some of the metadata of
8932 @var{file} is part of the archive; for instance, when @var{file} is a
8933 regular file, the hash is different depending on whether @var{file} is
8934 executable or not. Metadata such as time stamps has no impact on the
8935 hash (@pxref{Invoking guix archive}).
8936 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8941 When combined with @option{--recursive}, exclude version control system
8942 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8945 As an example, here is how you would compute the hash of a Git checkout,
8946 which is useful when using the @code{git-fetch} method (@pxref{origin
8950 $ git clone http://example.org/foo.git
8956 @node Invoking guix import
8957 @section Invoking @command{guix import}
8959 @cindex importing packages
8960 @cindex package import
8961 @cindex package conversion
8962 @cindex Invoking @command{guix import}
8963 The @command{guix import} command is useful for people who would like to
8964 add a package to the distribution with as little work as
8965 possible---a legitimate demand. The command knows of a few
8966 repositories from which it can ``import'' package metadata. The result
8967 is a package definition, or a template thereof, in the format we know
8968 (@pxref{Defining Packages}).
8970 The general syntax is:
8973 guix import @var{importer} @var{options}@dots{}
8976 @var{importer} specifies the source from which to import package
8977 metadata, and @var{options} specifies a package identifier and other
8978 options specific to @var{importer}.
8980 Some of the importers rely on the ability to run the @command{gpgv} command.
8981 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8984 Currently, the available ``importers'' are:
8988 Import metadata for the given GNU package. This provides a template
8989 for the latest version of that GNU package, including the hash of its
8990 source tarball, and its canonical synopsis and description.
8992 Additional information such as the package dependencies and its
8993 license needs to be figured out manually.
8995 For example, the following command returns a package definition for
8999 guix import gnu hello
9002 Specific command-line options are:
9005 @item --key-download=@var{policy}
9006 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
9007 keys when verifying the package signature. @xref{Invoking guix
9008 refresh, @code{--key-download}}.
9013 Import metadata from the @uref{https://pypi.python.org/, Python Package
9014 Index}. Information is taken from the JSON-formatted description
9015 available at @code{pypi.python.org} and usually includes all the relevant
9016 information, including package dependencies. For maximum efficiency, it
9017 is recommended to install the @command{unzip} utility, so that the
9018 importer can unzip Python wheels and gather data from them.
9020 The command below imports metadata for the @code{itsdangerous} Python
9024 guix import pypi itsdangerous
9030 Traverse the dependency graph of the given upstream package recursively
9031 and generate package expressions for all those packages that are not yet
9037 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9038 is taken from the JSON-formatted description available at
9039 @code{rubygems.org} and includes most relevant information, including
9040 runtime dependencies. There are some caveats, however. The metadata
9041 doesn't distinguish between synopses and descriptions, so the same string
9042 is used for both fields. Additionally, the details of non-Ruby
9043 dependencies required to build native extensions is unavailable and left
9044 as an exercise to the packager.
9046 The command below imports metadata for the @code{rails} Ruby package:
9049 guix import gem rails
9055 Traverse the dependency graph of the given upstream package recursively
9056 and generate package expressions for all those packages that are not yet
9062 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9063 Information is taken from the JSON-formatted metadata provided through
9064 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9065 relevant information, such as module dependencies. License information
9066 should be checked closely. If Perl is available in the store, then the
9067 @code{corelist} utility will be used to filter core modules out of the
9068 list of dependencies.
9070 The command command below imports metadata for the @code{Acme::Boolean}
9074 guix import cpan Acme::Boolean
9079 @cindex Bioconductor
9080 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9081 central repository for the @uref{https://r-project.org, GNU@tie{}R
9082 statistical and graphical environment}.
9084 Information is extracted from the @code{DESCRIPTION} file of the package.
9086 The command command below imports metadata for the @code{Cairo}
9090 guix import cran Cairo
9093 When @code{--recursive} is added, the importer will traverse the
9094 dependency graph of the given upstream package recursively and generate
9095 package expressions for all those packages that are not yet in Guix.
9097 When @code{--archive=bioconductor} is added, metadata is imported from
9098 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9099 packages for for the analysis and comprehension of high-throughput
9100 genomic data in bioinformatics.
9102 Information is extracted from the @code{DESCRIPTION} file contained in the
9105 The command below imports metadata for the @code{GenomicRanges}
9109 guix import cran --archive=bioconductor GenomicRanges
9112 Finally, you can also import R packages that have not yet been published on
9113 CRAN or Bioconductor as long as they are in a git repository. Use
9114 @code{--archive=git} followed by the URL of the git repository:
9117 guix import cran --archive=git https://github.com/immunogenomics/harmony
9123 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9124 comprehensive TeX archive network for TeX packages that are part of the
9125 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9127 Information about the package is obtained through the XML API provided
9128 by CTAN, while the source code is downloaded from the SVN repository of
9129 the Tex Live project. This is done because the CTAN does not keep
9132 The command command below imports metadata for the @code{fontspec}
9136 guix import texlive fontspec
9139 When @code{--archive=DIRECTORY} is added, the source code is downloaded
9140 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
9141 tree in the TeX Live SVN repository, but from the specified sibling
9142 directory under the same root.
9144 The command below imports metadata for the @code{ifxetex} package from
9145 CTAN while fetching the sources from the directory
9146 @file{texmf/source/generic}:
9149 guix import texlive --archive=generic ifxetex
9153 @cindex JSON, import
9154 Import package metadata from a local JSON file. Consider the following
9155 example package definition in JSON format:
9161 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9162 "build-system": "gnu",
9163 "home-page": "https://www.gnu.org/software/hello/",
9164 "synopsis": "Hello, GNU world: An example GNU package",
9165 "description": "GNU Hello prints a greeting.",
9166 "license": "GPL-3.0+",
9167 "native-inputs": ["gettext"]
9171 The field names are the same as for the @code{<package>} record
9172 (@xref{Defining Packages}). References to other packages are provided
9173 as JSON lists of quoted package specification strings such as
9174 @code{guile} or @code{guile@@2.0}.
9176 The importer also supports a more explicit source definition using the
9177 common fields for @code{<origin>} records:
9183 "method": "url-fetch",
9184 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9186 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9193 The command below reads metadata from the JSON file @code{hello.json}
9194 and outputs a package expression:
9197 guix import json hello.json
9201 Import metadata from a local copy of the source of the
9202 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9203 relies on the @command{nix-instantiate} command of
9204 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9205 typically written in a mixture of Nix-language and Bash code. This
9206 command only imports the high-level package structure that is written in
9207 the Nix language. It normally includes all the basic fields of a
9210 When importing a GNU package, the synopsis and descriptions are replaced
9211 by their canonical upstream variant.
9213 Usually, you will first need to do:
9216 export NIX_REMOTE=daemon
9220 so that @command{nix-instantiate} does not try to open the Nix database.
9222 As an example, the command below imports the package definition of
9223 LibreOffice (more precisely, it imports the definition of the package
9224 bound to the @code{libreoffice} top-level attribute):
9227 guix import nix ~/path/to/nixpkgs libreoffice
9232 Import metadata from the Haskell community's central package archive
9233 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9234 Cabal files and includes all the relevant information, including package
9237 Specific command-line options are:
9242 Read a Cabal file from standard input.
9243 @item --no-test-dependencies
9245 Do not include dependencies required only by the test suites.
9246 @item --cabal-environment=@var{alist}
9247 @itemx -e @var{alist}
9248 @var{alist} is a Scheme alist defining the environment in which the
9249 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9250 @code{arch}, @code{impl} and a string representing the name of a flag.
9251 The value associated with a flag has to be either the symbol
9252 @code{true} or @code{false}. The value associated with other keys
9253 has to conform to the Cabal file format definition. The default value
9254 associated with the keys @code{os}, @code{arch} and @code{impl} is
9255 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9258 Traverse the dependency graph of the given upstream package recursively
9259 and generate package expressions for all those packages that are not yet
9263 The command below imports metadata for the latest version of the
9264 @code{HTTP} Haskell package without including test dependencies and
9265 specifying the value of the flag @samp{network-uri} as @code{false}:
9268 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9271 A specific package version may optionally be specified by following the
9272 package name by an at-sign and a version number as in the following example:
9275 guix import hackage mtl@@2.1.3.1
9280 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9281 It takes a package name, looks up the package version included in a
9282 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9283 release and uses the @code{hackage} importer to retrieve its metadata.
9284 Note that it is up to you to select an LTS release compatible with the
9285 GHC compiler used by Guix.
9287 Specific command-line options are:
9290 @item --no-test-dependencies
9292 Do not include dependencies required only by the test suites.
9293 @item --lts-version=@var{version}
9294 @itemx -l @var{version}
9295 @var{version} is the desired LTS release version. If omitted the latest
9299 Traverse the dependency graph of the given upstream package recursively
9300 and generate package expressions for all those packages that are not yet
9304 The command below imports metadata for the @code{HTTP} Haskell package
9305 included in the LTS Stackage release version 7.18:
9308 guix import stackage --lts-version=7.18 HTTP
9313 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9314 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9316 Specific command-line options are:
9319 @item --archive=@var{repo}
9320 @itemx -a @var{repo}
9321 @var{repo} identifies the archive repository from which to retrieve the
9322 information. Currently the supported repositories and their identifiers
9326 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9327 identifier. This is the default.
9329 Packages from @code{elpa.gnu.org} are signed with one of the keys
9330 contained in the GnuPG keyring at
9331 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9332 @code{emacs} package (@pxref{Package Installation, ELPA package
9333 signatures,, emacs, The GNU Emacs Manual}).
9336 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9337 @code{melpa-stable} identifier.
9340 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9346 Traverse the dependency graph of the given upstream package recursively
9347 and generate package expressions for all those packages that are not yet
9353 Import metadata from the crates.io Rust package repository
9354 @uref{https://crates.io, crates.io}, as in this example:
9357 guix import crate blake2-rfc
9360 The crate importer also allows you to specify a version string:
9363 guix import crate constant-time-eq@@0.1.0
9366 Additional options include:
9371 Traverse the dependency graph of the given upstream package recursively
9372 and generate package expressions for all those packages that are not yet
9379 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9380 repository used by the OCaml community.
9383 The structure of the @command{guix import} code is modular. It would be
9384 useful to have more importers for other package formats, and your help
9385 is welcome here (@pxref{Contributing}).
9387 @node Invoking guix refresh
9388 @section Invoking @command{guix refresh}
9390 @cindex @command {guix refresh}
9391 The primary audience of the @command{guix refresh} command is developers
9392 of the GNU software distribution. By default, it reports any packages
9393 provided by the distribution that are outdated compared to the latest
9394 upstream version, like this:
9398 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9399 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9402 Alternately, one can specify packages to consider, in which case a
9403 warning is emitted for packages that lack an updater:
9406 $ guix refresh coreutils guile guile-ssh
9407 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9408 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9411 @command{guix refresh} browses the upstream repository of each package and determines
9412 the highest version number of the releases therein. The command
9413 knows how to update specific types of packages: GNU packages, ELPA
9414 packages, etc.---see the documentation for @option{--type} below. There
9415 are many packages, though, for which it lacks a method to determine
9416 whether a new upstream release is available. However, the mechanism is
9417 extensible, so feel free to get in touch with us to add a new method!
9422 Consider the packages specified, and all the packages upon which they depend.
9425 $ guix refresh --recursive coreutils
9426 gnu/packages/acl.scm:35:2: warning: no updater for acl
9427 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9428 gnu/packages/xml.scm:68:2: warning: no updater for expat
9429 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9435 Sometimes the upstream name differs from the package name used in Guix,
9436 and @command{guix refresh} needs a little help. Most updaters honor the
9437 @code{upstream-name} property in package definitions, which can be used
9441 (define-public network-manager
9443 (name "network-manager")
9445 (properties '((upstream-name . "NetworkManager")))))
9448 When passed @code{--update}, it modifies distribution source files to
9449 update the version numbers and source tarball hashes of those package
9450 recipes (@pxref{Defining Packages}). This is achieved by downloading
9451 each package's latest source tarball and its associated OpenPGP
9452 signature, authenticating the downloaded tarball against its signature
9453 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9454 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9457 key used to sign the tarball is missing from the user's keyring, an
9458 attempt is made to automatically retrieve it from a public key server;
9459 when this is successful, the key is added to the user's keyring; otherwise,
9460 @command{guix refresh} reports an error.
9462 The following options are supported:
9466 @item --expression=@var{expr}
9467 @itemx -e @var{expr}
9468 Consider the package @var{expr} evaluates to.
9470 This is useful to precisely refer to a package, as in this example:
9473 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9476 This command lists the dependents of the ``final'' libc (essentially all
9481 Update distribution source files (package recipes) in place. This is
9482 usually run from a checkout of the Guix source tree (@pxref{Running
9483 Guix Before It Is Installed}):
9486 $ ./pre-inst-env guix refresh -s non-core -u
9489 @xref{Defining Packages}, for more information on package definitions.
9491 @item --select=[@var{subset}]
9492 @itemx -s @var{subset}
9493 Select all the packages in @var{subset}, one of @code{core} or
9496 The @code{core} subset refers to all the packages at the core of the
9497 distribution---i.e., packages that are used to build ``everything
9498 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9499 changing one of these packages in the distribution entails a rebuild of
9500 all the others. Thus, such updates are an inconvenience to users in
9501 terms of build time or bandwidth used to achieve the upgrade.
9503 The @code{non-core} subset refers to the remaining packages. It is
9504 typically useful in cases where an update of the core packages would be
9507 @item --manifest=@var{file}
9508 @itemx -m @var{file}
9509 Select all the packages from the manifest in @var{file}. This is useful to
9510 check if any packages of the user manifest can be updated.
9512 @item --type=@var{updater}
9513 @itemx -t @var{updater}
9514 Select only packages handled by @var{updater} (may be a comma-separated
9515 list of updaters). Currently, @var{updater} may be one of:
9519 the updater for GNU packages;
9521 the updater for GNOME packages;
9523 the updater for KDE packages;
9525 the updater for X.org packages;
9527 the updater for packages hosted on kernel.org;
9529 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9531 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9533 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9535 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9537 the updater for @uref{https://pypi.python.org, PyPI} packages.
9539 the updater for @uref{https://rubygems.org, RubyGems} packages.
9541 the updater for @uref{https://github.com, GitHub} packages.
9543 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9545 the updater for @uref{https://www.stackage.org, Stackage} packages.
9547 the updater for @uref{https://crates.io, Crates} packages.
9549 the updater for @uref{https://launchpad.net, Launchpad} packages.
9552 For instance, the following command only checks for updates of Emacs
9553 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9556 $ guix refresh --type=elpa,cran
9557 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9558 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9563 In addition, @command{guix refresh} can be passed one or more package
9564 names, as in this example:
9567 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9571 The command above specifically updates the @code{emacs} and
9572 @code{idutils} packages. The @code{--select} option would have no
9573 effect in this case.
9575 When considering whether to upgrade a package, it is sometimes
9576 convenient to know which packages would be affected by the upgrade and
9577 should be checked for compatibility. For this the following option may
9578 be used when passing @command{guix refresh} one or more package names:
9582 @item --list-updaters
9584 List available updaters and exit (see @option{--type} above.)
9586 For each updater, display the fraction of packages it covers; at the
9587 end, display the fraction of packages covered by all these updaters.
9589 @item --list-dependent
9591 List top-level dependent packages that would need to be rebuilt as a
9592 result of upgrading one or more packages.
9594 @xref{Invoking guix graph, the @code{reverse-package} type of
9595 @command{guix graph}}, for information on how to visualize the list of
9596 dependents of a package.
9600 Be aware that the @code{--list-dependent} option only
9601 @emph{approximates} the rebuilds that would be required as a result of
9602 an upgrade. More rebuilds might be required under some circumstances.
9605 $ guix refresh --list-dependent flex
9606 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9607 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9610 The command above lists a set of packages that could be built to check
9611 for compatibility with an upgraded @code{flex} package.
9615 @item --list-transitive
9616 List all the packages which one or more packages depend upon.
9619 $ guix refresh --list-transitive flex
9620 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9621 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{}
9626 The command above lists a set of packages which, when changed, would cause
9627 @code{flex} to be rebuilt.
9629 The following options can be used to customize GnuPG operation:
9633 @item --gpg=@var{command}
9634 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9635 for in @code{$PATH}.
9637 @item --keyring=@var{file}
9638 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9639 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9640 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9641 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9642 information on a tool to manipulate keybox files).
9644 When this option is omitted, @command{guix refresh} uses
9645 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9646 signing keys. OpenPGP signatures are checked against keys from this keyring;
9647 missing keys are downloaded to this keyring as well (see
9648 @option{--key-download} below.)
9650 You can export keys from your default GPG keyring into a keybox file using
9651 commands like this one:
9654 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9657 Likewise, you can fetch keys to a specific keybox file like this:
9660 gpg --no-default-keyring --keyring mykeyring.kbx \
9661 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9664 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9665 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9667 @item --key-download=@var{policy}
9668 Handle missing OpenPGP keys according to @var{policy}, which may be one
9673 Always download missing OpenPGP keys from the key server, and add them
9674 to the user's GnuPG keyring.
9677 Never try to download missing OpenPGP keys. Instead just bail out.
9680 When a package signed with an unknown OpenPGP key is encountered, ask
9681 the user whether to download it or not. This is the default behavior.
9684 @item --key-server=@var{host}
9685 Use @var{host} as the OpenPGP key server when importing a public key.
9687 @item --load-path=@var{directory}
9688 Add @var{directory} to the front of the package module search path
9689 (@pxref{Package Modules}).
9691 This allows users to define their own packages and make them visible to
9692 the command-line tools.
9696 The @code{github} updater uses the
9697 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9698 releases. When used repeatedly e.g.@: when refreshing all packages,
9699 GitHub will eventually refuse to answer any further API requests. By
9700 default 60 API requests per hour are allowed, and a full refresh on all
9701 GitHub packages in Guix requires more than this. Authentication with
9702 GitHub through the use of an API token alleviates these limits. To use
9703 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9704 token procured from @uref{https://github.com/settings/tokens} or
9708 @node Invoking guix lint
9709 @section Invoking @command{guix lint}
9711 @cindex @command{guix lint}
9712 @cindex package, checking for errors
9713 The @command{guix lint} command is meant to help package developers avoid
9714 common errors and use a consistent style. It runs a number of checks on
9715 a given set of packages in order to find common mistakes in their
9716 definitions. Available @dfn{checkers} include (see
9717 @code{--list-checkers} for a complete list):
9722 Validate certain typographical and stylistic rules about package
9723 descriptions and synopses.
9725 @item inputs-should-be-native
9726 Identify inputs that should most likely be native inputs.
9732 @itemx source-file-name
9733 Probe @code{home-page} and @code{source} URLs and report those that are
9734 invalid. Suggest a @code{mirror://} URL when applicable. If the
9735 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9736 URL. Check that the source file name is meaningful, e.g.@: is not just a
9737 version number or ``git-checkout'', without a declared @code{file-name}
9738 (@pxref{origin Reference}).
9740 @item source-unstable-tarball
9741 Parse the @code{source} URL to determine if a tarball from GitHub is
9742 autogenerated or if it is a release tarball. Unfortunately GitHub's
9743 autogenerated tarballs are sometimes regenerated.
9746 @cindex Software Heritage, source code archive
9747 @cindex archival of source code, Software Heritage
9748 Checks whether the package's source code is archived at
9749 @uref{https://www.softwareheritage.org, Software Heritage}.
9751 When the source code that is not archived comes from a version-control system
9752 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9753 ``save'' request so that it eventually archives it. This ensures that the
9754 source will remain available in the long term, and that Guix can fall back to
9755 Software Heritage should the source code disappear from its original host.
9756 The status of recent ``save'' requests can be
9757 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9759 When source code is a tarball obtained with @code{url-fetch}, simply print a
9760 message when it is not archived. As of this writing, Software Heritage does
9761 not allow requests to save arbitrary tarballs; we are working on ways to
9762 ensure that non-VCS source code is also archived.
9765 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9766 request rate per IP address}. When the limit is reached, @command{guix lint}
9767 prints a message and the @code{archival} checker stops doing anything until
9768 that limit has been reset.
9771 @cindex security vulnerabilities
9772 @cindex CVE, Common Vulnerabilities and Exposures
9773 Report known vulnerabilities found in the Common Vulnerabilities and
9774 Exposures (CVE) databases of the current and past year
9775 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9778 To view information about a particular vulnerability, visit pages such as:
9782 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9784 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9788 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9789 @code{CVE-2015-7554}.
9791 Package developers can specify in package recipes the
9792 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9793 name and version of the package when they differ from the name or version
9794 that Guix uses, as in this example:
9800 ;; CPE calls this package "grub2".
9801 (properties '((cpe-name . "grub2")
9802 (cpe-version . "2.3"))))
9805 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9806 Some entries in the CVE database do not specify which version of a
9807 package they apply to, and would thus ``stick around'' forever. Package
9808 developers who found CVE alerts and verified they can be ignored can
9809 declare them as in this example:
9815 ;; These CVEs no longer apply and can be safely ignored.
9816 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9819 "CVE-2011-5244")))))
9823 Warn about obvious source code formatting issues: trailing white space,
9824 use of tabulations, etc.
9827 The general syntax is:
9830 guix lint @var{options} @var{package}@dots{}
9833 If no package is given on the command line, then all packages are checked.
9834 The @var{options} may be zero or more of the following:
9837 @item --list-checkers
9839 List and describe all the available checkers that will be run on packages
9844 Only enable the checkers specified in a comma-separated list using the
9845 names returned by @code{--list-checkers}.
9847 @item --load-path=@var{directory}
9848 @itemx -L @var{directory}
9849 Add @var{directory} to the front of the package module search path
9850 (@pxref{Package Modules}).
9852 This allows users to define their own packages and make them visible to
9853 the command-line tools.
9857 @node Invoking guix size
9858 @section Invoking @command{guix size}
9861 @cindex package size
9863 @cindex @command{guix size}
9864 The @command{guix size} command helps package developers profile the
9865 disk usage of packages. It is easy to overlook the impact of an
9866 additional dependency added to a package, or the impact of using a
9867 single output for a package that could easily be split (@pxref{Packages
9868 with Multiple Outputs}). Such are the typical issues that
9869 @command{guix size} can highlight.
9871 The command can be passed one or more package specifications
9872 such as @code{gcc@@4.8}
9873 or @code{guile:debug}, or a file name in the store. Consider this
9877 $ guix size coreutils
9878 store item total self
9879 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9880 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9881 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9882 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9883 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9884 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9885 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9886 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9891 The store items listed here constitute the @dfn{transitive closure} of
9892 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9893 would be returned by:
9896 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9899 Here the output shows three columns next to store items. The first column,
9900 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9901 the store item---that is, its own size plus the size of all its
9902 dependencies. The next column, labeled ``self'', shows the size of the
9903 item itself. The last column shows the ratio of the size of the item
9904 itself to the space occupied by all the items listed here.
9906 In this example, we see that the closure of Coreutils weighs in at
9907 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9908 libraries. (That libc and GCC's libraries represent a large fraction of
9909 the closure is not a problem @i{per se} because they are always available
9910 on the system anyway.)
9912 When the package(s) passed to @command{guix size} are available in the
9913 store@footnote{More precisely, @command{guix size} looks for the
9914 @emph{ungrafted} variant of the given package(s), as returned by
9915 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9916 for information on grafts.}, @command{guix size} queries the daemon to determine its
9917 dependencies, and measures its size in the store, similar to @command{du
9918 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9921 When the given packages are @emph{not} in the store, @command{guix size}
9922 reports information based on the available substitutes
9923 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9924 store items that are not even on disk, only available remotely.
9926 You can also specify several package names:
9929 $ guix size coreutils grep sed bash
9930 store item total self
9931 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9932 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9933 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9934 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9940 In this example we see that the combination of the four packages takes
9941 102.3@tie{}MiB in total, which is much less than the sum of each closure
9942 since they have a lot of dependencies in common.
9944 The available options are:
9948 @item --substitute-urls=@var{urls}
9949 Use substitute information from @var{urls}.
9950 @xref{client-substitute-urls, the same option for @code{guix build}}.
9952 @item --sort=@var{key}
9953 Sort lines according to @var{key}, one of the following options:
9957 the size of each item (the default);
9959 the total size of the item's closure.
9962 @item --map-file=@var{file}
9963 Write a graphical map of disk usage in PNG format to @var{file}.
9965 For the example above, the map looks like this:
9967 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9968 produced by @command{guix size}}
9970 This option requires that
9971 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9972 installed and visible in Guile's module search path. When that is not
9973 the case, @command{guix size} fails as it tries to load it.
9975 @item --system=@var{system}
9976 @itemx -s @var{system}
9977 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9979 @item --load-path=@var{directory}
9980 @itemx -L @var{directory}
9981 Add @var{directory} to the front of the package module search path
9982 (@pxref{Package Modules}).
9984 This allows users to define their own packages and make them visible to
9985 the command-line tools.
9988 @node Invoking guix graph
9989 @section Invoking @command{guix graph}
9992 @cindex @command{guix graph}
9993 @cindex package dependencies
9994 Packages and their dependencies form a @dfn{graph}, specifically a
9995 directed acyclic graph (DAG). It can quickly become difficult to have a
9996 mental model of the package DAG, so the @command{guix graph} command
9997 provides a visual representation of the DAG. By default,
9998 @command{guix graph} emits a DAG representation in the input format of
9999 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10000 directly to the @command{dot} command of Graphviz. It can also emit an
10001 HTML page with embedded JavaScript code to display a ``chord diagram''
10002 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10003 emit Cypher queries to construct a graph in a graph database supporting
10004 the @uref{https://www.opencypher.org/, openCypher} query language.
10005 The general syntax is:
10008 guix graph @var{options} @var{package}@dots{}
10011 For example, the following command generates a PDF file representing the
10012 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10016 guix graph coreutils | dot -Tpdf > dag.pdf
10019 The output looks like this:
10021 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10023 Nice little graph, no?
10025 But there is more than one graph! The one above is concise: it is the
10026 graph of package objects, omitting implicit inputs such as GCC, libc,
10027 grep, etc. It is often useful to have such a concise graph, but
10028 sometimes one may want to see more details. @command{guix graph} supports
10029 several types of graphs, allowing you to choose the level of detail:
10033 This is the default type used in the example above. It shows the DAG of
10034 package objects, excluding implicit dependencies. It is concise, but
10035 filters out many details.
10037 @item reverse-package
10038 This shows the @emph{reverse} DAG of packages. For example:
10041 guix graph --type=reverse-package ocaml
10044 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10045 you are also interested in cases where OCaml is an implicit dependency, see
10046 @code{reverse-bag} below.)
10048 Note that for core packages this can yield huge graphs. If all you want
10049 is to know the number of packages that depend on a given package, use
10050 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10051 @option{--list-dependent}}).
10054 This is the package DAG, @emph{including} implicit inputs.
10056 For instance, the following command:
10059 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
10062 ...@: yields this bigger graph:
10064 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10066 At the bottom of the graph, we see all the implicit inputs of
10067 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10069 Now, note that the dependencies of these implicit inputs---that is, the
10070 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10071 here, for conciseness.
10074 Similar to @code{bag-emerged}, but this time including all the bootstrap
10077 @item bag-with-origins
10078 Similar to @code{bag}, but also showing origins and their dependencies.
10081 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10082 it also takes implicit dependencies into account. For example:
10085 guix graph -t reverse-bag dune
10089 ...@: yields the graph of all packages that depend on Dune, directly or
10090 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10091 @i{via} @code{dune-build-system}, this shows a large number of packages,
10092 whereas @code{reverse-package} would show very few if any.
10095 This is the most detailed representation: It shows the DAG of
10096 derivations (@pxref{Derivations}) and plain store items. Compared to
10097 the above representation, many additional nodes are visible, including
10098 build scripts, patches, Guile modules, etc.
10100 For this type of graph, it is also possible to pass a @file{.drv} file
10101 name instead of a package name, as in:
10104 guix graph -t derivation `guix system build -d my-config.scm`
10108 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10109 For example, the following command shows the graph for the package
10110 module that defines the @code{guile} package:
10113 guix graph -t module guile | dot -Tpdf > module-graph.pdf
10117 All the types above correspond to @emph{build-time dependencies}. The
10118 following graph type represents the @emph{run-time dependencies}:
10122 This is the graph of @dfn{references} of a package output, as returned
10123 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10125 If the given package output is not available in the store, @command{guix
10126 graph} attempts to obtain dependency information from substitutes.
10128 Here you can also pass a store file name instead of a package name. For
10129 example, the command below produces the reference graph of your profile
10130 (which can be big!):
10133 guix graph -t references `readlink -f ~/.guix-profile`
10137 This is the graph of the @dfn{referrers} of a store item, as returned by
10138 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10140 This relies exclusively on local information from your store. For
10141 instance, let us suppose that the current Inkscape is available in 10
10142 profiles on your machine; @command{guix graph -t referrers inkscape}
10143 will show a graph rooted at Inkscape and with those 10 profiles linked
10146 It can help determine what is preventing a store item from being garbage
10151 The available options are the following:
10154 @item --type=@var{type}
10155 @itemx -t @var{type}
10156 Produce a graph output of @var{type}, where @var{type} must be one of
10157 the values listed above.
10160 List the supported graph types.
10162 @item --backend=@var{backend}
10163 @itemx -b @var{backend}
10164 Produce a graph using the selected @var{backend}.
10166 @item --list-backends
10167 List the supported graph backends.
10169 Currently, the available backends are Graphviz and d3.js.
10171 @item --expression=@var{expr}
10172 @itemx -e @var{expr}
10173 Consider the package @var{expr} evaluates to.
10175 This is useful to precisely refer to a package, as in this example:
10178 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10181 @item --system=@var{system}
10182 @itemx -s @var{system}
10183 Display the graph for @var{system}---e.g., @code{i686-linux}.
10185 The package dependency graph is largely architecture-independent, but there
10186 are some architecture-dependent bits that this option allows you to visualize.
10188 @item --load-path=@var{directory}
10189 @itemx -L @var{directory}
10190 Add @var{directory} to the front of the package module search path
10191 (@pxref{Package Modules}).
10193 This allows users to define their own packages and make them visible to
10194 the command-line tools.
10197 On top of that, @command{guix graph} supports all the usual package
10198 transformation options (@pxref{Package Transformation Options}). This
10199 makes it easy to view the effect of a graph-rewriting transformation
10200 such as @option{--with-input}. For example, the command below outputs
10201 the graph of @code{git} once @code{openssl} has been replaced by
10202 @code{libressl} everywhere in the graph:
10205 guix graph git --with-input=openssl=libressl
10208 So many possibilities, so much fun!
10210 @node Invoking guix publish
10211 @section Invoking @command{guix publish}
10213 @cindex @command{guix publish}
10214 The purpose of @command{guix publish} is to enable users to easily share
10215 their store with others, who can then use it as a substitute server
10216 (@pxref{Substitutes}).
10218 When @command{guix publish} runs, it spawns an HTTP server which allows
10219 anyone with network access to obtain substitutes from it. This means
10220 that any machine running Guix can also act as if it were a build farm,
10221 since the HTTP interface is compatible with Cuirass, the software behind
10222 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10224 For security, each substitute is signed, allowing recipients to check
10225 their authenticity and integrity (@pxref{Substitutes}). Because
10226 @command{guix publish} uses the signing key of the system, which is only
10227 readable by the system administrator, it must be started as root; the
10228 @code{--user} option makes it drop root privileges early on.
10230 The signing key pair must be generated before @command{guix publish} is
10231 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10234 The general syntax is:
10237 guix publish @var{options}@dots{}
10240 Running @command{guix publish} without any additional arguments will
10241 spawn an HTTP server on port 8080:
10247 Once a publishing server has been authorized (@pxref{Invoking guix
10248 archive}), the daemon may download substitutes from it:
10251 guix-daemon --substitute-urls=http://example.org:8080
10254 By default, @command{guix publish} compresses archives on the fly as it
10255 serves them. This ``on-the-fly'' mode is convenient in that it requires
10256 no setup and is immediately available. However, when serving lots of
10257 clients, we recommend using the @option{--cache} option, which enables
10258 caching of the archives before they are sent to clients---see below for
10259 details. The @command{guix weather} command provides a handy way to
10260 check what a server provides (@pxref{Invoking guix weather}).
10262 As a bonus, @command{guix publish} also serves as a content-addressed
10263 mirror for source files referenced in @code{origin} records
10264 (@pxref{origin Reference}). For instance, assuming @command{guix
10265 publish} is running on @code{example.org}, the following URL returns the
10266 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10267 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10270 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10273 Obviously, these URLs only work for files that are in the store; in
10274 other cases, they return 404 (``Not Found'').
10276 @cindex build logs, publication
10277 Build logs are available from @code{/log} URLs like:
10280 http://example.org/log/gwspk@dots{}-guile-2.2.3
10284 When @command{guix-daemon} is configured to save compressed build logs,
10285 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10286 URLs return the compressed log as-is, with an appropriate
10287 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10288 running @command{guix-daemon} with @code{--log-compression=gzip} since
10289 Web browsers can automatically decompress it, which is not the case with
10292 The following options are available:
10295 @item --port=@var{port}
10296 @itemx -p @var{port}
10297 Listen for HTTP requests on @var{port}.
10299 @item --listen=@var{host}
10300 Listen on the network interface for @var{host}. The default is to
10301 accept connections from any interface.
10303 @item --user=@var{user}
10304 @itemx -u @var{user}
10305 Change privileges to @var{user} as soon as possible---i.e., once the
10306 server socket is open and the signing key has been read.
10308 @item --compression[=@var{method}[:@var{level}]]
10309 @itemx -C [@var{method}[:@var{level}]]
10310 Compress data using the given @var{method} and @var{level}. @var{method} is
10311 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10314 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10315 to different compression levels: 1 is the fastest, and 9 is the best
10316 (CPU-intensive). The default is 3.
10318 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10319 increase in CPU usage; see
10320 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10323 Unless @option{--cache} is used, compression occurs on the fly and
10324 the compressed streams are not
10325 cached. Thus, to reduce load on the machine that runs @command{guix
10326 publish}, it may be a good idea to choose a low compression level, to
10327 run @command{guix publish} behind a caching proxy, or to use
10328 @option{--cache}. Using @option{--cache} has the advantage that it
10329 allows @command{guix publish} to add @code{Content-Length} HTTP header
10332 This option can be repeated, in which case every substitute gets compressed
10333 using all the selected methods, and all of them are advertised. This is
10334 useful when users may not support all the compression methods: they can select
10335 the one they support.
10337 @item --cache=@var{directory}
10338 @itemx -c @var{directory}
10339 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10340 and only serve archives that are in cache.
10342 When this option is omitted, archives and meta-data are created
10343 on-the-fly. This can reduce the available bandwidth, especially when
10344 compression is enabled, since this may become CPU-bound. Another
10345 drawback of the default mode is that the length of archives is not known
10346 in advance, so @command{guix publish} does not add a
10347 @code{Content-Length} HTTP header to its responses, which in turn
10348 prevents clients from knowing the amount of data being downloaded.
10350 Conversely, when @option{--cache} is used, the first request for a store
10351 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10352 background process to @dfn{bake} the archive---computing its
10353 @code{.narinfo} and compressing the archive, if needed. Once the
10354 archive is cached in @var{directory}, subsequent requests succeed and
10355 are served directly from the cache, which guarantees that clients get
10356 the best possible bandwidth.
10358 The ``baking'' process is performed by worker threads. By default, one
10359 thread per CPU core is created, but this can be customized. See
10360 @option{--workers} below.
10362 When @option{--ttl} is used, cached entries are automatically deleted
10363 when they have expired.
10365 @item --workers=@var{N}
10366 When @option{--cache} is used, request the allocation of @var{N} worker
10367 threads to ``bake'' archives.
10369 @item --ttl=@var{ttl}
10370 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10371 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10372 days, @code{1m} means 1 month, and so on.
10374 This allows the user's Guix to keep substitute information in cache for
10375 @var{ttl}. However, note that @code{guix publish} does not itself
10376 guarantee that the store items it provides will indeed remain available
10377 for as long as @var{ttl}.
10379 Additionally, when @option{--cache} is used, cached entries that have
10380 not been accessed for @var{ttl} and that no longer have a corresponding
10381 item in the store, may be deleted.
10383 @item --nar-path=@var{path}
10384 Use @var{path} as the prefix for the URLs of ``nar'' files
10385 (@pxref{Invoking guix archive, normalized archives}).
10387 By default, nars are served at a URL such as
10388 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10389 change the @code{/nar} part to @var{path}.
10391 @item --public-key=@var{file}
10392 @itemx --private-key=@var{file}
10393 Use the specific @var{file}s as the public/private key pair used to sign
10394 the store items being published.
10396 The files must correspond to the same key pair (the private key is used
10397 for signing and the public key is merely advertised in the signature
10398 metadata). They must contain keys in the canonical s-expression format
10399 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10400 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10401 @file{/etc/guix/signing-key.sec} are used.
10403 @item --repl[=@var{port}]
10404 @itemx -r [@var{port}]
10405 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10406 Reference Manual}) on @var{port} (37146 by default). This is used
10407 primarily for debugging a running @command{guix publish} server.
10410 Enabling @command{guix publish} on Guix System is a one-liner: just
10411 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10412 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10413 @code{guix-publish-service-type}}).
10415 If you are instead running Guix on a ``foreign distro'', follow these
10420 If your host distro uses the systemd init system:
10423 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10424 /etc/systemd/system/
10425 # systemctl start guix-publish && systemctl enable guix-publish
10429 If your host distro uses the Upstart init system:
10432 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10433 # start guix-publish
10437 Otherwise, proceed similarly with your distro's init system.
10440 @node Invoking guix challenge
10441 @section Invoking @command{guix challenge}
10443 @cindex reproducible builds
10444 @cindex verifiable builds
10445 @cindex @command{guix challenge}
10447 Do the binaries provided by this server really correspond to the source
10448 code it claims to build? Is a package build process deterministic?
10449 These are the questions the @command{guix challenge} command attempts to
10452 The former is obviously an important question: Before using a substitute
10453 server (@pxref{Substitutes}), one had better @emph{verify} that it
10454 provides the right binaries, and thus @emph{challenge} it. The latter
10455 is what enables the former: If package builds are deterministic, then
10456 independent builds of the package should yield the exact same result,
10457 bit for bit; if a server provides a binary different from the one
10458 obtained locally, it may be either corrupt or malicious.
10460 We know that the hash that shows up in @file{/gnu/store} file names is
10461 the hash of all the inputs of the process that built the file or
10462 directory---compilers, libraries, build scripts,
10463 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10464 one store file name should map to exactly one build output.
10465 @command{guix challenge} checks whether there is, indeed, a single
10466 mapping by comparing the build outputs of several independent builds of
10467 any given store item.
10469 The command output looks like this:
10472 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10473 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10474 updating list of substitutes from 'https://guix.example.org'... 100.0%
10475 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10476 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10477 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10478 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10480 /lib/libcrypto.so.1.1
10483 /gnu/store/@dots{}-git-2.5.0 contents differ:
10484 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10485 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10486 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10488 /libexec/git-core/git-fsck
10490 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10491 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10492 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10493 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10495 /share/man/man1/pius.1.gz
10499 6,406 store items were analyzed:
10500 - 4,749 (74.1%) were identical
10501 - 525 (8.2%) differed
10502 - 1,132 (17.7%) were inconclusive
10506 In this example, @command{guix challenge} first scans the store to
10507 determine the set of locally-built derivations---as opposed to store
10508 items that were downloaded from a substitute server---and then queries
10509 all the substitute servers. It then reports those store items for which
10510 the servers obtained a result different from the local build.
10512 @cindex non-determinism, in package builds
10513 As an example, @code{guix.example.org} always gets a different answer.
10514 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10515 case of Git. This might indicate that the build process of Git is
10516 non-deterministic, meaning that its output varies as a function of
10517 various things that Guix does not fully control, in spite of building
10518 packages in isolated environments (@pxref{Features}). Most common
10519 sources of non-determinism include the addition of timestamps in build
10520 results, the inclusion of random numbers, and directory listings sorted
10521 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10524 To find out what is wrong with this Git binary, the easiest approach is
10528 guix challenge git \
10529 --diff=diffoscope \
10530 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10533 This automatically invokes @command{diffoscope}, which displays detailed
10534 information about files that differ.
10536 Alternately, we can do something along these lines (@pxref{Invoking guix
10540 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10541 | guix archive -x /tmp/git
10542 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10545 This command shows the difference between the files resulting from the
10546 local build, and the files resulting from the build on
10547 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10548 diffutils, Comparing and Merging Files}). The @command{diff} command
10549 works great for text files. When binary files differ, a better option
10550 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10551 visualize differences for all kinds of files.
10553 Once you have done that work, you can tell whether the differences are due
10554 to a non-deterministic build process or to a malicious server. We try
10555 hard to remove sources of non-determinism in packages to make it easier
10556 to verify substitutes, but of course, this is a process that
10557 involves not just Guix, but a large part of the free software community.
10558 In the meantime, @command{guix challenge} is one tool to help address
10561 If you are writing packages for Guix, you are encouraged to check
10562 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10563 same build result as you did with:
10566 $ guix challenge @var{package}
10570 where @var{package} is a package specification such as
10571 @code{guile@@2.0} or @code{glibc:debug}.
10573 The general syntax is:
10576 guix challenge @var{options} [@var{packages}@dots{}]
10579 When a difference is found between the hash of a locally-built item and
10580 that of a server-provided substitute, or among substitutes provided by
10581 different servers, the command displays it as in the example above and
10582 its exit code is 2 (other non-zero exit codes denote other kinds of
10585 The one option that matters is:
10589 @item --substitute-urls=@var{urls}
10590 Consider @var{urls} the whitespace-separated list of substitute source
10591 URLs to compare to.
10593 @item --diff=@var{mode}
10594 Upon mismatches, show differences according to @var{mode}, one of:
10597 @item @code{simple} (the default)
10598 Show the list of files that differ.
10600 @item @code{diffoscope}
10601 @itemx @var{command}
10602 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10603 two directories whose contents do not match.
10605 When @var{command} is an absolute file name, run @var{command} instead
10609 Do not show further details about the differences.
10612 Thus, unless @code{--diff=none} is passed, @command{guix challenge}
10613 downloads the store items from the given substitute servers so that it
10618 Show details about matches (identical contents) in addition to
10619 information about mismatches.
10623 @node Invoking guix copy
10624 @section Invoking @command{guix copy}
10626 @cindex copy, of store items, over SSH
10627 @cindex SSH, copy of store items
10628 @cindex sharing store items across machines
10629 @cindex transferring store items across machines
10630 The @command{guix copy} command copies items from the store of one
10631 machine to that of another machine over a secure shell (SSH)
10632 connection@footnote{This command is available only when Guile-SSH was
10633 found. @xref{Requirements}, for details.}. For example, the following
10634 command copies the @code{coreutils} package, the user's profile, and all
10635 their dependencies over to @var{host}, logged in as @var{user}:
10638 guix copy --to=@var{user}@@@var{host} \
10639 coreutils `readlink -f ~/.guix-profile`
10642 If some of the items to be copied are already present on @var{host},
10643 they are not actually sent.
10645 The command below retrieves @code{libreoffice} and @code{gimp} from
10646 @var{host}, assuming they are available there:
10649 guix copy --from=@var{host} libreoffice gimp
10652 The SSH connection is established using the Guile-SSH client, which is
10653 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10654 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10656 The key used to sign items that are sent must be accepted by the remote
10657 machine. Likewise, the key used by the remote machine to sign items you
10658 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10659 own daemon. @xref{Invoking guix archive}, for more information about
10660 store item authentication.
10662 The general syntax is:
10665 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10668 You must always specify one of the following options:
10671 @item --to=@var{spec}
10672 @itemx --from=@var{spec}
10673 Specify the host to send to or receive from. @var{spec} must be an SSH
10674 spec such as @code{example.org}, @code{charlie@@example.org}, or
10675 @code{charlie@@example.org:2222}.
10678 The @var{items} can be either package names, such as @code{gimp}, or
10679 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10681 When specifying the name of a package to send, it is first built if
10682 needed, unless @option{--dry-run} was specified. Common build options
10683 are supported (@pxref{Common Build Options}).
10686 @node Invoking guix container
10687 @section Invoking @command{guix container}
10689 @cindex @command{guix container}
10691 As of version @value{VERSION}, this tool is experimental. The interface
10692 is subject to radical change in the future.
10695 The purpose of @command{guix container} is to manipulate processes
10696 running within an isolated environment, commonly known as a
10697 ``container'', typically created by the @command{guix environment}
10698 (@pxref{Invoking guix environment}) and @command{guix system container}
10699 (@pxref{Invoking guix system}) commands.
10701 The general syntax is:
10704 guix container @var{action} @var{options}@dots{}
10707 @var{action} specifies the operation to perform with a container, and
10708 @var{options} specifies the context-specific arguments for the action.
10710 The following actions are available:
10714 Execute a command within the context of a running container.
10719 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10722 @var{pid} specifies the process ID of the running container.
10723 @var{program} specifies an executable file name within the root file
10724 system of the container. @var{arguments} are the additional options that
10725 will be passed to @var{program}.
10727 The following command launches an interactive login shell inside a
10728 Guix system container, started by @command{guix system container}, and whose
10729 process ID is 9001:
10732 guix container exec 9001 /run/current-system/profile/bin/bash --login
10735 Note that the @var{pid} cannot be the parent process of a container. It
10736 must be PID 1 of the container or one of its child processes.
10740 @node Invoking guix weather
10741 @section Invoking @command{guix weather}
10743 Occasionally you're grumpy because substitutes are lacking and you end
10744 up building packages by yourself (@pxref{Substitutes}). The
10745 @command{guix weather} command reports on substitute availability on the
10746 specified servers so you can have an idea of whether you'll be grumpy
10747 today. It can sometimes be useful info as a user, but it is primarily
10748 useful to people running @command{guix publish} (@pxref{Invoking guix
10751 @cindex statistics, for substitutes
10752 @cindex availability of substitutes
10753 @cindex substitute availability
10754 @cindex weather, substitute availability
10755 Here's a sample run:
10758 $ guix weather --substitute-urls=https://guix.example.org
10759 computing 5,872 package derivations for x86_64-linux...
10760 looking for 6,128 store items on https://guix.example.org..
10761 updating list of substitutes from 'https://guix.example.org'... 100.0%
10762 https://guix.example.org
10763 43.4% substitutes available (2,658 out of 6,128)
10764 7,032.5 MiB of nars (compressed)
10765 19,824.2 MiB on disk (uncompressed)
10766 0.030 seconds per request (182.9 seconds in total)
10767 33.5 requests per second
10769 9.8% (342 out of 3,470) of the missing items are queued
10771 x86_64-linux: 518 (59.7%)
10772 i686-linux: 221 (25.5%)
10773 aarch64-linux: 128 (14.8%)
10774 build rate: 23.41 builds per hour
10775 x86_64-linux: 11.16 builds per hour
10776 i686-linux: 6.03 builds per hour
10777 aarch64-linux: 6.41 builds per hour
10780 @cindex continuous integration, statistics
10781 As you can see, it reports the fraction of all the packages for which
10782 substitutes are available on the server---regardless of whether
10783 substitutes are enabled, and regardless of whether this server's signing
10784 key is authorized. It also reports the size of the compressed archives
10785 (``nars'') provided by the server, the size the corresponding store
10786 items occupy in the store (assuming deduplication is turned off), and
10787 the server's throughput. The second part gives continuous integration
10788 (CI) statistics, if the server supports it. In addition, using the
10789 @option{--coverage} option, @command{guix weather} can list ``important''
10790 package substitutes missing on the server (see below).
10792 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10793 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10794 challenge}, it ignores signatures on those substitutes, which is
10795 innocuous since the command only gathers statistics and cannot install
10798 The general syntax is:
10801 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10804 When @var{packages} is omitted, @command{guix weather} checks the availability
10805 of substitutes for @emph{all} the packages, or for those specified with
10806 @option{--manifest}; otherwise it only considers the specified packages. It
10807 is also possible to query specific system types with @option{--system}.
10808 @command{guix weather} exits with a non-zero code when the fraction of
10809 available substitutes is below 100%.
10811 The available options are listed below.
10814 @item --substitute-urls=@var{urls}
10815 @var{urls} is the space-separated list of substitute server URLs to
10816 query. When this option is omitted, the default set of substitute
10817 servers is queried.
10819 @item --system=@var{system}
10820 @itemx -s @var{system}
10821 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10822 option can be repeated, in which case @command{guix weather} will query
10823 substitutes for several system types.
10825 @item --manifest=@var{file}
10826 Instead of querying substitutes for all the packages, only ask for those
10827 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10828 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10831 This option can be repeated several times, in which case the manifests
10834 @item --coverage[=@var{count}]
10835 @itemx -c [@var{count}]
10836 Report on substitute coverage for packages: list packages with at least
10837 @var{count} dependents (zero by default) for which substitutes are
10838 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10839 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10840 @var{b} usually lacks substitutes as well. The result looks like this:
10843 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10844 computing 8,983 package derivations for x86_64-linux...
10845 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10846 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10847 @value{SUBSTITUTE-URL}
10848 64.7% substitutes available (6,047 out of 9,343)
10850 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10851 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10852 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10853 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10857 What this example shows is that @code{kcoreaddons} and presumably the 58
10858 packages that depend on it have no substitutes at @code{ci.guix.info};
10859 likewise for @code{qgpgme} and the 46 packages that depend on it.
10861 If you are a Guix developer, or if you are taking care of this build farm,
10862 you'll probably want to have a closer look at these packages: they may simply
10865 @item --display-missing
10866 Display the list of store items for which substitutes are missing.
10869 @node Invoking guix processes
10870 @section Invoking @command{guix processes}
10872 The @command{guix processes} command can be useful to developers and system
10873 administrators, especially on multi-user machines and on build farms: it lists
10874 the current sessions (connections to the daemon), as well as information about
10875 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10876 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10877 listed.}. Here's an example of the information it returns:
10880 $ sudo guix processes
10883 ClientCommand: guix environment --ad-hoc python
10887 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10891 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10892 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10893 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10894 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10895 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10896 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10897 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10900 In this example we see that @command{guix-daemon} has three clients:
10901 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10902 integration tool; their process identifier (PID) is given by the
10903 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10904 @command{guix-daemon} sub-process of this particular session.
10906 The @code{LockHeld} fields show which store items are currently locked by this
10907 session, which corresponds to store items being built or substituted (the
10908 @code{LockHeld} field is not displayed when @command{guix processes} is not
10909 running as root.) Last, by looking at the @code{ChildProcess} field, we
10910 understand that these three builds are being offloaded (@pxref{Daemon Offload
10913 The output is in Recutils format so we can use the handy @command{recsel}
10914 command to select sessions of interest (@pxref{Selection Expressions,,,
10915 recutils, GNU recutils manual}). As an example, the command shows the command
10916 line and PID of the client that triggered the build of a Perl package:
10919 $ sudo guix processes | \
10920 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10922 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10925 @node System Configuration
10926 @chapter System Configuration
10928 @cindex system configuration
10929 Guix System supports a consistent whole-system configuration
10930 mechanism. By that we mean that all aspects of the global system
10931 configuration---such as the available system services, timezone and
10932 locale settings, user accounts---are declared in a single place. Such
10933 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10935 One of the advantages of putting all the system configuration under the
10936 control of Guix is that it supports transactional system upgrades, and
10937 makes it possible to roll back to a previous system instantiation,
10938 should something go wrong with the new one (@pxref{Features}). Another
10939 advantage is that it makes it easy to replicate the exact same configuration
10940 across different machines, or at different points in time, without
10941 having to resort to additional administration tools layered on top of
10942 the own tools of the system.
10943 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10945 This section describes this mechanism. First we focus on the system
10946 administrator's viewpoint---explaining how the system is configured and
10947 instantiated. Then we show how this mechanism can be extended, for
10948 instance to support new system services.
10951 * Using the Configuration System:: Customizing your GNU system.
10952 * operating-system Reference:: Detail of operating-system declarations.
10953 * File Systems:: Configuring file system mounts.
10954 * Mapped Devices:: Block device extra processing.
10955 * User Accounts:: Specifying user accounts.
10956 * Keyboard Layout:: How the system interprets key strokes.
10957 * Locales:: Language and cultural convention settings.
10958 * Services:: Specifying system services.
10959 * Setuid Programs:: Programs running with root privileges.
10960 * X.509 Certificates:: Authenticating HTTPS servers.
10961 * Name Service Switch:: Configuring libc's name service switch.
10962 * Initial RAM Disk:: Linux-Libre bootstrapping.
10963 * Bootloader Configuration:: Configuring the boot loader.
10964 * Invoking guix system:: Instantiating a system configuration.
10965 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10966 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10967 * Defining Services:: Adding new service definitions.
10970 @node Using the Configuration System
10971 @section Using the Configuration System
10973 The operating system is configured by providing an
10974 @code{operating-system} declaration in a file that can then be passed to
10975 the @command{guix system} command (@pxref{Invoking guix system}). A
10976 simple setup, with the default system services, the default Linux-Libre
10977 kernel, initial RAM disk, and boot loader looks like this:
10979 @findex operating-system
10981 @include os-config-bare-bones.texi
10984 This example should be self-describing. Some of the fields defined
10985 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10986 Others, such as @code{packages} and @code{services}, can be omitted, in
10987 which case they get a default value.
10989 Below we discuss the effect of some of the most important fields
10990 (@pxref{operating-system Reference}, for details about all the available
10991 fields), and how to @dfn{instantiate} the operating system using
10992 @command{guix system}.
10994 @unnumberedsubsec Bootloader
10996 @cindex legacy boot, on Intel machines
10997 @cindex BIOS boot, on Intel machines
11000 The @code{bootloader} field describes the method that will be used to boot
11001 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11002 mode, as in the example above. However, more recent machines rely instead on
11003 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11004 the @code{bootloader} field should contain something along these lines:
11007 (bootloader-configuration
11008 (bootloader grub-efi-bootloader)
11009 (target "/boot/efi"))
11012 @xref{Bootloader Configuration}, for more information on the available
11013 configuration options.
11015 @unnumberedsubsec Globally-Visible Packages
11017 @vindex %base-packages
11018 The @code{packages} field lists packages that will be globally visible
11019 on the system, for all user accounts---i.e., in every user's @code{PATH}
11020 environment variable---in addition to the per-user profiles
11021 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11022 provides all the tools one would expect for basic user and administrator
11023 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11024 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11025 etc. The example above adds GNU@tie{}Screen to those,
11026 taken from the @code{(gnu packages screen)}
11027 module (@pxref{Package Modules}). The
11028 @code{(list package output)} syntax can be used to add a specific output
11032 (use-modules (gnu packages))
11033 (use-modules (gnu packages dns))
11037 (packages (cons (list bind "utils")
11041 @findex specification->package
11042 Referring to packages by variable name, like @code{bind} above, has
11043 the advantage of being unambiguous; it also allows typos and such to be
11044 diagnosed right away as ``unbound variables''. The downside is that one
11045 needs to know which module defines which package, and to augment the
11046 @code{use-package-modules} line accordingly. To avoid that, one can use
11047 the @code{specification->package} procedure of the @code{(gnu packages)}
11048 module, which returns the best package for a given name or name and
11052 (use-modules (gnu packages))
11056 (packages (append (map specification->package
11057 '("tcpdump" "htop" "gnupg@@2.0"))
11061 @unnumberedsubsec System Services
11064 @vindex %base-services
11065 The @code{services} field lists @dfn{system services} to be made
11066 available when the system starts (@pxref{Services}).
11067 The @code{operating-system} declaration above specifies that, in
11068 addition to the basic services, we want the OpenSSH secure shell
11069 daemon listening on port 2222 (@pxref{Networking Services,
11070 @code{openssh-service-type}}). Under the hood,
11071 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11072 right command-line options, possibly with supporting configuration files
11073 generated as needed (@pxref{Defining Services}).
11075 @cindex customization, of services
11076 @findex modify-services
11077 Occasionally, instead of using the base services as is, you will want to
11078 customize them. To do this, use @code{modify-services} (@pxref{Service
11079 Reference, @code{modify-services}}) to modify the list.
11081 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11082 (the console log-in) in the @code{%base-services} list (@pxref{Base
11083 Services, @code{%base-services}}). To do that, you can write the
11084 following in your operating system declaration:
11087 (define %my-services
11088 ;; My very own list of services.
11089 (modify-services %base-services
11090 (guix-service-type config =>
11091 (guix-configuration
11093 (use-substitutes? #f)
11094 (extra-options '("--gc-keep-derivations"))))
11095 (mingetty-service-type config =>
11096 (mingetty-configuration
11097 (inherit config)))))
11101 (services %my-services))
11104 This changes the configuration---i.e., the service parameters---of the
11105 @code{guix-service-type} instance, and that of all the
11106 @code{mingetty-service-type} instances in the @code{%base-services} list.
11107 Observe how this is accomplished: first, we arrange for the original
11108 configuration to be bound to the identifier @code{config} in the
11109 @var{body}, and then we write the @var{body} so that it evaluates to the
11110 desired configuration. In particular, notice how we use @code{inherit}
11111 to create a new configuration which has the same values as the old
11112 configuration, but with a few modifications.
11114 @cindex encrypted disk
11115 The configuration for a typical ``desktop'' usage, with an encrypted
11116 root partition, the X11 display
11117 server, GNOME and Xfce (users can choose which of these desktop
11118 environments to use at the log-in screen by pressing @kbd{F1}), network
11119 management, power management, and more, would look like this:
11122 @include os-config-desktop.texi
11125 A graphical system with a choice of lightweight window managers
11126 instead of full-blown desktop environments would look like this:
11129 @include os-config-lightweight-desktop.texi
11132 This example refers to the @file{/boot/efi} file system by its UUID,
11133 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11134 as returned by the @command{blkid} command.
11136 @xref{Desktop Services}, for the exact list of services provided by
11137 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11138 information about the @code{nss-certs} package that is used here.
11140 Again, @code{%desktop-services} is just a list of service objects. If
11141 you want to remove services from there, you can do so using the
11142 procedures for list filtering (@pxref{SRFI-1 Filtering and
11143 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11144 following expression returns a list that contains all the services in
11145 @code{%desktop-services} minus the Avahi service:
11148 (remove (lambda (service)
11149 (eq? (service-kind service) avahi-service-type))
11153 @unnumberedsubsec Instantiating the System
11155 Assuming the @code{operating-system} declaration
11156 is stored in the @file{my-system-config.scm}
11157 file, the @command{guix system reconfigure my-system-config.scm} command
11158 instantiates that configuration, and makes it the default GRUB boot
11159 entry (@pxref{Invoking guix system}).
11161 The normal way to change the system configuration is by updating this
11162 file and re-running @command{guix system reconfigure}. One should never
11163 have to touch files in @file{/etc} or to run commands that modify the
11164 system state such as @command{useradd} or @command{grub-install}. In
11165 fact, you must avoid that since that would not only void your warranty
11166 but also prevent you from rolling back to previous versions of your
11167 system, should you ever need to.
11169 @cindex roll-back, of the operating system
11170 Speaking of roll-back, each time you run @command{guix system
11171 reconfigure}, a new @dfn{generation} of the system is created---without
11172 modifying or deleting previous generations. Old system generations get
11173 an entry in the bootloader boot menu, allowing you to boot them in case
11174 something went wrong with the latest generation. Reassuring, no? The
11175 @command{guix system list-generations} command lists the system
11176 generations available on disk. It is also possible to roll back the
11177 system via the commands @command{guix system roll-back} and
11178 @command{guix system switch-generation}.
11180 Although the @command{guix system reconfigure} command will not modify
11181 previous generations, you must take care when the current generation is not
11182 the latest (e.g., after invoking @command{guix system roll-back}), since
11183 the operation might overwrite a later generation (@pxref{Invoking guix
11186 @unnumberedsubsec The Programming Interface
11188 At the Scheme level, the bulk of an @code{operating-system} declaration
11189 is instantiated with the following monadic procedure (@pxref{The Store
11192 @deffn {Monadic Procedure} operating-system-derivation os
11193 Return a derivation that builds @var{os}, an @code{operating-system}
11194 object (@pxref{Derivations}).
11196 The output of the derivation is a single directory that refers to all
11197 the packages, configuration files, and other supporting files needed to
11198 instantiate @var{os}.
11201 This procedure is provided by the @code{(gnu system)} module. Along
11202 with @code{(gnu services)} (@pxref{Services}), this module contains the
11203 guts of Guix System. Make sure to visit it!
11206 @node operating-system Reference
11207 @section @code{operating-system} Reference
11209 This section summarizes all the options available in
11210 @code{operating-system} declarations (@pxref{Using the Configuration
11213 @deftp {Data Type} operating-system
11214 This is the data type representing an operating system configuration.
11215 By that, we mean all the global system configuration, not per-user
11216 configuration (@pxref{Using the Configuration System}).
11219 @item @code{kernel} (default: @var{linux-libre})
11220 The package object of the operating system kernel to use@footnote{Currently
11221 only the Linux-libre kernel is supported. In the future, it will be
11222 possible to use the GNU@tie{}Hurd.}.
11224 @item @code{kernel-loadable-modules} (default: '())
11225 A list of objects (usually packages) to collect loadable kernel modules
11226 from--e.g. @code{(list ddcci-driver-linux)}.
11228 @item @code{kernel-arguments} (default: @code{'("quiet")})
11229 List of strings or gexps representing additional arguments to pass on
11230 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11232 @item @code{bootloader}
11233 The system bootloader configuration object. @xref{Bootloader Configuration}.
11236 This is the label (a string) as it appears in the bootloader's menu entry.
11237 The default label includes the kernel name and version.
11239 @item @code{keyboard-layout} (default: @code{#f})
11240 This field specifies the keyboard layout to use in the console. It can be
11241 either @code{#f}, in which case the default keyboard layout is used (usually
11242 US English), or a @code{<keyboard-layout>} record.
11244 This keyboard layout is in effect as soon as the kernel has booted. For
11245 instance, it is the keyboard layout in effect when you type a passphrase if
11246 your root file system is on a @code{luks-device-mapping} mapped device
11247 (@pxref{Mapped Devices}).
11250 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11251 that used by the graphical display server. @xref{Bootloader Configuration},
11252 for information on how to specify the bootloader's keyboard layout. @xref{X
11253 Window}, for information on how to specify the keyboard layout used by the X
11257 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11259 @cindex initial RAM disk
11260 The list of Linux kernel modules that need to be available in the
11261 initial RAM disk. @xref{Initial RAM Disk}.
11263 @item @code{initrd} (default: @code{base-initrd})
11264 A procedure that returns an initial RAM disk for the Linux
11265 kernel. This field is provided to support low-level customization and
11266 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11268 @item @code{firmware} (default: @code{%base-firmware})
11270 List of firmware packages loadable by the operating system kernel.
11272 The default includes firmware needed for Atheros- and Broadcom-based
11273 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11274 respectively). @xref{Hardware Considerations}, for more info on
11275 supported hardware.
11277 @item @code{host-name}
11280 @item @code{hosts-file}
11282 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11283 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11284 Reference Manual}). The default is a file with entries for
11285 @code{localhost} and @var{host-name}.
11287 @item @code{mapped-devices} (default: @code{'()})
11288 A list of mapped devices. @xref{Mapped Devices}.
11290 @item @code{file-systems}
11291 A list of file systems. @xref{File Systems}.
11293 @item @code{swap-devices} (default: @code{'()})
11294 @cindex swap devices
11295 A list of strings identifying devices or files to be used for ``swap
11296 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11297 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11298 It is possible to specify a swap file in a file system on a mapped
11299 device, provided that the necessary device mapping and file system are
11300 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11302 @item @code{users} (default: @code{%base-user-accounts})
11303 @itemx @code{groups} (default: @code{%base-groups})
11304 List of user accounts and groups. @xref{User Accounts}.
11306 If the @code{users} list lacks a user account with UID@tie{}0, a
11307 ``root'' account with UID@tie{}0 is automatically added.
11309 @item @code{skeletons} (default: @code{(default-skeletons)})
11310 A list target file name/file-like object tuples (@pxref{G-Expressions,
11311 file-like objects}). These are the skeleton files that will be added to
11312 the home directory of newly-created user accounts.
11314 For instance, a valid value may look like this:
11317 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11318 (".guile" ,(plain-file "guile"
11319 "(use-modules (ice-9 readline))
11320 (activate-readline)")))
11323 @item @code{issue} (default: @code{%default-issue})
11324 A string denoting the contents of the @file{/etc/issue} file, which is
11325 displayed when users log in on a text console.
11327 @item @code{packages} (default: @code{%base-packages})
11328 The set of packages installed in the global profile, which is accessible
11329 at @file{/run/current-system/profile}.
11331 The default set includes core utilities and it is good practice to
11332 install non-core utilities in user profiles (@pxref{Invoking guix
11335 @item @code{timezone}
11336 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11338 You can run the @command{tzselect} command to find out which timezone
11339 string corresponds to your region. Choosing an invalid timezone name
11340 causes @command{guix system} to fail.
11342 @item @code{locale} (default: @code{"en_US.utf8"})
11343 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11344 Library Reference Manual}). @xref{Locales}, for more information.
11346 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11347 The list of locale definitions to be compiled and that may be used at
11348 run time. @xref{Locales}.
11350 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11351 The list of GNU@tie{}libc packages whose locale data and tools are used
11352 to build the locale definitions. @xref{Locales}, for compatibility
11353 considerations that justify this option.
11355 @item @code{name-service-switch} (default: @code{%default-nss})
11356 Configuration of the libc name service switch (NSS)---a
11357 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11360 @item @code{services} (default: @code{%base-services})
11361 A list of service objects denoting system services. @xref{Services}.
11363 @cindex essential services
11364 @item @code{essential-services} (default: ...)
11365 The list of ``essential services''---i.e., things like instances of
11366 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11367 Reference}), which are derived from the operating system definition itself.
11368 As a user you should @emph{never} need to touch this field.
11370 @item @code{pam-services} (default: @code{(base-pam-services)})
11372 @cindex pluggable authentication modules
11373 Linux @dfn{pluggable authentication module} (PAM) services.
11374 @c FIXME: Add xref to PAM services section.
11376 @item @code{setuid-programs} (default: @var{%setuid-programs})
11377 List of string-valued G-expressions denoting setuid programs.
11378 @xref{Setuid Programs}.
11380 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11381 @cindex sudoers file
11382 The contents of the @file{/etc/sudoers} file as a file-like object
11383 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11385 This file specifies which users can use the @command{sudo} command, what
11386 they are allowed to do, and what privileges they may gain. The default
11387 is that only @code{root} and members of the @code{wheel} group may use
11392 @deffn {Scheme Syntax} this-operating-system
11393 When used in the @emph{lexical scope} of an operating system field definition,
11394 this identifier resolves to the operating system being defined.
11396 The example below shows how to refer to the operating system being defined in
11397 the definition of the @code{label} field:
11400 (use-modules (gnu) (guix))
11404 (label (package-full-name
11405 (operating-system-kernel this-operating-system))))
11408 It is an error to refer to @code{this-operating-system} outside an operating
11415 @section File Systems
11417 The list of file systems to be mounted is specified in the
11418 @code{file-systems} field of the operating system declaration
11419 (@pxref{Using the Configuration System}). Each file system is declared
11420 using the @code{file-system} form, like this:
11424 (mount-point "/home")
11425 (device "/dev/sda3")
11429 As usual, some of the fields are mandatory---those shown in the example
11430 above---while others can be omitted. These are described below.
11432 @deftp {Data Type} file-system
11433 Objects of this type represent file systems to be mounted. They
11434 contain the following members:
11438 This is a string specifying the type of the file system---e.g.,
11441 @item @code{mount-point}
11442 This designates the place where the file system is to be mounted.
11444 @item @code{device}
11445 This names the ``source'' of the file system. It can be one of three
11446 things: a file system label, a file system UUID, or the name of a
11447 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11448 systems without having to hard-code their actual device
11449 name@footnote{Note that, while it is tempting to use
11450 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11451 result, this is not recommended: These special device nodes are created
11452 by the udev daemon and may be unavailable at the time the device is
11455 @findex file-system-label
11456 File system labels are created using the @code{file-system-label}
11457 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11458 plain strings. Here's an example of a file system referred to by its
11459 label, as shown by the @command{e2label} command:
11463 (mount-point "/home")
11465 (device (file-system-label "my-home")))
11469 UUIDs are converted from their string representation (as shown by the
11470 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11471 @code{uuid} form expects 16-byte UUIDs as defined in
11472 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11473 form of UUID used by the ext2 family of file systems and others, but it
11474 is different from ``UUIDs'' found in FAT file systems, for instance.},
11479 (mount-point "/home")
11481 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11484 When the source of a file system is a mapped device (@pxref{Mapped
11485 Devices}), its @code{device} field @emph{must} refer to the mapped
11486 device name---e.g., @file{"/dev/mapper/root-partition"}.
11487 This is required so that
11488 the system knows that mounting the file system depends on having the
11489 corresponding device mapping established.
11491 @item @code{flags} (default: @code{'()})
11492 This is a list of symbols denoting mount flags. Recognized flags
11493 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11494 access to special files), @code{no-suid} (ignore setuid and setgid
11495 bits), @code{no-atime} (do not update file access times),
11496 @code{strict-atime} (update file access time), @code{lazy-time} (only
11497 update time on the in-memory version of the file inode), and
11498 @code{no-exec} (disallow program execution).
11499 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11500 Manual}, for more information on these flags.
11502 @item @code{options} (default: @code{#f})
11503 This is either @code{#f}, or a string denoting mount options passed to the
11504 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11505 Reference Manual}, for details and run @command{man 8 mount} for options for
11506 various file systems.
11508 @item @code{mount?} (default: @code{#t})
11509 This value indicates whether to automatically mount the file system when
11510 the system is brought up. When set to @code{#f}, the file system gets
11511 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11512 is not automatically mounted.
11514 @item @code{needed-for-boot?} (default: @code{#f})
11515 This Boolean value indicates whether the file system is needed when
11516 booting. If that is true, then the file system is mounted when the
11517 initial RAM disk (initrd) is loaded. This is always the case, for
11518 instance, for the root file system.
11520 @item @code{check?} (default: @code{#t})
11521 This Boolean indicates whether the file system needs to be checked for
11522 errors before being mounted.
11524 @item @code{create-mount-point?} (default: @code{#f})
11525 When true, the mount point is created if it does not exist yet.
11527 @item @code{dependencies} (default: @code{'()})
11528 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11529 representing file systems that must be mounted or mapped devices that
11530 must be opened before (and unmounted or closed after) this one.
11532 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11533 a dependency of @file{/sys/fs/cgroup/cpu} and
11534 @file{/sys/fs/cgroup/memory}.
11536 Another example is a file system that depends on a mapped device, for
11537 example for an encrypted partition (@pxref{Mapped Devices}).
11541 The @code{(gnu system file-systems)} exports the following useful
11544 @defvr {Scheme Variable} %base-file-systems
11545 These are essential file systems that are required on normal systems,
11546 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11547 below.) Operating system declarations should always contain at least
11551 @defvr {Scheme Variable} %pseudo-terminal-file-system
11552 This is the file system to be mounted as @file{/dev/pts}. It supports
11553 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11554 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11555 Manual}). Pseudo-terminals are used by terminal emulators such as
11559 @defvr {Scheme Variable} %shared-memory-file-system
11560 This file system is mounted as @file{/dev/shm} and is used to support
11561 memory sharing across processes (@pxref{Memory-mapped I/O,
11562 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11565 @defvr {Scheme Variable} %immutable-store
11566 This file system performs a read-only ``bind mount'' of
11567 @file{/gnu/store}, making it read-only for all the users including
11568 @code{root}. This prevents against accidental modification by software
11569 running as @code{root} or by system administrators.
11571 The daemon itself is still able to write to the store: it remounts it
11572 read-write in its own ``name space.''
11575 @defvr {Scheme Variable} %binary-format-file-system
11576 The @code{binfmt_misc} file system, which allows handling of arbitrary
11577 executable file types to be delegated to user space. This requires the
11578 @code{binfmt.ko} kernel module to be loaded.
11581 @defvr {Scheme Variable} %fuse-control-file-system
11582 The @code{fusectl} file system, which allows unprivileged users to mount
11583 and unmount user-space FUSE file systems. This requires the
11584 @code{fuse.ko} kernel module to be loaded.
11587 @node Mapped Devices
11588 @section Mapped Devices
11590 @cindex device mapping
11591 @cindex mapped devices
11592 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11593 such as a hard disk partition, can be @dfn{mapped} into another device,
11594 usually in @code{/dev/mapper/},
11595 with additional processing over the data that flows through
11596 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11597 concept of a ``mapped device'' and that of a file system: both boil down
11598 to @emph{translating} input/output operations made on a file to
11599 operations on its backing store. Thus, the Hurd implements mapped
11600 devices, like file systems, using the generic @dfn{translator} mechanism
11601 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11602 typical example is encryption device mapping: all writes to the mapped
11603 device are encrypted, and all reads are deciphered, transparently.
11604 Guix extends this notion by considering any device or set of devices that
11605 are @dfn{transformed} in some way to create a new device; for instance,
11606 RAID devices are obtained by @dfn{assembling} several other devices, such
11607 as hard disks or partitions, into a new one that behaves as one partition.
11608 Other examples, not yet implemented, are LVM logical volumes.
11610 Mapped devices are declared using the @code{mapped-device} form,
11611 defined as follows; for examples, see below.
11613 @deftp {Data Type} mapped-device
11614 Objects of this type represent device mappings that will be made when
11615 the system boots up.
11619 This is either a string specifying the name of the block device to be mapped,
11620 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11621 need to be assembled for creating a new one.
11624 This string specifies the name of the resulting mapped device. For
11625 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11626 specifying @code{"my-partition"} leads to the creation of
11627 the @code{"/dev/mapper/my-partition"} device.
11628 For RAID devices of type @code{raid-device-mapping}, the full device name
11629 such as @code{"/dev/md0"} needs to be given.
11632 This must be a @code{mapped-device-kind} object, which specifies how
11633 @var{source} is mapped to @var{target}.
11637 @defvr {Scheme Variable} luks-device-mapping
11638 This defines LUKS block device encryption using the @command{cryptsetup}
11639 command from the package with the same name. It relies on the
11640 @code{dm-crypt} Linux kernel module.
11643 @defvr {Scheme Variable} raid-device-mapping
11644 This defines a RAID device, which is assembled using the @code{mdadm}
11645 command from the package with the same name. It requires a Linux kernel
11646 module for the appropriate RAID level to be loaded, such as @code{raid456}
11647 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11650 @cindex disk encryption
11652 The following example specifies a mapping from @file{/dev/sda3} to
11653 @file{/dev/mapper/home} using LUKS---the
11654 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11655 standard mechanism for disk encryption.
11656 The @file{/dev/mapper/home}
11657 device can then be used as the @code{device} of a @code{file-system}
11658 declaration (@pxref{File Systems}).
11662 (source "/dev/sda3")
11664 (type luks-device-mapping))
11667 Alternatively, to become independent of device numbering, one may obtain
11668 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11672 cryptsetup luksUUID /dev/sda3
11675 and use it as follows:
11679 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11681 (type luks-device-mapping))
11684 @cindex swap encryption
11685 It is also desirable to encrypt swap space, since swap space may contain
11686 sensitive data. One way to accomplish that is to use a swap file in a
11687 file system on a device mapped via LUKS encryption. In this way, the
11688 swap file is encrypted because the entire device is encrypted.
11689 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11691 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11692 may be declared as follows:
11696 (source (list "/dev/sda1" "/dev/sdb1"))
11697 (target "/dev/md0")
11698 (type raid-device-mapping))
11701 The @file{/dev/md0} device can then be used as the @code{device} of a
11702 @code{file-system} declaration (@pxref{File Systems}).
11703 Note that the RAID level need not be given; it is chosen during the
11704 initial creation and formatting of the RAID device and is determined
11705 automatically later.
11708 @node User Accounts
11709 @section User Accounts
11713 @cindex user accounts
11714 User accounts and groups are entirely managed through the
11715 @code{operating-system} declaration. They are specified with the
11716 @code{user-account} and @code{user-group} forms:
11722 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11723 "audio" ;sound card
11724 "video" ;video devices such as webcams
11725 "cdrom")) ;the good ol' CD-ROM
11726 (comment "Bob's sister")
11727 (home-directory "/home/alice"))
11730 When booting or upon completion of @command{guix system reconfigure},
11731 the system ensures that only the user accounts and groups specified in
11732 the @code{operating-system} declaration exist, and with the specified
11733 properties. Thus, account or group creations or modifications made by
11734 directly invoking commands such as @command{useradd} are lost upon
11735 reconfiguration or reboot. This ensures that the system remains exactly
11738 @deftp {Data Type} user-account
11739 Objects of this type represent user accounts. The following members may
11744 The name of the user account.
11748 This is the name (a string) or identifier (a number) of the user group
11749 this account belongs to.
11751 @item @code{supplementary-groups} (default: @code{'()})
11752 Optionally, this can be defined as a list of group names that this
11753 account belongs to.
11755 @item @code{uid} (default: @code{#f})
11756 This is the user ID for this account (a number), or @code{#f}. In the
11757 latter case, a number is automatically chosen by the system when the
11758 account is created.
11760 @item @code{comment} (default: @code{""})
11761 A comment about the account, such as the account owner's full name.
11763 @item @code{home-directory}
11764 This is the name of the home directory for the account.
11766 @item @code{create-home-directory?} (default: @code{#t})
11767 Indicates whether the home directory of this account should be created
11768 if it does not exist yet.
11770 @item @code{shell} (default: Bash)
11771 This is a G-expression denoting the file name of a program to be used as
11772 the shell (@pxref{G-Expressions}).
11774 @item @code{system?} (default: @code{#f})
11775 This Boolean value indicates whether the account is a ``system''
11776 account. System accounts are sometimes treated specially; for instance,
11777 graphical login managers do not list them.
11779 @anchor{user-account-password}
11780 @cindex password, for user accounts
11781 @item @code{password} (default: @code{#f})
11782 You would normally leave this field to @code{#f}, initialize user
11783 passwords as @code{root} with the @command{passwd} command, and then let
11784 users change it with @command{passwd}. Passwords set with
11785 @command{passwd} are of course preserved across reboot and
11788 If you @emph{do} want to set an initial password for an account, then
11789 this field must contain the encrypted password, as a string. You can use the
11790 @code{crypt} procedure for this purpose:
11797 ;; Specify a SHA-512-hashed initial password.
11798 (password (crypt "InitialPassword!" "$6$abc")))
11802 The hash of this initial password will be available in a file in
11803 @file{/gnu/store}, readable by all the users, so this method must be used with
11807 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11808 more information on password encryption, and @ref{Encryption,,, guile, GNU
11809 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11815 User group declarations are even simpler:
11818 (user-group (name "students"))
11821 @deftp {Data Type} user-group
11822 This type is for, well, user groups. There are just a few fields:
11826 The name of the group.
11828 @item @code{id} (default: @code{#f})
11829 The group identifier (a number). If @code{#f}, a new number is
11830 automatically allocated when the group is created.
11832 @item @code{system?} (default: @code{#f})
11833 This Boolean value indicates whether the group is a ``system'' group.
11834 System groups have low numerical IDs.
11836 @item @code{password} (default: @code{#f})
11837 What, user groups can have a password? Well, apparently yes. Unless
11838 @code{#f}, this field specifies the password of the group.
11843 For convenience, a variable lists all the basic user groups one may
11846 @defvr {Scheme Variable} %base-groups
11847 This is the list of basic user groups that users and/or packages expect
11848 to be present on the system. This includes groups such as ``root'',
11849 ``wheel'', and ``users'', as well as groups used to control access to
11850 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11853 @defvr {Scheme Variable} %base-user-accounts
11854 This is the list of basic system accounts that programs may expect to
11855 find on a GNU/Linux system, such as the ``nobody'' account.
11857 Note that the ``root'' account is not included here. It is a
11858 special-case and is automatically added whether or not it is specified.
11861 @node Keyboard Layout
11862 @section Keyboard Layout
11864 @cindex keyboard layout
11866 To specify what each key of your keyboard does, you need to tell the operating
11867 system what @dfn{keyboard layout} you want to use. The default, when nothing
11868 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11869 However, German speakers will usually prefer the German QWERTZ layout, French
11870 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11871 or bépo, and they might even want to further customize the effect of some of
11872 the keys. This section explains how to get that done.
11874 @cindex keyboard layout, definition
11875 There are three components that will want to know about your keyboard layout:
11879 The @emph{bootloader} may want to know what keyboard layout you want to use
11880 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11881 you want, for instance, to make sure that you can type the passphrase of your
11882 encrypted root partition using the right layout.
11885 The @emph{operating system kernel}, Linux, will need that so that the console
11886 is properly configured (@pxref{operating-system Reference,
11887 @code{keyboard-layout}}).
11890 The @emph{graphical display server}, usually Xorg, also has its own idea of
11891 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11894 Guix allows you to configure all three separately but, fortunately, it allows
11895 you to share the same keyboard layout for all three components.
11897 @cindex XKB, keyboard layouts
11898 Keyboard layouts are represented by records created by the
11899 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11900 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11901 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11902 optional variant name, an optional keyboard model name, and a possibly empty
11903 list of additional options. In most cases the layout name is all you care
11904 about. Here are a few example:
11907 ;; The German QWERTZ layout. Here we assume a standard
11908 ;; "pc105" keyboard model.
11909 (keyboard-layout "de")
11911 ;; The bépo variant of the French layout.
11912 (keyboard-layout "fr" "bepo")
11914 ;; The Catalan layout.
11915 (keyboard-layout "es" "cat")
11917 ;; The Latin American Spanish layout. In addition, the
11918 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11919 ;; and the "Menu" key is used as a "Compose" key to enter
11920 ;; accented letters.
11921 (keyboard-layout "latam"
11922 #:options '("ctrl:nocaps" "compose:menu"))
11924 ;; The Russian layout for a ThinkPad keyboard.
11925 (keyboard-layout "ru" #:model "thinkpad")
11927 ;; The "US international" layout, which is the US layout plus
11928 ;; dead keys to enter accented characters. This is for an
11929 ;; Apple MacBook keyboard.
11930 (keyboard-layout "us" "intl" #:model "macbook78")
11933 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11934 for a complete list of supported layouts, variants, and models.
11936 @cindex keyboard layout, configuration
11937 Let's say you want your system to use the Turkish keyboard layout throughout
11938 your system---bootloader, console, and Xorg. Here's what your system
11939 configuration would look like:
11941 @findex set-xorg-configuration
11943 ;; Using the Turkish layout for the bootloader, the console,
11948 (keyboard-layout (keyboard-layout "tr")) ;for the console
11949 (bootloader (bootloader-configuration
11950 (bootloader grub-efi-bootloader)
11951 (target "/boot/efi")
11952 (keyboard-layout keyboard-layout))) ;for GRUB
11953 (services (cons (set-xorg-configuration
11954 (xorg-configuration ;for Xorg
11955 (keyboard-layout keyboard-layout)))
11956 %desktop-services)))
11959 In the example above, for GRUB and for Xorg, we just refer to the
11960 @code{keyboard-layout} field defined above, but we could just as well refer to
11961 a different layout. The @code{set-xorg-configuration} procedure communicates
11962 the desired Xorg configuration to the graphical log-in manager, by default
11965 We've discussed how to specify the @emph{default} keyboard layout of your
11966 system when it starts, but you can also adjust it at run time:
11970 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11971 where you can select one or more keyboard layouts.
11974 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11975 allows you to change the current layout. For example, this is how you would
11976 change the layout to US Dvorak:
11979 setxkbmap us dvorak
11983 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11984 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11985 keyboard layout categorization described above. The command below loads the
11986 French bépo layout:
11997 A @dfn{locale} defines cultural conventions for a particular language
11998 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11999 Reference Manual}). Each locale has a name that typically has the form
12000 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12001 @code{fr_LU.utf8} designates the locale for the French language, with
12002 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12004 @cindex locale definition
12005 Usually, you will want to specify the default locale for the machine
12006 using the @code{locale} field of the @code{operating-system} declaration
12007 (@pxref{operating-system Reference, @code{locale}}).
12009 The selected locale is automatically added to the @dfn{locale
12010 definitions} known to the system if needed, with its codeset inferred
12011 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12012 @code{UTF-8} codeset. Additional locale definitions can be specified in
12013 the @code{locale-definitions} slot of @code{operating-system}---this is
12014 useful, for instance, if the codeset could not be inferred from the
12015 locale name. The default set of locale definitions includes some widely
12016 used locales, but not all the available locales, in order to save space.
12018 For instance, to add the North Frisian locale for Germany, the value of
12022 (cons (locale-definition
12023 (name "fy_DE.utf8") (source "fy_DE"))
12024 %default-locale-definitions)
12027 Likewise, to save space, one might want @code{locale-definitions} to
12028 list only the locales that are actually used, as in:
12031 (list (locale-definition
12032 (name "ja_JP.eucjp") (source "ja_JP")
12033 (charset "EUC-JP")))
12037 The compiled locale definitions are available at
12038 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12039 version, which is the default location where the GNU@tie{}libc provided
12040 by Guix looks for locale data. This can be overridden using the
12041 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
12042 @code{LOCPATH} and locale packages}).
12044 The @code{locale-definition} form is provided by the @code{(gnu system
12045 locale)} module. Details are given below.
12047 @deftp {Data Type} locale-definition
12048 This is the data type of a locale definition.
12053 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12054 Reference Manual}, for more information on locale names.
12056 @item @code{source}
12057 The name of the source for that locale. This is typically the
12058 @code{@var{language}_@var{territory}} part of the locale name.
12060 @item @code{charset} (default: @code{"UTF-8"})
12061 The ``character set'' or ``code set'' for that locale,
12062 @uref{https://www.iana.org/assignments/character-sets, as defined by
12068 @defvr {Scheme Variable} %default-locale-definitions
12069 A list of commonly used UTF-8 locales, used as the default
12070 value of the @code{locale-definitions} field of @code{operating-system}
12073 @cindex locale name
12074 @cindex normalized codeset in locale names
12075 These locale definitions use the @dfn{normalized codeset} for the part
12076 that follows the dot in the name (@pxref{Using gettextized software,
12077 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12078 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12079 @code{uk_UA.UTF-8}.
12082 @subsection Locale Data Compatibility Considerations
12084 @cindex incompatibility, of locale data
12085 @code{operating-system} declarations provide a @code{locale-libcs} field
12086 to specify the GNU@tie{}libc packages that are used to compile locale
12087 declarations (@pxref{operating-system Reference}). ``Why would I
12088 care?'', you may ask. Well, it turns out that the binary format of
12089 locale data is occasionally incompatible from one libc version to
12092 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12093 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12094 For instance, a program linked against libc version 2.21 is unable to
12095 read locale data produced with libc 2.22; worse, that program
12096 @emph{aborts} instead of simply ignoring the incompatible locale
12097 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12098 the incompatible locale data, which is already an improvement.}.
12099 Similarly, a program linked against libc 2.22 can read most, but not
12100 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
12101 data is incompatible); thus calls to @code{setlocale} may fail, but
12102 programs will not abort.
12104 The ``problem'' with Guix is that users have a lot of freedom: They can
12105 choose whether and when to upgrade software in their profiles, and might
12106 be using a libc version different from the one the system administrator
12107 used to build the system-wide locale data.
12109 Fortunately, unprivileged users can also install their own locale data
12110 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12111 @code{GUIX_LOCPATH} and locale packages}).
12113 Still, it is best if the system-wide locale data at
12114 @file{/run/current-system/locale} is built for all the libc versions
12115 actually in use on the system, so that all the programs can access
12116 it---this is especially crucial on a multi-user system. To do that, the
12117 administrator can specify several libc packages in the
12118 @code{locale-libcs} field of @code{operating-system}:
12121 (use-package-modules base)
12125 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12128 This example would lead to a system containing locale definitions for
12129 both libc 2.21 and the current version of libc in
12130 @file{/run/current-system/locale}.
12136 @cindex system services
12137 An important part of preparing an @code{operating-system} declaration is
12138 listing @dfn{system services} and their configuration (@pxref{Using the
12139 Configuration System}). System services are typically daemons launched
12140 when the system boots, or other actions needed at that time---e.g.,
12141 configuring network access.
12143 Guix has a broad definition of ``service'' (@pxref{Service
12144 Composition}), but many services are managed by the GNU@tie{}Shepherd
12145 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12146 command allows you to list the available services, show their status,
12147 start and stop them, or do other specific operations (@pxref{Jump
12148 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12154 The above command, run as @code{root}, lists the currently defined
12155 services. The @command{herd doc} command shows a synopsis of the given
12156 service and its associated actions:
12160 Run libc's name service cache daemon (nscd).
12162 # herd doc nscd action invalidate
12163 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12166 The @command{start}, @command{stop}, and @command{restart} sub-commands
12167 have the effect you would expect. For instance, the commands below stop
12168 the nscd service and restart the Xorg display server:
12172 Service nscd has been stopped.
12173 # herd restart xorg-server
12174 Service xorg-server has been stopped.
12175 Service xorg-server has been started.
12178 The following sections document the available services, starting with
12179 the core services, that may be used in an @code{operating-system}
12183 * Base Services:: Essential system services.
12184 * Scheduled Job Execution:: The mcron service.
12185 * Log Rotation:: The rottlog service.
12186 * Networking Services:: Network setup, SSH daemon, etc.
12187 * X Window:: Graphical display.
12188 * Printing Services:: Local and remote printer support.
12189 * Desktop Services:: D-Bus and desktop services.
12190 * Sound Services:: ALSA and Pulseaudio services.
12191 * Database Services:: SQL databases, key-value stores, etc.
12192 * Mail Services:: IMAP, POP3, SMTP, and all that.
12193 * Messaging Services:: Messaging services.
12194 * Telephony Services:: Telephony services.
12195 * Monitoring Services:: Monitoring services.
12196 * Kerberos Services:: Kerberos services.
12197 * LDAP Services:: LDAP services.
12198 * Web Services:: Web servers.
12199 * Certificate Services:: TLS certificates via Let's Encrypt.
12200 * DNS Services:: DNS daemons.
12201 * VPN Services:: VPN daemons.
12202 * Network File System:: NFS related services.
12203 * Continuous Integration:: The Cuirass service.
12204 * Power Management Services:: Extending battery life.
12205 * Audio Services:: The MPD.
12206 * Virtualization Services:: Virtualization services.
12207 * Version Control Services:: Providing remote access to Git repositories.
12208 * Game Services:: Game servers.
12209 * PAM Mount Service:: Service to mount volumes when logging in.
12210 * Guix Services:: Services relating specifically to Guix.
12211 * Linux Services:: Services tied to the Linux kernel.
12212 * Miscellaneous Services:: Other services.
12215 @node Base Services
12216 @subsection Base Services
12218 The @code{(gnu services base)} module provides definitions for the basic
12219 services that one expects from the system. The services exported by
12220 this module are listed below.
12222 @defvr {Scheme Variable} %base-services
12223 This variable contains a list of basic services (@pxref{Service Types
12224 and Services}, for more information on service objects) one would
12225 expect from the system: a login service (mingetty) on each tty, syslogd,
12226 the libc name service cache daemon (nscd), the udev device manager, and
12229 This is the default value of the @code{services} field of
12230 @code{operating-system} declarations. Usually, when customizing a
12231 system, you will want to append services to @code{%base-services}, like
12235 (append (list (service avahi-service-type)
12236 (service openssh-service-type))
12241 @defvr {Scheme Variable} special-files-service-type
12242 This is the service that sets up ``special files'' such as
12243 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12245 The value associated with @code{special-files-service-type} services
12246 must be a list of tuples where the first element is the ``special file''
12247 and the second element is its target. By default it is:
12249 @cindex @file{/bin/sh}
12250 @cindex @file{sh}, in @file{/bin}
12252 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12255 @cindex @file{/usr/bin/env}
12256 @cindex @file{env}, in @file{/usr/bin}
12257 If you want to add, say, @code{/usr/bin/env} to your system, you can
12261 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12262 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12265 Since this is part of @code{%base-services}, you can use
12266 @code{modify-services} to customize the set of special files
12267 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12268 to add a special file is @i{via} the @code{extra-special-file} procedure
12272 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12273 Use @var{target} as the ``special file'' @var{file}.
12275 For example, adding the following lines to the @code{services} field of
12276 your operating system declaration leads to a @file{/usr/bin/env}
12280 (extra-special-file "/usr/bin/env"
12281 (file-append coreutils "/bin/env"))
12285 @deffn {Scheme Procedure} host-name-service @var{name}
12286 Return a service that sets the host name to @var{name}.
12289 @deffn {Scheme Procedure} login-service @var{config}
12290 Return a service to run login according to @var{config}, a
12291 @code{<login-configuration>} object, which specifies the message of the day,
12292 among other things.
12295 @deftp {Data Type} login-configuration
12296 This is the data type representing the configuration of login.
12301 @cindex message of the day
12302 A file-like object containing the ``message of the day''.
12304 @item @code{allow-empty-passwords?} (default: @code{#t})
12305 Allow empty passwords by default so that first-time users can log in when
12306 the 'root' account has just been created.
12311 @deffn {Scheme Procedure} mingetty-service @var{config}
12312 Return a service to run mingetty according to @var{config}, a
12313 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12317 @deftp {Data Type} mingetty-configuration
12318 This is the data type representing the configuration of Mingetty, which
12319 provides the default implementation of virtual console log-in.
12324 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12326 @item @code{auto-login} (default: @code{#f})
12327 When true, this field must be a string denoting the user name under
12328 which the system automatically logs in. When it is @code{#f}, a
12329 user name and password must be entered to log in.
12331 @item @code{login-program} (default: @code{#f})
12332 This must be either @code{#f}, in which case the default log-in program
12333 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12334 the name of the log-in program.
12336 @item @code{login-pause?} (default: @code{#f})
12337 When set to @code{#t} in conjunction with @var{auto-login}, the user
12338 will have to press a key before the log-in shell is launched.
12340 @item @code{mingetty} (default: @var{mingetty})
12341 The Mingetty package to use.
12346 @deffn {Scheme Procedure} agetty-service @var{config}
12347 Return a service to run agetty according to @var{config}, an
12348 @code{<agetty-configuration>} object, which specifies the tty to run,
12349 among other things.
12352 @deftp {Data Type} agetty-configuration
12353 This is the data type representing the configuration of agetty, which
12354 implements virtual and serial console log-in. See the @code{agetty(8)}
12355 man page for more information.
12360 The name of the console this agetty runs on, as a string---e.g.,
12361 @code{"ttyS0"}. This argument is optional, it will default to
12362 a reasonable default serial port used by the kernel Linux.
12364 For this, if there is a value for an option @code{agetty.tty} in the kernel
12365 command line, agetty will extract the device name of the serial port
12366 from it and use that.
12368 If not and if there is a value for an option @code{console} with a tty in
12369 the Linux command line, agetty will extract the device name of the
12370 serial port from it and use that.
12372 In both cases, agetty will leave the other serial device settings
12373 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12376 @item @code{baud-rate} (default: @code{#f})
12377 A string containing a comma-separated list of one or more baud rates, in
12380 @item @code{term} (default: @code{#f})
12381 A string containing the value used for the @code{TERM} environment
12384 @item @code{eight-bits?} (default: @code{#f})
12385 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
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{no-reset?} (default: @code{#f})
12393 When @code{#t}, don't reset terminal cflags (control modes).
12395 @item @code{host} (default: @code{#f})
12396 This accepts a string containing the "login_host", which will be written
12397 into the @file{/var/run/utmpx} file.
12399 @item @code{remote?} (default: @code{#f})
12400 When set to @code{#t} in conjunction with @var{host}, this will add an
12401 @code{-r} fakehost option to the command line of the login program
12402 specified in @var{login-program}.
12404 @item @code{flow-control?} (default: @code{#f})
12405 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12407 @item @code{no-issue?} (default: @code{#f})
12408 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12409 not be displayed before presenting the login prompt.
12411 @item @code{init-string} (default: @code{#f})
12412 This accepts a string that will be sent to the tty or modem before
12413 sending anything else. It can be used to initialize a modem.
12415 @item @code{no-clear?} (default: @code{#f})
12416 When set to @code{#t}, agetty will not clear the screen before showing
12419 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12420 This must be either a gexp denoting the name of a log-in program, or
12421 unset, in which case the default value is the @command{login} from the
12424 @item @code{local-line} (default: @code{#f})
12425 Control the CLOCAL line flag. This accepts one of three symbols as
12426 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12427 the default value chosen by agetty is @code{'auto}.
12429 @item @code{extract-baud?} (default: @code{#f})
12430 When set to @code{#t}, instruct agetty to try to extract the baud rate
12431 from the status messages produced by certain types of modems.
12433 @item @code{skip-login?} (default: @code{#f})
12434 When set to @code{#t}, do not prompt the user for a login name. This
12435 can be used with @var{login-program} field to use non-standard login
12438 @item @code{no-newline?} (default: @code{#f})
12439 When set to @code{#t}, do not print a newline before printing the
12440 @file{/etc/issue} file.
12442 @c Is this dangerous only when used with login-program, or always?
12443 @item @code{login-options} (default: @code{#f})
12444 This option accepts a string containing options that are passed to the
12445 login program. When used with the @var{login-program}, be aware that a
12446 malicious user could try to enter a login name containing embedded
12447 options that could be parsed by the login program.
12449 @item @code{login-pause} (default: @code{#f})
12450 When set to @code{#t}, wait for any key before showing the login prompt.
12451 This can be used in conjunction with @var{auto-login} to save memory by
12452 lazily spawning shells.
12454 @item @code{chroot} (default: @code{#f})
12455 Change root to the specified directory. This option accepts a directory
12458 @item @code{hangup?} (default: @code{#f})
12459 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12460 specified terminal.
12462 @item @code{keep-baud?} (default: @code{#f})
12463 When set to @code{#t}, try to keep the existing baud rate. The baud
12464 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12467 @item @code{timeout} (default: @code{#f})
12468 When set to an integer value, terminate if no user name could be read
12469 within @var{timeout} seconds.
12471 @item @code{detect-case?} (default: @code{#f})
12472 When set to @code{#t}, turn on support for detecting an uppercase-only
12473 terminal. This setting will detect a login name containing only
12474 uppercase letters as indicating an uppercase-only terminal and turn on
12475 some upper-to-lower case conversions. Note that this will not support
12476 Unicode characters.
12478 @item @code{wait-cr?} (default: @code{#f})
12479 When set to @code{#t}, wait for the user or modem to send a
12480 carriage-return or linefeed character before displaying
12481 @file{/etc/issue} or login prompt. This is typically used with the
12482 @var{init-string} option.
12484 @item @code{no-hints?} (default: @code{#f})
12485 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12488 @item @code{no-hostname?} (default: @code{#f})
12489 By default, the hostname is printed. When this option is set to
12490 @code{#t}, no hostname will be shown at all.
12492 @item @code{long-hostname?} (default: @code{#f})
12493 By default, the hostname is only printed until the first dot. When this
12494 option is set to @code{#t}, the fully qualified hostname by
12495 @code{gethostname} or @code{getaddrinfo} is shown.
12497 @item @code{erase-characters} (default: @code{#f})
12498 This option accepts a string of additional characters that should be
12499 interpreted as backspace when the user types their login name.
12501 @item @code{kill-characters} (default: @code{#f})
12502 This option accepts a string that should be interpreted to mean "ignore
12503 all previous characters" (also called a "kill" character) when the user
12504 types their login name.
12506 @item @code{chdir} (default: @code{#f})
12507 This option accepts, as a string, a directory path that will be changed
12510 @item @code{delay} (default: @code{#f})
12511 This options accepts, as an integer, the number of seconds to sleep
12512 before opening the tty and displaying the login prompt.
12514 @item @code{nice} (default: @code{#f})
12515 This option accepts, as an integer, the nice value with which to run the
12516 @command{login} program.
12518 @item @code{extra-options} (default: @code{'()})
12519 This option provides an "escape hatch" for the user to provide arbitrary
12520 command-line arguments to @command{agetty} as a list of strings.
12525 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12526 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12527 according to @var{config}, a @code{<kmscon-configuration>} object, which
12528 specifies the tty to run, among other things.
12531 @deftp {Data Type} kmscon-configuration
12532 This is the data type representing the configuration of Kmscon, which
12533 implements virtual console log-in.
12537 @item @code{virtual-terminal}
12538 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12540 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12541 A gexp denoting the name of the log-in program. The default log-in program is
12542 @command{login} from the Shadow tool suite.
12544 @item @code{login-arguments} (default: @code{'("-p")})
12545 A list of arguments to pass to @command{login}.
12547 @item @code{auto-login} (default: @code{#f})
12548 When passed a login name, as a string, the specified user will be logged
12549 in automatically without prompting for their login name or password.
12551 @item @code{hardware-acceleration?} (default: #f)
12552 Whether to use hardware acceleration.
12554 @item @code{kmscon} (default: @var{kmscon})
12555 The Kmscon package to use.
12560 @cindex name service cache daemon
12562 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12563 [#:name-services '()]
12564 Return a service that runs the libc name service cache daemon (nscd) with the
12565 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12566 Service Switch}, for an example.
12568 For convenience, the Shepherd service for nscd provides the following actions:
12572 @cindex cache invalidation, nscd
12573 @cindex nscd, cache invalidation
12574 This invalidate the given cache. For instance, running:
12577 herd invalidate nscd hosts
12581 invalidates the host name lookup cache of nscd.
12584 Running @command{herd statistics nscd} displays information about nscd usage
12590 @defvr {Scheme Variable} %nscd-default-configuration
12591 This is the default @code{<nscd-configuration>} value (see below) used
12592 by @code{nscd-service}. It uses the caches defined by
12593 @var{%nscd-default-caches}; see below.
12596 @deftp {Data Type} nscd-configuration
12597 This is the data type representing the name service cache daemon (nscd)
12602 @item @code{name-services} (default: @code{'()})
12603 List of packages denoting @dfn{name services} that must be visible to
12604 the nscd---e.g., @code{(list @var{nss-mdns})}.
12606 @item @code{glibc} (default: @var{glibc})
12607 Package object denoting the GNU C Library providing the @command{nscd}
12610 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12611 Name of the nscd log file. This is where debugging output goes when
12612 @code{debug-level} is strictly positive.
12614 @item @code{debug-level} (default: @code{0})
12615 Integer denoting the debugging levels. Higher numbers mean that more
12616 debugging output is logged.
12618 @item @code{caches} (default: @var{%nscd-default-caches})
12619 List of @code{<nscd-cache>} objects denoting things to be cached; see
12625 @deftp {Data Type} nscd-cache
12626 Data type representing a cache database of nscd and its parameters.
12630 @item @code{database}
12631 This is a symbol representing the name of the database to be cached.
12632 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12633 @code{services}, which designate the corresponding NSS database
12634 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12636 @item @code{positive-time-to-live}
12637 @itemx @code{negative-time-to-live} (default: @code{20})
12638 A number representing the number of seconds during which a positive or
12639 negative lookup result remains in cache.
12641 @item @code{check-files?} (default: @code{#t})
12642 Whether to check for updates of the files corresponding to
12645 For instance, when @var{database} is @code{hosts}, setting this flag
12646 instructs nscd to check for updates in @file{/etc/hosts} and to take
12649 @item @code{persistent?} (default: @code{#t})
12650 Whether the cache should be stored persistently on disk.
12652 @item @code{shared?} (default: @code{#t})
12653 Whether the cache should be shared among users.
12655 @item @code{max-database-size} (default: 32@tie{}MiB)
12656 Maximum size in bytes of the database cache.
12658 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12659 @c settings, so leave them out.
12664 @defvr {Scheme Variable} %nscd-default-caches
12665 List of @code{<nscd-cache>} objects used by default by
12666 @code{nscd-configuration} (see above).
12668 It enables persistent and aggressive caching of service and host name
12669 lookups. The latter provides better host name lookup performance,
12670 resilience in the face of unreliable name servers, and also better
12671 privacy---often the result of host name lookups is in local cache, so
12672 external name servers do not even need to be queried.
12675 @anchor{syslog-configuration-type}
12678 @deftp {Data Type} syslog-configuration
12679 This data type represents the configuration of the syslog daemon.
12682 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12683 The syslog daemon to use.
12685 @item @code{config-file} (default: @code{%default-syslog.conf})
12686 The syslog configuration file to use.
12691 @anchor{syslog-service}
12693 @deffn {Scheme Procedure} syslog-service @var{config}
12694 Return a service that runs a syslog daemon according to @var{config}.
12696 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12697 information on the configuration file syntax.
12700 @defvr {Scheme Variable} guix-service-type
12701 This is the type of the service that runs the build daemon,
12702 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12703 @code{guix-configuration} record as described below.
12706 @anchor{guix-configuration-type}
12707 @deftp {Data Type} guix-configuration
12708 This data type represents the configuration of the Guix build daemon.
12709 @xref{Invoking guix-daemon}, for more information.
12712 @item @code{guix} (default: @var{guix})
12713 The Guix package to use.
12715 @item @code{build-group} (default: @code{"guixbuild"})
12716 Name of the group for build user accounts.
12718 @item @code{build-accounts} (default: @code{10})
12719 Number of build user accounts to create.
12721 @item @code{authorize-key?} (default: @code{#t})
12722 @cindex substitutes, authorization thereof
12723 Whether to authorize the substitute keys listed in
12724 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12725 (@pxref{Substitutes}).
12727 @vindex %default-authorized-guix-keys
12728 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12729 The list of authorized key files for archive imports, as a list of
12730 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12731 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12733 @item @code{use-substitutes?} (default: @code{#t})
12734 Whether to use substitutes.
12736 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12737 The list of URLs where to look for substitutes by default.
12739 @item @code{max-silent-time} (default: @code{0})
12740 @itemx @code{timeout} (default: @code{0})
12741 The number of seconds of silence and the number of seconds of activity,
12742 respectively, after which a build process times out. A value of zero
12743 disables the timeout.
12745 @item @code{log-compression} (default: @code{'bzip2})
12746 The type of compression used for build logs---one of @code{gzip},
12747 @code{bzip2}, or @code{none}.
12749 @item @code{extra-options} (default: @code{'()})
12750 List of extra command-line options for @command{guix-daemon}.
12752 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12753 File where @command{guix-daemon}'s standard output and standard error
12756 @item @code{http-proxy} (default: @code{#f})
12757 The HTTP proxy used for downloading fixed-output derivations and
12760 @item @code{tmpdir} (default: @code{#f})
12761 A directory path where the @command{guix-daemon} will perform builds.
12766 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12767 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12768 udev rules can be provided as a list of files through the @var{rules}
12769 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12770 @code{(gnu services base)} simplify the creation of such rule files.
12773 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12774 Return a udev-rule file named @var{file-name} containing the rules
12775 defined by the @var{contents} literal.
12777 In the following example, a rule for a USB device is defined to be
12778 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12779 upon detecting a USB device with a given product identifier.
12782 (define %example-udev-rule
12784 "90-usb-thing.rules"
12785 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12786 "ATTR@{product@}==\"Example\", "
12787 "RUN+=\"/path/to/script\"")))
12790 The @command{herd rules udev} command, as root, returns the name of the
12791 directory containing all the active udev rules.
12794 Here we show how the default @var{udev-service} can be extended with it.
12800 (modify-services %desktop-services
12801 (udev-service-type config =>
12802 (udev-configuration (inherit config)
12803 (rules (append (udev-configuration-rules config)
12804 (list %example-udev-rule))))))))
12807 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12808 Return a udev file named @var{file-name} containing the rules defined
12809 within @var{file}, a file-like object.
12811 The following example showcases how we can use an existing rule file.
12814 (use-modules (guix download) ;for url-fetch
12815 (guix packages) ;for origin
12818 (define %android-udev-rules
12820 "51-android-udev.rules"
12821 (let ((version "20170910"))
12824 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12825 "android-udev-rules/" version "/51-android.rules"))
12827 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12831 Additionally, Guix package definitions can be included in @var{rules} in
12832 order to extend the udev rules with the definitions found under their
12833 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12834 @var{file->udev-rule} example, we could have used the
12835 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12836 packages android)} module.
12838 The following example shows how to use the @var{android-udev-rules}
12839 package so that the Android tool @command{adb} can detect devices
12840 without root privileges. It also details how to create the
12841 @code{adbusers} group, which is required for the proper functioning of
12842 the rules defined within the @var{android-udev-rules} package. To
12843 create such a group, we must define it both as part of the
12844 @var{supplementary-groups} of our @var{user-account} declaration, as
12845 well as in the @var{groups} field of the @var{operating-system} record.
12848 (use-modules (gnu packages android) ;for android-udev-rules
12849 (gnu system shadow) ;for user-group
12854 (users (cons (user-acount
12856 (supplementary-groups
12857 '("adbusers" ;for adb
12858 "wheel" "netdev" "audio" "video")))))
12860 (groups (cons (user-group (system? #t) (name "adbusers"))
12866 (modify-services %desktop-services
12869 (udev-configuration (inherit config)
12870 (rules (cons android-udev-rules
12871 (udev-configuration-rules config))))))))
12874 @defvr {Scheme Variable} urandom-seed-service-type
12875 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12876 when rebooting. It also tries to seed @file{/dev/urandom} from
12877 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12881 @defvr {Scheme Variable} %random-seed-file
12882 This is the name of the file where some random bytes are saved by
12883 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12884 It defaults to @file{/var/lib/random-seed}.
12889 @defvr {Scheme Variable} gpm-service-type
12890 This is the type of the service that runs GPM, the @dfn{general-purpose
12891 mouse daemon}, which provides mouse support to the Linux console. GPM
12892 allows users to use the mouse in the console, notably to select, copy,
12895 The value for services of this type must be a @code{gpm-configuration}
12896 (see below). This service is not part of @code{%base-services}.
12899 @deftp {Data Type} gpm-configuration
12900 Data type representing the configuration of GPM.
12903 @item @code{options} (default: @code{%default-gpm-options})
12904 Command-line options passed to @command{gpm}. The default set of
12905 options instruct @command{gpm} to listen to mouse events on
12906 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12909 @item @code{gpm} (default: @code{gpm})
12910 The GPM package to use.
12915 @anchor{guix-publish-service-type}
12916 @deffn {Scheme Variable} guix-publish-service-type
12917 This is the service type for @command{guix publish} (@pxref{Invoking
12918 guix publish}). Its value must be a @code{guix-publish-configuration}
12919 object, as described below.
12921 This assumes that @file{/etc/guix} already contains a signing key pair as
12922 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12923 archive}). If that is not the case, the service will fail to start.
12926 @deftp {Data Type} guix-publish-configuration
12927 Data type representing the configuration of the @code{guix publish}
12931 @item @code{guix} (default: @code{guix})
12932 The Guix package to use.
12934 @item @code{port} (default: @code{80})
12935 The TCP port to listen for connections.
12937 @item @code{host} (default: @code{"localhost"})
12938 The host (and thus, network interface) to listen to. Use
12939 @code{"0.0.0.0"} to listen on all the network interfaces.
12941 @item @code{compression} (default: @code{'(("gzip" 3))})
12942 This is a list of compression method/level tuple used when compressing
12943 substitutes. For example, to compress all substitutes with @emph{both} lzip
12944 at level 7 and gzip at level 9, write:
12947 '(("lzip" 7) ("gzip" 9))
12950 Level 9 achieves the best compression ratio at the expense of increased CPU
12951 usage, whereas level 1 achieves fast compression.
12953 An empty list disables compression altogether.
12955 @item @code{nar-path} (default: @code{"nar"})
12956 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12957 publish, @code{--nar-path}}, for details.
12959 @item @code{cache} (default: @code{#f})
12960 When it is @code{#f}, disable caching and instead generate archives on
12961 demand. Otherwise, this should be the name of a directory---e.g.,
12962 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12963 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12964 @option{--cache}}, for more information on the tradeoffs involved.
12966 @item @code{workers} (default: @code{#f})
12967 When it is an integer, this is the number of worker threads used for
12968 caching; when @code{#f}, the number of processors is used.
12969 @xref{Invoking guix publish, @option{--workers}}, for more information.
12971 @item @code{ttl} (default: @code{#f})
12972 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12973 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12974 for more information.
12978 @anchor{rngd-service}
12979 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12980 [#:device "/dev/hwrng"]
12981 Return a service that runs the @command{rngd} program from @var{rng-tools}
12982 to add @var{device} to the kernel's entropy pool. The service will fail if
12983 @var{device} does not exist.
12986 @anchor{pam-limits-service}
12987 @cindex session limits
12992 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12994 Return a service that installs a configuration file for the
12995 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12996 @code{pam_limits} module}. The procedure optionally takes a list of
12997 @code{pam-limits-entry} values, which can be used to specify
12998 @code{ulimit} limits and nice priority limits to user sessions.
13000 The following limits definition sets two hard and soft limits for all
13001 login sessions of users in the @code{realtime} group:
13004 (pam-limits-service
13006 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13007 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13010 The first entry increases the maximum realtime priority for
13011 non-privileged processes; the second entry lifts any restriction of the
13012 maximum address space that can be locked in memory. These settings are
13013 commonly used for real-time audio systems.
13016 @node Scheduled Job Execution
13017 @subsection Scheduled Job Execution
13021 @cindex scheduling jobs
13022 The @code{(gnu services mcron)} module provides an interface to
13023 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13024 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13025 Unix @command{cron} daemon; the main difference is that it is
13026 implemented in Guile Scheme, which provides a lot of flexibility when
13027 specifying the scheduling of jobs and their actions.
13029 The example below defines an operating system that runs the
13030 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13031 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13032 well as the @command{mkid} command on behalf of an unprivileged user
13033 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13034 gexps to introduce job definitions that are passed to mcron
13035 (@pxref{G-Expressions}).
13038 (use-modules (guix) (gnu) (gnu services mcron))
13039 (use-package-modules base idutils)
13041 (define updatedb-job
13042 ;; Run 'updatedb' at 3AM every day. Here we write the
13043 ;; job's action as a Scheme procedure.
13044 #~(job '(next-hour '(3))
13046 (execl (string-append #$findutils "/bin/updatedb")
13048 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13050 (define garbage-collector-job
13051 ;; Collect garbage 5 minutes after midnight every day.
13052 ;; The job's action is a shell command.
13053 #~(job "5 0 * * *" ;Vixie cron syntax
13056 (define idutils-job
13057 ;; Update the index database as user "charlie" at 12:15PM
13058 ;; and 19:15PM. This runs from the user's home directory.
13059 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13060 (string-append #$idutils "/bin/mkid src")
13065 (services (cons (service mcron-service-type
13066 (mcron-configuration
13067 (jobs (list garbage-collector-job
13073 For more complex jobs defined in Scheme where you need control over the top
13074 level, for instance to introduce a @code{use-modules} form, you can move your
13075 code to a separate program using the @code{program-file} procedure of the
13076 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13080 (define %battery-alert-job
13081 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13083 '(next-minute (range 0 60 1))
13085 "battery-alert.scm"
13086 (with-imported-modules (source-module-closure
13087 '((guix build utils)))
13089 (define %min-level 20)
13090 (use-modules (guix build utils)
13093 (ice-9 textual-ports)
13095 (setenv "LC_ALL" "C") ;ensure English output
13096 (and-let* ((input-pipe (open-pipe*
13098 #$(file-append acpi "/bin/acpi")))
13099 (output (get-string-all input-pipe))
13100 (m (string-match "Discharging, ([0-9]+)%" output))
13101 (level (string->number (match:substring m 1)))
13102 ((< level %min-level)))
13103 (format #t "warning: Battery level is low (~a%)~%" level)
13104 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13107 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13108 for more information on mcron job specifications. Below is the
13109 reference of the mcron service.
13111 On a running system, you can use the @code{schedule} action of the service to
13112 visualize the mcron jobs that will be executed next:
13115 # herd schedule mcron
13119 The example above lists the next five tasks that will be executed, but you can
13120 also specify the number of tasks to display:
13123 # herd schedule mcron 10
13126 @defvr {Scheme Variable} mcron-service-type
13127 This is the type of the @code{mcron} service, whose value is an
13128 @code{mcron-configuration} object.
13130 This service type can be the target of a service extension that provides
13131 it additional job specifications (@pxref{Service Composition}). In
13132 other words, it is possible to define services that provide additional
13136 @deftp {Data Type} mcron-configuration
13137 Data type representing the configuration of mcron.
13140 @item @code{mcron} (default: @var{mcron})
13141 The mcron package to use.
13144 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13145 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13146 specifications,, mcron, GNU@tie{}mcron}).
13152 @subsection Log Rotation
13155 @cindex log rotation
13157 Log files such as those found in @file{/var/log} tend to grow endlessly,
13158 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13159 their contents in separate files, possibly compressed. The @code{(gnu
13160 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13161 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13163 The example below defines an operating system that provides log rotation
13164 with the default settings, for commonly encountered log files.
13167 (use-modules (guix) (gnu))
13168 (use-service-modules admin mcron)
13169 (use-package-modules base idutils)
13173 (services (cons (service rottlog-service-type)
13177 @defvr {Scheme Variable} rottlog-service-type
13178 This is the type of the Rottlog service, whose value is a
13179 @code{rottlog-configuration} object.
13181 Other services can extend this one with new @code{log-rotation} objects
13182 (see below), thereby augmenting the set of files to be rotated.
13184 This service type can define mcron jobs (@pxref{Scheduled Job
13185 Execution}) to run the rottlog service.
13188 @deftp {Data Type} rottlog-configuration
13189 Data type representing the configuration of rottlog.
13192 @item @code{rottlog} (default: @code{rottlog})
13193 The Rottlog package to use.
13195 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13196 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13197 rottlog, GNU Rot[t]log Manual}).
13199 @item @code{rotations} (default: @code{%default-rotations})
13200 A list of @code{log-rotation} objects as defined below.
13203 This is a list of gexps where each gexp corresponds to an mcron job
13204 specification (@pxref{Scheduled Job Execution}).
13208 @deftp {Data Type} log-rotation
13209 Data type representing the rotation of a group of log files.
13211 Taking an example from the Rottlog manual (@pxref{Period Related File
13212 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13218 (files '("/var/log/apache/*"))
13219 (options '("storedir apache-archives"
13225 The list of fields is as follows:
13228 @item @code{frequency} (default: @code{'weekly})
13229 The log rotation frequency, a symbol.
13232 The list of files or file glob patterns to rotate.
13234 @item @code{options} (default: @code{'()})
13235 The list of rottlog options for this rotation (@pxref{Configuration
13236 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13238 @item @code{post-rotate} (default: @code{#f})
13239 Either @code{#f} or a gexp to execute once the rotation has completed.
13243 @defvr {Scheme Variable} %default-rotations
13244 Specifies weekly rotation of @var{%rotated-files} and of
13245 @file{/var/log/guix-daemon.log}.
13248 @defvr {Scheme Variable} %rotated-files
13249 The list of syslog-controlled files to be rotated. By default it is:
13250 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13251 "/var/log/maillog")}.
13254 @node Networking Services
13255 @subsection Networking Services
13257 The @code{(gnu services networking)} module provides services to configure
13258 the network interface.
13260 @cindex DHCP, networking service
13261 @defvr {Scheme Variable} dhcp-client-service-type
13262 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13263 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13264 is the DHCP client package to use, @code{isc-dhcp} by default.
13267 @deffn {Scheme Procedure} dhcpd-service-type
13268 This type defines a service that runs a DHCP daemon. To create a
13269 service of this type, you must supply a @code{<dhcpd-configuration>}.
13273 (service dhcpd-service-type
13274 (dhcpd-configuration
13275 (config-file (local-file "my-dhcpd.conf"))
13276 (interfaces '("enp0s25"))))
13280 @deftp {Data Type} dhcpd-configuration
13282 @item @code{package} (default: @code{isc-dhcp})
13283 The package that provides the DHCP daemon. This package is expected to
13284 provide the daemon at @file{sbin/dhcpd} relative to its output
13285 directory. The default package is the
13286 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13287 @item @code{config-file} (default: @code{#f})
13288 The configuration file to use. This is required. It will be passed to
13289 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13290 object (@pxref{G-Expressions, file-like objects}). See @code{man
13291 dhcpd.conf} for details on the configuration file syntax.
13292 @item @code{version} (default: @code{"4"})
13293 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13294 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13295 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13297 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13298 The run directory to use. At service activation time, this directory
13299 will be created if it does not exist.
13300 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13301 The PID file to use. This corresponds to the @code{-pf} option of
13302 @code{dhcpd}. See @code{man dhcpd} for details.
13303 @item @code{interfaces} (default: @code{'()})
13304 The names of the network interfaces on which dhcpd should listen for
13305 broadcasts. If this list is not empty, then its elements (which must be
13306 strings) will be appended to the @code{dhcpd} invocation when starting
13307 the daemon. It may not be necessary to explicitly specify any
13308 interfaces here; see @code{man dhcpd} for details.
13312 @defvr {Scheme Variable} static-networking-service-type
13313 This is the type for statically-configured network interfaces.
13314 @c TODO Document <static-networking> data structures.
13317 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13318 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13319 [#:requirement @code{'(udev)}]
13320 Return a service that starts @var{interface} with address @var{ip}. If
13321 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13322 it must be a string specifying the default network gateway. @var{requirement}
13323 can be used to declare a dependency on another service before configuring the
13326 This procedure can be called several times, one for each network
13327 interface of interest. Behind the scenes what it does is extend
13328 @code{static-networking-service-type} with additional network interfaces
13334 (static-networking-service "eno1" "192.168.1.82"
13335 #:gateway "192.168.1.2"
13336 #:name-servers '("192.168.1.2"))
13343 @cindex network management
13344 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13345 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13346 management daemon that aims to simplify wired and wireless networking.
13348 This service adds the @var{wicd} package to the global profile, providing
13349 several commands to interact with the daemon and configure networking:
13350 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13351 and @command{wicd-curses} user interfaces.
13354 @cindex ModemManager
13356 @defvr {Scheme Variable} modem-manager-service-type
13357 This is the service type for the
13358 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13359 service. The value for this service type is a
13360 @code{modem-manager-configuration} record.
13362 This service is part of @code{%desktop-services} (@pxref{Desktop
13366 @deftp {Data Type} modem-manager-configuration
13367 Data type representing the configuration of ModemManager.
13370 @item @code{modem-manager} (default: @code{modem-manager})
13371 The ModemManager package to use.
13376 @cindex USB_ModeSwitch
13377 @cindex Modeswitching
13379 @defvr {Scheme Variable} usb-modeswitch-service-type
13380 This is the service type for the
13381 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13382 value for this service type is a @code{usb-modeswitch-configuration} record.
13384 When plugged in, some USB modems (and other USB devices) initially present
13385 themselves as a read-only storage medium and not as a modem. They need to be
13386 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13387 installs udev rules to automatically modeswitch these devices when they are
13390 This service is part of @code{%desktop-services} (@pxref{Desktop
13394 @deftp {Data Type} usb-modeswitch-configuration
13395 Data type representing the configuration of USB_ModeSwitch.
13398 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13399 The USB_ModeSwitch package providing the binaries for modeswitching.
13401 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13402 The package providing the device data and udev rules file used by
13405 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13406 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13407 config file shipped with USB_ModeSwitch is used which disables logging to
13408 @file{/var/log} among other default settings. If set to @code{#f}, no config
13414 @cindex NetworkManager
13416 @defvr {Scheme Variable} network-manager-service-type
13417 This is the service type for the
13418 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13419 service. The value for this service type is a
13420 @code{network-manager-configuration} record.
13422 This service is part of @code{%desktop-services} (@pxref{Desktop
13426 @deftp {Data Type} network-manager-configuration
13427 Data type representing the configuration of NetworkManager.
13430 @item @code{network-manager} (default: @code{network-manager})
13431 The NetworkManager package to use.
13433 @item @code{dns} (default: @code{"default"})
13434 Processing mode for DNS, which affects how NetworkManager uses the
13435 @code{resolv.conf} configuration file.
13439 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13440 provided by currently active connections.
13443 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13444 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13445 then update @code{resolv.conf} to point to the local nameserver.
13447 With this setting, you can share your network connection. For example when
13448 you want to share your network connection to another laptop @i{via} an
13449 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13450 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13451 and reestablish the connection (or reboot).
13453 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13454 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13455 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13456 browser on your host system, or connect to the VM @i{via} SSH
13457 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13458 host-to-guest connection, run this command once:
13461 nmcli connection add type tun \
13462 connection.interface-name tap0 \
13463 tun.mode tap tun.owner $(id -u) \
13464 ipv4.method shared \
13465 ipv4.addresses 172.28.112.1/24
13468 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13469 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13470 @command{qemu-system-...}.
13473 NetworkManager will not modify @code{resolv.conf}.
13476 @item @code{vpn-plugins} (default: @code{'()})
13477 This is the list of available plugins for virtual private networks
13478 (VPNs). An example of this is the @code{network-manager-openvpn}
13479 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13485 @deffn {Scheme Variable} connman-service-type
13486 This is the service type to run @url{https://01.org/connman,Connman},
13487 a network connection manager.
13489 Its value must be an
13490 @code{connman-configuration} record as in this example:
13493 (service connman-service-type
13494 (connman-configuration
13495 (disable-vpn? #t)))
13498 See below for details about @code{connman-configuration}.
13501 @deftp {Data Type} connman-configuration
13502 Data Type representing the configuration of connman.
13505 @item @code{connman} (default: @var{connman})
13506 The connman package to use.
13508 @item @code{disable-vpn?} (default: @code{#f})
13509 When true, disable connman's vpn plugin.
13513 @cindex WPA Supplicant
13514 @defvr {Scheme Variable} wpa-supplicant-service-type
13515 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13516 supplicant}, an authentication daemon required to authenticate against
13517 encrypted WiFi or ethernet networks.
13520 @deftp {Data Type} wpa-supplicant-configuration
13521 Data type representing the configuration of WPA Supplicant.
13523 It takes the following parameters:
13526 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13527 The WPA Supplicant package to use.
13529 @item @code{dbus?} (default: @code{#t})
13530 Whether to listen for requests on D-Bus.
13532 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13533 Where to store the PID file.
13535 @item @code{interface} (default: @code{#f})
13536 If this is set, it must specify the name of a network interface that
13537 WPA supplicant will control.
13539 @item @code{config-file} (default: @code{#f})
13540 Optional configuration file to use.
13542 @item @code{extra-options} (default: @code{'()})
13543 List of additional command-line arguments to pass to the daemon.
13548 @defvr {Scheme Variable} iptables-service-type
13549 This is the service type to set up an iptables configuration. iptables is a
13550 packet filtering framework supported by the Linux kernel. This service
13551 supports configuring iptables for both IPv4 and IPv6. A simple example
13552 configuration rejecting all incoming connections except those to the ssh port
13556 (service iptables-service-type
13557 (iptables-configuration
13558 (ipv4-rules (plain-file "iptables.rules" "*filter
13562 -A INPUT -p tcp --dport 22 -j ACCEPT
13563 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13566 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13570 -A INPUT -p tcp --dport 22 -j ACCEPT
13571 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13577 @deftp {Data Type} iptables-configuration
13578 The data type representing the configuration of iptables.
13581 @item @code{iptables} (default: @code{iptables})
13582 The iptables package that provides @code{iptables-restore} and
13583 @code{ip6tables-restore}.
13584 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13585 The iptables rules to use. It will be passed to @code{iptables-restore}.
13586 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13588 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13589 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13590 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13596 @defvr {Scheme Variable} nftables-service-type
13597 This is the service type to set up a nftables configuration. nftables is a
13598 netfilter project that aims to replace the existing iptables, ip6tables,
13599 arptables and ebtables framework. It provides a new packet filtering
13600 framework, a new user-space utility @command{nft}, and a compatibility layer
13601 for iptables. This service comes with a default ruleset
13602 @code{%default-nftables-ruleset} that rejecting all incomming connections
13603 except those to the ssh port 22. To use it, simply write:
13606 (service nftables-service-type)
13610 @deftp {Data Type} nftables-configuration
13611 The data type representing the configuration of nftables.
13614 @item @code{package} (default: @code{nftables})
13615 The nftables package that provides @command{nft}.
13616 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13617 The nftables ruleset to use. This may be any ``file-like'' object
13618 (@pxref{G-Expressions, file-like objects}).
13622 @cindex NTP (Network Time Protocol), service
13623 @cindex ntpd, service for the Network Time Protocol daemon
13624 @cindex real time clock
13625 @defvr {Scheme Variable} ntp-service-type
13626 This is the type of the service running the @uref{https://www.ntp.org,
13627 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13628 system clock synchronized with that of the specified NTP servers.
13630 The value of this service is an @code{ntpd-configuration} object, as described
13634 @deftp {Data Type} ntp-configuration
13635 This is the data type for the NTP service configuration.
13638 @item @code{servers} (default: @code{%ntp-servers})
13639 This is the list of servers (@code{<ntp-server>} records) with which
13640 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13643 @item @code{allow-large-adjustment?} (default: @code{#t})
13644 This determines whether @command{ntpd} is allowed to make an initial
13645 adjustment of more than 1,000 seconds.
13647 @item @code{ntp} (default: @code{ntp})
13648 The NTP package to use.
13652 @defvr {Scheme Variable} %ntp-servers
13653 List of host names used as the default NTP servers. These are servers of the
13654 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13657 @deftp {Data Type} ntp-server
13658 The data type representing the configuration of a NTP server.
13661 @item @code{type} (default: @code{'server})
13662 The type of the NTP server, given as a symbol. One of @code{'pool},
13663 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13665 @item @code{address}
13666 The address of the server, as a string.
13668 @item @code{options}
13669 NTPD options to use with that specific server, given as a list of option names
13670 and/or of option names and values tuples. The following example define a server
13671 to use with the options @option{iburst} and @option{prefer}, as well as
13672 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13677 (address "some.ntp.server.org")
13678 (options `(iburst (version 3) (maxpoll 16) prefer))))
13684 @deffn {Scheme Procedure} openntpd-service-type
13685 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13686 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13687 clock synchronized with that of the given servers.
13691 openntpd-service-type
13692 (openntpd-configuration
13693 (listen-on '("127.0.0.1" "::1"))
13694 (sensor '("udcf0 correction 70000"))
13695 (constraint-from '("www.gnu.org"))
13696 (constraints-from '("https://www.google.com/"))
13697 (allow-large-adjustment? #t)))
13702 @defvr {Scheme Variable} %openntpd-servers
13703 This variable is a list of the server addresses defined in
13704 @var{%ntp-servers}.
13707 @deftp {Data Type} openntpd-configuration
13709 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13710 The openntpd executable to use.
13711 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13712 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13713 @item @code{query-from} (default: @code{'()})
13714 A list of local IP address the ntpd daemon should use for outgoing queries.
13715 @item @code{sensor} (default: @code{'()})
13716 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13717 will listen to each sensor that actually exists and ignore non-existent ones.
13718 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13720 @item @code{server} (default: @code{'()})
13721 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13722 @item @code{servers} (default: @var{%openntp-servers})
13723 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13724 @item @code{constraint-from} (default: @code{'()})
13725 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13726 This time information is not used for precision but acts as an authenticated
13727 constraint, thereby reducing the impact of unauthenticated NTP
13728 man-in-the-middle attacks.
13729 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13731 @item @code{constraints-from} (default: @code{'()})
13732 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13733 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13734 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13735 @item @code{allow-large-adjustment?} (default: @code{#f})
13736 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13742 @deffn {Scheme variable} inetd-service-type
13743 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13744 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13745 connections on internet sockets, and lazily starts the specified server
13746 program when a connection is made on one of these sockets.
13748 The value of this service is an @code{inetd-configuration} object. The
13749 following example configures the @command{inetd} daemon to provide the
13750 built-in @command{echo} service, as well as an smtp service which
13751 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13752 gateway @code{hostname}:
13757 (inetd-configuration
13761 (socket-type 'stream)
13768 (socket-type 'stream)
13772 (program (file-append openssh "/bin/ssh"))
13774 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13775 "-W" "smtp-server:25" "user@@hostname")))))))
13778 See below for more details about @code{inetd-configuration}.
13781 @deftp {Data Type} inetd-configuration
13782 Data type representing the configuration of @command{inetd}.
13785 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13786 The @command{inetd} executable to use.
13788 @item @code{entries} (default: @code{'()})
13789 A list of @command{inetd} service entries. Each entry should be created
13790 by the @code{inetd-entry} constructor.
13794 @deftp {Data Type} inetd-entry
13795 Data type representing an entry in the @command{inetd} configuration.
13796 Each entry corresponds to a socket where @command{inetd} will listen for
13800 @item @code{node} (default: @code{#f})
13801 Optional string, a comma-separated list of local addresses
13802 @command{inetd} should use when listening for this service.
13803 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13804 description of all options.
13806 A string, the name must correspond to an entry in @code{/etc/services}.
13807 @item @code{socket-type}
13808 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13810 @item @code{protocol}
13811 A string, must correspond to an entry in @code{/etc/protocols}.
13812 @item @code{wait?} (default: @code{#t})
13813 Whether @command{inetd} should wait for the server to exit before
13814 listening to new service requests.
13816 A string containing the user (and, optionally, group) name of the user
13817 as whom the server should run. The group name can be specified in a
13818 suffix, separated by a colon or period, i.e.@: @code{"user"},
13819 @code{"user:group"} or @code{"user.group"}.
13820 @item @code{program} (default: @code{"internal"})
13821 The server program which will serve the requests, or @code{"internal"}
13822 if @command{inetd} should use a built-in service.
13823 @item @code{arguments} (default: @code{'()})
13824 A list strings or file-like objects, which are the server program's
13825 arguments, starting with the zeroth argument, i.e.@: the name of the
13826 program itself. For @command{inetd}'s internal services, this entry
13827 must be @code{'()} or @code{'("internal")}.
13830 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13831 detailed discussion of each configuration field.
13835 @defvr {Scheme Variable} tor-service-type
13836 This is the type for a service that runs the @uref{https://torproject.org,
13837 Tor} anonymous networking daemon. The service is configured using a
13838 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13839 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13843 @deftp {Data Type} tor-configuration
13845 @item @code{tor} (default: @code{tor})
13846 The package that provides the Tor daemon. This package is expected to provide
13847 the daemon at @file{bin/tor} relative to its output directory. The default
13848 package is the @uref{https://www.torproject.org, Tor Project's}
13851 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13852 The configuration file to use. It will be appended to a default configuration
13853 file, and the final configuration file will be passed to @code{tor} via its
13854 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13855 file-like objects}). See @code{man tor} for details on the configuration file
13858 @item @code{hidden-services} (default: @code{'()})
13859 The list of @code{<hidden-service>} records to use. For any hidden service
13860 you include in this list, appropriate configuration to enable the hidden
13861 service will be automatically added to the default configuration file. You
13862 may conveniently create @code{<hidden-service>} records using the
13863 @code{tor-hidden-service} procedure described below.
13865 @item @code{socks-socket-type} (default: @code{'tcp})
13866 The default socket type that Tor should use for its SOCKS socket. This must
13867 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13868 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13869 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13870 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13873 If you want to customize the SOCKS socket in more detail, leave
13874 @code{socks-socket-type} at its default value of @code{'tcp} and use
13875 @code{config-file} to override the default by providing your own
13876 @code{SocksPort} option.
13880 @cindex hidden service
13881 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13882 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13883 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13886 '((22 "127.0.0.1:22")
13887 (80 "127.0.0.1:8080"))
13890 In this example, port 22 of the hidden service is mapped to local port 22, and
13891 port 80 is mapped to local port 8080.
13893 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13894 the @file{hostname} file contains the @code{.onion} host name for the hidden
13897 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13898 project's documentation} for more information.
13901 The @code{(gnu services rsync)} module provides the following services:
13903 You might want an rsync daemon if you have files that you want available
13904 so anyone (or just yourself) can download existing files or upload new
13907 @deffn {Scheme Variable} rsync-service-type
13908 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13909 The value for this service type is a
13910 @command{rsync-configuration} record as in this example:
13913 (service rsync-service-type)
13916 See below for details about @code{rsync-configuration}.
13919 @deftp {Data Type} rsync-configuration
13920 Data type representing the configuration for @code{rsync-service}.
13923 @item @code{package} (default: @var{rsync})
13924 @code{rsync} package to use.
13926 @item @code{port-number} (default: @code{873})
13927 TCP port on which @command{rsync} listens for incoming connections. If port
13928 is less than @code{1024} @command{rsync} needs to be started as the
13929 @code{root} user and group.
13931 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13932 Name of the file where @command{rsync} writes its PID.
13934 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13935 Name of the file where @command{rsync} writes its lock file.
13937 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13938 Name of the file where @command{rsync} writes its log file.
13940 @item @code{use-chroot?} (default: @var{#t})
13941 Whether to use chroot for @command{rsync} shared directory.
13943 @item @code{share-path} (default: @file{/srv/rsync})
13944 Location of the @command{rsync} shared directory.
13946 @item @code{share-comment} (default: @code{"Rsync share"})
13947 Comment of the @command{rsync} shared directory.
13949 @item @code{read-only?} (default: @var{#f})
13950 Read-write permissions to shared directory.
13952 @item @code{timeout} (default: @code{300})
13953 I/O timeout in seconds.
13955 @item @code{user} (default: @var{"root"})
13956 Owner of the @code{rsync} process.
13958 @item @code{group} (default: @var{"root"})
13959 Group of the @code{rsync} process.
13961 @item @code{uid} (default: @var{"rsyncd"})
13962 User name or user ID that file transfers to and from that module should take
13963 place as when the daemon was run as @code{root}.
13965 @item @code{gid} (default: @var{"rsyncd"})
13966 Group name or group ID that will be used when accessing the module.
13971 Furthermore, @code{(gnu services ssh)} provides the following services.
13975 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13976 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13977 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13978 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13979 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13980 [#:public-key-authentication? #t] [#:initialize? #t]
13981 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13982 @var{host-key} must designate a file containing the host key, and readable
13985 When @var{daemonic?} is true, @command{lshd} will detach from the
13986 controlling terminal and log its output to syslogd, unless one sets
13987 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13988 depend on existence of syslogd service. When @var{pid-file?} is true,
13989 @command{lshd} writes its PID to the file called @var{pid-file}.
13991 When @var{initialize?} is true, automatically create the seed and host key
13992 upon service activation if they do not exist yet. This may take long and
13993 require interaction.
13995 When @var{initialize?} is false, it is up to the user to initialize the
13996 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13997 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13998 basics,,, lsh, LSH Manual}).
14000 When @var{interfaces} is empty, lshd listens for connections on all the
14001 network interfaces; otherwise, @var{interfaces} must be a list of host names
14004 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14005 passwords, and @var{root-login?} specifies whether to accept log-ins as
14008 The other options should be self-descriptive.
14013 @deffn {Scheme Variable} openssh-service-type
14014 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14015 shell daemon, @command{sshd}. Its value must be an
14016 @code{openssh-configuration} record as in this example:
14019 (service openssh-service-type
14020 (openssh-configuration
14021 (x11-forwarding? #t)
14022 (permit-root-login 'without-password)
14024 `(("alice" ,(local-file "alice.pub"))
14025 ("bob" ,(local-file "bob.pub"))))))
14028 See below for details about @code{openssh-configuration}.
14030 This service can be extended with extra authorized keys, as in this
14034 (service-extension openssh-service-type
14035 (const `(("charlie"
14036 ,(local-file "charlie.pub")))))
14040 @deftp {Data Type} openssh-configuration
14041 This is the configuration record for OpenSSH's @command{sshd}.
14044 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14045 Name of the file where @command{sshd} writes its PID.
14047 @item @code{port-number} (default: @code{22})
14048 TCP port on which @command{sshd} listens for incoming connections.
14050 @item @code{permit-root-login} (default: @code{#f})
14051 This field determines whether and when to allow logins as root. If
14052 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14053 If it's the symbol @code{'without-password}, then root logins are
14054 permitted but not with password-based authentication.
14056 @item @code{allow-empty-passwords?} (default: @code{#f})
14057 When true, users with empty passwords may log in. When false, they may
14060 @item @code{password-authentication?} (default: @code{#t})
14061 When true, users may log in with their password. When false, they have
14062 other authentication methods.
14064 @item @code{public-key-authentication?} (default: @code{#t})
14065 When true, users may log in using public key authentication. When
14066 false, users have to use other authentication method.
14068 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14069 This is used only by protocol version 2.
14071 @item @code{x11-forwarding?} (default: @code{#f})
14072 When true, forwarding of X11 graphical client connections is
14073 enabled---in other words, @command{ssh} options @option{-X} and
14074 @option{-Y} will work.
14076 @item @code{allow-agent-forwarding?} (default: @code{#t})
14077 Whether to allow agent forwarding.
14079 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14080 Whether to allow TCP forwarding.
14082 @item @code{gateway-ports?} (default: @code{#f})
14083 Whether to allow gateway ports.
14085 @item @code{challenge-response-authentication?} (default: @code{#f})
14086 Specifies whether challenge response authentication is allowed (e.g.@: via
14089 @item @code{use-pam?} (default: @code{#t})
14090 Enables the Pluggable Authentication Module interface. If set to
14091 @code{#t}, this will enable PAM authentication using
14092 @code{challenge-response-authentication?} and
14093 @code{password-authentication?}, in addition to PAM account and session
14094 module processing for all authentication types.
14096 Because PAM challenge response authentication usually serves an
14097 equivalent role to password authentication, you should disable either
14098 @code{challenge-response-authentication?} or
14099 @code{password-authentication?}.
14101 @item @code{print-last-log?} (default: @code{#t})
14102 Specifies whether @command{sshd} should print the date and time of the
14103 last user login when a user logs in interactively.
14105 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14106 Configures external subsystems (e.g.@: file transfer daemon).
14108 This is a list of two-element lists, each of which containing the
14109 subsystem name and a command (with optional arguments) to execute upon
14112 The command @command{internal-sftp} implements an in-process SFTP
14113 server. Alternately, one can specify the @command{sftp-server} command:
14115 (service openssh-service-type
14116 (openssh-configuration
14118 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14121 @item @code{accepted-environment} (default: @code{'()})
14122 List of strings describing which environment variables may be exported.
14124 Each string gets on its own line. See the @code{AcceptEnv} option in
14125 @code{man sshd_config}.
14127 This example allows ssh-clients to export the @code{COLORTERM} variable.
14128 It is set by terminal emulators, which support colors. You can use it in
14129 your shell's resource file to enable colors for the prompt and commands
14130 if this variable is set.
14133 (service openssh-service-type
14134 (openssh-configuration
14135 (accepted-environment '("COLORTERM"))))
14138 @item @code{authorized-keys} (default: @code{'()})
14139 @cindex authorized keys, SSH
14140 @cindex SSH authorized keys
14141 This is the list of authorized keys. Each element of the list is a user
14142 name followed by one or more file-like objects that represent SSH public
14146 (openssh-configuration
14148 `(("rekado" ,(local-file "rekado.pub"))
14149 ("chris" ,(local-file "chris.pub"))
14150 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
14154 registers the specified public keys for user accounts @code{rekado},
14155 @code{chris}, and @code{root}.
14157 Additional authorized keys can be specified @i{via}
14158 @code{service-extension}.
14160 Note that this does @emph{not} interfere with the use of
14161 @file{~/.ssh/authorized_keys}.
14163 @item @code{log-level} (default: @code{'info})
14164 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14165 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14166 page for @file{sshd_config} for the full list of level names.
14168 @item @code{extra-content} (default: @code{""})
14169 This field can be used to append arbitrary text to the configuration file. It
14170 is especially useful for elaborate configurations that cannot be expressed
14171 otherwise. This configuration, for example, would generally disable root
14172 logins, but permit them from one specific IP address:
14175 (openssh-configuration
14177 Match Address 192.168.0.1
14178 PermitRootLogin yes"))
14184 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14185 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14186 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14189 For example, to specify a Dropbear service listening on port 1234, add
14190 this call to the operating system's @code{services} field:
14193 (dropbear-service (dropbear-configuration
14194 (port-number 1234)))
14198 @deftp {Data Type} dropbear-configuration
14199 This data type represents the configuration of a Dropbear SSH daemon.
14202 @item @code{dropbear} (default: @var{dropbear})
14203 The Dropbear package to use.
14205 @item @code{port-number} (default: 22)
14206 The TCP port where the daemon waits for incoming connections.
14208 @item @code{syslog-output?} (default: @code{#t})
14209 Whether to enable syslog output.
14211 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14212 File name of the daemon's PID file.
14214 @item @code{root-login?} (default: @code{#f})
14215 Whether to allow @code{root} logins.
14217 @item @code{allow-empty-passwords?} (default: @code{#f})
14218 Whether to allow empty passwords.
14220 @item @code{password-authentication?} (default: @code{#t})
14221 Whether to enable password-based authentication.
14225 @defvr {Scheme Variable} %facebook-host-aliases
14226 This variable contains a string for use in @file{/etc/hosts}
14227 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14228 line contains a entry that maps a known server name of the Facebook
14229 on-line service---e.g., @code{www.facebook.com}---to the local
14230 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14232 This variable is typically used in the @code{hosts-file} field of an
14233 @code{operating-system} declaration (@pxref{operating-system Reference,
14234 @file{/etc/hosts}}):
14237 (use-modules (gnu) (guix))
14240 (host-name "mymachine")
14243 ;; Create a /etc/hosts file with aliases for "localhost"
14244 ;; and "mymachine", as well as for Facebook servers.
14245 (plain-file "hosts"
14246 (string-append (local-host-aliases host-name)
14247 %facebook-host-aliases))))
14250 This mechanism can prevent programs running locally, such as Web
14251 browsers, from accessing Facebook.
14254 The @code{(gnu services avahi)} provides the following definition.
14256 @defvr {Scheme Variable} avahi-service-type
14257 This is the service that runs @command{avahi-daemon}, a system-wide
14258 mDNS/DNS-SD responder that allows for service discovery and
14259 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14260 Its value must be a @code{zero-configuration} record---see below.
14262 This service extends the name service cache daemon (nscd) so that it can
14263 resolve @code{.local} host names using
14264 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14265 Service Switch}, for information on host name resolution.
14267 Additionally, add the @var{avahi} package to the system profile so that
14268 commands such as @command{avahi-browse} are directly usable.
14271 @deftp {Data Type} avahi-configuration
14272 Data type representation the configuration for Avahi.
14276 @item @code{host-name} (default: @code{#f})
14277 If different from @code{#f}, use that as the host name to
14278 publish for this machine; otherwise, use the machine's actual host name.
14280 @item @code{publish?} (default: @code{#t})
14281 When true, allow host names and services to be published (broadcast) over the
14284 @item @code{publish-workstation?} (default: @code{#t})
14285 When true, @command{avahi-daemon} publishes the machine's host name and IP
14286 address via mDNS on the local network. To view the host names published on
14287 your local network, you can run:
14290 avahi-browse _workstation._tcp
14293 @item @code{wide-area?} (default: @code{#f})
14294 When true, DNS-SD over unicast DNS is enabled.
14296 @item @code{ipv4?} (default: @code{#t})
14297 @itemx @code{ipv6?} (default: @code{#t})
14298 These fields determine whether to use IPv4/IPv6 sockets.
14300 @item @code{domains-to-browse} (default: @code{'()})
14301 This is a list of domains to browse.
14305 @deffn {Scheme Variable} openvswitch-service-type
14306 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14307 service, whose value should be an @code{openvswitch-configuration}
14311 @deftp {Data Type} openvswitch-configuration
14312 Data type representing the configuration of Open vSwitch, a multilayer
14313 virtual switch which is designed to enable massive network automation
14314 through programmatic extension.
14317 @item @code{package} (default: @var{openvswitch})
14318 Package object of the Open vSwitch.
14323 @defvr {Scheme Variable} pagekite-service-type
14324 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14325 a tunneling solution for making localhost servers publicly visible, even from
14326 behind restrictive firewalls or NAT without forwarded ports. The value for
14327 this service type is a @code{pagekite-configuration} record.
14329 Here's an example exposing the local HTTP and SSH daemons:
14332 (service pagekite-service-type
14333 (pagekite-configuration
14334 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14335 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14336 (extra-file "/etc/pagekite.rc")))
14340 @deftp {Data Type} pagekite-configuration
14341 Data type representing the configuration of PageKite.
14344 @item @code{package} (default: @var{pagekite})
14345 Package object of PageKite.
14347 @item @code{kitename} (default: @code{#f})
14348 PageKite name for authenticating to the frontend server.
14350 @item @code{kitesecret} (default: @code{#f})
14351 Shared secret for authenticating to the frontend server. You should probably
14352 put this inside @code{extra-file} instead.
14354 @item @code{frontend} (default: @code{#f})
14355 Connect to the named PageKite frontend server instead of the
14356 @uref{https://pagekite.net,,pagekite.net} service.
14358 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14359 List of service kites to use. Exposes HTTP on port 80 by default. The format
14360 is @code{proto:kitename:host:port:secret}.
14362 @item @code{extra-file} (default: @code{#f})
14363 Extra configuration file to read, which you are expected to create manually.
14364 Use this to add additional options and manage shared secrets out-of-band.
14370 @subsection X Window
14373 @cindex X Window System
14374 @cindex login manager
14375 Support for the X Window graphical display system---specifically
14376 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14377 there is no @code{xorg-service} procedure. Instead, the X server is
14378 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14381 @cindex GNOME, login manager
14382 GDM of course allows users to log in into window managers and desktop
14383 environments other than GNOME; for those using GNOME, GDM is required for
14384 features such as automatic screen locking.
14386 @cindex window manager
14387 To use X11, you must install at least one @dfn{window manager}---for
14388 example the @code{windowmaker} or @code{openbox} packages---preferably
14389 by adding it to the @code{packages} field of your operating system
14390 definition (@pxref{operating-system Reference, system-wide packages}).
14392 @defvr {Scheme Variable} gdm-service-type
14393 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14394 Desktop Manager} (GDM), a program that manages graphical display servers and
14395 handles graphical user logins. Its value must be a @code{gdm-configuration}
14398 @cindex session types (X11)
14399 @cindex X11 session types
14400 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14401 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14402 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14403 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14404 set of packages automatically makes them available at the log-in screen.
14406 In addition, @file{~/.xsession} files are honored. When available,
14407 @file{~/.xsession} must be an executable that starts a window manager
14408 and/or other X clients.
14411 @deftp {Data Type} gdm-configuration
14413 @item @code{auto-login?} (default: @code{#f})
14414 @itemx @code{default-user} (default: @code{#f})
14415 When @code{auto-login?} is false, GDM presents a log-in screen.
14417 When @code{auto-login?} is true, GDM logs in directly as
14418 @code{default-user}.
14420 @item @code{debug?} (default: @code{#f})
14421 When true, GDM writes debug messages to its log.
14423 @item @code{gnome-shell-assets} (default: ...)
14424 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14426 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14427 Configuration of the Xorg graphical server.
14429 @item @code{xsession} (default: @code{(xinitrc)})
14430 Script to run before starting a X session.
14432 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14433 File name of the @code{dbus-daemon} executable.
14435 @item @code{gdm} (default: @code{gdm})
14436 The GDM package to use.
14440 @defvr {Scheme Variable} slim-service-type
14441 This is the type for the SLiM graphical login manager for X11.
14443 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14444 allows users to choose a session from the log-in screen using @kbd{F1}. It
14445 also honors @file{~/.xsession} files.
14447 Unlike GDM, SLiM does not spawn the user session on a different VT after
14448 logging in, which means that you can only start one graphical session. If you
14449 want to be able to run multiple graphical sessions at the same time you have
14450 to add multiple SLiM services to your system services. The following example
14451 shows how to replace the default GDM service with two SLiM services on tty7
14455 (use-modules (gnu services)
14456 (gnu services desktop)
14457 (gnu services xorg)
14458 (srfi srfi-1)) ;for 'remove'
14462 (services (cons* (service slim-service-type (slim-configuration
14465 (service slim-service-type (slim-configuration
14468 (remove (lambda (service)
14469 (eq? (service-kind service) gdm-service-type))
14470 %desktop-services))))
14475 @deftp {Data Type} slim-configuration
14476 Data type representing the configuration of @code{slim-service-type}.
14479 @item @code{allow-empty-passwords?} (default: @code{#t})
14480 Whether to allow logins with empty passwords.
14482 @item @code{auto-login?} (default: @code{#f})
14483 @itemx @code{default-user} (default: @code{""})
14484 When @code{auto-login?} is false, SLiM presents a log-in screen.
14486 When @code{auto-login?} is true, SLiM logs in directly as
14487 @code{default-user}.
14489 @item @code{theme} (default: @code{%default-slim-theme})
14490 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14491 The graphical theme to use and its name.
14493 @item @code{auto-login-session} (default: @code{#f})
14494 If true, this must be the name of the executable to start as the default
14495 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14497 If false, a session described by one of the available @file{.desktop}
14498 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14502 You must install at least one window manager in the system profile or in
14503 your user profile. Failing to do that, if @code{auto-login-session} is
14504 false, you will be unable to log in.
14507 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14508 Configuration of the Xorg graphical server.
14510 @item @code{display} (default @code{":0"})
14511 The display on which to start the Xorg graphical server.
14513 @item @code{vt} (default @code{"vt7"})
14514 The VT on which to start the Xorg graphical server.
14516 @item @code{xauth} (default: @code{xauth})
14517 The XAuth package to use.
14519 @item @code{shepherd} (default: @code{shepherd})
14520 The Shepherd package used when invoking @command{halt} and
14523 @item @code{sessreg} (default: @code{sessreg})
14524 The sessreg package used in order to register the session.
14526 @item @code{slim} (default: @code{slim})
14527 The SLiM package to use.
14531 @defvr {Scheme Variable} %default-theme
14532 @defvrx {Scheme Variable} %default-theme-name
14533 The default SLiM theme and its name.
14537 @deftp {Data Type} sddm-configuration
14538 This is the data type representing the sddm service configuration.
14541 @item @code{display-server} (default: "x11")
14542 Select display server to use for the greeter. Valid values are "x11"
14545 @item @code{numlock} (default: "on")
14546 Valid values are "on", "off" or "none".
14548 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14549 Command to run when halting.
14551 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14552 Command to run when rebooting.
14554 @item @code{theme} (default "maldives")
14555 Theme to use. Default themes provided by SDDM are "elarun", "maldives" or "maya".
14557 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14558 Directory to look for themes.
14560 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14561 Directory to look for faces.
14563 @item @code{default-path} (default "/run/current-system/profile/bin")
14564 Default PATH to use.
14566 @item @code{minimum-uid} (default: 1000)
14567 Minimum UID displayed in SDDM and allowed for log-in.
14569 @item @code{maximum-uid} (default: 2000)
14570 Maximum UID to display in SDDM.
14572 @item @code{remember-last-user?} (default #t)
14573 Remember last user.
14575 @item @code{remember-last-session?} (default #t)
14576 Remember last session.
14578 @item @code{hide-users} (default "")
14579 Usernames to hide from SDDM greeter.
14581 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14582 Users with shells listed will be hidden from the SDDM greeter.
14584 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14585 Script to run before starting a wayland session.
14587 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14588 Directory to look for desktop files starting wayland sessions.
14590 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14591 Configuration of the Xorg graphical server.
14593 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14596 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14599 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14600 Script to run after starting xorg-server.
14602 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14603 Script to run before stopping xorg-server.
14605 @item @code{xsession-command} (default: @code{xinitrc})
14606 Script to run before starting a X session.
14608 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14609 Directory to look for desktop files starting X sessions.
14611 @item @code{minimum-vt} (default: 7)
14614 @item @code{auto-login-user} (default "")
14615 User to use for auto-login.
14617 @item @code{auto-login-session} (default "")
14618 Desktop file to use for auto-login.
14620 @item @code{relogin?} (default #f)
14621 Relogin after logout.
14626 @cindex login manager
14628 @defvr {Scheme Variable} sddm-service-type
14629 This is the type of the service to run the
14630 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
14631 must be a @code{sddm-configuration} record (see below).
14633 Here's an example use:
14636 (service sddm-service-type
14637 (sddm-configuration
14638 (auto-login-user "alice")
14639 (auto-login-session "xfce.desktop")))
14643 @deftp {Data Type} sddm-configuration
14644 This data type represents the configuration of the SDDM login manager.
14645 The available fields are:
14648 @item @code{sddm} (default: @code{sddm})
14649 The SDDM package to use.
14651 @item @code{display-server} (default: @code{"x11"})
14652 This must be either @code{"x11"} or @code{"wayland"}.
14654 @c FIXME: Add more fields.
14656 @item @code{auto-login-user} (default: @code{""})
14657 If non-empty, this is the user account under which to log in
14660 @item @code{auto-login-session} (default: @code{""})
14661 If non-empty, this is the @file{.desktop} file name to use as the
14662 auto-login session.
14666 @cindex Xorg, configuration
14667 @deftp {Data Type} xorg-configuration
14668 This data type represents the configuration of the Xorg graphical display
14669 server. Note that there is not Xorg service; instead, the X server is started
14670 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14671 of these display managers aggregates an @code{xorg-configuration} record.
14674 @item @code{modules} (default: @code{%default-xorg-modules})
14675 This is a list of @dfn{module packages} loaded by the Xorg
14676 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14678 @item @code{fonts} (default: @code{%default-xorg-fonts})
14679 This is a list of font directories to add to the server's @dfn{font path}.
14681 @item @code{drivers} (default: @code{'()})
14682 This must be either the empty list, in which case Xorg chooses a graphics
14683 driver automatically, or a list of driver names that will be tried in this
14684 order---e.g., @code{("modesetting" "vesa")}.
14686 @item @code{resolutions} (default: @code{'()})
14687 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14688 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14691 @cindex keyboard layout, for Xorg
14692 @cindex keymap, for Xorg
14693 @item @code{keyboard-layout} (default: @code{#f})
14694 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14695 English (``qwerty'') for a 105-key PC keyboard.
14697 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14698 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14699 information on how to specify the keyboard layout.
14701 @item @code{extra-config} (default: @code{'()})
14702 This is a list of strings or objects appended to the configuration file. It
14703 is used to pass extra text to be added verbatim to the configuration file.
14705 @item @code{server} (default: @code{xorg-server})
14706 This is the package providing the Xorg server.
14708 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14709 This is the list of command-line arguments to pass to the X server. The
14710 default is @code{-nolisten tcp}.
14714 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14715 [@var{login-manager-service-type}]
14716 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14717 @var{config}, an @code{<xorg-configuration>} record.
14719 Since the Xorg configuration is embedded in the log-in manager's
14720 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14721 shorthand to set the Xorg configuration.
14724 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14725 Return a @code{startx} script in which the modules, fonts, etc. specified
14726 in @var{config}, are available. The result should be used in place of
14729 Usually the X server is started by a login manager.
14733 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14734 Add @var{package}, a package for a screen locker or screen saver whose
14735 command is @var{program}, to the set of setuid programs and add a PAM entry
14736 for it. For example:
14739 (screen-locker-service xlockmore "xlock")
14742 makes the good ol' XlockMore usable.
14746 @node Printing Services
14747 @subsection Printing Services
14749 @cindex printer support with CUPS
14750 The @code{(gnu services cups)} module provides a Guix service definition
14751 for the CUPS printing service. To add printer support to a Guix
14752 system, add a @code{cups-service} to the operating system definition:
14754 @deffn {Scheme Variable} cups-service-type
14755 The service type for the CUPS print server. Its value should be a valid
14756 CUPS configuration (see below). To use the default settings, simply
14759 (service cups-service-type)
14763 The CUPS configuration controls the basic things about your CUPS
14764 installation: what interfaces it listens on, what to do if a print job
14765 fails, how much logging to do, and so on. To actually add a printer,
14766 you have to visit the @url{http://localhost:631} URL, or use a tool such
14767 as GNOME's printer configuration services. By default, configuring a
14768 CUPS service will generate a self-signed certificate if needed, for
14769 secure connections to the print server.
14771 Suppose you want to enable the Web interface of CUPS and also add
14772 support for Epson printers @i{via} the @code{escpr} package and for HP
14773 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14774 like this (you need to use the @code{(gnu packages cups)} module):
14777 (service cups-service-type
14778 (cups-configuration
14779 (web-interface? #t)
14781 (list cups-filters escpr hplip-minimal))))
14784 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14785 package then it is suggested that you install the @code{hplip} package,
14786 either in your OS configuration file or as your user.
14788 The available configuration parameters follow. Each parameter
14789 definition is preceded by its type; for example, @samp{string-list foo}
14790 indicates that the @code{foo} parameter should be specified as a list of
14791 strings. There is also a way to specify the configuration as a string,
14792 if you have an old @code{cupsd.conf} file that you want to port over
14793 from some other system; see the end for more details.
14795 @c The following documentation was initially generated by
14796 @c (generate-documentation) in (gnu services cups). Manually maintained
14797 @c documentation is better, so we shouldn't hesitate to edit below as
14798 @c needed. However if the change you want to make to this documentation
14799 @c can be done in an automated way, it's probably easier to change
14800 @c (generate-documentation) than to make it below and have to deal with
14801 @c the churn as CUPS updates.
14804 Available @code{cups-configuration} fields are:
14806 @deftypevr {@code{cups-configuration} parameter} package cups
14810 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14811 Drivers and other extensions to the CUPS package.
14814 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14815 Configuration of where to write logs, what directories to use for print
14816 spools, and related privileged configuration parameters.
14818 Available @code{files-configuration} fields are:
14820 @deftypevr {@code{files-configuration} parameter} log-location access-log
14821 Defines the access log filename. Specifying a blank filename disables
14822 access log generation. The value @code{stderr} causes log entries to be
14823 sent to the standard error file when the scheduler is running in the
14824 foreground, or to the system log daemon when run in the background. The
14825 value @code{syslog} causes log entries to be sent to the system log
14826 daemon. The server name may be included in filenames using the string
14827 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14829 Defaults to @samp{"/var/log/cups/access_log"}.
14832 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14833 Where CUPS should cache data.
14835 Defaults to @samp{"/var/cache/cups"}.
14838 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14839 Specifies the permissions for all configuration files that the scheduler
14842 Note that the permissions for the printers.conf file are currently
14843 masked to only allow access from the scheduler user (typically root).
14844 This is done because printer device URIs sometimes contain sensitive
14845 authentication information that should not be generally known on the
14846 system. There is no way to disable this security feature.
14848 Defaults to @samp{"0640"}.
14851 @deftypevr {@code{files-configuration} parameter} log-location error-log
14852 Defines the error log filename. Specifying a blank filename disables
14853 error log generation. The value @code{stderr} causes log entries to be
14854 sent to the standard error file when the scheduler is running in the
14855 foreground, or to the system log daemon when run in the background. The
14856 value @code{syslog} causes log entries to be sent to the system log
14857 daemon. The server name may be included in filenames using the string
14858 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14860 Defaults to @samp{"/var/log/cups/error_log"}.
14863 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14864 Specifies which errors are fatal, causing the scheduler to exit. The
14869 No errors are fatal.
14872 All of the errors below are fatal.
14875 Browsing initialization errors are fatal, for example failed connections
14876 to the DNS-SD daemon.
14879 Configuration file syntax errors are fatal.
14882 Listen or Port errors are fatal, except for IPv6 failures on the
14883 loopback or @code{any} addresses.
14886 Log file creation or write errors are fatal.
14889 Bad startup file permissions are fatal, for example shared TLS
14890 certificate and key files with world-read permissions.
14893 Defaults to @samp{"all -browse"}.
14896 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14897 Specifies whether the file pseudo-device can be used for new printer
14898 queues. The URI @uref{file:///dev/null} is always allowed.
14900 Defaults to @samp{#f}.
14903 @deftypevr {@code{files-configuration} parameter} string group
14904 Specifies the group name or ID that will be used when executing external
14907 Defaults to @samp{"lp"}.
14910 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14911 Specifies the permissions for all log files that the scheduler writes.
14913 Defaults to @samp{"0644"}.
14916 @deftypevr {@code{files-configuration} parameter} log-location page-log
14917 Defines the page log filename. Specifying a blank filename disables
14918 page log generation. The value @code{stderr} causes log entries to be
14919 sent to the standard error file when the scheduler is running in the
14920 foreground, or to the system log daemon when run in the background. The
14921 value @code{syslog} causes log entries to be sent to the system log
14922 daemon. The server name may be included in filenames using the string
14923 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14925 Defaults to @samp{"/var/log/cups/page_log"}.
14928 @deftypevr {@code{files-configuration} parameter} string remote-root
14929 Specifies the username that is associated with unauthenticated accesses
14930 by clients claiming to be the root user. The default is @code{remroot}.
14932 Defaults to @samp{"remroot"}.
14935 @deftypevr {@code{files-configuration} parameter} file-name request-root
14936 Specifies the directory that contains print jobs and other HTTP request
14939 Defaults to @samp{"/var/spool/cups"}.
14942 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14943 Specifies the level of security sandboxing that is applied to print
14944 filters, backends, and other child processes of the scheduler; either
14945 @code{relaxed} or @code{strict}. This directive is currently only
14946 used/supported on macOS.
14948 Defaults to @samp{strict}.
14951 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14952 Specifies the location of TLS certificates and private keys. CUPS will
14953 look for public and private keys in this directory: a @code{.crt} files
14954 for PEM-encoded certificates and corresponding @code{.key} files for
14955 PEM-encoded private keys.
14957 Defaults to @samp{"/etc/cups/ssl"}.
14960 @deftypevr {@code{files-configuration} parameter} file-name server-root
14961 Specifies the directory containing the server configuration files.
14963 Defaults to @samp{"/etc/cups"}.
14966 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14967 Specifies whether the scheduler calls fsync(2) after writing
14968 configuration or state files.
14970 Defaults to @samp{#f}.
14973 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14974 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14977 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14978 Specifies the directory where temporary files are stored.
14980 Defaults to @samp{"/var/spool/cups/tmp"}.
14983 @deftypevr {@code{files-configuration} parameter} string user
14984 Specifies the user name or ID that is used when running external
14987 Defaults to @samp{"lp"}.
14990 @deftypevr {@code{files-configuration} parameter} string set-env
14991 Set the specified environment variable to be passed to child processes.
14993 Defaults to @samp{"variable value"}.
14997 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14998 Specifies the logging level for the AccessLog file. The @code{config}
14999 level logs when printers and classes are added, deleted, or modified and
15000 when configuration files are accessed or updated. The @code{actions}
15001 level logs when print jobs are submitted, held, released, modified, or
15002 canceled, and any of the conditions for @code{config}. The @code{all}
15003 level logs all requests.
15005 Defaults to @samp{actions}.
15008 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
15009 Specifies whether to purge job history data automatically when it is no
15010 longer required for quotas.
15012 Defaults to @samp{#f}.
15015 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
15016 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
15017 For example, @samp{"_cups" "_print"} will tell network clients that both
15018 CUPS sharing and IPP Everywhere are supported.
15020 Defaults to @samp{"_cups"}.
15023 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
15024 Specifies which protocols to use for local printer sharing.
15026 Defaults to @samp{dnssd}.
15029 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
15030 Specifies whether the CUPS web interface is advertised.
15032 Defaults to @samp{#f}.
15035 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
15036 Specifies whether shared printers are advertised.
15038 Defaults to @samp{#f}.
15041 @deftypevr {@code{cups-configuration} parameter} string classification
15042 Specifies the security classification of the server. Any valid banner
15043 name can be used, including "classified", "confidential", "secret",
15044 "topsecret", and "unclassified", or the banner can be omitted to disable
15045 secure printing functions.
15047 Defaults to @samp{""}.
15050 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
15051 Specifies whether users may override the classification (cover page) of
15052 individual print jobs using the @code{job-sheets} option.
15054 Defaults to @samp{#f}.
15057 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
15058 Specifies the default type of authentication to use.
15060 Defaults to @samp{Basic}.
15063 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
15064 Specifies whether encryption will be used for authenticated requests.
15066 Defaults to @samp{Required}.
15069 @deftypevr {@code{cups-configuration} parameter} string default-language
15070 Specifies the default language to use for text and web content.
15072 Defaults to @samp{"en"}.
15075 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
15076 Specifies the default paper size for new print queues. @samp{"Auto"}
15077 uses a locale-specific default, while @samp{"None"} specifies there is
15078 no default paper size. Specific size names are typically
15079 @samp{"Letter"} or @samp{"A4"}.
15081 Defaults to @samp{"Auto"}.
15084 @deftypevr {@code{cups-configuration} parameter} string default-policy
15085 Specifies the default access policy to use.
15087 Defaults to @samp{"default"}.
15090 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
15091 Specifies whether local printers are shared by default.
15093 Defaults to @samp{#t}.
15096 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
15097 Specifies the delay for updating of configuration and state files, in
15098 seconds. A value of 0 causes the update to happen as soon as possible,
15099 typically within a few milliseconds.
15101 Defaults to @samp{30}.
15104 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
15105 Specifies what to do when an error occurs. Possible values are
15106 @code{abort-job}, which will discard the failed print job;
15107 @code{retry-job}, which will retry the job at a later time;
15108 @code{retry-current-job}, which retries the failed job immediately; and
15109 @code{stop-printer}, which stops the printer.
15111 Defaults to @samp{stop-printer}.
15114 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
15115 Specifies the maximum cost of filters that are run concurrently, which
15116 can be used to minimize disk, memory, and CPU resource problems. A
15117 limit of 0 disables filter limiting. An average print to a
15118 non-PostScript printer needs a filter limit of about 200. A PostScript
15119 printer needs about half that (100). Setting the limit below these
15120 thresholds will effectively limit the scheduler to printing a single job
15123 Defaults to @samp{0}.
15126 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
15127 Specifies the scheduling priority of filters that are run to print a
15128 job. The nice value ranges from 0, the highest priority, to 19, the
15131 Defaults to @samp{0}.
15134 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
15135 Specifies whether to do reverse lookups on connecting clients. The
15136 @code{double} setting causes @code{cupsd} to verify that the hostname
15137 resolved from the address matches one of the addresses returned for that
15138 hostname. Double lookups also prevent clients with unregistered
15139 addresses from connecting to your server. Only set this option to
15140 @code{#t} or @code{double} if absolutely required.
15142 Defaults to @samp{#f}.
15145 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
15146 Specifies the number of seconds to wait before killing the filters and
15147 backend associated with a canceled or held job.
15149 Defaults to @samp{30}.
15152 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
15153 Specifies the interval between retries of jobs in seconds. This is
15154 typically used for fax queues but can also be used with normal print
15155 queues whose error policy is @code{retry-job} or
15156 @code{retry-current-job}.
15158 Defaults to @samp{30}.
15161 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
15162 Specifies the number of retries that are done for jobs. This is
15163 typically used for fax queues but can also be used with normal print
15164 queues whose error policy is @code{retry-job} or
15165 @code{retry-current-job}.
15167 Defaults to @samp{5}.
15170 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15171 Specifies whether to support HTTP keep-alive connections.
15173 Defaults to @samp{#t}.
15176 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15177 Specifies how long an idle client connection remains open, in seconds.
15179 Defaults to @samp{30}.
15182 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15183 Specifies the maximum size of print files, IPP requests, and HTML form
15184 data. A limit of 0 disables the limit check.
15186 Defaults to @samp{0}.
15189 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15190 Listens on the specified interfaces for connections. Valid values are
15191 of the form @var{address}:@var{port}, where @var{address} is either an
15192 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15193 indicate all addresses. Values can also be file names of local UNIX
15194 domain sockets. The Listen directive is similar to the Port directive
15195 but allows you to restrict access to specific interfaces or networks.
15198 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15199 Specifies the number of pending connections that will be allowed. This
15200 normally only affects very busy servers that have reached the MaxClients
15201 limit, but can also be triggered by large numbers of simultaneous
15202 connections. When the limit is reached, the operating system will
15203 refuse additional connections until the scheduler can accept the pending
15206 Defaults to @samp{128}.
15209 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15210 Specifies a set of additional access controls.
15212 Available @code{location-access-controls} fields are:
15214 @deftypevr {@code{location-access-controls} parameter} file-name path
15215 Specifies the URI path to which the access control applies.
15218 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15219 Access controls for all access to this path, in the same format as the
15220 @code{access-controls} of @code{operation-access-control}.
15222 Defaults to @samp{()}.
15225 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15226 Access controls for method-specific access to this path.
15228 Defaults to @samp{()}.
15230 Available @code{method-access-controls} fields are:
15232 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15233 If @code{#t}, apply access controls to all methods except the listed
15234 methods. Otherwise apply to only the listed methods.
15236 Defaults to @samp{#f}.
15239 @deftypevr {@code{method-access-controls} parameter} method-list methods
15240 Methods to which this access control applies.
15242 Defaults to @samp{()}.
15245 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15246 Access control directives, as a list of strings. Each string should be
15247 one directive, such as "Order allow,deny".
15249 Defaults to @samp{()}.
15254 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15255 Specifies the number of debugging messages that are retained for logging
15256 if an error occurs in a print job. Debug messages are logged regardless
15257 of the LogLevel setting.
15259 Defaults to @samp{100}.
15262 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15263 Specifies the level of logging for the ErrorLog file. The value
15264 @code{none} stops all logging while @code{debug2} logs everything.
15266 Defaults to @samp{info}.
15269 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15270 Specifies the format of the date and time in the log files. The value
15271 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15273 Defaults to @samp{standard}.
15276 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15277 Specifies the maximum number of simultaneous clients that are allowed by
15280 Defaults to @samp{100}.
15283 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15284 Specifies the maximum number of simultaneous clients that are allowed
15285 from a single address.
15287 Defaults to @samp{100}.
15290 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15291 Specifies the maximum number of copies that a user can print of each
15294 Defaults to @samp{9999}.
15297 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15298 Specifies the maximum time a job may remain in the @code{indefinite}
15299 hold state before it is canceled. A value of 0 disables cancellation of
15302 Defaults to @samp{0}.
15305 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15306 Specifies the maximum number of simultaneous jobs that are allowed. Set
15307 to 0 to allow an unlimited number of jobs.
15309 Defaults to @samp{500}.
15312 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15313 Specifies the maximum number of simultaneous jobs that are allowed per
15314 printer. A value of 0 allows up to MaxJobs jobs per printer.
15316 Defaults to @samp{0}.
15319 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15320 Specifies the maximum number of simultaneous jobs that are allowed per
15321 user. A value of 0 allows up to MaxJobs jobs per user.
15323 Defaults to @samp{0}.
15326 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15327 Specifies the maximum time a job may take to print before it is
15328 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15330 Defaults to @samp{10800}.
15333 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15334 Specifies the maximum size of the log files before they are rotated, in
15335 bytes. The value 0 disables log rotation.
15337 Defaults to @samp{1048576}.
15340 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15341 Specifies the maximum amount of time to allow between files in a
15342 multiple file print job, in seconds.
15344 Defaults to @samp{300}.
15347 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15348 Specifies the format of PageLog lines. Sequences beginning with percent
15349 (@samp{%}) characters are replaced with the corresponding information,
15350 while all other characters are copied literally. The following percent
15351 sequences are recognized:
15355 insert a single percent character
15358 insert the value of the specified IPP attribute
15361 insert the number of copies for the current page
15364 insert the current page number
15367 insert the current date and time in common log format
15373 insert the printer name
15376 insert the username
15379 A value of the empty string disables page logging. The string @code{%p
15380 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15381 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15384 Defaults to @samp{""}.
15387 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15388 Passes the specified environment variable(s) to child processes; a list
15391 Defaults to @samp{()}.
15394 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15395 Specifies named access control policies.
15397 Available @code{policy-configuration} fields are:
15399 @deftypevr {@code{policy-configuration} parameter} string name
15400 Name of the policy.
15403 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15404 Specifies an access list for a job's private values. @code{@@ACL} maps
15405 to the printer's requesting-user-name-allowed or
15406 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15407 owner. @code{@@SYSTEM} maps to the groups listed for the
15408 @code{system-group} field of the @code{files-config} configuration,
15409 which is reified into the @code{cups-files.conf(5)} file. Other
15410 possible elements of the access list include specific user names, and
15411 @code{@@@var{group}} to indicate members of a specific group. The
15412 access list may also be simply @code{all} or @code{default}.
15414 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15417 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15418 Specifies the list of job values to make private, or @code{all},
15419 @code{default}, or @code{none}.
15421 Defaults to @samp{"job-name job-originating-host-name
15422 job-originating-user-name phone"}.
15425 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15426 Specifies an access list for a subscription's private values.
15427 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15428 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15429 owner. @code{@@SYSTEM} maps to the groups listed for the
15430 @code{system-group} field of the @code{files-config} configuration,
15431 which is reified into the @code{cups-files.conf(5)} file. Other
15432 possible elements of the access list include specific user names, and
15433 @code{@@@var{group}} to indicate members of a specific group. The
15434 access list may also be simply @code{all} or @code{default}.
15436 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15439 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15440 Specifies the list of job values to make private, or @code{all},
15441 @code{default}, or @code{none}.
15443 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15444 notify-subscriber-user-name notify-user-data"}.
15447 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15448 Access control by IPP operation.
15450 Defaults to @samp{()}.
15454 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15455 Specifies whether job files (documents) are preserved after a job is
15456 printed. If a numeric value is specified, job files are preserved for
15457 the indicated number of seconds after printing. Otherwise a boolean
15458 value applies indefinitely.
15460 Defaults to @samp{86400}.
15463 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15464 Specifies whether the job history is preserved after a job is printed.
15465 If a numeric value is specified, the job history is preserved for the
15466 indicated number of seconds after printing. If @code{#t}, the job
15467 history is preserved until the MaxJobs limit is reached.
15469 Defaults to @samp{#t}.
15472 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15473 Specifies the amount of time to wait for job completion before
15474 restarting the scheduler.
15476 Defaults to @samp{30}.
15479 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15480 Specifies the maximum amount of memory to use when converting documents
15481 into bitmaps for a printer.
15483 Defaults to @samp{"128m"}.
15486 @deftypevr {@code{cups-configuration} parameter} string server-admin
15487 Specifies the email address of the server administrator.
15489 Defaults to @samp{"root@@localhost.localdomain"}.
15492 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15493 The ServerAlias directive is used for HTTP Host header validation when
15494 clients connect to the scheduler from external interfaces. Using the
15495 special name @code{*} can expose your system to known browser-based DNS
15496 rebinding attacks, even when accessing sites through a firewall. If the
15497 auto-discovery of alternate names does not work, we recommend listing
15498 each alternate name with a ServerAlias directive instead of using
15501 Defaults to @samp{*}.
15504 @deftypevr {@code{cups-configuration} parameter} string server-name
15505 Specifies the fully-qualified host name of the server.
15507 Defaults to @samp{"localhost"}.
15510 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15511 Specifies what information is included in the Server header of HTTP
15512 responses. @code{None} disables the Server header. @code{ProductOnly}
15513 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15514 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15515 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15516 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15517 2.0.0 (@var{uname}) IPP/2.0}.
15519 Defaults to @samp{Minimal}.
15522 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15523 Listens on the specified interfaces for encrypted connections. Valid
15524 values are of the form @var{address}:@var{port}, where @var{address} is
15525 either an IPv6 address enclosed in brackets, an IPv4 address, or
15526 @code{*} to indicate all addresses.
15528 Defaults to @samp{()}.
15531 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15532 Sets encryption options. By default, CUPS only supports encryption
15533 using TLS v1.0 or higher using known secure cipher suites. Security is
15534 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15535 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15536 suites, which are required for some older clients. The @code{AllowSSL3} option
15537 enables SSL v3.0, which is required for some older clients that do not support
15538 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15539 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15540 protocol version to TLS v1.1.
15542 Defaults to @samp{()}.
15545 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15546 Specifies whether the scheduler requires clients to strictly adhere to
15547 the IPP specifications.
15549 Defaults to @samp{#f}.
15552 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15553 Specifies the HTTP request timeout, in seconds.
15555 Defaults to @samp{300}.
15559 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15560 Specifies whether the web interface is enabled.
15562 Defaults to @samp{#f}.
15565 At this point you're probably thinking ``oh dear, Guix manual, I like
15566 you but you can stop already with the configuration options''. Indeed.
15567 However, one more point: it could be that you have an existing
15568 @code{cupsd.conf} that you want to use. In that case, you can pass an
15569 @code{opaque-cups-configuration} as the configuration of a
15570 @code{cups-service-type}.
15572 Available @code{opaque-cups-configuration} fields are:
15574 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15578 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15579 The contents of the @code{cupsd.conf}, as a string.
15582 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15583 The contents of the @code{cups-files.conf} file, as a string.
15586 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15587 strings of the same name, you could instantiate a CUPS service like
15591 (service cups-service-type
15592 (opaque-cups-configuration
15593 (cupsd.conf cupsd.conf)
15594 (cups-files.conf cups-files.conf)))
15598 @node Desktop Services
15599 @subsection Desktop Services
15601 The @code{(gnu services desktop)} module provides services that are
15602 usually useful in the context of a ``desktop'' setup---that is, on a
15603 machine running a graphical display server, possibly with graphical user
15604 interfaces, etc. It also defines services that provide specific desktop
15605 environments like GNOME, Xfce or MATE.
15607 To simplify things, the module defines a variable containing the set of
15608 services that users typically expect on a machine with a graphical
15609 environment and networking:
15611 @defvr {Scheme Variable} %desktop-services
15612 This is a list of services that builds upon @code{%base-services} and
15613 adds or adjusts services for a typical ``desktop'' setup.
15615 In particular, it adds a graphical login manager (@pxref{X Window,
15616 @code{gdm-service-type}}), screen lockers, a network management tool
15617 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15618 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15619 energy and color management services, the @code{elogind} login and seat
15620 manager, the Polkit privilege service, the GeoClue location service, the
15621 AccountsService daemon that allows authorized users change system passwords,
15622 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15623 name service switch service configured to be able to use @code{nss-mdns}
15624 (@pxref{Name Service Switch, mDNS}).
15627 The @code{%desktop-services} variable can be used as the @code{services}
15628 field of an @code{operating-system} declaration (@pxref{operating-system
15629 Reference, @code{services}}).
15631 Additionally, the @code{gnome-desktop-service-type},
15632 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15633 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15634 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15635 services like the backlight adjustment helpers and the power management
15636 utilities are added to the system, extending @code{polkit} and @code{dbus}
15637 appropriately, allowing GNOME to operate with elevated privileges on a
15638 limited number of special-purpose system interfaces. Additionally,
15639 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15640 metapackage to the system profile. Likewise, adding the Xfce service
15641 not only adds the @code{xfce} metapackage to the system profile, but it
15642 also gives the Thunar file manager the ability to open a ``root-mode''
15643 file management window, if the user authenticates using the
15644 administrator's password via the standard polkit graphical interface.
15645 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15646 appropriately, allowing MATE to operate with elevated privileges on a
15647 limited number of special-purpose system interfaces. Additionally,
15648 adding a service of type @code{mate-desktop-service-type} adds the MATE
15649 metapackage to the system profile. ``Adding Enlightenment'' means that
15650 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15651 are set as setuid, allowing Enlightenment's screen locker and other
15652 functionality to work as expected.
15654 The desktop environments in Guix use the Xorg display server by
15655 default. If you'd like to use the newer display server protocol
15656 called Wayland, you need to use the @code{sddm-service} instead of
15657 GDM as the graphical login manager. You should then
15658 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15659 also try starting GNOME on Wayland manually from a TTY with the
15660 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15661 gnome-session``. Currently only GNOME has support for Wayland.
15663 @defvr {Scheme Variable} gnome-desktop-service-type
15664 This is the type of the service that adds the @uref{https://www.gnome.org,
15665 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15666 object (see below.)
15668 This service adds the @code{gnome} package to the system profile, and extends
15669 polkit with the actions from @code{gnome-settings-daemon}.
15672 @deftp {Data Type} gnome-desktop-configuration
15673 Configuration record for the GNOME desktop environment.
15676 @item @code{gnome} (default: @code{gnome})
15677 The GNOME package to use.
15681 @defvr {Scheme Variable} xfce-desktop-service-type
15682 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15683 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15686 This service adds the @code{xfce} package to the system profile, and
15687 extends polkit with the ability for @code{thunar} to manipulate the file
15688 system as root from within a user session, after the user has authenticated
15689 with the administrator's password.
15692 @deftp {Data Type} xfce-desktop-configuration
15693 Configuration record for the Xfce desktop environment.
15696 @item @code{xfce} (default: @code{xfce})
15697 The Xfce package to use.
15701 @deffn {Scheme Variable} mate-desktop-service-type
15702 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15703 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15704 object (see below.)
15706 This service adds the @code{mate} package to the system
15707 profile, and extends polkit with the actions from
15708 @code{mate-settings-daemon}.
15711 @deftp {Data Type} mate-desktop-configuration
15712 Configuration record for the MATE desktop environment.
15715 @item @code{mate} (default: @code{mate})
15716 The MATE package to use.
15720 @deffn {Scheme Variable} enlightenment-desktop-service-type
15721 Return a service that adds the @code{enlightenment} package to the system
15722 profile, and extends dbus with actions from @code{efl}.
15725 @deftp {Data Type} enlightenment-desktop-service-configuration
15727 @item @code{enlightenment} (default: @code{enlightenment})
15728 The enlightenment package to use.
15732 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15733 the default @code{%desktop-services} variable doesn't include any of
15734 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15735 @code{%desktop-services} in the @code{services} field of your
15736 @code{operating-system}:
15739 (use-modules (gnu))
15740 (use-service-modules desktop)
15743 ;; cons* adds items to the list given as its last argument.
15744 (services (cons* (service gnome-desktop-service-type)
15745 (service xfce-desktop-service)
15746 %desktop-services))
15750 These desktop environments will then be available as options in the
15751 graphical login window.
15753 The actual service definitions included in @code{%desktop-services} and
15754 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15755 are described below.
15757 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15758 Return a service that runs the ``system bus'', using @var{dbus}, with
15759 support for @var{services}.
15761 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15762 facility. Its system bus is used to allow system services to communicate
15763 and to be notified of system-wide events.
15765 @var{services} must be a list of packages that provide an
15766 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15767 and policy files. For example, to allow avahi-daemon to use the system bus,
15768 @var{services} must be equal to @code{(list avahi)}.
15771 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15772 Return a service that runs the @code{elogind} login and
15773 seat management daemon. @uref{https://github.com/elogind/elogind,
15774 Elogind} exposes a D-Bus interface that can be used to know which users
15775 are logged in, know what kind of sessions they have open, suspend the
15776 system, inhibit system suspend, reboot the system, and other tasks.
15778 Elogind handles most system-level power events for a computer, for
15779 example suspending the system when a lid is closed, or shutting it down
15780 when the power button is pressed.
15782 The @var{config} keyword argument specifies the configuration for
15783 elogind, and should be the result of an @code{(elogind-configuration
15784 (@var{parameter} @var{value})...)} invocation. Available parameters and
15785 their default values are:
15788 @item kill-user-processes?
15790 @item kill-only-users
15792 @item kill-exclude-users
15794 @item inhibit-delay-max-seconds
15796 @item handle-power-key
15798 @item handle-suspend-key
15800 @item handle-hibernate-key
15802 @item handle-lid-switch
15804 @item handle-lid-switch-docked
15806 @item power-key-ignore-inhibited?
15808 @item suspend-key-ignore-inhibited?
15810 @item hibernate-key-ignore-inhibited?
15812 @item lid-switch-ignore-inhibited?
15814 @item holdoff-timeout-seconds
15818 @item idle-action-seconds
15820 @item runtime-directory-size-percent
15822 @item runtime-directory-size
15826 @item suspend-state
15827 @code{("mem" "standby" "freeze")}
15830 @item hibernate-state
15832 @item hibernate-mode
15833 @code{("platform" "shutdown")}
15834 @item hybrid-sleep-state
15836 @item hybrid-sleep-mode
15837 @code{("suspend" "platform" "shutdown")}
15841 @deffn {Scheme Procedure} accountsservice-service @
15842 [#:accountsservice @var{accountsservice}]
15843 Return a service that runs AccountsService, a system service that can
15844 list available accounts, change their passwords, and so on.
15845 AccountsService integrates with PolicyKit to enable unprivileged users
15846 to acquire the capability to modify their system configuration.
15847 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15848 accountsservice web site} for more information.
15850 The @var{accountsservice} keyword argument is the @code{accountsservice}
15851 package to expose as a service.
15854 @deffn {Scheme Procedure} polkit-service @
15855 [#:polkit @var{polkit}]
15856 Return a service that runs the
15857 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15858 management service}, which allows system administrators to grant access to
15859 privileged operations in a structured way. By querying the Polkit service, a
15860 privileged system component can know when it should grant additional
15861 capabilities to ordinary users. For example, an ordinary user can be granted
15862 the capability to suspend the system if the user is logged in locally.
15865 @defvr {Scheme Variable} polkit-wheel-service
15866 Service that adds the @code{wheel} group as admins to the Polkit
15867 service. This makes it so that users in the @code{wheel} group are queried
15868 for their own passwords when performing administrative actions instead of
15869 @code{root}'s, similar to the behaviour used by @code{sudo}.
15872 @defvr {Scheme Variable} upower-service-type
15873 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15874 system-wide monitor for power consumption and battery levels, with the given
15875 configuration settings.
15877 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15878 notably used by GNOME.
15881 @deftp {Data Type} upower-configuration
15882 Data type representation the configuration for UPower.
15886 @item @code{upower} (default: @var{upower})
15887 Package to use for @code{upower}.
15889 @item @code{watts-up-pro?} (default: @code{#f})
15890 Enable the Watts Up Pro device.
15892 @item @code{poll-batteries?} (default: @code{#t})
15893 Enable polling the kernel for battery level changes.
15895 @item @code{ignore-lid?} (default: @code{#f})
15896 Ignore the lid state, this can be useful if it's incorrect on a device.
15898 @item @code{use-percentage-for-policy?} (default: @code{#f})
15899 Whether battery percentage based policy should be used. The default is to use
15900 the time left, change to @code{#t} to use the percentage.
15902 @item @code{percentage-low} (default: @code{10})
15903 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15904 at which the battery is considered low.
15906 @item @code{percentage-critical} (default: @code{3})
15907 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15908 at which the battery is considered critical.
15910 @item @code{percentage-action} (default: @code{2})
15911 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15912 at which action will be taken.
15914 @item @code{time-low} (default: @code{1200})
15915 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15916 seconds at which the battery is considered low.
15918 @item @code{time-critical} (default: @code{300})
15919 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15920 seconds at which the battery is considered critical.
15922 @item @code{time-action} (default: @code{120})
15923 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15924 seconds at which action will be taken.
15926 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15927 The action taken when @code{percentage-action} or @code{time-action} is
15928 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15930 Possible values are:
15940 @code{'hybrid-sleep}.
15946 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15947 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15948 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15949 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15950 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15953 @deffn {Scheme Variable} colord-service-type
15954 This is the type of the service that runs @command{colord}, a system
15955 service with a D-Bus
15956 interface to manage the color profiles of input and output devices such as
15957 screens and scanners. It is notably used by the GNOME Color Manager graphical
15958 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15959 site} for more information.
15962 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15963 Return a configuration allowing an application to access GeoClue
15964 location data. @var{name} is the Desktop ID of the application, without
15965 the @code{.desktop} part. If @var{allowed?} is true, the application
15966 will have access to location information by default. The boolean
15967 @var{system?} value indicates whether an application is a system component
15968 or not. Finally @var{users} is a list of UIDs of all users for which
15969 this application is allowed location info access. An empty users list
15970 means that all users are allowed.
15973 @cindex scanner access
15974 @deffn {Scheme Procedure} sane-service-type
15975 This service provides access to scanners @i{via}
15976 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
15980 @defvr {Scheme Variable} %standard-geoclue-applications
15981 The standard list of well-known GeoClue application configurations,
15982 granting authority to the GNOME date-and-time utility to ask for the
15983 current location in order to set the time zone, and allowing the
15984 IceCat and Epiphany web browsers to request location information.
15985 IceCat and Epiphany both query the user before allowing a web page to
15986 know the user's location.
15989 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15990 [#:whitelist '()] @
15991 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15992 [#:submit-data? #f]
15993 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15994 [#:submission-nick "geoclue"] @
15995 [#:applications %standard-geoclue-applications]
15996 Return a service that runs the GeoClue location service. This service
15997 provides a D-Bus interface to allow applications to request access to a
15998 user's physical location, and optionally to add information to online
15999 location databases. See
16000 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
16001 web site} for more information.
16004 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
16005 [@w{#:auto-enable? #f}]
16006 Return a service that runs the @command{bluetoothd} daemon, which
16007 manages all the Bluetooth devices and provides a number of D-Bus
16008 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
16009 powered automatically at boot, which can be useful when using a
16010 bluetooth keyboard or mouse.
16012 Users need to be in the @code{lp} group to access the D-Bus service.
16015 @defvr {Scheme Variable} gnome-keyring-service-type
16016 This is the type of the service that adds the
16017 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
16018 value is a @code{gnome-keyring-configuration} object (see below.)
16020 This service adds the @code{gnome-keyring} package to the system profile
16021 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
16022 a user's login keyring when they log in or setting its password with passwd.
16025 @deftp {Data Type} gnome-keyring-configuration
16026 Configuration record for the GNOME Keyring service.
16029 @item @code{keyring} (default: @code{gnome-keyring})
16030 The GNOME keyring package to use.
16032 @item @code{pam-services}
16033 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
16034 services to extend, where @var{service} is the name of an existing
16035 service to extend and @var{kind} is one of @code{login} or
16038 If @code{login} is given, it adds an optional
16039 @code{pam_gnome_keyring.so} to the auth block without arguments and to
16040 the session block with @code{auto_start}. If @code{passwd} is given, it
16041 adds an optional @code{pam_gnome_keyring.so} to the password block
16044 By default, this field contains ``gdm-password'' with the value @code{login}
16045 and ``passwd'' is with the value @code{passwd}.
16050 @node Sound Services
16051 @subsection Sound Services
16053 @cindex sound support
16055 @cindex PulseAudio, sound support
16057 The @code{(gnu services sound)} module provides a service to configure the
16058 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
16059 preferred ALSA output driver.
16061 @deffn {Scheme Variable} alsa-service-type
16062 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
16063 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
16064 configuration file. The value for this type is a @command{alsa-configuration}
16065 record as in this example:
16068 (service alsa-service-type)
16071 See below for details about @code{alsa-configuration}.
16074 @deftp {Data Type} alsa-configuration
16075 Data type representing the configuration for @code{alsa-service}.
16078 @item @code{alsa-plugins} (default: @var{alsa-plugins})
16079 @code{alsa-plugins} package to use.
16081 @item @code{pulseaudio?} (default: @var{#t})
16082 Whether ALSA applications should transparently be made to use the
16083 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
16085 Using PulseAudio allows you to run several sound-producing applications
16086 at the same time and to individual control them @i{via}
16087 @command{pavucontrol}, among other things.
16089 @item @code{extra-options} (default: @var{""})
16090 String to append to the @file{/etc/asound.conf} file.
16095 Individual users who want to override the system configuration of ALSA can do
16096 it with the @file{~/.asoundrc} file:
16099 # In guix, we have to specify the absolute path for plugins.
16101 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
16104 # Routing ALSA to jack:
16105 # <http://jackaudio.org/faq/routing_alsa.html>.
16109 0 system:playback_1
16110 1 system:playback_2
16127 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
16130 @deffn {Scheme Variable} pulseaudio-service-type
16131 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
16132 sound server. It exists to allow system overrides of the default settings
16133 via @code{pulseaudio-configuration}, see below.
16136 This service on its own does not ensure, that the @code{pulseaudio} package
16137 exists on your machine. It merely adds configuration files for it, as
16138 detailed below. In the (admittedly unlikely) case, that you find yourself
16139 without a @code{pulseaudio} package, consider enabling it through the
16140 @code{alsa-service-type} above.
16144 @deftp {Data Type} pulseaudio-configuration
16145 Data type representing the configuration for @code{pulseaudio-service}.
16148 @item @var{client-conf} (default: @code{'()})
16149 List of settings to set in @file{client.conf}.
16150 Accepts a list of strings or a symbol-value pairs. A string will be
16151 inserted as-is with a newline added. A pair will be formatted as
16152 ``key = value'', again with a newline added.
16154 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
16155 List of settings to set in @file{daemon.conf}, formatted just like
16158 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
16159 Script file to use as as @file{default.pa}.
16161 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
16162 Script file to use as as @file{system.pa}.
16166 @deffn {Scheme Variable} ladspa-service-type
16167 This service sets the @var{LADSPA_PATH} variable, so that programs, which
16168 respect it, e.g. PulseAudio, can load LADSPA plugins.
16170 The following example will setup the service to enable modules from the
16171 @code{swh-plugins} package:
16174 (service ladspa-service-type
16175 (ladspa-configuration (plugins (list swh-plugins))))
16178 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16183 @node Database Services
16184 @subsection Database Services
16188 The @code{(gnu services databases)} module provides the following services.
16190 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16191 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16192 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16193 Return a service that runs @var{postgresql}, the PostgreSQL database
16196 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16197 creates a database cluster with @var{locale} as the default
16198 locale, stored in @var{data-directory}. It then listens on @var{port}.
16200 @cindex postgresql extension-packages
16201 Additional extensions are loaded from packages listed in
16202 @var{extension-packages}. Extensions are available at runtime. For instance,
16203 to create a geographic database using the @code{postgis} extension, a user can
16204 configure the postgresql-service as in this example:
16208 (use-package-modules databases geo)
16212 ;; postgresql is required to run `psql' but postgis is not required for
16213 ;; proper operation.
16214 (packages (cons* postgresql %base-packages))
16217 (postgresql-service #:extension-packages (list postgis))
16221 Then the extension becomes visible and you can initialise an empty geographic
16222 database in this way:
16226 > create database postgistest;
16227 > \connect postgistest;
16228 > create extension postgis;
16229 > create extension postgis_topology;
16232 There is no need to add this field for contrib extensions such as hstore or
16233 dblink as they are already loadable by postgresql. This field is only
16234 required to add extensions provided by other packages.
16237 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16238 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16241 The optional @var{config} argument specifies the configuration for
16242 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16245 @deftp {Data Type} mysql-configuration
16246 Data type representing the configuration of @var{mysql-service}.
16249 @item @code{mysql} (default: @var{mariadb})
16250 Package object of the MySQL database server, can be either @var{mariadb}
16253 For MySQL, a temporary root password will be displayed at activation time.
16254 For MariaDB, the root password is empty.
16256 @item @code{port} (default: @code{3306})
16257 TCP port on which the database server listens for incoming connections.
16261 @defvr {Scheme Variable} memcached-service-type
16262 This is the service type for the @uref{https://memcached.org/,
16263 Memcached} service, which provides a distributed in memory cache. The
16264 value for the service type is a @code{memcached-configuration} object.
16268 (service memcached-service-type)
16271 @deftp {Data Type} memcached-configuration
16272 Data type representing the configuration of memcached.
16275 @item @code{memcached} (default: @code{memcached})
16276 The Memcached package to use.
16278 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16279 Network interfaces on which to listen.
16281 @item @code{tcp-port} (default: @code{11211})
16282 Port on which to accept connections on,
16284 @item @code{udp-port} (default: @code{11211})
16285 Port on which to accept UDP connections on, a value of 0 will disable
16286 listening on a UDP socket.
16288 @item @code{additional-options} (default: @code{'()})
16289 Additional command line options to pass to @code{memcached}.
16293 @defvr {Scheme Variable} mongodb-service-type
16294 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16295 The value for the service type is a @code{mongodb-configuration} object.
16299 (service mongodb-service-type)
16302 @deftp {Data Type} mongodb-configuration
16303 Data type representing the configuration of mongodb.
16306 @item @code{mongodb} (default: @code{mongodb})
16307 The MongoDB package to use.
16309 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16310 The configuration file for MongoDB.
16312 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16313 This value is used to create the directory, so that it exists and is
16314 owned by the mongodb user. It should match the data-directory which
16315 MongoDB is configured to use through the configuration file.
16319 @defvr {Scheme Variable} redis-service-type
16320 This is the service type for the @uref{https://redis.io/, Redis}
16321 key/value store, whose value is a @code{redis-configuration} object.
16324 @deftp {Data Type} redis-configuration
16325 Data type representing the configuration of redis.
16328 @item @code{redis} (default: @code{redis})
16329 The Redis package to use.
16331 @item @code{bind} (default: @code{"127.0.0.1"})
16332 Network interface on which to listen.
16334 @item @code{port} (default: @code{6379})
16335 Port on which to accept connections on, a value of 0 will disable
16336 listening on a TCP socket.
16338 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16339 Directory in which to store the database and related files.
16343 @node Mail Services
16344 @subsection Mail Services
16348 The @code{(gnu services mail)} module provides Guix service definitions
16349 for email services: IMAP, POP3, and LMTP servers, as well as mail
16350 transport agents (MTAs). Lots of acronyms! These services are detailed
16351 in the subsections below.
16353 @subsubheading Dovecot Service
16355 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16356 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16359 By default, Dovecot does not need much configuration; the default
16360 configuration object created by @code{(dovecot-configuration)} will
16361 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16362 certificate will be generated for TLS-protected connections, though
16363 Dovecot will also listen on cleartext ports by default. There are a
16364 number of options, though, which mail administrators might need to change,
16365 and as is the case with other services, Guix allows the system
16366 administrator to specify these parameters via a uniform Scheme interface.
16368 For example, to specify that mail is located at @code{maildir~/.mail},
16369 one would instantiate the Dovecot service like this:
16372 (dovecot-service #:config
16373 (dovecot-configuration
16374 (mail-location "maildir:~/.mail")))
16377 The available configuration parameters follow. Each parameter
16378 definition is preceded by its type; for example, @samp{string-list foo}
16379 indicates that the @code{foo} parameter should be specified as a list of
16380 strings. There is also a way to specify the configuration as a string,
16381 if you have an old @code{dovecot.conf} file that you want to port over
16382 from some other system; see the end for more details.
16384 @c The following documentation was initially generated by
16385 @c (generate-documentation) in (gnu services mail). Manually maintained
16386 @c documentation is better, so we shouldn't hesitate to edit below as
16387 @c needed. However if the change you want to make to this documentation
16388 @c can be done in an automated way, it's probably easier to change
16389 @c (generate-documentation) than to make it below and have to deal with
16390 @c the churn as dovecot updates.
16392 Available @code{dovecot-configuration} fields are:
16394 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16395 The dovecot package.
16398 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16399 A list of IPs or hosts where to listen for connections. @samp{*}
16400 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16401 interfaces. If you want to specify non-default ports or anything more
16402 complex, customize the address and port fields of the
16403 @samp{inet-listener} of the specific services you are interested in.
16406 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16407 List of protocols we want to serve. Available protocols include
16408 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16410 Available @code{protocol-configuration} fields are:
16412 @deftypevr {@code{protocol-configuration} parameter} string name
16413 The name of the protocol.
16416 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16417 UNIX socket path to the master authentication server to find users.
16418 This is used by imap (for shared users) and lda.
16419 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16422 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16423 Space separated list of plugins to load.
16426 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16427 Maximum number of IMAP connections allowed for a user from each IP
16428 address. NOTE: The username is compared case-sensitively.
16429 Defaults to @samp{10}.
16434 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16435 List of services to enable. Available services include @samp{imap},
16436 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16439 Available @code{service-configuration} fields are:
16441 @deftypevr {@code{service-configuration} parameter} string kind
16442 The service kind. Valid values include @code{director},
16443 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16444 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16445 @code{tcpwrap}, @code{quota-warning}, or anything else.
16448 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16449 Listeners for the service. A listener is either a
16450 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16451 an @code{inet-listener-configuration}.
16452 Defaults to @samp{()}.
16454 Available @code{unix-listener-configuration} fields are:
16456 @deftypevr {@code{unix-listener-configuration} parameter} string path
16457 Path to the file, relative to @code{base-dir} field. This is also used as
16461 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16462 The access mode for the socket.
16463 Defaults to @samp{"0600"}.
16466 @deftypevr {@code{unix-listener-configuration} parameter} string user
16467 The user to own the socket.
16468 Defaults to @samp{""}.
16471 @deftypevr {@code{unix-listener-configuration} parameter} string group
16472 The group to own the socket.
16473 Defaults to @samp{""}.
16477 Available @code{fifo-listener-configuration} fields are:
16479 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16480 Path to the file, relative to @code{base-dir} field. This is also used as
16484 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16485 The access mode for the socket.
16486 Defaults to @samp{"0600"}.
16489 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16490 The user to own the socket.
16491 Defaults to @samp{""}.
16494 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16495 The group to own the socket.
16496 Defaults to @samp{""}.
16500 Available @code{inet-listener-configuration} fields are:
16502 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16503 The protocol to listen for.
16506 @deftypevr {@code{inet-listener-configuration} parameter} string address
16507 The address on which to listen, or empty for all addresses.
16508 Defaults to @samp{""}.
16511 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16512 The port on which to listen.
16515 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16516 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16518 Defaults to @samp{#t}.
16523 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16524 Maximum number of simultaneous client connections per process. Once
16525 this number of connections is received, the next incoming connection
16526 will prompt Dovecot to spawn another process. If set to 0,
16527 @code{default-client-limit} is used instead.
16529 Defaults to @samp{0}.
16533 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16534 Number of connections to handle before starting a new process.
16535 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16536 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16537 Defaults to @samp{1}.
16541 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16542 Maximum number of processes that can exist for this service. If set to
16543 0, @code{default-process-limit} is used instead.
16545 Defaults to @samp{0}.
16549 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16550 Number of processes to always keep waiting for more connections.
16551 Defaults to @samp{0}.
16554 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16555 If you set @samp{service-count 0}, you probably need to grow
16557 Defaults to @samp{256000000}.
16562 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16563 Dict configuration, as created by the @code{dict-configuration}
16566 Available @code{dict-configuration} fields are:
16568 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16569 A list of key-value pairs that this dict should hold.
16570 Defaults to @samp{()}.
16575 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16576 A list of passdb configurations, each one created by the
16577 @code{passdb-configuration} constructor.
16579 Available @code{passdb-configuration} fields are:
16581 @deftypevr {@code{passdb-configuration} parameter} string driver
16582 The driver that the passdb should use. Valid values include
16583 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16585 Defaults to @samp{"pam"}.
16588 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16589 Space separated list of arguments to the passdb driver.
16590 Defaults to @samp{""}.
16595 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16596 List of userdb configurations, each one created by the
16597 @code{userdb-configuration} constructor.
16599 Available @code{userdb-configuration} fields are:
16601 @deftypevr {@code{userdb-configuration} parameter} string driver
16602 The driver that the userdb should use. Valid values include
16603 @samp{passwd} and @samp{static}.
16604 Defaults to @samp{"passwd"}.
16607 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16608 Space separated list of arguments to the userdb driver.
16609 Defaults to @samp{""}.
16612 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16613 Override fields from passwd.
16614 Defaults to @samp{()}.
16619 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16620 Plug-in configuration, created by the @code{plugin-configuration}
16624 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16625 List of namespaces. Each item in the list is created by the
16626 @code{namespace-configuration} constructor.
16628 Available @code{namespace-configuration} fields are:
16630 @deftypevr {@code{namespace-configuration} parameter} string name
16631 Name for this namespace.
16634 @deftypevr {@code{namespace-configuration} parameter} string type
16635 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16636 Defaults to @samp{"private"}.
16639 @deftypevr {@code{namespace-configuration} parameter} string separator
16640 Hierarchy separator to use. You should use the same separator for
16641 all namespaces or some clients get confused. @samp{/} is usually a good
16642 one. The default however depends on the underlying mail storage
16644 Defaults to @samp{""}.
16647 @deftypevr {@code{namespace-configuration} parameter} string prefix
16648 Prefix required to access this namespace. This needs to be
16649 different for all namespaces. For example @samp{Public/}.
16650 Defaults to @samp{""}.
16653 @deftypevr {@code{namespace-configuration} parameter} string location
16654 Physical location of the mailbox. This is in the same format as
16655 mail_location, which is also the default for it.
16656 Defaults to @samp{""}.
16659 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16660 There can be only one INBOX, and this setting defines which
16662 Defaults to @samp{#f}.
16665 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16666 If namespace is hidden, it's not advertised to clients via NAMESPACE
16667 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16668 useful when converting from another server with different namespaces
16669 which you want to deprecate but still keep working. For example you can
16670 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16672 Defaults to @samp{#f}.
16675 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16676 Show the mailboxes under this namespace with the LIST command. This
16677 makes the namespace visible for clients that do not support the NAMESPACE
16678 extension. The special @code{children} value lists child mailboxes, but
16679 hides the namespace prefix.
16680 Defaults to @samp{#t}.
16683 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16684 Namespace handles its own subscriptions. If set to @code{#f}, the
16685 parent namespace handles them. The empty prefix should always have this
16687 Defaults to @samp{#t}.
16690 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16691 List of predefined mailboxes in this namespace.
16692 Defaults to @samp{()}.
16694 Available @code{mailbox-configuration} fields are:
16696 @deftypevr {@code{mailbox-configuration} parameter} string name
16697 Name for this mailbox.
16700 @deftypevr {@code{mailbox-configuration} parameter} string auto
16701 @samp{create} will automatically create this mailbox.
16702 @samp{subscribe} will both create and subscribe to the mailbox.
16703 Defaults to @samp{"no"}.
16706 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16707 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16708 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16709 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16710 Defaults to @samp{()}.
16717 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16718 Base directory where to store runtime data.
16719 Defaults to @samp{"/var/run/dovecot/"}.
16722 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16723 Greeting message for clients.
16724 Defaults to @samp{"Dovecot ready."}.
16727 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16728 List of trusted network ranges. Connections from these IPs are
16729 allowed to override their IP addresses and ports (for logging and for
16730 authentication checks). @samp{disable-plaintext-auth} is also ignored
16731 for these networks. Typically you would specify your IMAP proxy servers
16733 Defaults to @samp{()}.
16736 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16737 List of login access check sockets (e.g.@: tcpwrap).
16738 Defaults to @samp{()}.
16741 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16742 Show more verbose process titles (in ps). Currently shows user name
16743 and IP address. Useful for seeing who is actually using the IMAP
16744 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16746 Defaults to @samp{#f}.
16749 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16750 Should all processes be killed when Dovecot master process shuts down.
16751 Setting this to @code{#f} means that Dovecot can be upgraded without
16752 forcing existing client connections to close (although that could also
16753 be a problem if the upgrade is e.g.@: due to a security fix).
16754 Defaults to @samp{#t}.
16757 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16758 If non-zero, run mail commands via this many connections to doveadm
16759 server, instead of running them directly in the same process.
16760 Defaults to @samp{0}.
16763 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16764 UNIX socket or host:port used for connecting to doveadm server.
16765 Defaults to @samp{"doveadm-server"}.
16768 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16769 List of environment variables that are preserved on Dovecot startup
16770 and passed down to all of its child processes. You can also give
16771 key=value pairs to always set specific settings.
16774 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16775 Disable LOGIN command and all other plaintext authentications unless
16776 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16777 matches the local IP (i.e.@: you're connecting from the same computer),
16778 the connection is considered secure and plaintext authentication is
16779 allowed. See also ssl=required setting.
16780 Defaults to @samp{#t}.
16783 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16784 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16785 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16786 for caching to be used.
16787 Defaults to @samp{0}.
16790 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16791 Time to live for cached data. After TTL expires the cached record
16792 is no longer used, *except* if the main database lookup returns internal
16793 failure. We also try to handle password changes automatically: If
16794 user's previous authentication was successful, but this one wasn't, the
16795 cache isn't used. For now this works only with plaintext
16797 Defaults to @samp{"1 hour"}.
16800 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16801 TTL for negative hits (user not found, password mismatch).
16802 0 disables caching them completely.
16803 Defaults to @samp{"1 hour"}.
16806 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16807 List of realms for SASL authentication mechanisms that need them.
16808 You can leave it empty if you don't want to support multiple realms.
16809 Many clients simply use the first one listed here, so keep the default
16811 Defaults to @samp{()}.
16814 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16815 Default realm/domain to use if none was specified. This is used for
16816 both SASL realms and appending @@domain to username in plaintext
16818 Defaults to @samp{""}.
16821 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16822 List of allowed characters in username. If the user-given username
16823 contains a character not listed in here, the login automatically fails.
16824 This is just an extra check to make sure user can't exploit any
16825 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16826 you want to allow all characters, set this value to empty.
16827 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16830 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16831 Username character translations before it's looked up from
16832 databases. The value contains series of from -> to characters. For
16833 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16834 translated to @samp{@@}.
16835 Defaults to @samp{""}.
16838 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16839 Username formatting before it's looked up from databases. You can
16840 use the standard variables here, e.g.@: %Lu would lowercase the username,
16841 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16842 change the @samp{@@} into @samp{-AT-}. This translation is done after
16843 @samp{auth-username-translation} changes.
16844 Defaults to @samp{"%Lu"}.
16847 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16848 If you want to allow master users to log in by specifying the master
16849 username within the normal username string (i.e.@: not using SASL
16850 mechanism's support for it), you can specify the separator character
16851 here. The format is then <username><separator><master username>.
16852 UW-IMAP uses @samp{*} as the separator, so that could be a good
16854 Defaults to @samp{""}.
16857 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16858 Username to use for users logging in with ANONYMOUS SASL
16860 Defaults to @samp{"anonymous"}.
16863 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16864 Maximum number of dovecot-auth worker processes. They're used to
16865 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16866 They're automatically created and destroyed as needed.
16867 Defaults to @samp{30}.
16870 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16871 Host name to use in GSSAPI principal names. The default is to use
16872 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16873 allow all keytab entries.
16874 Defaults to @samp{""}.
16877 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16878 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16879 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16880 need to change the auth service to run as root to be able to read this
16882 Defaults to @samp{""}.
16885 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16886 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16887 and @samp{ntlm-auth} helper.
16888 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16889 Defaults to @samp{#f}.
16892 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16893 Path for Samba's @samp{ntlm-auth} helper binary.
16894 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16897 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16898 Time to delay before replying to failed authentications.
16899 Defaults to @samp{"2 secs"}.
16902 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16903 Require a valid SSL client certificate or the authentication
16905 Defaults to @samp{#f}.
16908 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16909 Take the username from client's SSL certificate, using
16910 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16912 Defaults to @samp{#f}.
16915 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16916 List of wanted authentication mechanisms. Supported mechanisms are:
16917 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16918 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16919 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16920 @samp{disable-plaintext-auth} setting.
16923 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16924 List of IPs or hostnames to all director servers, including ourself.
16925 Ports can be specified as ip:port. The default port is the same as what
16926 director service's @samp{inet-listener} is using.
16927 Defaults to @samp{()}.
16930 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16931 List of IPs or hostnames to all backend mail servers. Ranges are
16932 allowed too, like 10.0.0.10-10.0.0.30.
16933 Defaults to @samp{()}.
16936 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16937 How long to redirect users to a specific server after it no longer
16938 has any connections.
16939 Defaults to @samp{"15 min"}.
16942 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16943 How the username is translated before being hashed. Useful values
16944 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16945 are shared within domain.
16946 Defaults to @samp{"%Lu"}.
16949 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16950 Log file to use for error messages. @samp{syslog} logs to syslog,
16951 @samp{/dev/stderr} logs to stderr.
16952 Defaults to @samp{"syslog"}.
16955 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16956 Log file to use for informational messages. Defaults to
16958 Defaults to @samp{""}.
16961 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16962 Log file to use for debug messages. Defaults to
16963 @samp{info-log-path}.
16964 Defaults to @samp{""}.
16967 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16968 Syslog facility to use if you're logging to syslog. Usually if you
16969 don't want to use @samp{mail}, you'll use local0..local7. Also other
16970 standard facilities are supported.
16971 Defaults to @samp{"mail"}.
16974 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16975 Log unsuccessful authentication attempts and the reasons why they
16977 Defaults to @samp{#f}.
16980 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16981 In case of password mismatches, log the attempted password. Valid
16982 values are no, plain and sha1. sha1 can be useful for detecting brute
16983 force password attempts vs. user simply trying the same password over
16984 and over again. You can also truncate the value to n chars by appending
16985 ":n" (e.g.@: sha1:6).
16986 Defaults to @samp{"no"}.
16989 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16990 Even more verbose logging for debugging purposes. Shows for example
16992 Defaults to @samp{#f}.
16995 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16996 In case of password mismatches, log the passwords and used scheme so
16997 the problem can be debugged. Enabling this also enables
16999 Defaults to @samp{#f}.
17002 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
17003 Enable mail process debugging. This can help you figure out why
17004 Dovecot isn't finding your mails.
17005 Defaults to @samp{#f}.
17008 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
17009 Show protocol level SSL errors.
17010 Defaults to @samp{#f}.
17013 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
17014 Prefix for each line written to log file. % codes are in
17015 strftime(3) format.
17016 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
17019 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
17020 List of elements we want to log. The elements which have a
17021 non-empty variable value are joined together to form a comma-separated
17025 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
17026 Login log format. %s contains @samp{login-log-format-elements}
17027 string, %$ contains the data we want to log.
17028 Defaults to @samp{"%$: %s"}.
17031 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
17032 Log prefix for mail processes. See doc/wiki/Variables.txt for list
17033 of possible variables you can use.
17034 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
17037 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
17038 Format to use for logging mail deliveries. You can use variables:
17041 Delivery status message (e.g.@: @samp{saved to INBOX})
17053 Defaults to @samp{"msgid=%m: %$"}.
17056 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
17057 Location for users' mailboxes. The default is empty, which means
17058 that Dovecot tries to find the mailboxes automatically. This won't work
17059 if the user doesn't yet have any mail, so you should explicitly tell
17060 Dovecot the full location.
17062 If you're using mbox, giving a path to the INBOX
17063 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
17064 where the other mailboxes are kept. This is called the "root mail
17065 directory", and it must be the first path given in the
17066 @samp{mail-location} setting.
17068 There are a few special variables you can use, eg.:
17074 user part in user@@domain, same as %u if there's no domain
17076 domain part in user@@domain, empty if there's no domain
17081 See doc/wiki/Variables.txt for full list. Some examples:
17083 @item maildir:~/Maildir
17084 @item mbox:~/mail:INBOX=/var/mail/%u
17085 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
17087 Defaults to @samp{""}.
17090 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
17091 System user and group used to access mails. If you use multiple,
17092 userdb can override these by returning uid or gid fields. You can use
17093 either numbers or names. <doc/wiki/UserIds.txt>.
17094 Defaults to @samp{""}.
17097 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
17099 Defaults to @samp{""}.
17102 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
17103 Group to enable temporarily for privileged operations. Currently
17104 this is used only with INBOX when either its initial creation or
17105 dotlocking fails. Typically this is set to "mail" to give access to
17107 Defaults to @samp{""}.
17110 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
17111 Grant access to these supplementary groups for mail processes.
17112 Typically these are used to set up access to shared mailboxes. Note
17113 that it may be dangerous to set these if users can create
17114 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
17115 could allow a user to delete others' mailboxes, or ln -s
17116 /secret/shared/box ~/mail/mybox would allow reading it).
17117 Defaults to @samp{""}.
17120 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
17121 Allow full file system access to clients. There's no access checks
17122 other than what the operating system does for the active UID/GID. It
17123 works with both maildir and mboxes, allowing you to prefix mailboxes
17124 names with e.g.@: /path/ or ~user/.
17125 Defaults to @samp{#f}.
17128 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
17129 Don't use mmap() at all. This is required if you store indexes to
17130 shared file systems (NFS or clustered file system).
17131 Defaults to @samp{#f}.
17134 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
17135 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
17136 supports @samp{O_EXCL} since version 3, so this should be safe to use
17137 nowadays by default.
17138 Defaults to @samp{#t}.
17141 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
17142 When to use fsync() or fdatasync() calls:
17145 Whenever necessary to avoid losing important data
17147 Useful with e.g.@: NFS when write()s are delayed
17149 Never use it (best performance, but crashes can lose data).
17151 Defaults to @samp{"optimized"}.
17154 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
17155 Mail storage exists in NFS. Set this to yes to make Dovecot flush
17156 NFS caches whenever needed. If you're using only a single mail server
17158 Defaults to @samp{#f}.
17161 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
17162 Mail index files also exist in NFS. Setting this to yes requires
17163 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
17164 Defaults to @samp{#f}.
17167 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
17168 Locking method for index files. Alternatives are fcntl, flock and
17169 dotlock. Dotlocking uses some tricks which may create more disk I/O
17170 than other locking methods. NFS users: flock doesn't work, remember to
17171 change @samp{mmap-disable}.
17172 Defaults to @samp{"fcntl"}.
17175 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17176 Directory in which LDA/LMTP temporarily stores incoming mails >128
17178 Defaults to @samp{"/tmp"}.
17181 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17182 Valid UID range for users. This is mostly to make sure that users can't
17183 log in as daemons or other system users. Note that denying root logins is
17184 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17186 Defaults to @samp{500}.
17189 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17191 Defaults to @samp{0}.
17194 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17195 Valid GID range for users. Users having non-valid GID as primary group ID
17196 aren't allowed to log in. If user belongs to supplementary groups with
17197 non-valid GIDs, those groups are not set.
17198 Defaults to @samp{1}.
17201 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17203 Defaults to @samp{0}.
17206 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17207 Maximum allowed length for mail keyword name. It's only forced when
17208 trying to create new keywords.
17209 Defaults to @samp{50}.
17212 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17213 List of directories under which chrooting is allowed for mail
17214 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
17215 too). This setting doesn't affect @samp{login-chroot}
17216 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17217 "/./" in home dirs are ignored. WARNING: Never add directories here
17218 which local users can modify, that may lead to root exploit. Usually
17219 this should be done only if you don't allow shell access for users.
17220 <doc/wiki/Chrooting.txt>.
17221 Defaults to @samp{()}.
17224 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17225 Default chroot directory for mail processes. This can be overridden
17226 for specific users in user database by giving /./ in user's home
17227 directory (e.g.@: /home/./user chroots into /home). Note that usually
17228 there is no real need to do chrooting, Dovecot doesn't allow users to
17229 access files outside their mail directory anyway. If your home
17230 directories are prefixed with the chroot directory, append "/."@: to
17231 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17232 Defaults to @samp{""}.
17235 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17236 UNIX socket path to master authentication server to find users.
17237 This is used by imap (for shared users) and lda.
17238 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17241 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17242 Directory where to look up mail plugins.
17243 Defaults to @samp{"/usr/lib/dovecot"}.
17246 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17247 List of plugins to load for all services. Plugins specific to IMAP,
17248 LDA, etc.@: are added to this list in their own .conf files.
17249 Defaults to @samp{()}.
17252 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17253 The minimum number of mails in a mailbox before updates are done to
17254 cache file. This allows optimizing Dovecot's behavior to do less disk
17255 writes at the cost of more disk reads.
17256 Defaults to @samp{0}.
17259 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17260 When IDLE command is running, mailbox is checked once in a while to
17261 see if there are any new mails or other changes. This setting defines
17262 the minimum time to wait between those checks. Dovecot can also use
17263 dnotify, inotify and kqueue to find out immediately when changes
17265 Defaults to @samp{"30 secs"}.
17268 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17269 Save mails with CR+LF instead of plain LF. This makes sending those
17270 mails take less CPU, especially with sendfile() syscall with Linux and
17271 FreeBSD. But it also creates a bit more disk I/O which may just make it
17272 slower. Also note that if other software reads the mboxes/maildirs,
17273 they may handle the extra CRs wrong and cause problems.
17274 Defaults to @samp{#f}.
17277 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17278 By default LIST command returns all entries in maildir beginning
17279 with a dot. Enabling this option makes Dovecot return only entries
17280 which are directories. This is done by stat()ing each entry, so it
17281 causes more disk I/O.
17282 (For systems setting struct @samp{dirent->d_type} this check is free
17283 and it's done always regardless of this setting).
17284 Defaults to @samp{#f}.
17287 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17288 When copying a message, do it with hard links whenever possible.
17289 This makes the performance much better, and it's unlikely to have any
17291 Defaults to @samp{#t}.
17294 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17295 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17296 directory only when its mtime changes unexpectedly or when we can't find
17297 the mail otherwise.
17298 Defaults to @samp{#f}.
17301 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17302 Which locking methods to use for locking mbox. There are four
17307 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17308 solution. If you want to use /var/mail/ like directory, the users will
17309 need write access to that directory.
17311 Same as dotlock, but if it fails because of permissions or because there
17312 isn't enough disk space, just skip it.
17314 Use this if possible. Works with NFS too if lockd is used.
17316 May not exist in all systems. Doesn't work with NFS.
17318 May not exist in all systems. Doesn't work with NFS.
17321 You can use multiple locking methods; if you do the order they're declared
17322 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17323 locking methods as well. Some operating systems don't allow using some of
17324 them simultaneously.
17327 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17331 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17332 Maximum time to wait for lock (all of them) before aborting.
17333 Defaults to @samp{"5 mins"}.
17336 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17337 If dotlock exists but the mailbox isn't modified in any way,
17338 override the lock file after this much time.
17339 Defaults to @samp{"2 mins"}.
17342 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17343 When mbox changes unexpectedly we have to fully read it to find out
17344 what changed. If the mbox is large this can take a long time. Since
17345 the change is usually just a newly appended mail, it'd be faster to
17346 simply read the new mails. If this setting is enabled, Dovecot does
17347 this but still safely fallbacks to re-reading the whole mbox file
17348 whenever something in mbox isn't how it's expected to be. The only real
17349 downside to this setting is that if some other MUA changes message
17350 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17351 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17352 Defaults to @samp{#t}.
17355 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17356 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17357 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17358 @samp{mbox-dirty-syncs} is ignored.
17359 Defaults to @samp{#f}.
17362 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17363 Delay writing mbox headers until doing a full write sync (EXPUNGE
17364 and CHECK commands and when closing the mailbox). This is especially
17365 useful for POP3 where clients often delete all mails. The downside is
17366 that our changes aren't immediately visible to other MUAs.
17367 Defaults to @samp{#t}.
17370 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17371 If mbox size is smaller than this (e.g.@: 100k), don't write index
17372 files. If an index file already exists it's still read, just not
17374 Defaults to @samp{0}.
17377 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17378 Maximum dbox file size until it's rotated.
17379 Defaults to @samp{10000000}.
17382 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17383 Maximum dbox file age until it's rotated. Typically in days. Day
17384 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17386 Defaults to @samp{"1d"}.
17389 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17390 When creating new mdbox files, immediately preallocate their size to
17391 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17392 with some file systems (ext4, xfs).
17393 Defaults to @samp{#f}.
17396 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17397 sdbox and mdbox support saving mail attachments to external files,
17398 which also allows single instance storage for them. Other backends
17399 don't support this for now.
17401 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17403 Directory root where to store mail attachments. Disabled, if empty.
17404 Defaults to @samp{""}.
17407 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17408 Attachments smaller than this aren't saved externally. It's also
17409 possible to write a plugin to disable saving specific attachments
17411 Defaults to @samp{128000}.
17414 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17415 File system backend to use for saving attachments:
17418 No SiS done by Dovecot (but this might help FS's own deduplication)
17420 SiS with immediate byte-by-byte comparison during saving
17421 @item sis-queue posix
17422 SiS with delayed comparison and deduplication.
17424 Defaults to @samp{"sis posix"}.
17427 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17428 Hash format to use in attachment filenames. You can add any text and
17429 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17430 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17431 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17432 Defaults to @samp{"%@{sha1@}"}.
17435 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17437 Defaults to @samp{100}.
17440 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17442 Defaults to @samp{1000}.
17445 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17446 Default VSZ (virtual memory size) limit for service processes.
17447 This is mainly intended to catch and kill processes that leak memory
17448 before they eat up everything.
17449 Defaults to @samp{256000000}.
17452 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17453 Login user is internally used by login processes. This is the most
17454 untrusted user in Dovecot system. It shouldn't have access to anything
17456 Defaults to @samp{"dovenull"}.
17459 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17460 Internal user is used by unprivileged processes. It should be
17461 separate from login user, so that login processes can't disturb other
17463 Defaults to @samp{"dovecot"}.
17466 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17467 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17468 Defaults to @samp{"required"}.
17471 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17472 PEM encoded X.509 SSL/TLS certificate (public key).
17473 Defaults to @samp{"</etc/dovecot/default.pem"}.
17476 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17477 PEM encoded SSL/TLS private key. The key is opened before
17478 dropping root privileges, so keep the key file unreadable by anyone but
17480 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17483 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17484 If key file is password protected, give the password here.
17485 Alternatively give it when starting dovecot with -p parameter. Since
17486 this file is often world-readable, you may want to place this setting
17487 instead to a different.
17488 Defaults to @samp{""}.
17491 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17492 PEM encoded trusted certificate authority. Set this only if you
17493 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17494 contain the CA certificate(s) followed by the matching
17495 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17496 Defaults to @samp{""}.
17499 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17500 Require that CRL check succeeds for client certificates.
17501 Defaults to @samp{#t}.
17504 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17505 Request client to send a certificate. If you also want to require
17506 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17507 Defaults to @samp{#f}.
17510 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17511 Which field from certificate to use for username. commonName and
17512 x500UniqueIdentifier are the usual choices. You'll also need to set
17513 @samp{auth-ssl-username-from-cert? #t}.
17514 Defaults to @samp{"commonName"}.
17517 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17518 Minimum SSL protocol version to accept.
17519 Defaults to @samp{"TLSv1"}.
17522 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17523 SSL ciphers to use.
17524 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17527 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17528 SSL crypto device to use, for valid values run "openssl engine".
17529 Defaults to @samp{""}.
17532 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17533 Address to use when sending rejection mails.
17534 %d expands to recipient domain.
17535 Defaults to @samp{"postmaster@@%d"}.
17538 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17539 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17540 and in LMTP replies. Default is the system's real hostname@@domain.
17541 Defaults to @samp{""}.
17544 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17545 If user is over quota, return with temporary failure instead of
17547 Defaults to @samp{#f}.
17550 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17551 Binary to use for sending mails.
17552 Defaults to @samp{"/usr/sbin/sendmail"}.
17555 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17556 If non-empty, send mails via this SMTP host[:port] instead of
17558 Defaults to @samp{""}.
17561 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17562 Subject: header to use for rejection mails. You can use the same
17563 variables as for @samp{rejection-reason} below.
17564 Defaults to @samp{"Rejected: %s"}.
17567 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17568 Human readable error message for rejection mails. You can use
17581 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17584 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17585 Delimiter character between local-part and detail in email
17587 Defaults to @samp{"+"}.
17590 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17591 Header where the original recipient address (SMTP's RCPT TO:
17592 address) is taken from if not available elsewhere. With dovecot-lda -a
17593 parameter overrides this. A commonly used header for this is
17595 Defaults to @samp{""}.
17598 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17599 Should saving a mail to a nonexistent mailbox automatically create
17601 Defaults to @samp{#f}.
17604 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17605 Should automatically created mailboxes be also automatically
17607 Defaults to @samp{#f}.
17610 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17611 Maximum IMAP command line length. Some clients generate very long
17612 command lines with huge mailboxes, so you may need to raise this if you
17613 get "Too long argument" or "IMAP command line too large" errors
17615 Defaults to @samp{64000}.
17618 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17619 IMAP logout format string:
17622 total number of bytes read from client
17624 total number of bytes sent to client.
17626 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17627 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@}"}.
17630 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17631 Override the IMAP CAPABILITY response. If the value begins with '+',
17632 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17633 Defaults to @samp{""}.
17636 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17637 How long to wait between "OK Still here" notifications when client
17639 Defaults to @samp{"2 mins"}.
17642 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17643 ID field names and values to send to clients. Using * as the value
17644 makes Dovecot use the default value. The following fields have default
17645 values currently: name, version, os, os-version, support-url,
17647 Defaults to @samp{""}.
17650 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17651 ID fields sent by client to log. * means everything.
17652 Defaults to @samp{""}.
17655 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17656 Workarounds for various client bugs:
17659 @item delay-newmail
17660 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17661 CHECK commands. Some clients ignore them otherwise, for example OSX
17662 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17663 may show user "Message no longer in server" errors. Note that OE6
17664 still breaks even with this workaround if synchronization is set to
17667 @item tb-extra-mailbox-sep
17668 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17669 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17670 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17672 @item tb-lsub-flags
17673 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17674 This makes Thunderbird realize they aren't selectable and show them
17675 greyed out, instead of only later giving "not selectable" popup error.
17677 Defaults to @samp{()}.
17680 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17681 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17682 Defaults to @samp{""}.
17686 Whew! Lots of configuration options. The nice thing about it though is
17687 that Guix has a complete interface to Dovecot's configuration
17688 language. This allows not only a nice way to declare configurations,
17689 but also offers reflective capabilities as well: users can write code to
17690 inspect and transform configurations from within Scheme.
17692 However, it could be that you just want to get a @code{dovecot.conf} up
17693 and running. In that case, you can pass an
17694 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17695 @code{dovecot-service}. As its name indicates, an opaque configuration
17696 does not have easy reflective capabilities.
17698 Available @code{opaque-dovecot-configuration} fields are:
17700 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17701 The dovecot package.
17704 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17705 The contents of the @code{dovecot.conf}, as a string.
17708 For example, if your @code{dovecot.conf} is just the empty string, you
17709 could instantiate a dovecot service like this:
17712 (dovecot-service #:config
17713 (opaque-dovecot-configuration
17717 @subsubheading OpenSMTPD Service
17719 @deffn {Scheme Variable} opensmtpd-service-type
17720 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17721 service, whose value should be an @code{opensmtpd-configuration} object
17722 as in this example:
17725 (service opensmtpd-service-type
17726 (opensmtpd-configuration
17727 (config-file (local-file "./my-smtpd.conf"))))
17731 @deftp {Data Type} opensmtpd-configuration
17732 Data type representing the configuration of opensmtpd.
17735 @item @code{package} (default: @var{opensmtpd})
17736 Package object of the OpenSMTPD SMTP server.
17738 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17739 File-like object of the OpenSMTPD configuration file to use. By default
17740 it listens on the loopback network interface, and allows for mail from
17741 users and daemons on the local machine, as well as permitting email to
17742 remote servers. Run @command{man smtpd.conf} for more information.
17747 @subsubheading Exim Service
17749 @cindex mail transfer agent (MTA)
17750 @cindex MTA (mail transfer agent)
17753 @deffn {Scheme Variable} exim-service-type
17754 This is the type of the @uref{https://exim.org, Exim} mail transfer
17755 agent (MTA), whose value should be an @code{exim-configuration} object
17756 as in this example:
17759 (service exim-service-type
17760 (exim-configuration
17761 (config-file (local-file "./my-exim.conf"))))
17765 In order to use an @code{exim-service-type} service you must also have a
17766 @code{mail-aliases-service-type} service present in your
17767 @code{operating-system} (even if it has no aliases).
17769 @deftp {Data Type} exim-configuration
17770 Data type representing the configuration of exim.
17773 @item @code{package} (default: @var{exim})
17774 Package object of the Exim server.
17776 @item @code{config-file} (default: @code{#f})
17777 File-like object of the Exim configuration file to use. If its value is
17778 @code{#f} then use the default configuration file from the package
17779 provided in @code{package}. The resulting configuration file is loaded
17780 after setting the @code{exim_user} and @code{exim_group} configuration
17786 @subsubheading Getmail service
17791 @deffn {Scheme Variable} getmail-service-type
17792 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17793 mail retriever, whose value should be an @code{getmail-configuration}.
17796 Available @code{getmail-configuration} fields are:
17798 @deftypevr {@code{getmail-configuration} parameter} symbol name
17799 A symbol to identify the getmail service.
17801 Defaults to @samp{"unset"}.
17805 @deftypevr {@code{getmail-configuration} parameter} package package
17806 The getmail package to use.
17810 @deftypevr {@code{getmail-configuration} parameter} string user
17811 The user to run getmail as.
17813 Defaults to @samp{"getmail"}.
17817 @deftypevr {@code{getmail-configuration} parameter} string group
17818 The group to run getmail as.
17820 Defaults to @samp{"getmail"}.
17824 @deftypevr {@code{getmail-configuration} parameter} string directory
17825 The getmail directory to use.
17827 Defaults to @samp{"/var/lib/getmail/default"}.
17831 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17832 The getmail configuration file to use.
17834 Available @code{getmail-configuration-file} fields are:
17836 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17837 What mail account to retrieve mail from, and how to access that account.
17839 Available @code{getmail-retriever-configuration} fields are:
17841 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17842 The type of mail retriever to use. Valid values include @samp{passwd}
17845 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17849 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17850 Username to login to the mail server with.
17852 Defaults to @samp{unset}.
17856 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17857 Username to login to the mail server with.
17859 Defaults to @samp{unset}.
17863 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17864 Port number to connect to.
17866 Defaults to @samp{#f}.
17870 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17871 Override fields from passwd.
17873 Defaults to @samp{""}.
17877 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17878 Override fields from passwd.
17880 Defaults to @samp{()}.
17884 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17885 PEM-formatted key file to use for the TLS negotiation.
17887 Defaults to @samp{""}.
17891 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17892 PEM-formatted certificate file to use for the TLS negotiation.
17894 Defaults to @samp{""}.
17898 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17899 CA certificates to use.
17901 Defaults to @samp{""}.
17905 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17906 Extra retriever parameters.
17908 Defaults to @samp{()}.
17914 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17915 What to do with retrieved messages.
17917 Available @code{getmail-destination-configuration} fields are:
17919 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17920 The type of mail destination. Valid values include @samp{Maildir},
17921 @samp{Mboxrd} and @samp{MDA_external}.
17923 Defaults to @samp{unset}.
17927 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17928 The path option for the mail destination. The behaviour depends on the
17931 Defaults to @samp{""}.
17935 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17936 Extra destination parameters
17938 Defaults to @samp{()}.
17944 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17947 Available @code{getmail-options-configuration} fields are:
17949 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17950 If set to @samp{0}, getmail will only print warnings and errors. A
17951 value of @samp{1} means that messages will be printed about retrieving
17952 and deleting messages. If set to @samp{2}, getmail will print messages
17953 about each of it's actions.
17955 Defaults to @samp{1}.
17959 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17960 If true, getmail will retrieve all available messages. Otherwise it
17961 will only retrieve messages it hasn't seen previously.
17963 Defaults to @samp{#t}.
17967 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17968 If set to true, messages will be deleted from the server after
17969 retrieving and successfully delivering them. Otherwise, messages will
17970 be left on the server.
17972 Defaults to @samp{#f}.
17976 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17977 Getmail will delete messages this number of days after seeing them, if
17978 they have been delivered. This means messages will be left on the
17979 server this number of days after delivering them. A value of @samp{0}
17980 disabled this feature.
17982 Defaults to @samp{0}.
17986 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17987 Delete messages larger than this of bytes after retrieving them, even if
17988 the delete and delete-after options are disabled. A value of @samp{0}
17989 disables this feature.
17991 Defaults to @samp{0}.
17995 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17996 Retrieve messages totalling up to this number of bytes before closing
17997 the session with the server. A value of @samp{0} disables this feature.
17999 Defaults to @samp{0}.
18003 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
18004 Don't retrieve messages larger than this number of bytes. A value of
18005 @samp{0} disables this feature.
18007 Defaults to @samp{0}.
18011 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
18012 If true, getmail will add a Delivered-To header to messages.
18014 Defaults to @samp{#t}.
18018 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
18019 If set, getmail adds a Received header to the messages.
18021 Defaults to @samp{#t}.
18025 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
18026 Getmail will record a log of its actions to the named file. A value of
18027 @samp{""} disables this feature.
18029 Defaults to @samp{""}.
18033 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
18034 If true, getmail will record a log of its actions using the system
18037 Defaults to @samp{#f}.
18041 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
18042 If true, getmail will log information about messages not retrieved and
18043 the reason for not retrieving them, as well as starting and ending
18046 Defaults to @samp{#f}.
18050 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
18051 Extra options to include.
18053 Defaults to @samp{()}.
18061 @deftypevr {@code{getmail-configuration} parameter} list idle
18062 A list of mailboxes that getmail should wait on the server for new mail
18063 notifications. This depends on the server supporting the IDLE
18066 Defaults to @samp{()}.
18070 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
18071 Environment variables to set for getmail.
18073 Defaults to @samp{()}.
18077 @subsubheading Mail Aliases Service
18079 @cindex email aliases
18080 @cindex aliases, for email addresses
18082 @deffn {Scheme Variable} mail-aliases-service-type
18083 This is the type of the service which provides @code{/etc/aliases},
18084 specifying how to deliver mail to users on this system.
18087 (service mail-aliases-service-type
18088 '(("postmaster" "bob")
18089 ("bob" "bob@@example.com" "bob@@example2.com")))
18093 The configuration for a @code{mail-aliases-service-type} service is an
18094 association list denoting how to deliver mail that comes to this
18095 system. Each entry is of the form @code{(alias addresses ...)}, with
18096 @code{alias} specifying the local alias and @code{addresses} specifying
18097 where to deliver this user's mail.
18099 The aliases aren't required to exist as users on the local system. In
18100 the above example, there doesn't need to be a @code{postmaster} entry in
18101 the @code{operating-system}'s @code{user-accounts} in order to deliver
18102 the @code{postmaster} mail to @code{bob} (which subsequently would
18103 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
18105 @subsubheading GNU Mailutils IMAP4 Daemon
18106 @cindex GNU Mailutils IMAP4 Daemon
18108 @deffn {Scheme Variable} imap4d-service-type
18109 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
18110 mailutils, GNU Mailutils Manual}), whose value should be an
18111 @code{imap4d-configuration} object as in this example:
18114 (service imap4d-service-type
18115 (imap4d-configuration
18116 (config-file (local-file "imap4d.conf"))))
18120 @deftp {Data Type} imap4d-configuration
18121 Data type representing the configuration of @command{imap4d}.
18124 @item @code{package} (default: @code{mailutils})
18125 The package that provides @command{imap4d}.
18127 @item @code{config-file} (default: @code{%default-imap4d-config-file})
18128 File-like object of the configuration file to use, by default it will listen
18129 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
18130 Mailutils Manual}, for details.
18135 @node Messaging Services
18136 @subsection Messaging Services
18141 The @code{(gnu services messaging)} module provides Guix service
18142 definitions for messaging services: currently only Prosody is supported.
18144 @subsubheading Prosody Service
18146 @deffn {Scheme Variable} prosody-service-type
18147 This is the type for the @uref{https://prosody.im, Prosody XMPP
18148 communication server}. Its value must be a @code{prosody-configuration}
18149 record as in this example:
18152 (service prosody-service-type
18153 (prosody-configuration
18154 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
18157 (int-component-configuration
18158 (hostname "conference.example.net")
18160 (mod-muc (mod-muc-configuration)))))
18163 (virtualhost-configuration
18164 (domain "example.net"))))))
18167 See below for details about @code{prosody-configuration}.
18171 By default, Prosody does not need much configuration. Only one
18172 @code{virtualhosts} field is needed: it specifies the domain you wish
18175 You can perform various sanity checks on the generated configuration
18176 with the @code{prosodyctl check} command.
18178 Prosodyctl will also help you to import certificates from the
18179 @code{letsencrypt} directory so that the @code{prosody} user can access
18180 them. See @url{https://prosody.im/doc/letsencrypt}.
18183 prosodyctl --root cert import /etc/letsencrypt/live
18186 The available configuration parameters follow. Each parameter
18187 definition is preceded by its type; for example, @samp{string-list foo}
18188 indicates that the @code{foo} parameter should be specified as a list of
18189 strings. Types starting with @code{maybe-} denote parameters that won't
18190 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18192 There is also a way to specify the configuration as a string, if you
18193 have an old @code{prosody.cfg.lua} file that you want to port over from
18194 some other system; see the end for more details.
18196 The @code{file-object} type designates either a file-like object
18197 (@pxref{G-Expressions, file-like objects}) or a file name.
18199 @c The following documentation was initially generated by
18200 @c (generate-documentation) in (gnu services messaging). Manually maintained
18201 @c documentation is better, so we shouldn't hesitate to edit below as
18202 @c needed. However if the change you want to make to this documentation
18203 @c can be done in an automated way, it's probably easier to change
18204 @c (generate-documentation) than to make it below and have to deal with
18205 @c the churn as Prosody updates.
18207 Available @code{prosody-configuration} fields are:
18209 @deftypevr {@code{prosody-configuration} parameter} package prosody
18210 The Prosody package.
18213 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18214 Location of the Prosody data storage directory. See
18215 @url{https://prosody.im/doc/configure}.
18216 Defaults to @samp{"/var/lib/prosody"}.
18219 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18220 Additional plugin directories. They are searched in all the specified
18221 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18222 Defaults to @samp{()}.
18225 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18226 Every virtual host and component needs a certificate so that clients and
18227 servers can securely verify its identity. Prosody will automatically load
18228 certificates/keys from the directory specified here.
18229 Defaults to @samp{"/etc/prosody/certs"}.
18232 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18233 This is a list of accounts that are admins for the server. Note that you
18234 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18235 @url{https://prosody.im/doc/creating_accounts}.
18236 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18237 Defaults to @samp{()}.
18240 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18241 Enable use of libevent for better performance under high load. See
18242 @url{https://prosody.im/doc/libevent}.
18243 Defaults to @samp{#f}.
18246 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18247 This is the list of modules Prosody will load on startup. It looks for
18248 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18249 Documentation on modules can be found at:
18250 @url{https://prosody.im/doc/modules}.
18251 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18254 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18255 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18256 should you want to disable them then add them to this list.
18257 Defaults to @samp{()}.
18260 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18261 Path to a text file where the shared groups are defined. If this path is
18262 empty then @samp{mod_groups} does nothing. See
18263 @url{https://prosody.im/doc/modules/mod_groups}.
18264 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18267 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18268 Disable account creation by default, for security. See
18269 @url{https://prosody.im/doc/creating_accounts}.
18270 Defaults to @samp{#f}.
18273 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18274 These are the SSL/TLS-related settings. Most of them are disabled so to
18275 use Prosody's defaults. If you do not completely understand these options, do
18276 not add them to your config, it is easy to lower the security of your server
18277 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18279 Available @code{ssl-configuration} fields are:
18281 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18282 This determines what handshake to use.
18285 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18286 Path to your private key file.
18289 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18290 Path to your certificate file.
18293 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18294 Path to directory containing root certificates that you wish Prosody to
18295 trust when verifying the certificates of remote servers.
18296 Defaults to @samp{"/etc/ssl/certs"}.
18299 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18300 Path to a file containing root certificates that you wish Prosody to trust.
18301 Similar to @code{capath} but with all certificates concatenated together.
18304 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18305 A list of verification options (these mostly map to OpenSSL's
18306 @code{set_verify()} flags).
18309 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18310 A list of general options relating to SSL/TLS. These map to OpenSSL's
18311 @code{set_options()}. For a full list of options available in LuaSec, see the
18315 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18316 How long a chain of certificate authorities to check when looking for a
18317 trusted root certificate.
18320 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18321 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18322 clients, and in what order.
18325 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18326 A path to a file containing parameters for Diffie-Hellman key exchange. You
18327 can create such a file with:
18328 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18331 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18332 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18333 @samp{"secp384r1"}.
18336 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18337 A list of "extra" verification options.
18340 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18341 Password for encrypted private keys.
18346 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18347 Whether to force all client-to-server connections to be encrypted or not.
18348 See @url{https://prosody.im/doc/modules/mod_tls}.
18349 Defaults to @samp{#f}.
18352 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18353 Set of mechanisms that will never be offered. See
18354 @url{https://prosody.im/doc/modules/mod_saslauth}.
18355 Defaults to @samp{("DIGEST-MD5")}.
18358 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18359 Whether to force all server-to-server connections to be encrypted or not.
18360 See @url{https://prosody.im/doc/modules/mod_tls}.
18361 Defaults to @samp{#f}.
18364 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18365 Whether to require encryption and certificate authentication. This
18366 provides ideal security, but requires servers you communicate with to support
18367 encryption AND present valid, trusted certificates. See
18368 @url{https://prosody.im/doc/s2s#security}.
18369 Defaults to @samp{#f}.
18372 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18373 Many servers don't support encryption or have invalid or self-signed
18374 certificates. You can list domains here that will not be required to
18375 authenticate using certificates. They will be authenticated using DNS. See
18376 @url{https://prosody.im/doc/s2s#security}.
18377 Defaults to @samp{()}.
18380 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18381 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18382 valid certificates for some domains by specifying a list here. See
18383 @url{https://prosody.im/doc/s2s#security}.
18384 Defaults to @samp{()}.
18387 @deftypevr {@code{prosody-configuration} parameter} string authentication
18388 Select the authentication backend to use. The default provider stores
18389 passwords in plaintext and uses Prosody's configured data storage to store the
18390 authentication data. If you do not trust your server please see
18391 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18392 about using the hashed backend. See also
18393 @url{https://prosody.im/doc/authentication}
18394 Defaults to @samp{"internal_plain"}.
18397 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18398 Set logging options. Advanced logging configuration is not yet supported
18399 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18400 Defaults to @samp{"*syslog"}.
18403 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18404 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18405 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18408 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18409 Maximum allowed size of the HTTP body (in bytes).
18412 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18413 Some modules expose their own URL in various ways. This URL is built
18414 from the protocol, host and port used. If Prosody sits behind a proxy, the
18415 public URL will be @code{http-external-url} instead. See
18416 @url{https://prosody.im/doc/http#external_url}.
18419 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18420 A host in Prosody is a domain on which user accounts can be created. For
18421 example if you want your users to have addresses like
18422 @samp{"john.smith@@example.com"} then you need to add a host
18423 @samp{"example.com"}. All options in this list will apply only to this host.
18425 Note: the name "virtual" host is used in configuration to avoid confusion with
18426 the actual physical host that Prosody is installed on. A single Prosody
18427 instance can serve many domains, each one defined as a VirtualHost entry in
18428 Prosody's configuration. Conversely a server that hosts a single domain would
18429 have just one VirtualHost entry.
18431 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18433 Available @code{virtualhost-configuration} fields are:
18435 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:
18436 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18437 Domain you wish Prosody to serve.
18442 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18443 Components are extra services on a server which are available to clients,
18444 usually on a subdomain of the main server (such as
18445 @samp{"mycomponent.example.com"}). Example components might be chatroom
18446 servers, user directories, or gateways to other protocols.
18448 Internal components are implemented with Prosody-specific plugins. To add an
18449 internal component, you simply fill the hostname field, and the plugin you wish
18450 to use for the component.
18452 See @url{https://prosody.im/doc/components}.
18453 Defaults to @samp{()}.
18455 Available @code{int-component-configuration} fields are:
18457 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:
18458 @deftypevr {@code{int-component-configuration} parameter} string hostname
18459 Hostname of the component.
18462 @deftypevr {@code{int-component-configuration} parameter} string plugin
18463 Plugin you wish to use for the component.
18466 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18467 Multi-user chat (MUC) is Prosody's module for allowing you to create
18468 hosted chatrooms/conferences for XMPP users.
18470 General information on setting up and using multi-user chatrooms can be found
18471 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18472 which you should read if you are new to XMPP chatrooms.
18474 See also @url{https://prosody.im/doc/modules/mod_muc}.
18476 Available @code{mod-muc-configuration} fields are:
18478 @deftypevr {@code{mod-muc-configuration} parameter} string name
18479 The name to return in service discovery responses.
18480 Defaults to @samp{"Prosody Chatrooms"}.
18483 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18484 If @samp{#t}, this will only allow admins to create new chatrooms.
18485 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18486 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18487 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18488 restricts to service administrators only.
18489 Defaults to @samp{#f}.
18492 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18493 Maximum number of history messages that will be sent to the member that has
18494 just joined the room.
18495 Defaults to @samp{20}.
18502 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18503 External components use XEP-0114, which most standalone components
18504 support. To add an external component, you simply fill the hostname field. See
18505 @url{https://prosody.im/doc/components}.
18506 Defaults to @samp{()}.
18508 Available @code{ext-component-configuration} fields are:
18510 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:
18511 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18512 Password which the component will use to log in.
18515 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18516 Hostname of the component.
18521 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18522 Port(s) Prosody listens on for component connections.
18523 Defaults to @samp{(5347)}.
18526 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18527 Interface Prosody listens on for component connections.
18528 Defaults to @samp{"127.0.0.1"}.
18531 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18532 Raw content that will be added to the configuration file.
18535 It could be that you just want to get a @code{prosody.cfg.lua}
18536 up and running. In that case, you can pass an
18537 @code{opaque-prosody-configuration} record as the value of
18538 @code{prosody-service-type}. As its name indicates, an opaque configuration
18539 does not have easy reflective capabilities.
18540 Available @code{opaque-prosody-configuration} fields are:
18542 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18543 The prosody package.
18546 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18547 The contents of the @code{prosody.cfg.lua} to use.
18550 For example, if your @code{prosody.cfg.lua} is just the empty
18551 string, you could instantiate a prosody service like this:
18554 (service prosody-service-type
18555 (opaque-prosody-configuration
18556 (prosody.cfg.lua "")))
18559 @c end of Prosody auto-generated documentation
18561 @subsubheading BitlBee Service
18563 @cindex IRC (Internet Relay Chat)
18564 @cindex IRC gateway
18565 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18566 interface to a variety of messaging protocols such as XMPP.
18568 @defvr {Scheme Variable} bitlbee-service-type
18569 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18570 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18573 To have BitlBee listen on port 6667 on localhost, add this line to your
18577 (service bitlbee-service-type)
18581 @deftp {Data Type} bitlbee-configuration
18582 This is the configuration for BitlBee, with the following fields:
18585 @item @code{interface} (default: @code{"127.0.0.1"})
18586 @itemx @code{port} (default: @code{6667})
18587 Listen on the network interface corresponding to the IP address
18588 specified in @var{interface}, on @var{port}.
18590 When @var{interface} is @code{127.0.0.1}, only local clients can
18591 connect; when it is @code{0.0.0.0}, connections can come from any
18592 networking interface.
18594 @item @code{bitlbee} (default: @code{bitlbee})
18595 The BitlBee package to use.
18597 @item @code{plugins} (default: @code{'()})
18598 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18600 @item @code{extra-settings} (default: @code{""})
18601 Configuration snippet added as-is to the BitlBee configuration file.
18605 @subsubheading Quassel Service
18607 @cindex IRC (Internet Relay Chat)
18608 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18609 meaning that one or more clients can attach to and detach from the
18612 @defvr {Scheme Variable} quassel-service-type
18613 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18614 IRC backend daemon. Its value is a @code{quassel-configuration}
18618 @deftp {Data Type} quassel-configuration
18619 This is the configuration for Quassel, with the following fields:
18622 @item @code{quassel} (default: @code{quassel})
18623 The Quassel package to use.
18625 @item @code{interface} (default: @code{"::,0.0.0.0"})
18626 @item @code{port} (default: @code{4242})
18627 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18628 interfaces specified in the comma delimited @var{interface}, on
18631 @item @code{loglevel} (default: @code{"Info"})
18632 The level of logging desired. Accepted values are Debug, Info, Warning
18637 @node Telephony Services
18638 @subsection Telephony Services
18640 @cindex Murmur (VoIP server)
18641 @cindex VoIP server
18642 This section describes how to set up and run a Murmur server. Murmur is
18643 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18646 @deftp {Data Type} murmur-configuration
18647 The service type for the Murmur server. An example configuration can
18651 (service murmur-service-type
18652 (murmur-configuration
18654 "Welcome to this Mumble server running on Guix!")
18655 (cert-required? #t) ;disallow text password logins
18656 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18657 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18660 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18661 password with the command that is printed during the activation phase.
18663 It is recommended to register a normal Mumble user account
18664 and grant it admin or moderator rights.
18665 You can use the @code{mumble} client to
18666 login as new normal user, register yourself, and log out.
18667 For the next step login with the name @code{SuperUser} use
18668 the @code{SuperUser} password that you set previously,
18669 and grant your newly registered mumble user administrator or moderator
18670 rights and create some channels.
18672 Available @code{murmur-configuration} fields are:
18675 @item @code{package} (default: @code{mumble})
18676 Package that contains @code{bin/murmurd}.
18678 @item @code{user} (default: @code{"murmur"})
18679 User who will run the Murmur server.
18681 @item @code{group} (default: @code{"murmur"})
18682 Group of the user who will run the murmur server.
18684 @item @code{port} (default: @code{64738})
18685 Port on which the server will listen.
18687 @item @code{welcome-text} (default: @code{""})
18688 Welcome text sent to clients when they connect.
18690 @item @code{server-password} (default: @code{""})
18691 Password the clients have to enter in order to connect.
18693 @item @code{max-users} (default: @code{100})
18694 Maximum of users that can be connected to the server at once.
18696 @item @code{max-user-bandwidth} (default: @code{#f})
18697 Maximum voice traffic a user can send per second.
18699 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18700 File name of the sqlite database.
18701 The service's user will become the owner of the directory.
18703 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18704 File name of the log file.
18705 The service's user will become the owner of the directory.
18707 @item @code{autoban-attempts} (default: @code{10})
18708 Maximum number of logins a user can make in @code{autoban-timeframe}
18709 without getting auto banned for @code{autoban-time}.
18711 @item @code{autoban-timeframe} (default: @code{120})
18712 Timeframe for autoban in seconds.
18714 @item @code{autoban-time} (default: @code{300})
18715 Amount of time in seconds for which a client gets banned
18716 when violating the autoban limits.
18718 @item @code{opus-threshold} (default: @code{100})
18719 Percentage of clients that need to support opus
18720 before switching over to opus audio codec.
18722 @item @code{channel-nesting-limit} (default: @code{10})
18723 How deep channels can be nested at maximum.
18725 @item @code{channelname-regex} (default: @code{#f})
18726 A string in form of a Qt regular expression that channel names must conform to.
18728 @item @code{username-regex} (default: @code{#f})
18729 A string in form of a Qt regular expression that user names must conform to.
18731 @item @code{text-message-length} (default: @code{5000})
18732 Maximum size in bytes that a user can send in one text chat message.
18734 @item @code{image-message-length} (default: @code{(* 128 1024)})
18735 Maximum size in bytes that a user can send in one image message.
18737 @item @code{cert-required?} (default: @code{#f})
18738 If it is set to @code{#t} clients that use weak password authentication
18739 will not be accepted. Users must have completed the certificate wizard to join.
18741 @item @code{remember-channel?} (default: @code{#f})
18742 Should murmur remember the last channel each user was in when they disconnected
18743 and put them into the remembered channel when they rejoin.
18745 @item @code{allow-html?} (default: @code{#f})
18746 Should html be allowed in text messages, user comments, and channel descriptions.
18748 @item @code{allow-ping?} (default: @code{#f})
18749 Setting to true exposes the current user count, the maximum user count, and
18750 the server's maximum bandwidth per client to unauthenticated users. In the
18751 Mumble client, this information is shown in the Connect dialog.
18753 Disabling this setting will prevent public listing of the server.
18755 @item @code{bonjour?} (default: @code{#f})
18756 Should the server advertise itself in the local network through the bonjour protocol.
18758 @item @code{send-version?} (default: @code{#f})
18759 Should the murmur server version be exposed in ping requests.
18761 @item @code{log-days} (default: @code{31})
18762 Murmur also stores logs in the database, which are accessible via RPC.
18763 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18764 or -1 to disable logging to the database.
18766 @item @code{obfuscate-ips?} (default: @code{#t})
18767 Should logged ips be obfuscated to protect the privacy of users.
18769 @item @code{ssl-cert} (default: @code{#f})
18770 File name of the SSL/TLS certificate used for encrypted connections.
18773 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18775 @item @code{ssl-key} (default: @code{#f})
18776 Filepath to the ssl private key used for encrypted connections.
18778 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18781 @item @code{ssl-dh-params} (default: @code{#f})
18782 File name of a PEM-encoded file with Diffie-Hellman parameters
18783 for the SSL/TLS encryption. Alternatively you set it to
18784 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18785 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18787 @item @code{ssl-ciphers} (default: @code{#f})
18788 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18791 This option is specified using
18792 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18793 OpenSSL cipher list notation}.
18795 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18796 before setting it here, to get a feel for which cipher suites you will get.
18797 After setting this option, it is recommend that you inspect your Murmur log
18798 to ensure that Murmur is using the cipher suites that you expected it to.
18800 Note: Changing this option may impact the backwards compatibility of your
18801 Murmur server, and can remove the ability for older Mumble clients to be able
18804 @item @code{public-registration} (default: @code{#f})
18805 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18807 You can optionally register your server in the public server list that the
18808 @code{mumble} client shows on startup.
18809 You cannot register your server if you have set a @code{server-password},
18810 or set @code{allow-ping} to @code{#f}.
18812 It might take a few hours until it shows up in the public list.
18814 @item @code{file} (default: @code{#f})
18815 Optional alternative override for this configuration.
18819 @deftp {Data Type} murmur-public-registration-configuration
18820 Configuration for public registration of a murmur service.
18824 This is a display name for your server. Not to be confused with the hostname.
18826 @item @code{password}
18827 A password to identify your registration.
18828 Subsequent updates will need the same password. Don't lose your password.
18831 This should be a @code{http://} or @code{https://} link to your web
18834 @item @code{hostname} (default: @code{#f})
18835 By default your server will be listed by its IP address.
18836 If it is set your server will be linked by this host name instead.
18842 @node Monitoring Services
18843 @subsection Monitoring Services
18845 @subsubheading Tailon Service
18847 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18848 viewing and searching log files.
18850 The following example will configure the service with default values.
18851 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18854 (service tailon-service-type)
18857 The following example customises more of the Tailon configuration,
18858 adding @command{sed} to the list of allowed commands.
18861 (service tailon-service-type
18862 (tailon-configuration
18864 (tailon-configuration-file
18865 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18869 @deftp {Data Type} tailon-configuration
18870 Data type representing the configuration of Tailon.
18871 This type has the following parameters:
18874 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18875 The configuration file to use for Tailon. This can be set to a
18876 @dfn{tailon-configuration-file} record value, or any gexp
18877 (@pxref{G-Expressions}).
18879 For example, to instead use a local file, the @code{local-file} function
18883 (service tailon-service-type
18884 (tailon-configuration
18885 (config-file (local-file "./my-tailon.conf"))))
18888 @item @code{package} (default: @code{tailon})
18889 The tailon package to use.
18894 @deftp {Data Type} tailon-configuration-file
18895 Data type representing the configuration options for Tailon.
18896 This type has the following parameters:
18899 @item @code{files} (default: @code{(list "/var/log")})
18900 List of files to display. The list can include strings for a single file
18901 or directory, or a list, where the first item is the name of a
18902 subsection, and the remaining items are the files or directories in that
18905 @item @code{bind} (default: @code{"localhost:8080"})
18906 Address and port to which Tailon should bind on.
18908 @item @code{relative-root} (default: @code{#f})
18909 URL path to use for Tailon, set to @code{#f} to not use a path.
18911 @item @code{allow-transfers?} (default: @code{#t})
18912 Allow downloading the log files in the web interface.
18914 @item @code{follow-names?} (default: @code{#t})
18915 Allow tailing of not-yet existent files.
18917 @item @code{tail-lines} (default: @code{200})
18918 Number of lines to read initially from each file.
18920 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18921 Commands to allow running. By default, @code{sed} is disabled.
18923 @item @code{debug?} (default: @code{#f})
18924 Set @code{debug?} to @code{#t} to show debug messages.
18926 @item @code{wrap-lines} (default: @code{#t})
18927 Initial line wrapping state in the web interface. Set to @code{#t} to
18928 initially wrap lines (the default), or to @code{#f} to initially not
18931 @item @code{http-auth} (default: @code{#f})
18932 HTTP authentication type to use. Set to @code{#f} to disable
18933 authentication (the default). Supported values are @code{"digest"} or
18936 @item @code{users} (default: @code{#f})
18937 If HTTP authentication is enabled (see @code{http-auth}), access will be
18938 restricted to the credentials provided here. To configure users, use a
18939 list of pairs, where the first element of the pair is the username, and
18940 the 2nd element of the pair is the password.
18943 (tailon-configuration-file
18944 (http-auth "basic")
18945 (users '(("user1" . "password1")
18946 ("user2" . "password2"))))
18953 @subsubheading Darkstat Service
18955 Darkstat is a packet sniffer that captures network traffic, calculates
18956 statistics about usage, and serves reports over HTTP.
18958 @defvar {Scheme Variable} darkstat-service-type
18959 This is the service type for the
18960 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18961 service, its value must be a @code{darkstat-configuration} record as in
18965 (service darkstat-service-type
18966 (darkstat-configuration
18967 (interface "eno1")))
18971 @deftp {Data Type} darkstat-configuration
18972 Data type representing the configuration of @command{darkstat}.
18975 @item @code{package} (default: @code{darkstat})
18976 The darkstat package to use.
18978 @item @code{interface}
18979 Capture traffic on the specified network interface.
18981 @item @code{port} (default: @code{"667"})
18982 Bind the web interface to the specified port.
18984 @item @code{bind-address} (default: @code{"127.0.0.1"})
18985 Bind the web interface to the specified address.
18987 @item @code{base} (default: @code{"/"})
18988 Specify the path of the base URL. This can be useful if
18989 @command{darkstat} is accessed via a reverse proxy.
18994 @subsubheading Prometheus Node Exporter Service
18996 @cindex prometheus-node-exporter
18997 The Prometheus ``node exporter'' makes hardware and operating system statistics
18998 provided by the Linux kernel available for the Prometheus monitoring system.
18999 This service should be deployed on all physical nodes and virtual machines,
19000 where monitoring these statistics is desirable.
19002 @defvar {Scheme variable} prometheus-node-exporter-service-type
19003 This is the service type for the
19004 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
19005 service, its value must be a @code{prometheus-node-exporter-configuration}
19006 record as in this example:
19009 (service prometheus-node-exporter-service-type
19010 (prometheus-node-exporter-configuration
19011 (web-listen-address ":9100")))
19015 @deftp {Data Type} prometheus-node-exporter-configuration
19016 Data type representing the configuration of @command{node_exporter}.
19019 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
19020 The prometheus-node-exporter package to use.
19022 @item @code{web-listen-address} (default: @code{":9100"})
19023 Bind the web interface to the specified address.
19028 @subsubheading Zabbix server
19029 @cindex zabbix zabbix-server
19030 Zabbix provides monitoring metrics, among others network utilization, CPU load
19031 and disk space consumption:
19034 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
19035 @item Auto-discovery of servers and network devices and interfaces.
19036 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
19037 @item Distributed monitoring with centralized web administration.
19038 @item Native high performance agents.
19039 @item SLA, and ITIL KPI metrics on reporting.
19040 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
19041 @item Remote command execution through Zabbix proxies.
19044 @c %start of fragment
19046 Available @code{zabbix-server-configuration} fields are:
19048 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
19049 The zabbix-server package.
19053 @deftypevr {@code{zabbix-server-configuration} parameter} string user
19054 User who will run the Zabbix server.
19056 Defaults to @samp{"zabbix"}.
19060 @deftypevr {@code{zabbix-server-configuration} parameter} group group
19061 Group who will run the Zabbix server.
19063 Defaults to @samp{"zabbix"}.
19067 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
19068 Database host name.
19070 Defaults to @samp{"127.0.0.1"}.
19074 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
19077 Defaults to @samp{"zabbix"}.
19081 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
19084 Defaults to @samp{"zabbix"}.
19088 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
19089 Database password. Please, use @code{include-files} with
19090 @code{DBPassword=SECRET} inside a specified file instead.
19092 Defaults to @samp{""}.
19096 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
19099 Defaults to @samp{5432}.
19103 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
19104 Specifies where log messages are written to:
19108 @code{system} - syslog.
19111 @code{file} - file specified with @code{log-file} parameter.
19114 @code{console} - standard output.
19118 Defaults to @samp{""}.
19122 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
19123 Log file name for @code{log-type} @code{file} parameter.
19125 Defaults to @samp{"/var/log/zabbix/server.log"}.
19129 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
19132 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
19136 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
19137 The location of certificate authority (CA) files for SSL server
19138 certificate verification.
19140 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
19144 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
19145 Location of SSL client certificates.
19147 Defaults to @samp{"/etc/ssl/certs"}.
19151 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
19152 Extra options will be appended to Zabbix server configuration file.
19154 Defaults to @samp{""}.
19158 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
19159 You may include individual files or all files in a directory in the
19160 configuration file.
19162 Defaults to @samp{()}.
19166 @c %end of fragment
19168 @subsubheading Zabbix agent
19169 @cindex zabbix zabbix-agent
19171 Zabbix agent gathers information for Zabbix server.
19173 @c %start of fragment
19175 Available @code{zabbix-agent-configuration} fields are:
19177 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19178 The zabbix-agent package.
19182 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19183 User who will run the Zabbix agent.
19185 Defaults to @samp{"zabbix"}.
19189 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19190 Group who will run the Zabbix agent.
19192 Defaults to @samp{"zabbix"}.
19196 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19197 Unique, case sensitive hostname which is required for active checks and
19198 must match hostname as configured on the server.
19200 Defaults to @samp{"Zabbix server"}.
19204 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19205 Specifies where log messages are written to:
19209 @code{system} - syslog.
19212 @code{file} - file specified with @code{log-file} parameter.
19215 @code{console} - standard output.
19219 Defaults to @samp{""}.
19223 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19224 Log file name for @code{log-type} @code{file} parameter.
19226 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19230 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19233 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19237 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19238 List of IP addresses, optionally in CIDR notation, or hostnames of
19239 Zabbix servers and Zabbix proxies. Incoming connections will be
19240 accepted only from the hosts listed here.
19242 Defaults to @samp{("127.0.0.1")}.
19246 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19247 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19248 proxies for active checks. If port is not specified, default port is
19249 used. If this parameter is not specified, active checks are disabled.
19251 Defaults to @samp{("127.0.0.1")}.
19255 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19256 Extra options will be appended to Zabbix server configuration file.
19258 Defaults to @samp{""}.
19262 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19263 You may include individual files or all files in a directory in the
19264 configuration file.
19266 Defaults to @samp{()}.
19270 @c %end of fragment
19272 @subsubheading Zabbix front-end
19273 @cindex zabbix zabbix-front-end
19275 This service provides a WEB interface to Zabbix server.
19277 @c %start of fragment
19279 Available @code{zabbix-front-end-configuration} fields are:
19281 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19282 NGINX configuration.
19286 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19287 Database host name.
19289 Defaults to @samp{"localhost"}.
19293 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19296 Defaults to @samp{5432}.
19300 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19303 Defaults to @samp{"zabbix"}.
19307 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19310 Defaults to @samp{"zabbix"}.
19314 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19315 Database password. Please, use @code{db-secret-file} instead.
19317 Defaults to @samp{""}.
19321 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19322 Secret file which will be appended to @file{zabbix.conf.php} file. This
19323 file contains credentials for use by Zabbix front-end. You are expected
19324 to create it manually.
19326 Defaults to @samp{""}.
19330 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19331 Zabbix server hostname.
19333 Defaults to @samp{"localhost"}.
19337 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19338 Zabbix server port.
19340 Defaults to @samp{10051}.
19345 @c %end of fragment
19347 @node Kerberos Services
19348 @subsection Kerberos Services
19351 The @code{(gnu services kerberos)} module provides services relating to
19352 the authentication protocol @dfn{Kerberos}.
19354 @subsubheading Krb5 Service
19356 Programs using a Kerberos client library normally
19357 expect a configuration file in @file{/etc/krb5.conf}.
19358 This service generates such a file from a definition provided in the
19359 operating system declaration.
19360 It does not cause any daemon to be started.
19362 No ``keytab'' files are provided by this service---you must explicitly create them.
19363 This service is known to work with the MIT client library, @code{mit-krb5}.
19364 Other implementations have not been tested.
19366 @defvr {Scheme Variable} krb5-service-type
19367 A service type for Kerberos 5 clients.
19371 Here is an example of its use:
19373 (service krb5-service-type
19374 (krb5-configuration
19375 (default-realm "EXAMPLE.COM")
19376 (allow-weak-crypto? #t)
19379 (name "EXAMPLE.COM")
19380 (admin-server "groucho.example.com")
19381 (kdc "karl.example.com"))
19384 (admin-server "kerb-admin.argrx.edu")
19385 (kdc "keys.argrx.edu"))))))
19389 This example provides a Kerberos@tie{}5 client configuration which:
19391 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19392 of which have distinct administration servers and key distribution centers;
19393 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19394 specified by clients;
19395 @item Accepts services which only support encryption types known to be weak.
19398 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19399 Only the most commonly used ones are described here.
19400 For a full list, and more detailed explanation of each, see the MIT
19401 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19405 @deftp {Data Type} krb5-realm
19406 @cindex realm, kerberos
19409 This field is a string identifying the name of the realm.
19410 A common convention is to use the fully qualified DNS name of your organization,
19411 converted to upper case.
19413 @item @code{admin-server}
19414 This field is a string identifying the host where the administration server is
19418 This field is a string identifying the key distribution center
19423 @deftp {Data Type} krb5-configuration
19426 @item @code{allow-weak-crypto?} (default: @code{#f})
19427 If this flag is @code{#t} then services which only offer encryption algorithms
19428 known to be weak will be accepted.
19430 @item @code{default-realm} (default: @code{#f})
19431 This field should be a string identifying the default Kerberos
19432 realm for the client.
19433 You should set this field to the name of your Kerberos realm.
19434 If this value is @code{#f}
19435 then a realm must be specified with every Kerberos principal when invoking programs
19436 such as @command{kinit}.
19438 @item @code{realms}
19439 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19441 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19447 @subsubheading PAM krb5 Service
19450 The @code{pam-krb5} service allows for login authentication and password
19451 management via Kerberos.
19452 You will need this service if you want PAM enabled applications to authenticate
19453 users using Kerberos.
19455 @defvr {Scheme Variable} pam-krb5-service-type
19456 A service type for the Kerberos 5 PAM module.
19459 @deftp {Data Type} pam-krb5-configuration
19460 Data type representing the configuration of the Kerberos 5 PAM module.
19461 This type has the following parameters:
19463 @item @code{pam-krb5} (default: @code{pam-krb5})
19464 The pam-krb5 package to use.
19466 @item @code{minimum-uid} (default: @code{1000})
19467 The smallest user ID for which Kerberos authentications should be attempted.
19468 Local accounts with lower values will silently fail to authenticate.
19473 @node LDAP Services
19474 @subsection LDAP Services
19476 @cindex nslcd, LDAP service
19478 The @code{(gnu services authentication)} module provides the
19479 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19480 server. In addition to configuring the service itself, you may want to add
19481 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19482 Switch} for detailed information.
19484 Here is a simple operating system declaration with a default configuration of
19485 the @code{nslcd-service-type} and a Name Service Switch configuration that
19486 consults the @code{ldap} name service last:
19489 (use-service-modules authentication)
19490 (use-modules (gnu system nss))
19496 (service nslcd-service-type)
19497 (service dhcp-client-service-type)
19499 (name-service-switch
19500 (let ((services (list (name-service (name "db"))
19501 (name-service (name "files"))
19502 (name-service (name "ldap")))))
19503 (name-service-switch
19504 (inherit %mdns-host-lookup-nss)
19505 (password services)
19508 (netgroup services)
19509 (gshadow services)))))
19512 @c %start of generated documentation for nslcd-configuration
19514 Available @code{nslcd-configuration} fields are:
19516 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19517 The @code{nss-pam-ldapd} package to use.
19521 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19522 The number of threads to start that can handle requests and perform LDAP
19523 queries. Each thread opens a separate connection to the LDAP server.
19524 The default is to start 5 threads.
19526 Defaults to @samp{disabled}.
19530 @deftypevr {@code{nslcd-configuration} parameter} string uid
19531 This specifies the user id with which the daemon should be run.
19533 Defaults to @samp{"nslcd"}.
19537 @deftypevr {@code{nslcd-configuration} parameter} string gid
19538 This specifies the group id with which the daemon should be run.
19540 Defaults to @samp{"nslcd"}.
19544 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19545 This option controls the way logging is done via a list containing
19546 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19547 or "syslog", or an absolute file name. The LEVEL argument is optional
19548 and specifies the log level. The log level may be one of the following
19549 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19550 messages with the specified log level or higher are logged.
19552 Defaults to @samp{("/var/log/nslcd" info)}.
19556 @deftypevr {@code{nslcd-configuration} parameter} list uri
19557 The list of LDAP server URIs. Normally, only the first server will be
19558 used with the following servers as fall-back.
19560 Defaults to @samp{("ldap://localhost:389/")}.
19564 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19565 The version of the LDAP protocol to use. The default is to use the
19566 maximum version supported by the LDAP library.
19568 Defaults to @samp{disabled}.
19572 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19573 Specifies the distinguished name with which to bind to the directory
19574 server for lookups. The default is to bind anonymously.
19576 Defaults to @samp{disabled}.
19580 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19581 Specifies the credentials with which to bind. This option is only
19582 applicable when used with binddn.
19584 Defaults to @samp{disabled}.
19588 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19589 Specifies the distinguished name to use when the root user tries to
19590 modify a user's password using the PAM module.
19592 Defaults to @samp{disabled}.
19596 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19597 Specifies the credentials with which to bind if the root user tries to
19598 change a user's password. This option is only applicable when used with
19601 Defaults to @samp{disabled}.
19605 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19606 Specifies the SASL mechanism to be used when performing SASL
19609 Defaults to @samp{disabled}.
19613 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19614 Specifies the SASL realm to be used when performing SASL authentication.
19616 Defaults to @samp{disabled}.
19620 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19621 Specifies the authentication identity to be used when performing SASL
19624 Defaults to @samp{disabled}.
19628 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19629 Specifies the authorization identity to be used when performing SASL
19632 Defaults to @samp{disabled}.
19636 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19637 Determines whether the LDAP server host name should be canonicalised. If
19638 this is enabled the LDAP library will do a reverse host name lookup. By
19639 default, it is left up to the LDAP library whether this check is
19642 Defaults to @samp{disabled}.
19646 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19647 Set the name for the GSS-API Kerberos credentials cache.
19649 Defaults to @samp{disabled}.
19653 @deftypevr {@code{nslcd-configuration} parameter} string base
19654 The directory search base.
19656 Defaults to @samp{"dc=example,dc=com"}.
19660 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19661 Specifies the search scope (subtree, onelevel, base or children). The
19662 default scope is subtree; base scope is almost never useful for name
19663 service lookups; children scope is not supported on all servers.
19665 Defaults to @samp{(subtree)}.
19669 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19670 Specifies the policy for dereferencing aliases. The default policy is
19671 to never dereference aliases.
19673 Defaults to @samp{disabled}.
19677 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19678 Specifies whether automatic referral chasing should be enabled. The
19679 default behaviour is to chase referrals.
19681 Defaults to @samp{disabled}.
19685 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19686 This option allows for custom attributes to be looked up instead of the
19687 default RFC 2307 attributes. It is a list of maps, each consisting of
19688 the name of a map, the RFC 2307 attribute to match and the query
19689 expression for the attribute as it is available in the directory.
19691 Defaults to @samp{()}.
19695 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19696 A list of filters consisting of the name of a map to which the filter
19697 applies and an LDAP search filter expression.
19699 Defaults to @samp{()}.
19703 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19704 Specifies the time limit in seconds to use when connecting to the
19705 directory server. The default value is 10 seconds.
19707 Defaults to @samp{disabled}.
19711 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19712 Specifies the time limit (in seconds) to wait for a response from the
19713 LDAP server. A value of zero, which is the default, is to wait
19714 indefinitely for searches to be completed.
19716 Defaults to @samp{disabled}.
19720 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19721 Specifies the period if inactivity (in seconds) after which the con‐
19722 nection to the LDAP server will be closed. The default is not to time
19725 Defaults to @samp{disabled}.
19729 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19730 Specifies the number of seconds to sleep when connecting to all LDAP
19731 servers fails. By default one second is waited between the first
19732 failure and the first retry.
19734 Defaults to @samp{disabled}.
19738 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19739 Specifies the time after which the LDAP server is considered to be
19740 permanently unavailable. Once this time is reached retries will be done
19741 only once per this time period. The default value is 10 seconds.
19743 Defaults to @samp{disabled}.
19747 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19748 Specifies whether to use SSL/TLS or not (the default is not to). If
19749 'start-tls is specified then StartTLS is used rather than raw LDAP over
19752 Defaults to @samp{disabled}.
19756 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19757 Specifies what checks to perform on a server-supplied certificate. The
19758 meaning of the values is described in the ldap.conf(5) manual page.
19760 Defaults to @samp{disabled}.
19764 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19765 Specifies the directory containing X.509 certificates for peer authen‐
19766 tication. This parameter is ignored when using GnuTLS.
19768 Defaults to @samp{disabled}.
19772 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19773 Specifies the path to the X.509 certificate for peer authentication.
19775 Defaults to @samp{disabled}.
19779 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19780 Specifies the path to an entropy source. This parameter is ignored when
19783 Defaults to @samp{disabled}.
19787 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19788 Specifies the ciphers to use for TLS as a string.
19790 Defaults to @samp{disabled}.
19794 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19795 Specifies the path to the file containing the local certificate for
19796 client TLS authentication.
19798 Defaults to @samp{disabled}.
19802 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19803 Specifies the path to the file containing the private key for client TLS
19806 Defaults to @samp{disabled}.
19810 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19811 Set this to a number greater than 0 to request paged results from the
19812 LDAP server in accordance with RFC2696. The default (0) is to not
19813 request paged results.
19815 Defaults to @samp{disabled}.
19819 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19820 This option prevents group membership lookups through LDAP for the
19821 specified users. Alternatively, the value 'all-local may be used. With
19822 that value nslcd builds a full list of non-LDAP users on startup.
19824 Defaults to @samp{disabled}.
19828 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19829 This option ensures that LDAP users with a numeric user id lower than
19830 the specified value are ignored.
19832 Defaults to @samp{disabled}.
19836 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19837 This option specifies an offset that is added to all LDAP numeric user
19838 ids. This can be used to avoid user id collisions with local users.
19840 Defaults to @samp{disabled}.
19844 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19845 This option specifies an offset that is added to all LDAP numeric group
19846 ids. This can be used to avoid user id collisions with local groups.
19848 Defaults to @samp{disabled}.
19852 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19853 If this option is set, the member attribute of a group may point to
19854 another group. Members of nested groups are also returned in the higher
19855 level group and parent groups are returned when finding groups for a
19856 specific user. The default is not to perform extra searches for nested
19859 Defaults to @samp{disabled}.
19863 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19864 If this option is set, the group member list is not retrieved when
19865 looking up groups. Lookups for finding which groups a user belongs to
19866 will remain functional so the user will likely still get the correct
19867 groups assigned on login.
19869 Defaults to @samp{disabled}.
19873 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19874 If this option is set, functions which cause all user/group entries to
19875 be loaded from the directory will not succeed in doing so. This can
19876 dramatically reduce LDAP server load in situations where there are a
19877 great number of users and/or groups. This option is not recommended for
19878 most configurations.
19880 Defaults to @samp{disabled}.
19884 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19885 This option can be used to specify how user and group names are verified
19886 within the system. This pattern is used to check all user and group
19887 names that are requested and returned from LDAP.
19889 Defaults to @samp{disabled}.
19893 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19894 This specifies whether or not to perform searches using case-insensitive
19895 matching. Enabling this could open up the system to authorization
19896 bypass vulnerabilities and introduce nscd cache poisoning
19897 vulnerabilities which allow denial of service.
19899 Defaults to @samp{disabled}.
19903 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19904 This option specifies whether password policy controls are requested and
19905 handled from the LDAP server when performing user authentication.
19907 Defaults to @samp{disabled}.
19911 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19912 By default nslcd performs an LDAP search with the user's credentials
19913 after BIND (authentication) to ensure that the BIND operation was
19914 successful. The default search is a simple check to see if the user's
19915 DN exists. A search filter can be specified that will be used instead.
19916 It should return at least one entry.
19918 Defaults to @samp{disabled}.
19922 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19923 This option allows flexible fine tuning of the authorisation check that
19924 should be performed. The search filter specified is executed and if any
19925 entries match, access is granted, otherwise access is denied.
19927 Defaults to @samp{disabled}.
19931 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19932 If this option is set password modification using pam_ldap will be
19933 denied and the specified message will be presented to the user instead.
19934 The message can be used to direct the user to an alternative means of
19935 changing their password.
19937 Defaults to @samp{disabled}.
19941 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19942 List of pam service names for which LDAP authentication should suffice.
19944 Defaults to @samp{()}.
19948 @c %end of generated documentation for nslcd-configuration
19952 @subsection Web Services
19957 The @code{(gnu services web)} module provides the Apache HTTP Server,
19958 the nginx web server, and also a fastcgi wrapper daemon.
19960 @subsubheading Apache HTTP Server
19962 @deffn {Scheme Variable} httpd-service-type
19963 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19964 (@dfn{httpd}). The value for this service type is a
19965 @code{httpd-configuration} record.
19967 A simple example configuration is given below.
19970 (service httpd-service-type
19971 (httpd-configuration
19974 (server-name "www.example.com")
19975 (document-root "/srv/http/www.example.com")))))
19978 Other services can also extend the @code{httpd-service-type} to add to
19982 (simple-service 'www.example.com-server httpd-service-type
19986 (list (string-join '("ServerName www.example.com"
19987 "DocumentRoot /srv/http/www.example.com")
19992 The details for the @code{httpd-configuration}, @code{httpd-module},
19993 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19996 @deffn {Data Type} httpd-configuration
19997 This data type represents the configuration for the httpd service.
20000 @item @code{package} (default: @code{httpd})
20001 The httpd package to use.
20003 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20004 The pid file used by the shepherd-service.
20006 @item @code{config} (default: @code{(httpd-config-file)})
20007 The configuration file to use with the httpd service. The default value
20008 is a @code{httpd-config-file} record, but this can also be a different
20009 G-expression that generates a file, for example a @code{plain-file}. A
20010 file outside of the store can also be specified through a string.
20015 @deffn {Data Type} httpd-module
20016 This data type represents a module for the httpd service.
20020 The name of the module.
20023 The file for the module. This can be relative to the httpd package being
20024 used, the absolute location of a file, or a G-expression for a file
20025 within the store, for example @code{(file-append mod-wsgi
20026 "/modules/mod_wsgi.so")}.
20031 @defvr {Scheme Variable} %default-httpd-modules
20032 A default list of @code{httpd-module} objects.
20035 @deffn {Data Type} httpd-config-file
20036 This data type represents a configuration file for the httpd service.
20039 @item @code{modules} (default: @code{%default-httpd-modules})
20040 The modules to load. Additional modules can be added here, or loaded by
20041 additional configuration.
20043 For example, in order to handle requests for PHP files, you can use Apache’s
20044 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
20047 (service httpd-service-type
20048 (httpd-configuration
20053 (name "proxy_module")
20054 (file "modules/mod_proxy.so"))
20056 (name "proxy_fcgi_module")
20057 (file "modules/mod_proxy_fcgi.so"))
20058 %default-httpd-modules))
20059 (extra-config (list "\
20060 <FilesMatch \\.php$>
20061 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
20062 </FilesMatch>"))))))
20063 (service php-fpm-service-type
20064 (php-fpm-configuration
20065 (socket "/var/run/php-fpm.sock")
20066 (socket-group "httpd")))
20069 @item @code{server-root} (default: @code{httpd})
20070 The @code{ServerRoot} in the configuration file, defaults to the httpd
20071 package. Directives including @code{Include} and @code{LoadModule} are
20072 taken as relative to the server root.
20074 @item @code{server-name} (default: @code{#f})
20075 The @code{ServerName} in the configuration file, used to specify the
20076 request scheme, hostname and port that the server uses to identify
20079 This doesn't need to be set in the server config, and can be specified
20080 in virtual hosts. The default is @code{#f} to not specify a
20083 @item @code{document-root} (default: @code{"/srv/http"})
20084 The @code{DocumentRoot} from which files will be served.
20086 @item @code{listen} (default: @code{'("80")})
20087 The list of values for the @code{Listen} directives in the config
20088 file. The value should be a list of strings, when each string can
20089 specify the port number to listen on, and optionally the IP address and
20092 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20093 The @code{PidFile} to use. This should match the @code{pid-file} set in
20094 the @code{httpd-configuration} so that the Shepherd service is
20095 configured correctly.
20097 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
20098 The @code{ErrorLog} to which the server will log errors.
20100 @item @code{user} (default: @code{"httpd"})
20101 The @code{User} which the server will answer requests as.
20103 @item @code{group} (default: @code{"httpd"})
20104 The @code{Group} which the server will answer requests as.
20106 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
20107 A flat list of strings and G-expressions which will be added to the end
20108 of the configuration file.
20110 Any values which the service is extended with will be appended to this
20116 @deffn {Data Type} httpd-virtualhost
20117 This data type represents a virtualhost configuration block for the httpd service.
20119 These should be added to the extra-config for the httpd-service.
20122 (simple-service 'www.example.com-server httpd-service-type
20126 (list (string-join '("ServerName www.example.com"
20127 "DocumentRoot /srv/http/www.example.com")
20132 @item @code{addresses-and-ports}
20133 The addresses and ports for the @code{VirtualHost} directive.
20135 @item @code{contents}
20136 The contents of the @code{VirtualHost} directive, this should be a list
20137 of strings and G-expressions.
20142 @subsubheading NGINX
20144 @deffn {Scheme Variable} nginx-service-type
20145 Service type for the @uref{https://nginx.org/,NGinx} web server. The
20146 value for this service type is a @code{<nginx-configuration>} record.
20148 A simple example configuration is given below.
20151 (service nginx-service-type
20152 (nginx-configuration
20154 (list (nginx-server-configuration
20155 (server-name '("www.example.com"))
20156 (root "/srv/http/www.example.com"))))))
20159 In addition to adding server blocks to the service configuration
20160 directly, this service can be extended by other services to add server
20161 blocks, as in this example:
20164 (simple-service 'my-extra-server nginx-service-type
20165 (list (nginx-server-configuration
20166 (root "/srv/http/extra-website")
20167 (try-files (list "$uri" "$uri/index.html")))))
20171 At startup, @command{nginx} has not yet read its configuration file, so
20172 it uses a default file to log error messages. If it fails to load its
20173 configuration file, that is where error messages are logged. After the
20174 configuration file is loaded, the default error log file changes as per
20175 configuration. In our case, startup error messages can be found in
20176 @file{/var/run/nginx/logs/error.log}, and after configuration in
20177 @file{/var/log/nginx/error.log}. The second location can be changed
20178 with the @var{log-directory} configuration option.
20180 @deffn {Data Type} nginx-configuration
20181 This data type represents the configuration for NGinx. Some
20182 configuration can be done through this and the other provided record
20183 types, or alternatively, a config file can be provided.
20186 @item @code{nginx} (default: @code{nginx})
20187 The nginx package to use.
20189 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20190 The directory to which NGinx will write log files.
20192 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20193 The directory in which NGinx will create a pid file, and write temporary
20196 @item @code{server-blocks} (default: @code{'()})
20197 A list of @dfn{server blocks} to create in the generated configuration
20198 file, the elements should be of type
20199 @code{<nginx-server-configuration>}.
20201 The following example would setup NGinx to serve @code{www.example.com}
20202 from the @code{/srv/http/www.example.com} directory, without using
20205 (service nginx-service-type
20206 (nginx-configuration
20208 (list (nginx-server-configuration
20209 (server-name '("www.example.com"))
20210 (root "/srv/http/www.example.com"))))))
20213 @item @code{upstream-blocks} (default: @code{'()})
20214 A list of @dfn{upstream blocks} to create in the generated configuration
20215 file, the elements should be of type
20216 @code{<nginx-upstream-configuration>}.
20218 Configuring upstreams through the @code{upstream-blocks} can be useful
20219 when combined with @code{locations} in the
20220 @code{<nginx-server-configuration>} records. The following example
20221 creates a server configuration with one location configuration, that
20222 will proxy requests to a upstream configuration, which will handle
20223 requests with two servers.
20228 (nginx-configuration
20230 (list (nginx-server-configuration
20231 (server-name '("www.example.com"))
20232 (root "/srv/http/www.example.com")
20235 (nginx-location-configuration
20237 (body '("proxy_pass http://server-proxy;"))))))))
20239 (list (nginx-upstream-configuration
20240 (name "server-proxy")
20241 (servers (list "server1.example.com"
20242 "server2.example.com")))))))
20245 @item @code{file} (default: @code{#f})
20246 If a configuration @var{file} is provided, this will be used, rather than
20247 generating a configuration file from the provided @code{log-directory},
20248 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20249 proper operation, these arguments should match what is in @var{file} to ensure
20250 that the directories are created when the service is activated.
20252 This can be useful if you have an existing configuration file, or it's
20253 not possible to do what is required through the other parts of the
20254 nginx-configuration record.
20256 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20257 Bucket size for the server names hash tables, defaults to @code{#f} to
20258 use the size of the processors cache line.
20260 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20261 Maximum bucket size for the server names hash tables.
20263 @item @code{modules} (default: @code{'()})
20264 List of nginx dynamic modules to load. This should be a list of file
20265 names of loadable modules, as in this example:
20270 (file-append nginx-accept-language-module "\
20271 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20274 @item @code{global-directives} (default: @code{'((events . ()))})
20275 Association list of global directives for the top level of the nginx
20276 configuration. Values may themselves be association lists.
20280 `((worker_processes . 16)
20282 (events . ((worker_connections . 1024)))))
20285 @item @code{extra-content} (default: @code{""})
20286 Extra content for the @code{http} block. Should be string or a string
20287 valued G-expression.
20292 @deftp {Data Type} nginx-server-configuration
20293 Data type representing the configuration of an nginx server block.
20294 This type has the following parameters:
20297 @item @code{listen} (default: @code{'("80" "443 ssl")})
20298 Each @code{listen} directive sets the address and port for IP, or the
20299 path for a UNIX-domain socket on which the server will accept requests.
20300 Both address and port, or only address or only port can be specified.
20301 An address may also be a hostname, for example:
20304 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20307 @item @code{server-name} (default: @code{(list 'default)})
20308 A list of server names this server represents. @code{'default} represents the
20309 default server for connections matching no other server.
20311 @item @code{root} (default: @code{"/srv/http"})
20312 Root of the website nginx will serve.
20314 @item @code{locations} (default: @code{'()})
20315 A list of @dfn{nginx-location-configuration} or
20316 @dfn{nginx-named-location-configuration} records to use within this
20319 @item @code{index} (default: @code{(list "index.html")})
20320 Index files to look for when clients ask for a directory. If it cannot be found,
20321 Nginx will send the list of files in the directory.
20323 @item @code{try-files} (default: @code{'()})
20324 A list of files whose existence is checked in the specified order.
20325 @code{nginx} will use the first file it finds to process the request.
20327 @item @code{ssl-certificate} (default: @code{#f})
20328 Where to find the certificate for secure connections. Set it to @code{#f} if
20329 you don't have a certificate or you don't want to use HTTPS.
20331 @item @code{ssl-certificate-key} (default: @code{#f})
20332 Where to find the private key for secure connections. Set it to @code{#f} if
20333 you don't have a key or you don't want to use HTTPS.
20335 @item @code{server-tokens?} (default: @code{#f})
20336 Whether the server should add its configuration to response.
20338 @item @code{raw-content} (default: @code{'()})
20339 A list of raw lines added to the server block.
20344 @deftp {Data Type} nginx-upstream-configuration
20345 Data type representing the configuration of an nginx @code{upstream}
20346 block. This type has the following parameters:
20350 Name for this group of servers.
20352 @item @code{servers}
20353 Specify the addresses of the servers in the group. The address can be
20354 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20355 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20356 prefix @samp{unix:}. For addresses using an IP address or domain name,
20357 the default port is 80, and a different port can be specified
20363 @deftp {Data Type} nginx-location-configuration
20364 Data type representing the configuration of an nginx @code{location}
20365 block. This type has the following parameters:
20369 URI which this location block matches.
20371 @anchor{nginx-location-configuration body}
20373 Body of the location block, specified as a list of strings. This can contain
20375 configuration directives. For example, to pass requests to a upstream
20376 server group defined using an @code{nginx-upstream-configuration} block,
20377 the following directive would be specified in the body @samp{(list "proxy_pass
20378 http://upstream-name;")}.
20383 @deftp {Data Type} nginx-named-location-configuration
20384 Data type representing the configuration of an nginx named location
20385 block. Named location blocks are used for request redirection, and not
20386 used for regular request processing. This type has the following
20391 Name to identify this location block.
20394 @xref{nginx-location-configuration body}, as the body for named location
20395 blocks can be used in a similar way to the
20396 @code{nginx-location-configuration body}. One restriction is that the
20397 body of a named location block cannot contain location blocks.
20402 @subsubheading Varnish Cache
20404 Varnish is a fast cache server that sits in between web applications
20405 and end users. It proxies requests from clients and caches the
20406 accessed URLs such that multiple requests for the same resource only
20407 creates one request to the back-end.
20409 @defvr {Scheme Variable} varnish-service-type
20410 Service type for the Varnish daemon.
20413 @deftp {Data Type} varnish-configuration
20414 Data type representing the @code{varnish} service configuration.
20415 This type has the following parameters:
20418 @item @code{package} (default: @code{varnish})
20419 The Varnish package to use.
20421 @item @code{name} (default: @code{"default"})
20422 A name for this Varnish instance. Varnish will create a directory in
20423 @file{/var/varnish/} with this name and keep temporary files there. If
20424 the name starts with a forward slash, it is interpreted as an absolute
20427 Pass the @code{-n} argument to other Varnish programs to connect to the
20428 named instance, e.g.@: @command{varnishncsa -n default}.
20430 @item @code{backend} (default: @code{"localhost:8080"})
20431 The backend to use. This option has no effect if @code{vcl} is set.
20433 @item @code{vcl} (default: #f)
20434 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20435 is @code{#f}, Varnish will proxy @code{backend} using the default
20436 configuration. Otherwise this must be a file-like object with valid
20439 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20440 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
20441 can do something along these lines:
20444 (define %gnu-mirror
20445 (plain-file "gnu.vcl"
20447 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20451 (services (cons (service varnish-service-type
20452 (varnish-configuration
20454 (vcl %gnu-mirror)))
20458 The configuration of an already running Varnish instance can be inspected
20459 and changed using the @command{varnishadm} program.
20461 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20462 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20463 comprehensive documentation on Varnish and its configuration language.
20465 @item @code{listen} (default: @code{'("localhost:80")})
20466 List of addresses Varnish will listen on.
20468 @item @code{storage} (default: @code{'("malloc,128m")})
20469 List of storage backends that will be available in VCL.
20471 @item @code{parameters} (default: @code{'()})
20472 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20474 @item @code{extra-options} (default: @code{'()})
20475 Additional arguments to pass to the @command{varnishd} process.
20480 @subsubheading Patchwork
20482 Patchwork is a patch tracking system. It can collect patches sent to a
20483 mailing list, and display them in a web interface.
20485 @defvr {Scheme Variable} patchwork-service-type
20486 Service type for Patchwork.
20489 The following example is an example of a minimal service for Patchwork, for
20490 the @code{patchwork.example.com} domain.
20493 (service patchwork-service-type
20494 (patchwork-configuration
20495 (domain "patchwork.example.com")
20497 (patchwork-settings-module
20498 (allowed-hosts (list domain))
20499 (default-from-email "patchwork@@patchwork.example.com")))
20500 (getmail-retriever-config
20501 (getmail-retriever-configuration
20502 (type "SimpleIMAPSSLRetriever")
20503 (server "imap.example.com")
20505 (username "patchwork")
20507 (list (file-append coreutils "/bin/cat")
20508 "/etc/getmail-patchwork-imap-password"))
20510 '((mailboxes . ("Patches"))))))))
20514 There are three records for configuring the Patchwork service. The
20515 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20516 within the HTTPD service.
20518 The @code{settings-module} field within the @code{<patchwork-configuration>}
20519 record can be populated with the @code{<patchwork-settings-module>} record,
20520 which describes a settings module that is generated within the Guix store.
20522 For the @code{database-configuration} field within the
20523 @code{<patchwork-settings-module>}, the
20524 @code{<patchwork-database-configuration>} must be used.
20526 @deftp {Data Type} patchwork-configuration
20527 Data type representing the Patchwork service configuration. This type has the
20528 following parameters:
20531 @item @code{patchwork} (default: @code{patchwork})
20532 The Patchwork package to use.
20534 @item @code{domain}
20535 The domain to use for Patchwork, this is used in the HTTPD service virtual
20538 @item @code{settings-module}
20539 The settings module to use for Patchwork. As a Django application, Patchwork
20540 is configured with a Python module containing the settings. This can either be
20541 an instance of the @code{<patchwork-settings-module>} record, any other record
20542 that represents the settings in the store, or a directory outside of the
20545 @item @code{static-path} (default: @code{"/static/"})
20546 The path under which the HTTPD service should serve the static files.
20548 @item @code{getmail-retriever-config}
20549 The getmail-retriever-configuration record value to use with
20550 Patchwork. Getmail will be configured with this value, the messages will be
20551 delivered to Patchwork.
20556 @deftp {Data Type} patchwork-settings-module
20557 Data type representing a settings module for Patchwork. Some of these
20558 settings relate directly to Patchwork, but others relate to Django, the web
20559 framework used by Patchwork, or the Django Rest Framework library. This type
20560 has the following parameters:
20563 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20564 The database connection settings used for Patchwork. See the
20565 @code{<patchwork-database-configuration>} record type for more information.
20567 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20568 Patchwork, as a Django web application uses a secret key for cryptographically
20569 signing values. This file should contain a unique unpredictable value.
20571 If this file does not exist, it will be created and populated with a random
20572 value by the patchwork-setup shepherd service.
20574 This setting relates to Django.
20576 @item @code{allowed-hosts}
20577 A list of valid hosts for this Patchwork service. This should at least include
20578 the domain specified in the @code{<patchwork-configuration>} record.
20580 This is a Django setting.
20582 @item @code{default-from-email}
20583 The email address from which Patchwork should send email by default.
20585 This is a Patchwork setting.
20587 @item @code{static-url} (default: @code{#f})
20588 The URL to use when serving static assets. It can be part of a URL, or a full
20589 URL, but must end in a @code{/}.
20591 If the default value is used, the @code{static-path} value from the
20592 @code{<patchwork-configuration>} record will be used.
20594 This is a Django setting.
20596 @item @code{admins} (default: @code{'()})
20597 Email addresses to send the details of errors that occur. Each value should
20598 be a list containing two elements, the name and then the email address.
20600 This is a Django setting.
20602 @item @code{debug?} (default: @code{#f})
20603 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20604 messages will be shown.
20606 This is a Django setting.
20608 @item @code{enable-rest-api?} (default: @code{#t})
20609 Whether to enable the Patchwork REST API.
20611 This is a Patchwork setting.
20613 @item @code{enable-xmlrpc?} (default: @code{#t})
20614 Whether to enable the XML RPC API.
20616 This is a Patchwork setting.
20618 @item @code{force-https-links?} (default: @code{#t})
20619 Whether to use HTTPS links on Patchwork pages.
20621 This is a Patchwork setting.
20623 @item @code{extra-settings} (default: @code{""})
20624 Extra code to place at the end of the Patchwork settings module.
20629 @deftp {Data Type} patchwork-database-configuration
20630 Data type representing the database configuration for Patchwork.
20633 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20634 The database engine to use.
20636 @item @code{name} (default: @code{"patchwork"})
20637 The name of the database to use.
20639 @item @code{user} (default: @code{"httpd"})
20640 The user to connect to the database as.
20642 @item @code{password} (default: @code{""})
20643 The password to use when connecting to the database.
20645 @item @code{host} (default: @code{""})
20646 The host to make the database connection to.
20648 @item @code{port} (default: @code{""})
20649 The port on which to connect to the database.
20654 @subsubheading Mumi
20656 @cindex Mumi, Debbugs Web interface
20657 @cindex Debbugs, Mumi Web interface
20658 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
20659 Web interface to the Debbugs bug tracker, by default for
20660 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
20661 but it also fetches and indexes mail retrieved from Debbugs.
20663 @defvr {Scheme Variable} mumi-service-type
20664 This is the service type for Mumi.
20667 @subsubheading FastCGI
20670 FastCGI is an interface between the front-end and the back-end of a web
20671 service. It is a somewhat legacy facility; new web services should
20672 generally just talk HTTP between the front-end and the back-end.
20673 However there are a number of back-end services such as PHP or the
20674 optimized HTTP Git repository access that use FastCGI, so we have
20675 support for it in Guix.
20677 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20678 dispatch some subset of its requests to the fastcgi backend, which
20679 listens on a local TCP or UNIX socket. There is an intermediary
20680 @code{fcgiwrap} program that sits between the actual backend process and
20681 the web server. The front-end indicates which backend program to run,
20682 passing that information to the @code{fcgiwrap} process.
20684 @defvr {Scheme Variable} fcgiwrap-service-type
20685 A service type for the @code{fcgiwrap} FastCGI proxy.
20688 @deftp {Data Type} fcgiwrap-configuration
20689 Data type representing the configuration of the @code{fcgiwrap} service.
20690 This type has the following parameters:
20692 @item @code{package} (default: @code{fcgiwrap})
20693 The fcgiwrap package to use.
20695 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20696 The socket on which the @code{fcgiwrap} process should listen, as a
20697 string. Valid @var{socket} values include
20698 @code{unix:@var{/path/to/unix/socket}},
20699 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20700 @code{tcp6:[@var{ipv6_addr}]:port}.
20702 @item @code{user} (default: @code{fcgiwrap})
20703 @itemx @code{group} (default: @code{fcgiwrap})
20704 The user and group names, as strings, under which to run the
20705 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20706 the user asks for the specific user or group names @code{fcgiwrap} that
20707 the corresponding user and/or group is present on the system.
20709 It is possible to configure a FastCGI-backed web service to pass HTTP
20710 authentication information from the front-end to the back-end, and to
20711 allow @code{fcgiwrap} to run the back-end process as a corresponding
20712 local user. To enable this capability on the back-end, run
20713 @code{fcgiwrap} as the @code{root} user and group. Note that this
20714 capability also has to be configured on the front-end as well.
20719 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20720 with some additional features useful for sites of any size.
20722 These features include:
20724 @item Adaptive process spawning
20725 @item Basic statistics (similar to Apache's mod_status)
20726 @item Advanced process management with graceful stop/start
20727 @item Ability to start workers with different uid/gid/chroot/environment
20728 and different php.ini (replaces safe_mode)
20729 @item Stdout & stderr logging
20730 @item Emergency restart in case of accidental opcode cache destruction
20731 @item Accelerated upload support
20732 @item Support for a "slowlog"
20733 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20734 a special function to finish request & flush all data while continuing to do
20735 something time-consuming (video converting, stats processing, etc.)
20737 ...@: and much more.
20739 @defvr {Scheme Variable} php-fpm-service-type
20740 A Service type for @code{php-fpm}.
20743 @deftp {Data Type} php-fpm-configuration
20744 Data Type for php-fpm service configuration.
20746 @item @code{php} (default: @code{php})
20747 The php package to use.
20748 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20749 The address on which to accept FastCGI requests. Valid syntaxes are:
20751 @item @code{"ip.add.re.ss:port"}
20752 Listen on a TCP socket to a specific address on a specific port.
20753 @item @code{"port"}
20754 Listen on a TCP socket to all addresses on a specific port.
20755 @item @code{"/path/to/unix/socket"}
20756 Listen on a unix socket.
20759 @item @code{user} (default: @code{php-fpm})
20760 User who will own the php worker processes.
20761 @item @code{group} (default: @code{php-fpm})
20762 Group of the worker processes.
20763 @item @code{socket-user} (default: @code{php-fpm})
20764 User who can speak to the php-fpm socket.
20765 @item @code{socket-group} (default: @code{nginx})
20766 Group that can speak to the php-fpm socket.
20767 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20768 The process id of the php-fpm process is written to this file
20769 once the service has started.
20770 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20771 Log for the php-fpm master process.
20772 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20773 Detailed settings for the php-fpm process manager.
20776 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20777 @item @code{<php-fpm-static-process-manager-configuration>}
20778 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20780 @item @code{display-errors} (default @code{#f})
20781 Determines whether php errors and warning should be sent to clients
20782 and displayed in their browsers.
20783 This is useful for local php development, but a security risk for public sites,
20784 as error messages can reveal passwords and personal data.
20785 @item @code{timezone} (default @code{#f})
20786 Specifies @code{php_admin_value[date.timezone]} parameter.
20787 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20788 This file will log the @code{stderr} outputs of php worker processes.
20789 Can be set to @code{#f} to disable logging.
20790 @item @code{file} (default @code{#f})
20791 An optional override of the whole configuration.
20792 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20796 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20797 Data Type for the @code{dynamic} php-fpm process manager. With the
20798 @code{dynamic} process manager, spare worker processes are kept around
20799 based on it's configured limits.
20801 @item @code{max-children} (default: @code{5})
20802 Maximum of worker processes.
20803 @item @code{start-servers} (default: @code{2})
20804 How many worker processes should be started on start-up.
20805 @item @code{min-spare-servers} (default: @code{1})
20806 How many spare worker processes should be kept around at minimum.
20807 @item @code{max-spare-servers} (default: @code{3})
20808 How many spare worker processes should be kept around at maximum.
20812 @deftp {Data type} php-fpm-static-process-manager-configuration
20813 Data Type for the @code{static} php-fpm process manager. With the
20814 @code{static} process manager, an unchanging number of worker processes
20817 @item @code{max-children} (default: @code{5})
20818 Maximum of worker processes.
20822 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20823 Data Type for the @code{on-demand} php-fpm process manager. With the
20824 @code{on-demand} process manager, worker processes are only created as
20827 @item @code{max-children} (default: @code{5})
20828 Maximum of worker processes.
20829 @item @code{process-idle-timeout} (default: @code{10})
20830 The time in seconds after which a process with no requests is killed.
20835 @deffn {Scheme Procedure} nginx-php-fpm-location @
20836 [#:nginx-package nginx] @
20837 [socket (string-append "/var/run/php" @
20838 (version-major (package-version php)) @
20840 A helper function to quickly add php to an @code{nginx-server-configuration}.
20843 A simple services setup for nginx with php can look like this:
20845 (services (cons* (service dhcp-client-service-type)
20846 (service php-fpm-service-type)
20847 (service nginx-service-type
20848 (nginx-server-configuration
20849 (server-name '("example.com"))
20850 (root "/srv/http/")
20852 (list (nginx-php-location)))
20854 (ssl-certificate #f)
20855 (ssl-certificate-key #f)))
20859 @cindex cat-avatar-generator
20860 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20861 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20862 the hash of a user's email address.
20864 @deffn {Scheme Procedure} cat-avatar-generator-service @
20865 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20866 [#:package cat-avatar-generator] @
20867 [#:configuration (nginx-server-configuration)]
20868 Returns an nginx-server-configuration that inherits @code{configuration}. It
20869 extends the nginx configuration to add a server block that serves @code{package},
20870 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20871 be able to use @code{cache-dir} as its cache directory.
20874 A simple setup for cat-avatar-generator can look like this:
20876 (services (cons* (cat-avatar-generator-service
20878 (nginx-server-configuration
20879 (server-name '("example.com"))))
20884 @subsubheading Hpcguix-web
20886 @cindex hpcguix-web
20887 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20888 program is a customizable web interface to browse Guix packages,
20889 initially designed for users of high-performance computing (HPC)
20892 @defvr {Scheme Variable} hpcguix-web-service-type
20893 The service type for @code{hpcguix-web}.
20896 @deftp {Data Type} hpcguix-web-configuration
20897 Data type for the hpcguix-web service configuration.
20901 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20902 configuration. The main items available in this spec are:
20905 @item @code{title-prefix} (default: @code{"hpcguix | "})
20906 The page title prefix.
20908 @item @code{guix-command} (default: @code{"guix"})
20909 The @command{guix} command.
20911 @item @code{package-filter-proc} (default: @code{(const #t)})
20912 A procedure specifying how to filter packages that are displayed.
20914 @item @code{package-page-extension-proc} (default: @code{(const '())})
20915 Extension package for @code{hpcguix-web}.
20917 @item @code{menu} (default: @code{'()})
20918 Additional entry in page @code{menu}.
20920 @item @code{channels} (default: @code{%default-channels})
20921 List of channels from which the package list is built (@pxref{Channels}).
20923 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20924 The expiration time, in seconds, after which the package list is rebuilt from
20925 the latest instances of the given channels.
20928 See the hpcguix-web repository for a
20929 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20932 @item @code{package} (default: @code{hpcguix-web})
20933 The hpcguix-web package to use.
20937 A typical hpcguix-web service declaration looks like this:
20940 (service hpcguix-web-service-type
20941 (hpcguix-web-configuration
20943 #~(define site-config
20944 (hpcweb-configuration
20945 (title-prefix "Guix-HPC - ")
20946 (menu '(("/about" "ABOUT"))))))))
20950 The hpcguix-web service periodically updates the package list it publishes by
20951 pulling channels from Git. To that end, it needs to access X.509 certificates
20952 so that it can authenticate Git servers when communicating over HTTPS, and it
20953 assumes that @file{/etc/ssl/certs} contains those certificates.
20955 Thus, make sure to add @code{nss-certs} or another certificate package to the
20956 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20957 more information on X.509 certificates.
20960 @node Certificate Services
20961 @subsection Certificate Services
20964 @cindex HTTP, HTTPS
20965 @cindex Let's Encrypt
20966 @cindex TLS certificates
20967 The @code{(gnu services certbot)} module provides a service to
20968 automatically obtain a valid TLS certificate from the Let's Encrypt
20969 certificate authority. These certificates can then be used to serve
20970 content securely over HTTPS or other TLS-based protocols, with the
20971 knowledge that the client will be able to verify the server's
20974 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20975 @code{certbot} tool to automate the certification process. This tool
20976 first securely generates a key on the server. It then makes a request
20977 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20978 checks that the request originates from the host in question by using a
20979 challenge-response protocol, requiring the server to provide its
20980 response over HTTP. If that protocol completes successfully, the CA
20981 signs the key, resulting in a certificate. That certificate is valid
20982 for a limited period of time, and therefore to continue to provide TLS
20983 services, the server needs to periodically ask the CA to renew its
20986 The certbot service automates this process: the initial key
20987 generation, the initial certification request to the Let's Encrypt
20988 service, the web server challenge/response integration, writing the
20989 certificate to disk, the automated periodic renewals, and the deployment
20990 tasks associated with the renewal (e.g.@: reloading services, copying keys
20991 with different permissions).
20993 Certbot is run twice a day, at a random minute within the hour. It
20994 won't do anything until your certificates are due for renewal or
20995 revoked, but running it regularly would give your service a chance of
20996 staying online in case a Let's Encrypt-initiated revocation happened for
20999 By using this service, you agree to the ACME Subscriber Agreement, which
21000 can be found there:
21001 @url{https://acme-v01.api.letsencrypt.org/directory}.
21003 @defvr {Scheme Variable} certbot-service-type
21004 A service type for the @code{certbot} Let's Encrypt client. Its value
21005 must be a @code{certbot-configuration} record as in this example:
21008 (define %nginx-deploy-hook
21010 "nginx-deploy-hook"
21011 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
21012 (kill pid SIGHUP))))
21014 (service certbot-service-type
21015 (certbot-configuration
21016 (email "foo@@example.net")
21019 (certificate-configuration
21020 (domains '("example.net" "www.example.net"))
21021 (deploy-hook %nginx-deploy-hook))
21022 (certificate-configuration
21023 (domains '("bar.example.net")))))))
21026 See below for details about @code{certbot-configuration}.
21029 @deftp {Data Type} certbot-configuration
21030 Data type representing the configuration of the @code{certbot} service.
21031 This type has the following parameters:
21034 @item @code{package} (default: @code{certbot})
21035 The certbot package to use.
21037 @item @code{webroot} (default: @code{/var/www})
21038 The directory from which to serve the Let's Encrypt challenge/response
21041 @item @code{certificates} (default: @code{()})
21042 A list of @code{certificates-configuration}s for which to generate
21043 certificates and request signatures. Each certificate has a @code{name}
21044 and several @code{domains}.
21047 Mandatory email used for registration, recovery contact, and important
21048 account notifications.
21050 @item @code{server} (default: @code{#f})
21051 Optional URL of ACME server. Setting this overrides certbot's default,
21052 which is the Let's Encrypt server.
21054 @item @code{rsa-key-size} (default: @code{2048})
21055 Size of the RSA key.
21057 @item @code{default-location} (default: @i{see below})
21058 The default @code{nginx-location-configuration}. Because @code{certbot}
21059 needs to be able to serve challenges and responses, it needs to be able
21060 to run a web server. It does so by extending the @code{nginx} web
21061 service with an @code{nginx-server-configuration} listening on the
21062 @var{domains} on port 80, and which has a
21063 @code{nginx-location-configuration} for the @code{/.well-known/} URI
21064 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
21065 these nginx configuration data types.
21067 Requests to other URL paths will be matched by the
21068 @code{default-location}, which if present is added to all
21069 @code{nginx-server-configuration}s.
21071 By default, the @code{default-location} will issue a redirect from
21072 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
21073 you to define what to serve on your site via @code{https}.
21075 Pass @code{#f} to not issue a default location.
21079 @deftp {Data Type} certificate-configuration
21080 Data type representing the configuration of a certificate.
21081 This type has the following parameters:
21084 @item @code{name} (default: @i{see below})
21085 This name is used by Certbot for housekeeping and in file paths; it
21086 doesn't affect the content of the certificate itself. To see
21087 certificate names, run @code{certbot certificates}.
21089 Its default is the first provided domain.
21091 @item @code{domains} (default: @code{()})
21092 The first domain provided will be the subject CN of the certificate, and
21093 all domains will be Subject Alternative Names on the certificate.
21095 @item @code{challenge} (default: @code{#f})
21096 The challenge type that has to be run by certbot. If @code{#f} is specified,
21097 default to the HTTP challenge. If a value is specified, defaults to the
21098 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
21099 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
21100 and gives Let's Encrypt permission to log the public IP address of the
21101 requesting machine.
21103 @item @code{authentication-hook} (default: @code{#f})
21104 Command to be run in a shell once for each certificate challenge to be
21105 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
21106 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
21107 contains the validation string and @code{$CERTBOT_TOKEN} contains the
21108 file name of the resource requested when performing an HTTP-01 challenge.
21110 @item @code{cleanup-hook} (default: @code{#f})
21111 Command to be run in a shell once for each certificate challenge that
21112 have been answered by the @code{auth-hook}. For this command, the shell
21113 variables available in the @code{auth-hook} script are still available, and
21114 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
21115 of the @code{auth-hook} script.
21117 @item @code{deploy-hook} (default: @code{#f})
21118 Command to be run in a shell once for each successfully issued
21119 certificate. For this command, the shell variable
21120 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
21121 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
21122 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
21123 contain a space-delimited list of renewed certificate domains (for
21124 example, @samp{"example.com www.example.com"}.
21129 For each @code{certificate-configuration}, the certificate is saved to
21130 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
21131 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
21133 @subsection DNS Services
21134 @cindex DNS (domain name system)
21135 @cindex domain name system (DNS)
21137 The @code{(gnu services dns)} module provides services related to the
21138 @dfn{domain name system} (DNS). It provides a server service for hosting
21139 an @emph{authoritative} DNS server for multiple zones, slave or master.
21140 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
21141 caching and forwarding DNS server for the LAN, which uses
21142 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
21144 @subsubheading Knot Service
21146 An example configuration of an authoritative server for two zones, one master
21150 (define-zone-entries example.org.zone
21151 ;; Name TTL Class Type Data
21152 ("@@" "" "IN" "A" "127.0.0.1")
21153 ("@@" "" "IN" "NS" "ns")
21154 ("ns" "" "IN" "A" "127.0.0.1"))
21156 (define master-zone
21157 (knot-zone-configuration
21158 (domain "example.org")
21160 (origin "example.org")
21161 (entries example.org.zone)))))
21164 (knot-zone-configuration
21165 (domain "plop.org")
21166 (dnssec-policy "default")
21167 (master (list "plop-master"))))
21169 (define plop-master
21170 (knot-remote-configuration
21172 (address (list "208.76.58.171"))))
21176 (services (cons* (service knot-service-type
21177 (knot-configuration
21178 (remotes (list plop-master))
21179 (zones (list master-zone slave-zone))))
21184 @deffn {Scheme Variable} knot-service-type
21185 This is the type for the Knot DNS server.
21187 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
21188 zones, that is to say domain names you would buy from a registrar. This server
21189 is not a resolver, meaning that it can only resolve names for which it is
21190 authoritative. This server can be configured to serve zones as a master server
21191 or a slave server as a per-zone basis. Slave zones will get their data from
21192 masters, and will serve it as an authoritative server. From the point of view
21193 of a resolver, there is no difference between master and slave.
21195 The following data types are used to configure the Knot DNS server:
21198 @deftp {Data Type} knot-key-configuration
21199 Data type representing a key.
21200 This type has the following parameters:
21203 @item @code{id} (default: @code{""})
21204 An identifier for other configuration fields to refer to this key. IDs must
21205 be unique and must not be empty.
21207 @item @code{algorithm} (default: @code{#f})
21208 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21209 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21210 and @code{'hmac-sha512}.
21212 @item @code{secret} (default: @code{""})
21213 The secret key itself.
21218 @deftp {Data Type} knot-acl-configuration
21219 Data type representing an Access Control List (ACL) configuration.
21220 This type has the following parameters:
21223 @item @code{id} (default: @code{""})
21224 An identifier for ether configuration fields to refer to this key. IDs must be
21225 unique and must not be empty.
21227 @item @code{address} (default: @code{'()})
21228 An ordered list of IP addresses, network subnets, or network ranges represented
21229 with strings. The query must match one of them. Empty value means that
21230 address match is not required.
21232 @item @code{key} (default: @code{'()})
21233 An ordered list of references to keys represented with strings. The string
21234 must match a key ID defined in a @code{knot-key-configuration}. No key means
21235 that a key is not require to match that ACL.
21237 @item @code{action} (default: @code{'()})
21238 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21239 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21240 and @code{'update}.
21242 @item @code{deny?} (default: @code{#f})
21243 When true, the ACL defines restrictions. Listed actions are forbidden. When
21244 false, listed actions are allowed.
21249 @deftp {Data Type} zone-entry
21250 Data type representing a record entry in a zone file.
21251 This type has the following parameters:
21254 @item @code{name} (default: @code{"@@"})
21255 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21256 are relative to the origin of the zone. For example, in the @code{example.org}
21257 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21258 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21259 refers to @code{ns.example.org}.
21261 @item @code{ttl} (default: @code{""})
21262 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21264 @item @code{class} (default: @code{"IN"})
21265 The class of the record. Knot currently supports only @code{"IN"} and
21266 partially @code{"CH"}.
21268 @item @code{type} (default: @code{"A"})
21269 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21270 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21273 @item @code{data} (default: @code{""})
21274 The data contained in the record. For instance an IP address associated with
21275 an A record, or a domain name associated with an NS record. Remember that
21276 domain names are relative to the origin unless they end with a dot.
21281 @deftp {Data Type} zone-file
21282 Data type representing the content of a zone file.
21283 This type has the following parameters:
21286 @item @code{entries} (default: @code{'()})
21287 The list of entries. The SOA record is taken care of, so you don't need to
21288 put it in the list of entries. This list should probably contain an entry
21289 for your primary authoritative DNS server. Other than using a list of entries
21290 directly, you can use @code{define-zone-entries} to define a object containing
21291 the list of entries more easily, that you can later pass to the @code{entries}
21292 field of the @code{zone-file}.
21294 @item @code{origin} (default: @code{""})
21295 The name of your zone. This parameter cannot be empty.
21297 @item @code{ns} (default: @code{"ns"})
21298 The domain of your primary authoritative DNS server. The name is relative to
21299 the origin, unless it ends with a dot. It is mandatory that this primary
21300 DNS server corresponds to an NS record in the zone and that it is associated
21301 to an IP address in the list of entries.
21303 @item @code{mail} (default: @code{"hostmaster"})
21304 An email address people can contact you at, as the owner of the zone. This
21305 is translated as @code{<mail>@@<origin>}.
21307 @item @code{serial} (default: @code{1})
21308 The serial number of the zone. As this is used to keep track of changes by
21309 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21310 Always increment it when you make a change in your zone.
21312 @item @code{refresh} (default: @code{(* 2 24 3600)})
21313 The frequency at which slaves will do a zone transfer. This value is a number
21314 of seconds. It can be computed by multiplications or with
21315 @code{(string->duration)}.
21317 @item @code{retry} (default: @code{(* 15 60)})
21318 The period after which a slave will retry to contact its master when it fails
21319 to do so a first time.
21321 @item @code{expiry} (default: @code{(* 14 24 3600)})
21322 Default TTL of records. Existing records are considered correct for at most
21323 this amount of time. After this period, resolvers will invalidate their cache
21324 and check again that it still exists.
21326 @item @code{nx} (default: @code{3600})
21327 Default TTL of inexistant records. This delay is usually short because you want
21328 your new domains to reach everyone quickly.
21333 @deftp {Data Type} knot-remote-configuration
21334 Data type representing a remote configuration.
21335 This type has the following parameters:
21338 @item @code{id} (default: @code{""})
21339 An identifier for other configuration fields to refer to this remote. IDs must
21340 be unique and must not be empty.
21342 @item @code{address} (default: @code{'()})
21343 An ordered list of destination IP addresses. Addresses are tried in sequence.
21344 An optional port can be given with the @@ separator. For instance:
21345 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21347 @item @code{via} (default: @code{'()})
21348 An ordered list of source IP addresses. An empty list will have Knot choose
21349 an appropriate source IP. An optional port can be given with the @@ separator.
21350 The default is to choose at random.
21352 @item @code{key} (default: @code{#f})
21353 A reference to a key, that is a string containing the identifier of a key
21354 defined in a @code{knot-key-configuration} field.
21359 @deftp {Data Type} knot-keystore-configuration
21360 Data type representing a keystore to hold dnssec keys.
21361 This type has the following parameters:
21364 @item @code{id} (default: @code{""})
21365 The id of the keystore. It must not be empty.
21367 @item @code{backend} (default: @code{'pem})
21368 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21370 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21371 The configuration string of the backend. An example for the PKCS#11 is:
21372 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21373 For the pem backend, the string represents a path in the file system.
21378 @deftp {Data Type} knot-policy-configuration
21379 Data type representing a dnssec policy. Knot DNS is able to automatically
21380 sign your zones. It can either generate and manage your keys automatically or
21381 use keys that you generate.
21383 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21384 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21385 zone. In order to be trusted, the KSK needs to be present in the parent zone
21386 (usually a top-level domain). If your registrar supports dnssec, you will
21387 have to send them your KSK's hash so they can add a DS record in their zone.
21388 This is not automated and need to be done each time you change your KSK.
21390 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21391 easily and use weaker cryptographic functions (they use lower parameters) in
21392 order to sign records quickly, so they are changed often. The KSK however
21393 requires manual interaction with the registrar, so they are changed less often
21394 and use stronger parameters because they sign only one record.
21396 This type has the following parameters:
21399 @item @code{id} (default: @code{""})
21400 The id of the policy. It must not be empty.
21402 @item @code{keystore} (default: @code{"default"})
21403 A reference to a keystore, that is a string containing the identifier of a
21404 keystore defined in a @code{knot-keystore-configuration} field. The
21405 @code{"default"} identifier means the default keystore (a kasp database that
21406 was setup by this service).
21408 @item @code{manual?} (default: @code{#f})
21409 Whether the key management is manual or automatic.
21411 @item @code{single-type-signing?} (default: @code{#f})
21412 When @code{#t}, use the Single-Type Signing Scheme.
21414 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21415 An algorithm of signing keys and issued signatures.
21417 @item @code{ksk-size} (default: @code{256})
21418 The length of the KSK. Note that this value is correct for the default
21419 algorithm, but would be unsecure for other algorithms.
21421 @item @code{zsk-size} (default: @code{256})
21422 The length of the ZSK. Note that this value is correct for the default
21423 algorithm, but would be unsecure for other algorithms.
21425 @item @code{dnskey-ttl} (default: @code{'default})
21426 The TTL value for DNSKEY records added into zone apex. The special
21427 @code{'default} value means same as the zone SOA TTL.
21429 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21430 The period between ZSK publication and the next rollover initiation.
21432 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21433 An extra delay added for each key rollover step. This value should be high
21434 enough to cover propagation of data from the master server to all slaves.
21436 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21437 A validity period of newly issued signatures.
21439 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21440 A period how long before a signature expiration the signature will be refreshed.
21442 @item @code{nsec3?} (default: @code{#f})
21443 When @code{#t}, NSEC3 will be used instead of NSEC.
21445 @item @code{nsec3-iterations} (default: @code{5})
21446 The number of additional times the hashing is performed.
21448 @item @code{nsec3-salt-length} (default: @code{8})
21449 The length of a salt field in octets, which is appended to the original owner
21450 name before hashing.
21452 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21453 The validity period of newly issued salt field.
21458 @deftp {Data Type} knot-zone-configuration
21459 Data type representing a zone served by Knot.
21460 This type has the following parameters:
21463 @item @code{domain} (default: @code{""})
21464 The domain served by this configuration. It must not be empty.
21466 @item @code{file} (default: @code{""})
21467 The file where this zone is saved. This parameter is ignored by master zones.
21468 Empty means default location that depends on the domain name.
21470 @item @code{zone} (default: @code{(zone-file)})
21471 The content of the zone file. This parameter is ignored by slave zones. It
21472 must contain a zone-file record.
21474 @item @code{master} (default: @code{'()})
21475 A list of master remotes. When empty, this zone is a master. When set, this
21476 zone is a slave. This is a list of remotes identifiers.
21478 @item @code{ddns-master} (default: @code{#f})
21479 The main master. When empty, it defaults to the first master in the list of
21482 @item @code{notify} (default: @code{'()})
21483 A list of slave remote identifiers.
21485 @item @code{acl} (default: @code{'()})
21486 A list of acl identifiers.
21488 @item @code{semantic-checks?} (default: @code{#f})
21489 When set, this adds more semantic checks to the zone.
21491 @item @code{disable-any?} (default: @code{#f})
21492 When set, this forbids queries of the ANY type.
21494 @item @code{zonefile-sync} (default: @code{0})
21495 The delay between a modification in memory and on disk. 0 means immediate
21498 @item @code{zonefile-load} (default: @code{#f})
21499 The way the zone file contents are applied during zone load. Possible values
21503 @item @code{#f} for using the default value from Knot,
21504 @item @code{'none} for not using the zone file at all,
21505 @item @code{'difference} for computing the difference between already available
21506 contents and zone contents and applying it to the current zone contents,
21507 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21508 ignoring the SOA serial in the zone file, while the server takes care of it
21510 @item @code{'whole} for loading zone contents from the zone file.
21513 @item @code{journal-content} (default: @code{#f})
21514 The way the journal is used to store zone and its changes. Possible values
21515 are @code{'none} to not use it at all, @code{'changes} to store changes and
21516 @code{'all} to store contents. @code{#f} does not set this option, so the
21517 default value from Knot is used.
21519 @item @code{max-journal-usage} (default: @code{#f})
21520 The maximum size for the journal on disk. @code{#f} does not set this option,
21521 so the default value from Knot is used.
21523 @item @code{max-journal-depth} (default: @code{#f})
21524 The maximum size of the history. @code{#f} does not set this option, so the
21525 default value from Knot is used.
21527 @item @code{max-zone-size} (default: @code{#f})
21528 The maximum size of the zone file. This limit is enforced for incoming
21529 transfer and updates. @code{#f} does not set this option, so the default
21530 value from Knot is used.
21532 @item @code{dnssec-policy} (default: @code{#f})
21533 A reference to a @code{knot-policy-configuration} record, or the special
21534 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21537 @item @code{serial-policy} (default: @code{'increment})
21538 A policy between @code{'increment} and @code{'unixtime}.
21543 @deftp {Data Type} knot-configuration
21544 Data type representing the Knot configuration.
21545 This type has the following parameters:
21548 @item @code{knot} (default: @code{knot})
21551 @item @code{run-directory} (default: @code{"/var/run/knot"})
21552 The run directory. This directory will be used for pid file and sockets.
21554 @item @code{includes} (default: @code{'()})
21555 A list of strings or file-like objects denoting other files that must be
21556 included at the top of the configuration file.
21558 @cindex secrets, Knot service
21559 This can be used to manage secrets out-of-band. For example, secret
21560 keys may be stored in an out-of-band file not managed by Guix, and
21561 thus not visible in @file{/gnu/store}---e.g., you could store secret
21562 key configuration in @file{/etc/knot/secrets.conf} and add this file
21563 to the @code{includes} list.
21565 One can generate a secret tsig key (for nsupdate and zone transfers with the
21566 keymgr command from the knot package. Note that the package is not automatically
21567 installed by the service. The following example shows how to generate a new
21571 keymgr -t mysecret > /etc/knot/secrets.conf
21572 chmod 600 /etc/knot/secrets.conf
21575 Also note that the generated key will be named @var{mysecret}, so it is the
21576 name that needs to be used in the @var{key} field of the
21577 @code{knot-acl-configuration} record and in other places that need to refer
21580 It can also be used to add configuration not supported by this interface.
21582 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21583 An ip address on which to listen.
21585 @item @code{listen-v6} (default: @code{"::"})
21586 An ip address on which to listen.
21588 @item @code{listen-port} (default: @code{53})
21589 A port on which to listen.
21591 @item @code{keys} (default: @code{'()})
21592 The list of knot-key-configuration used by this configuration.
21594 @item @code{acls} (default: @code{'()})
21595 The list of knot-acl-configuration used by this configuration.
21597 @item @code{remotes} (default: @code{'()})
21598 The list of knot-remote-configuration used by this configuration.
21600 @item @code{zones} (default: @code{'()})
21601 The list of knot-zone-configuration used by this configuration.
21606 @subsubheading Knot Resolver Service
21608 @deffn {Scheme Variable} knot-resolver-service-type
21609 This this the type of the knot resolver service, whose value should be
21610 an @code{knot-resolver-configuration} object as in this example:
21613 (service knot-resolver-service-type
21614 (knot-resolver-configuration
21615 (kresd-config-file (plain-file "kresd.conf" "
21616 net.listen('192.168.0.1', 5353)
21617 user('knot-resolver', 'knot-resolver')
21618 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21619 cache.size = 100 * MB
21623 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21626 @deftp {Data Type} knot-resolver-configuration
21627 Data type representing the configuration of knot-resolver.
21630 @item @code{package} (default: @var{knot-resolver})
21631 Package object of the knot DNS resolver.
21633 @item @code{kresd-config-file} (default: %kresd.conf)
21634 File-like object of the kresd configuration file to use, by default it
21635 will listen on @code{127.0.0.1} and @code{::1}.
21637 @item @code{garbage-collection-interval} (default: 1000)
21638 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21644 @subsubheading Dnsmasq Service
21646 @deffn {Scheme Variable} dnsmasq-service-type
21647 This is the type of the dnsmasq service, whose value should be an
21648 @code{dnsmasq-configuration} object as in this example:
21651 (service dnsmasq-service-type
21652 (dnsmasq-configuration
21654 (servers '("192.168.1.1"))))
21658 @deftp {Data Type} dnsmasq-configuration
21659 Data type representing the configuration of dnsmasq.
21662 @item @code{package} (default: @var{dnsmasq})
21663 Package object of the dnsmasq server.
21665 @item @code{no-hosts?} (default: @code{#f})
21666 When true, don't read the hostnames in /etc/hosts.
21668 @item @code{port} (default: @code{53})
21669 The port to listen on. Setting this to zero completely disables DNS
21670 responses, leaving only DHCP and/or TFTP functions.
21672 @item @code{local-service?} (default: @code{#t})
21673 Accept DNS queries only from hosts whose address is on a local subnet,
21674 ie a subnet for which an interface exists on the server.
21676 @item @code{listen-addresses} (default: @code{'()})
21677 Listen on the given IP addresses.
21679 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21680 The file to read the IP address of the upstream nameservers from.
21682 @item @code{no-resolv?} (default: @code{#f})
21683 When true, don't read @var{resolv-file}.
21685 @item @code{servers} (default: @code{'()})
21686 Specify IP address of upstream servers directly.
21688 @item @code{cache-size} (default: @code{150})
21689 Set the size of dnsmasq's cache. Setting the cache size to zero
21692 @item @code{negative-cache?} (default: @code{#t})
21693 When false, disable negative caching.
21698 @subsubheading ddclient Service
21701 The ddclient service described below runs the ddclient daemon, which takes
21702 care of automatically updating DNS entries for service providers such as
21703 @uref{https://dyn.com/dns/, Dyn}.
21705 The following example show instantiates the service with its default
21709 (service ddclient-service-type)
21712 Note that ddclient needs to access credentials that are stored in a
21713 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21714 @code{secret-file} below.) You are expected to create this file manually, in
21715 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21716 service configuration, for instance by using @code{plain-file}, but it will be
21717 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21718 @file{share/ddclient} directory of the @code{ddclient} package.
21720 @c %start of fragment
21722 Available @code{ddclient-configuration} fields are:
21724 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21725 The ddclient package.
21729 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21730 The period after which ddclient will retry to check IP and domain name.
21732 Defaults to @samp{300}.
21736 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21737 Use syslog for the output.
21739 Defaults to @samp{#t}.
21743 @deftypevr {@code{ddclient-configuration} parameter} string mail
21746 Defaults to @samp{"root"}.
21750 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21751 Mail failed update to user.
21753 Defaults to @samp{"root"}.
21757 @deftypevr {@code{ddclient-configuration} parameter} string pid
21758 The ddclient PID file.
21760 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21764 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21765 Enable SSL support.
21767 Defaults to @samp{#t}.
21771 @deftypevr {@code{ddclient-configuration} parameter} string user
21772 Specifies the user name or ID that is used when running ddclient
21775 Defaults to @samp{"ddclient"}.
21779 @deftypevr {@code{ddclient-configuration} parameter} string group
21780 Group of the user who will run the ddclient program.
21782 Defaults to @samp{"ddclient"}.
21786 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21787 Secret file which will be appended to @file{ddclient.conf} file. This
21788 file contains credentials for use by ddclient. You are expected to
21789 create it manually.
21791 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21795 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21796 Extra options will be appended to @file{ddclient.conf} file.
21798 Defaults to @samp{()}.
21803 @c %end of fragment
21807 @subsection VPN Services
21808 @cindex VPN (virtual private network)
21809 @cindex virtual private network (VPN)
21811 The @code{(gnu services vpn)} module provides services related to
21812 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21813 your machine to connect to a VPN, and a @emph{server} service for your machine
21814 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21816 @deffn {Scheme Procedure} openvpn-client-service @
21817 [#:config (openvpn-client-configuration)]
21819 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21822 @deffn {Scheme Procedure} openvpn-server-service @
21823 [#:config (openvpn-server-configuration)]
21825 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21827 Both can be run simultaneously.
21830 @c %automatically generated documentation
21832 Available @code{openvpn-client-configuration} fields are:
21834 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21835 The OpenVPN package.
21839 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21840 The OpenVPN pid file.
21842 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21846 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21847 The protocol (UDP or TCP) used to open a channel between clients and
21850 Defaults to @samp{udp}.
21854 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21855 The device type used to represent the VPN connection.
21857 Defaults to @samp{tun}.
21861 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21862 The certificate authority to check connections against.
21864 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21868 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21869 The certificate of the machine the daemon is running on. It should be
21870 signed by the authority given in @code{ca}.
21872 Defaults to @samp{"/etc/openvpn/client.crt"}.
21876 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21877 The key of the machine the daemon is running on. It must be the key whose
21878 certificate is @code{cert}.
21880 Defaults to @samp{"/etc/openvpn/client.key"}.
21884 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21885 Whether to use the lzo compression algorithm.
21887 Defaults to @samp{#t}.
21891 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21892 Don't re-read key files across SIGUSR1 or --ping-restart.
21894 Defaults to @samp{#t}.
21898 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21899 Don't close and reopen TUN/TAP device or run up/down scripts across
21900 SIGUSR1 or --ping-restart restarts.
21902 Defaults to @samp{#t}.
21906 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
21907 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
21908 poll/epoll/select prior to the write operation.
21910 Defaults to @samp{#f}.
21913 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21916 Defaults to @samp{3}.
21920 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21921 Add an additional layer of HMAC authentication on top of the TLS control
21922 channel to protect against DoS attacks.
21924 Defaults to @samp{#f}.
21928 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
21929 Authenticate with server using username/password. The option is a file
21930 containing username/password on 2 lines. Do not use a file-like object as it
21931 would be added to the store and readable by any user.
21933 Defaults to @samp{'disabled}.
21936 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21937 Whether to check the server certificate has server usage extension.
21939 Defaults to @samp{#t}.
21943 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21944 Bind to a specific local port number.
21946 Defaults to @samp{#f}.
21950 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21951 Retry resolving server address.
21953 Defaults to @samp{#t}.
21957 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21958 A list of remote servers to connect to.
21960 Defaults to @samp{()}.
21962 Available @code{openvpn-remote-configuration} fields are:
21964 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21967 Defaults to @samp{"my-server"}.
21971 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21972 Port number the server listens to.
21974 Defaults to @samp{1194}.
21979 @c %end of automatic openvpn-client documentation
21981 @c %automatically generated documentation
21983 Available @code{openvpn-server-configuration} fields are:
21985 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21986 The OpenVPN package.
21990 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21991 The OpenVPN pid file.
21993 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21997 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21998 The protocol (UDP or TCP) used to open a channel between clients and
22001 Defaults to @samp{udp}.
22005 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
22006 The device type used to represent the VPN connection.
22008 Defaults to @samp{tun}.
22012 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
22013 The certificate authority to check connections against.
22015 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22019 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
22020 The certificate of the machine the daemon is running on. It should be
22021 signed by the authority given in @code{ca}.
22023 Defaults to @samp{"/etc/openvpn/client.crt"}.
22027 @deftypevr {@code{openvpn-server-configuration} parameter} string key
22028 The key of the machine the daemon is running on. It must be the key whose
22029 certificate is @code{cert}.
22031 Defaults to @samp{"/etc/openvpn/client.key"}.
22035 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
22036 Whether to use the lzo compression algorithm.
22038 Defaults to @samp{#t}.
22042 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
22043 Don't re-read key files across SIGUSR1 or --ping-restart.
22045 Defaults to @samp{#t}.
22049 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
22050 Don't close and reopen TUN/TAP device or run up/down scripts across
22051 SIGUSR1 or --ping-restart restarts.
22053 Defaults to @samp{#t}.
22057 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
22058 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22059 poll/epoll/select prior to the write operation.
22061 Defaults to @samp{#f}.
22064 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
22067 Defaults to @samp{3}.
22071 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
22072 Add an additional layer of HMAC authentication on top of the TLS control
22073 channel to protect against DoS attacks.
22075 Defaults to @samp{#f}.
22079 @deftypevr {@code{openvpn-server-configuration} parameter} number port
22080 Specifies the port number on which the server listens.
22082 Defaults to @samp{1194}.
22086 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
22087 An ip and mask specifying the subnet inside the virtual network.
22089 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
22093 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
22094 A CIDR notation specifying the IPv6 subnet inside the virtual network.
22096 Defaults to @samp{#f}.
22100 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
22101 The Diffie-Hellman parameters file.
22103 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
22107 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
22108 The file that records client IPs.
22110 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
22114 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
22115 When true, the server will act as a gateway for its clients.
22117 Defaults to @samp{#f}.
22121 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
22122 When true, clients are allowed to talk to each other inside the VPN.
22124 Defaults to @samp{#f}.
22128 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
22129 Causes ping-like messages to be sent back and forth over the link so
22130 that each side knows when the other side has gone down. @code{keepalive}
22131 requires a pair. The first element is the period of the ping sending,
22132 and the second element is the timeout before considering the other side
22137 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
22138 The maximum number of clients.
22140 Defaults to @samp{100}.
22144 @deftypevr {@code{openvpn-server-configuration} parameter} string status
22145 The status file. This file shows a small report on current connection.
22146 It is truncated and rewritten every minute.
22148 Defaults to @samp{"/var/run/openvpn/status"}.
22152 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
22153 The list of configuration for some clients.
22155 Defaults to @samp{()}.
22157 Available @code{openvpn-ccd-configuration} fields are:
22159 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
22162 Defaults to @samp{"client"}.
22166 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
22169 Defaults to @samp{#f}.
22173 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
22176 Defaults to @samp{#f}.
22183 @c %end of automatic openvpn-server documentation
22186 @node Network File System
22187 @subsection Network File System
22190 The @code{(gnu services nfs)} module provides the following services,
22191 which are most commonly used in relation to mounting or exporting
22192 directory trees as @dfn{network file systems} (NFS).
22194 While it is possible to use the individual components that together make
22195 up a Network File System service, we recommended to configure an NFS
22196 server with the @code{nfs-service-type}.
22198 @subsubheading NFS Service
22199 @cindex NFS, server
22201 The NFS service takes care of setting up all NFS component services,
22202 kernel configuration file systems, and installs configuration files in
22203 the locations that NFS expects.
22205 @defvr {Scheme Variable} nfs-service-type
22206 A service type for a complete NFS server.
22209 @deftp {Data Type} nfs-configuration
22210 This data type represents the configuration of the NFS service and all
22213 It has the following parameters:
22215 @item @code{nfs-utils} (default: @code{nfs-utils})
22216 The nfs-utils package to use.
22218 @item @code{nfs-version} (default: @code{#f})
22219 If a string value is provided, the @command{rpc.nfsd} daemon will be
22220 limited to supporting the given version of the NFS protocol.
22222 @item @code{exports} (default: @code{'()})
22223 This is a list of directories the NFS server should export. Each entry
22224 is a list consisting of two elements: a directory name and a string
22225 containing all options. This is an example in which the directory
22226 @file{/export} is served to all NFS clients as a read-only share:
22232 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22235 @item @code{rpcmountd-port} (default: @code{#f})
22236 The network port that the @command{rpc.mountd} daemon should use.
22238 @item @code{rpcstatd-port} (default: @code{#f})
22239 The network port that the @command{rpc.statd} daemon should use.
22241 @item @code{rpcbind} (default: @code{rpcbind})
22242 The rpcbind package to use.
22244 @item @code{idmap-domain} (default: @code{"localdomain"})
22245 The local NFSv4 domain name.
22247 @item @code{nfsd-port} (default: @code{2049})
22248 The network port that the @command{nfsd} daemon should use.
22250 @item @code{nfsd-threads} (default: @code{8})
22251 The number of threads used by the @command{nfsd} daemon.
22253 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22254 The directory where the pipefs file system is mounted.
22256 @item @code{debug} (default: @code{'()"})
22257 A list of subsystems for which debugging output should be enabled. This
22258 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22259 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22263 If you don't need a complete NFS service or prefer to build it yourself
22264 you can use the individual component services that are documented below.
22266 @subsubheading RPC Bind Service
22269 The RPC Bind service provides a facility to map program numbers into
22270 universal addresses.
22271 Many NFS related services use this facility. Hence it is automatically
22272 started when a dependent service starts.
22274 @defvr {Scheme Variable} rpcbind-service-type
22275 A service type for the RPC portmapper daemon.
22279 @deftp {Data Type} rpcbind-configuration
22280 Data type representing the configuration of the RPC Bind Service.
22281 This type has the following parameters:
22283 @item @code{rpcbind} (default: @code{rpcbind})
22284 The rpcbind package to use.
22286 @item @code{warm-start?} (default: @code{#t})
22287 If this parameter is @code{#t}, then the daemon will read a
22288 state file on startup thus reloading state information saved by a previous
22294 @subsubheading Pipefs Pseudo File System
22298 The pipefs file system is used to transfer NFS related data
22299 between the kernel and user space programs.
22301 @defvr {Scheme Variable} pipefs-service-type
22302 A service type for the pipefs pseudo file system.
22305 @deftp {Data Type} pipefs-configuration
22306 Data type representing the configuration of the pipefs pseudo file system service.
22307 This type has the following parameters:
22309 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22310 The directory to which the file system is to be attached.
22315 @subsubheading GSS Daemon Service
22318 @cindex global security system
22320 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22322 Before exchanging RPC requests an RPC client must establish a security
22323 context. Typically this is done using the Kerberos command @command{kinit}
22324 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22326 @defvr {Scheme Variable} gss-service-type
22327 A service type for the Global Security System (GSS) daemon.
22330 @deftp {Data Type} gss-configuration
22331 Data type representing the configuration of the GSS daemon service.
22332 This type has the following parameters:
22334 @item @code{nfs-utils} (default: @code{nfs-utils})
22335 The package in which the @command{rpc.gssd} command is to be found.
22337 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22338 The directory where the pipefs file system is mounted.
22344 @subsubheading IDMAP Daemon Service
22346 @cindex name mapper
22348 The idmap daemon service provides mapping between user IDs and user names.
22349 Typically it is required in order to access file systems mounted via NFSv4.
22351 @defvr {Scheme Variable} idmap-service-type
22352 A service type for the Identity Mapper (IDMAP) daemon.
22355 @deftp {Data Type} idmap-configuration
22356 Data type representing the configuration of the IDMAP daemon service.
22357 This type has the following parameters:
22359 @item @code{nfs-utils} (default: @code{nfs-utils})
22360 The package in which the @command{rpc.idmapd} command is to be found.
22362 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22363 The directory where the pipefs file system is mounted.
22365 @item @code{domain} (default: @code{#f})
22366 The local NFSv4 domain name.
22367 This must be a string or @code{#f}.
22368 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22370 @item @code{verbosity} (default: @code{0})
22371 The verbosity level of the daemon.
22376 @node Continuous Integration
22377 @subsection Continuous Integration
22379 @cindex continuous integration
22380 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22381 continuous integration tool for Guix. It can be used both for development and
22382 for providing substitutes to others (@pxref{Substitutes}).
22384 The @code{(gnu services cuirass)} module provides the following service.
22386 @defvr {Scheme Procedure} cuirass-service-type
22387 The type of the Cuirass service. Its value must be a
22388 @code{cuirass-configuration} object, as described below.
22391 To add build jobs, you have to set the @code{specifications} field of the
22392 configuration. Here is an example of a service that polls the Guix repository
22393 and builds the packages from a manifest. Some of the packages are defined in
22394 the @code{"custom-packages"} input, which is the equivalent of
22395 @code{GUIX_PACKAGE_PATH}.
22398 (define %cuirass-specs
22400 '((#:name . "my-manifest")
22401 (#:load-path-inputs . ("guix"))
22402 (#:package-path-inputs . ("custom-packages"))
22403 (#:proc-input . "guix")
22404 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22405 (#:proc . cuirass-jobs)
22406 (#:proc-args . ((subset . "manifests")
22407 (systems . ("x86_64-linux"))
22408 (manifests . (("config" . "guix/manifest.scm")))))
22409 (#:inputs . (((#:name . "guix")
22410 (#:url . "git://git.savannah.gnu.org/guix.git")
22411 (#:load-path . ".")
22412 (#:branch . "master")
22413 (#:no-compile? . #t))
22414 ((#:name . "config")
22415 (#:url . "https://git.example.org/config.git")
22416 (#:load-path . ".")
22417 (#:branch . "master")
22418 (#:no-compile? . #t))
22419 ((#:name . "custom-packages")
22420 (#:url . "https://git.example.org/custom-packages.git")
22421 (#:load-path . ".")
22422 (#:branch . "master")
22423 (#:no-compile? . #t)))))))
22425 (service cuirass-service-type
22426 (cuirass-configuration
22427 (specifications %cuirass-specs)))
22430 While information related to build jobs is located directly in the
22431 specifications, global settings for the @command{cuirass} process are
22432 accessible in other @code{cuirass-configuration} fields.
22434 @deftp {Data Type} cuirass-configuration
22435 Data type representing the configuration of Cuirass.
22438 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22439 Location of the log file.
22441 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22442 Location of the log file used by the web interface.
22444 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22445 Location of the repository cache.
22447 @item @code{user} (default: @code{"cuirass"})
22448 Owner of the @code{cuirass} process.
22450 @item @code{group} (default: @code{"cuirass"})
22451 Owner's group of the @code{cuirass} process.
22453 @item @code{interval} (default: @code{60})
22454 Number of seconds between the poll of the repositories followed by the
22457 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22458 Location of sqlite database which contains the build results and previously
22459 added specifications.
22461 @item @code{ttl} (default: @code{(* 30 24 3600)})
22462 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22463 are registered for build results. This means that build results are protected
22464 from garbage collection for at least @var{ttl} seconds.
22466 @item @code{port} (default: @code{8081})
22467 Port number used by the HTTP server.
22469 @item @code{host} (default: @code{"localhost"})
22470 Listen on the network interface for @var{host}. The default is to
22471 accept connections from localhost.
22473 @item @code{specifications} (default: @code{#~'()})
22474 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22475 where a specification is an association list
22476 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22477 keys are keywords (@code{#:keyword-example}) as shown in the example
22480 @item @code{use-substitutes?} (default: @code{#f})
22481 This allows using substitutes to avoid building every dependencies of a job
22484 @item @code{one-shot?} (default: @code{#f})
22485 Only evaluate specifications and build derivations once.
22487 @item @code{fallback?} (default: @code{#f})
22488 When substituting a pre-built binary fails, fall back to building
22491 @item @code{extra-options} (default: @code{'()})
22492 Extra options to pass when running the Cuirass processes.
22494 @item @code{cuirass} (default: @code{cuirass})
22495 The Cuirass package to use.
22499 @node Power Management Services
22500 @subsection Power Management Services
22503 @cindex power management with TLP
22504 @subsubheading TLP daemon
22506 The @code{(gnu services pm)} module provides a Guix service definition
22507 for the Linux power management tool TLP.
22509 TLP enables various powersaving modes in userspace and kernel.
22510 Contrary to @code{upower-service}, it is not a passive,
22511 monitoring tool, as it will apply custom settings each time a new power
22512 source is detected. More information can be found at
22513 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22515 @deffn {Scheme Variable} tlp-service-type
22516 The service type for the TLP tool. Its value should be a valid
22517 TLP configuration (see below). To use the default settings, simply
22520 (service tlp-service-type)
22524 By default TLP does not need much configuration but most TLP parameters
22525 can be tweaked using @code{tlp-configuration}.
22527 Each parameter definition is preceded by its type; for example,
22528 @samp{boolean foo} indicates that the @code{foo} parameter
22529 should be specified as a boolean. Types starting with
22530 @code{maybe-} denote parameters that won't show up in TLP config file
22531 when their value is @code{'disabled}.
22533 @c The following documentation was initially generated by
22534 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22535 @c documentation is better, so we shouldn't hesitate to edit below as
22536 @c needed. However if the change you want to make to this documentation
22537 @c can be done in an automated way, it's probably easier to change
22538 @c (generate-documentation) than to make it below and have to deal with
22539 @c the churn as TLP updates.
22541 Available @code{tlp-configuration} fields are:
22543 @deftypevr {@code{tlp-configuration} parameter} package tlp
22548 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22549 Set to true if you wish to enable TLP.
22551 Defaults to @samp{#t}.
22555 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22556 Default mode when no power supply can be detected. Alternatives are AC
22559 Defaults to @samp{"AC"}.
22563 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22564 Number of seconds Linux kernel has to wait after the disk goes idle,
22565 before syncing on AC.
22567 Defaults to @samp{0}.
22571 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22572 Same as @code{disk-idle-ac} but on BAT mode.
22574 Defaults to @samp{2}.
22578 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22579 Dirty pages flushing periodicity, expressed in seconds.
22581 Defaults to @samp{15}.
22585 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22586 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22588 Defaults to @samp{60}.
22592 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22593 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22594 alternatives are powersave and performance. With acpi-cpufreq driver,
22595 alternatives are ondemand, powersave, performance and conservative.
22597 Defaults to @samp{disabled}.
22601 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22602 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22604 Defaults to @samp{disabled}.
22608 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22609 Set the min available frequency for the scaling governor on AC.
22611 Defaults to @samp{disabled}.
22615 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22616 Set the max available frequency for the scaling governor on AC.
22618 Defaults to @samp{disabled}.
22622 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22623 Set the min available frequency for the scaling governor on BAT.
22625 Defaults to @samp{disabled}.
22629 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22630 Set the max available frequency for the scaling governor on BAT.
22632 Defaults to @samp{disabled}.
22636 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22637 Limit the min P-state to control the power dissipation of the CPU, in AC
22638 mode. Values are stated as a percentage of the available performance.
22640 Defaults to @samp{disabled}.
22644 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22645 Limit the max P-state to control the power dissipation of the CPU, in AC
22646 mode. Values are stated as a percentage of the available performance.
22648 Defaults to @samp{disabled}.
22652 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22653 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22655 Defaults to @samp{disabled}.
22659 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22660 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22662 Defaults to @samp{disabled}.
22666 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22667 Enable CPU turbo boost feature on AC mode.
22669 Defaults to @samp{disabled}.
22673 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22674 Same as @code{cpu-boost-on-ac?} on BAT mode.
22676 Defaults to @samp{disabled}.
22680 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22681 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22682 used under light load conditions.
22684 Defaults to @samp{#f}.
22688 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22689 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22691 Defaults to @samp{#t}.
22695 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22696 Enable Linux kernel NMI watchdog.
22698 Defaults to @samp{#f}.
22702 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22703 For Linux kernels with PHC patch applied, change CPU voltages. An
22704 example value would be @samp{"F:V F:V F:V F:V"}.
22706 Defaults to @samp{disabled}.
22710 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22711 Set CPU performance versus energy saving policy on AC. Alternatives are
22712 performance, normal, powersave.
22714 Defaults to @samp{"performance"}.
22718 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22719 Same as @code{energy-perf-policy-ac} but on BAT mode.
22721 Defaults to @samp{"powersave"}.
22725 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22730 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22731 Hard disk advanced power management level.
22735 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22736 Same as @code{disk-apm-bat} but on BAT mode.
22740 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22741 Hard disk spin down timeout. One value has to be specified for each
22742 declared hard disk.
22744 Defaults to @samp{disabled}.
22748 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22749 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22751 Defaults to @samp{disabled}.
22755 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22756 Select IO scheduler for disk devices. One value has to be specified for
22757 each declared hard disk. Example alternatives are cfq, deadline and
22760 Defaults to @samp{disabled}.
22764 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22765 SATA aggressive link power management (ALPM) level. Alternatives are
22766 min_power, medium_power, max_performance.
22768 Defaults to @samp{"max_performance"}.
22772 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22773 Same as @code{sata-linkpwr-ac} but on BAT mode.
22775 Defaults to @samp{"min_power"}.
22779 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22780 Exclude specified SATA host devices for link power management.
22782 Defaults to @samp{disabled}.
22786 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22787 Enable Runtime Power Management for AHCI controller and disks on AC
22790 Defaults to @samp{disabled}.
22794 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22795 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22797 Defaults to @samp{disabled}.
22801 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22802 Seconds of inactivity before disk is suspended.
22804 Defaults to @samp{15}.
22808 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22809 PCI Express Active State Power Management level. Alternatives are
22810 default, performance, powersave.
22812 Defaults to @samp{"performance"}.
22816 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22817 Same as @code{pcie-aspm-ac} but on BAT mode.
22819 Defaults to @samp{"powersave"}.
22823 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22824 Radeon graphics clock speed level. Alternatives are low, mid, high,
22827 Defaults to @samp{"high"}.
22831 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22832 Same as @code{radeon-power-ac} but on BAT mode.
22834 Defaults to @samp{"low"}.
22838 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22839 Radeon dynamic power management method (DPM). Alternatives are battery,
22842 Defaults to @samp{"performance"}.
22846 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22847 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22849 Defaults to @samp{"battery"}.
22853 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22854 Radeon DPM performance level. Alternatives are auto, low, high.
22856 Defaults to @samp{"auto"}.
22860 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22861 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22863 Defaults to @samp{"auto"}.
22867 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22868 Wifi power saving mode.
22870 Defaults to @samp{#f}.
22874 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22875 Same as @code{wifi-power-ac?} but on BAT mode.
22877 Defaults to @samp{#t}.
22881 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22882 Disable wake on LAN.
22884 Defaults to @samp{#t}.
22888 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22889 Timeout duration in seconds before activating audio power saving on
22890 Intel HDA and AC97 devices. A value of 0 disables power saving.
22892 Defaults to @samp{0}.
22896 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22897 Same as @code{sound-powersave-ac} but on BAT mode.
22899 Defaults to @samp{1}.
22903 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22904 Disable controller in powersaving mode on Intel HDA devices.
22906 Defaults to @samp{#t}.
22910 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22911 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22912 powered on again by releasing (and reinserting) the eject lever or by
22913 pressing the disc eject button on newer models.
22915 Defaults to @samp{#f}.
22919 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22920 Name of the optical drive device to power off.
22922 Defaults to @samp{"sr0"}.
22926 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22927 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22930 Defaults to @samp{"on"}.
22934 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22935 Same as @code{runtime-pm-ac} but on BAT mode.
22937 Defaults to @samp{"auto"}.
22941 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22942 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22945 Defaults to @samp{#t}.
22949 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22950 Exclude specified PCI(e) device addresses from Runtime Power Management.
22952 Defaults to @samp{disabled}.
22956 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22957 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22962 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22963 Enable USB autosuspend feature.
22965 Defaults to @samp{#t}.
22969 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22970 Exclude specified devices from USB autosuspend.
22972 Defaults to @samp{disabled}.
22976 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22977 Exclude WWAN devices from USB autosuspend.
22979 Defaults to @samp{#t}.
22983 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22984 Include specified devices into USB autosuspend, even if they are already
22985 excluded by the driver or via @code{usb-blacklist-wwan?}.
22987 Defaults to @samp{disabled}.
22991 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22992 Enable USB autosuspend before shutdown.
22994 Defaults to @samp{disabled}.
22998 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22999 Restore radio device state (bluetooth, wifi, wwan) from previous
23000 shutdown on system startup.
23002 Defaults to @samp{#f}.
23007 @cindex CPU frequency scaling with thermald
23008 @subsubheading Thermald daemon
23010 The @code{(gnu services pm)} module provides an interface to
23011 thermald, a CPU frequency scaling service which helps prevent overheating.
23013 @defvr {Scheme Variable} thermald-service-type
23014 This is the service type for
23015 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
23016 Thermal Daemon, which is responsible for controlling the thermal state
23017 of processors and preventing overheating.
23020 @deftp {Data Type} thermald-configuration
23021 Data type representing the configuration of @code{thermald-service-type}.
23024 @item @code{ignore-cpuid-check?} (default: @code{#f})
23025 Ignore cpuid check for supported CPU models.
23027 @item @code{thermald} (default: @var{thermald})
23028 Package object of thermald.
23033 @node Audio Services
23034 @subsection Audio Services
23036 The @code{(gnu services audio)} module provides a service to start MPD
23037 (the Music Player Daemon).
23040 @subsubheading Music Player Daemon
23042 The Music Player Daemon (MPD) is a service that can play music while
23043 being controlled from the local machine or over the network by a variety
23046 The following example shows how one might run @code{mpd} as user
23047 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
23050 (service mpd-service-type
23056 @defvr {Scheme Variable} mpd-service-type
23057 The service type for @command{mpd}
23060 @deftp {Data Type} mpd-configuration
23061 Data type representing the configuration of @command{mpd}.
23064 @item @code{user} (default: @code{"mpd"})
23065 The user to run mpd as.
23067 @item @code{music-dir} (default: @code{"~/Music"})
23068 The directory to scan for music files.
23070 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
23071 The directory to store playlists.
23073 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
23074 The location of the music database.
23076 @item @code{state-file} (default: @code{"~/.mpd/state"})
23077 The location of the file that stores current MPD's state.
23079 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
23080 The location of the sticker database.
23082 @item @code{port} (default: @code{"6600"})
23083 The port to run mpd on.
23085 @item @code{address} (default: @code{"any"})
23086 The address that mpd will bind to. To use a Unix domain socket,
23087 an absolute path can be specified here.
23089 @item @code{outputs} (default: @code{"(list (mpd-output))"})
23090 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
23095 @deftp {Data Type} mpd-output
23096 Data type representing an @command{mpd} audio output.
23099 @item @code{name} (default: @code{"MPD"})
23100 The name of the audio output.
23102 @item @code{type} (default: @code{"pulse"})
23103 The type of audio output.
23105 @item @code{enabled?} (default: @code{#t})
23106 Specifies whether this audio output is enabled when MPD is started. By
23107 default, all audio outputs are enabled. This is just the default
23108 setting when there is no state file; with a state file, the previous
23111 @item @code{tags?} (default: @code{#t})
23112 If set to @code{#f}, then MPD will not send tags to this output. This
23113 is only useful for output plugins that can receive tags, for example the
23114 @code{httpd} output plugin.
23116 @item @code{always-on?} (default: @code{#f})
23117 If set to @code{#t}, then MPD attempts to keep this audio output always
23118 open. This may be useful for streaming servers, when you don’t want to
23119 disconnect all listeners even when playback is accidentally stopped.
23121 @item @code{mixer-type}
23122 This field accepts a symbol that specifies which mixer should be used
23123 for this audio output: the @code{hardware} mixer, the @code{software}
23124 mixer, the @code{null} mixer (allows setting the volume, but with no
23125 effect; this can be used as a trick to implement an external mixer
23126 External Mixer) or no mixer (@code{none}).
23128 @item @code{extra-options} (default: @code{'()"})
23129 An association list of option symbols to string values to be appended to
23130 the audio output configuration.
23135 The following example shows a configuration of @code{mpd} that provides
23136 an HTTP audio streaming output.
23139 (service mpd-service-type
23147 `((encoder . "vorbis")
23148 (port . "8080"))))))))
23152 @node Virtualization Services
23153 @subsection Virtualization services
23155 The @code{(gnu services virtualization)} module provides services for
23156 the libvirt and virtlog daemons, as well as other virtualization-related
23159 @subsubheading Libvirt daemon
23160 @code{libvirtd} is the server side daemon component of the libvirt
23161 virtualization management system. This daemon runs on host servers
23162 and performs required management tasks for virtualized guests.
23164 @deffn {Scheme Variable} libvirt-service-type
23165 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
23166 Its value must be a @code{libvirt-configuration}.
23169 (service libvirt-service-type
23170 (libvirt-configuration
23171 (unix-sock-group "libvirt")
23172 (tls-port "16555")))
23176 @c Auto-generated with (generate-libvirt-documentation)
23177 Available @code{libvirt-configuration} fields are:
23179 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
23184 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
23185 Flag listening for secure TLS connections on the public TCP/IP port.
23186 must set @code{listen} for this to have any effect.
23188 It is necessary to setup a CA and issue server certificates before using
23191 Defaults to @samp{#t}.
23195 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
23196 Listen for unencrypted TCP connections on the public TCP/IP port. must
23197 set @code{listen} for this to have any effect.
23199 Using the TCP socket requires SASL authentication by default. Only SASL
23200 mechanisms which support data encryption are allowed. This is
23201 DIGEST_MD5 and GSSAPI (Kerberos5)
23203 Defaults to @samp{#f}.
23207 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
23208 Port for accepting secure TLS connections This can be a port number, or
23211 Defaults to @samp{"16514"}.
23215 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23216 Port for accepting insecure TCP connections This can be a port number,
23219 Defaults to @samp{"16509"}.
23223 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23224 IP address or hostname used for client connections.
23226 Defaults to @samp{"0.0.0.0"}.
23230 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23231 Flag toggling mDNS advertisement of the libvirt service.
23233 Alternatively can disable for all services on a host by stopping the
23236 Defaults to @samp{#f}.
23240 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23241 Default mDNS advertisement name. This must be unique on the immediate
23244 Defaults to @samp{"Virtualization Host <hostname>"}.
23248 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23249 UNIX domain socket group ownership. This can be used to allow a
23250 'trusted' set of users access to management capabilities without
23253 Defaults to @samp{"root"}.
23257 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23258 UNIX socket permissions for the R/O socket. This is used for monitoring
23261 Defaults to @samp{"0777"}.
23265 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23266 UNIX socket permissions for the R/W socket. Default allows only root.
23267 If PolicyKit is enabled on the socket, the default will change to allow
23268 everyone (eg, 0777)
23270 Defaults to @samp{"0770"}.
23274 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23275 UNIX socket permissions for the admin socket. Default allows only owner
23276 (root), do not change it unless you are sure to whom you are exposing
23279 Defaults to @samp{"0777"}.
23283 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23284 The directory in which sockets will be found/created.
23286 Defaults to @samp{"/var/run/libvirt"}.
23290 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23291 Authentication scheme for UNIX read-only sockets. By default socket
23292 permissions allow anyone to connect
23294 Defaults to @samp{"polkit"}.
23298 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23299 Authentication scheme for UNIX read-write sockets. By default socket
23300 permissions only allow root. If PolicyKit support was compiled into
23301 libvirt, the default will be to use 'polkit' auth.
23303 Defaults to @samp{"polkit"}.
23307 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23308 Authentication scheme for TCP sockets. If you don't enable SASL, then
23309 all TCP traffic is cleartext. Don't do this outside of a dev/test
23312 Defaults to @samp{"sasl"}.
23316 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23317 Authentication scheme for TLS sockets. TLS sockets already have
23318 encryption provided by the TLS layer, and limited authentication is done
23321 It is possible to make use of any SASL authentication mechanism as well,
23322 by using 'sasl' for this option
23324 Defaults to @samp{"none"}.
23328 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23329 API access control scheme.
23331 By default an authenticated user is allowed access to all APIs. Access
23332 drivers can place restrictions on this.
23334 Defaults to @samp{()}.
23338 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23339 Server key file path. If set to an empty string, then no private key is
23342 Defaults to @samp{""}.
23346 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23347 Server key file path. If set to an empty string, then no certificate is
23350 Defaults to @samp{""}.
23354 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23355 Server key file path. If set to an empty string, then no CA certificate
23358 Defaults to @samp{""}.
23362 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23363 Certificate revocation list path. If set to an empty string, then no
23366 Defaults to @samp{""}.
23370 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23371 Disable verification of our own server certificates.
23373 When libvirtd starts it performs some sanity checks against its own
23376 Defaults to @samp{#f}.
23380 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23381 Disable verification of client certificates.
23383 Client certificate verification is the primary authentication mechanism.
23384 Any client which does not present a certificate signed by the CA will be
23387 Defaults to @samp{#f}.
23391 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23392 Whitelist of allowed x509 Distinguished Name.
23394 Defaults to @samp{()}.
23398 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23399 Whitelist of allowed SASL usernames. The format for username depends on
23400 the SASL authentication mechanism.
23402 Defaults to @samp{()}.
23406 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23407 Override the compile time default TLS priority string. The default is
23408 usually "NORMAL" unless overridden at build time. Only set this is it
23409 is desired for libvirt to deviate from the global default settings.
23411 Defaults to @samp{"NORMAL"}.
23415 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23416 Maximum number of concurrent client connections to allow over all
23419 Defaults to @samp{5000}.
23423 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23424 Maximum length of queue of connections waiting to be accepted by the
23425 daemon. Note, that some protocols supporting retransmission may obey
23426 this so that a later reattempt at connection succeeds.
23428 Defaults to @samp{1000}.
23432 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23433 Maximum length of queue of accepted but not yet authenticated clients.
23434 Set this to zero to turn this feature off
23436 Defaults to @samp{20}.
23440 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23441 Number of workers to start up initially.
23443 Defaults to @samp{5}.
23447 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23448 Maximum number of worker threads.
23450 If the number of active clients exceeds @code{min-workers}, then more
23451 threads are spawned, up to max_workers limit. Typically you'd want
23452 max_workers to equal maximum number of clients allowed.
23454 Defaults to @samp{20}.
23458 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23459 Number of priority workers. If all workers from above pool are stuck,
23460 some calls marked as high priority (notably domainDestroy) can be
23461 executed in this pool.
23463 Defaults to @samp{5}.
23467 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23468 Total global limit on concurrent RPC calls.
23470 Defaults to @samp{20}.
23474 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23475 Limit on concurrent requests from a single client connection. To avoid
23476 one client monopolizing the server this should be a small fraction of
23477 the global max_requests and max_workers parameter.
23479 Defaults to @samp{5}.
23483 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23484 Same as @code{min-workers} but for the admin interface.
23486 Defaults to @samp{1}.
23490 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23491 Same as @code{max-workers} but for the admin interface.
23493 Defaults to @samp{5}.
23497 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23498 Same as @code{max-clients} but for the admin interface.
23500 Defaults to @samp{5}.
23504 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23505 Same as @code{max-queued-clients} but for the admin interface.
23507 Defaults to @samp{5}.
23511 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23512 Same as @code{max-client-requests} but for the admin interface.
23514 Defaults to @samp{5}.
23518 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23519 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23521 Defaults to @samp{3}.
23525 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23528 A filter allows to select a different logging level for a given category
23529 of logs The format for a filter is one of:
23540 where @code{name} is a string which is matched against the category
23541 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23542 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23543 be a substring of the full category name, in order to match multiple
23544 similar categories), the optional "+" prefix tells libvirt to log stack
23545 trace for each message matching name, and @code{x} is the minimal level
23546 where matching messages should be logged:
23563 Multiple filters can be defined in a single filters statement, they just
23564 need to be separated by spaces.
23566 Defaults to @samp{"3:remote 4:event"}.
23570 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23573 An output is one of the places to save logging information. The format
23574 for an output can be:
23578 output goes to stderr
23580 @item x:syslog:name
23581 use syslog for the output and use the given name as the ident
23583 @item x:file:file_path
23584 output to a file, with the given filepath
23587 output to journald logging system
23591 In all case the x prefix is the minimal level, acting as a filter
23608 Multiple outputs can be defined, they just need to be separated by
23611 Defaults to @samp{"3:stderr"}.
23615 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23616 Allows usage of the auditing subsystem to be altered
23620 0: disable all auditing
23623 1: enable auditing, only if enabled on host
23626 2: enable auditing, and exit if disabled on host.
23630 Defaults to @samp{1}.
23634 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23635 Send audit messages via libvirt logging infrastructure.
23637 Defaults to @samp{#f}.
23641 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23642 Host UUID. UUID must not have all digits be the same.
23644 Defaults to @samp{""}.
23648 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23649 Source to read host UUID.
23653 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23656 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23660 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23663 Defaults to @samp{"smbios"}.
23667 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23668 A keepalive message is sent to a client after @code{keepalive_interval}
23669 seconds of inactivity to check if the client is still responding. If
23670 set to -1, libvirtd will never send keepalive requests; however clients
23671 can still send them and the daemon will send responses.
23673 Defaults to @samp{5}.
23677 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23678 Maximum number of keepalive messages that are allowed to be sent to the
23679 client without getting any response before the connection is considered
23682 In other words, the connection is automatically closed approximately
23683 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23684 the last message received from the client. When @code{keepalive-count}
23685 is set to 0, connections will be automatically closed after
23686 @code{keepalive-interval} seconds of inactivity without sending any
23687 keepalive messages.
23689 Defaults to @samp{5}.
23693 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23694 Same as above but for admin interface.
23696 Defaults to @samp{5}.
23700 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23701 Same as above but for admin interface.
23703 Defaults to @samp{5}.
23707 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23708 Timeout for Open vSwitch calls.
23710 The @code{ovs-vsctl} utility is used for the configuration and its
23711 timeout option is set by default to 5 seconds to avoid potential
23712 infinite waits blocking libvirt.
23714 Defaults to @samp{5}.
23718 @c %end of autogenerated docs
23720 @subsubheading Virtlog daemon
23721 The virtlogd service is a server side daemon component of libvirt that is
23722 used to manage logs from virtual machine consoles.
23724 This daemon is not used directly by libvirt client applications, rather it
23725 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23726 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23727 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23728 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23730 @deffn {Scheme Variable} virtlog-service-type
23731 This is the type of the virtlog daemon.
23732 Its value must be a @code{virtlog-configuration}.
23735 (service virtlog-service-type
23736 (virtlog-configuration
23737 (max-clients 1000)))
23741 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23742 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23744 Defaults to @samp{3}.
23748 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23751 A filter allows to select a different logging level for a given category
23752 of logs The format for a filter is one of:
23763 where @code{name} is a string which is matched against the category
23764 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23765 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23766 be a substring of the full category name, in order to match multiple
23767 similar categories), the optional "+" prefix tells libvirt to log stack
23768 trace for each message matching name, and @code{x} is the minimal level
23769 where matching messages should be logged:
23786 Multiple filters can be defined in a single filters statement, they just
23787 need to be separated by spaces.
23789 Defaults to @samp{"3:remote 4:event"}.
23793 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23796 An output is one of the places to save logging information The format
23797 for an output can be:
23801 output goes to stderr
23803 @item x:syslog:name
23804 use syslog for the output and use the given name as the ident
23806 @item x:file:file_path
23807 output to a file, with the given filepath
23810 output to journald logging system
23814 In all case the x prefix is the minimal level, acting as a filter
23831 Multiple outputs can be defined, they just need to be separated by
23834 Defaults to @samp{"3:stderr"}.
23838 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23839 Maximum number of concurrent client connections to allow over all
23842 Defaults to @samp{1024}.
23846 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23847 Maximum file size before rolling over.
23849 Defaults to @samp{2MB}
23853 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23854 Maximum number of backup files to keep.
23856 Defaults to @samp{3}
23860 @subsubheading Transparent Emulation with QEMU
23863 @cindex @code{binfmt_misc}
23864 @code{qemu-binfmt-service-type} provides support for transparent
23865 emulation of program binaries built for different architectures---e.g.,
23866 it allows you to transparently execute an ARMv7 program on an x86_64
23867 machine. It achieves this by combining the @uref{https://www.qemu.org,
23868 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23870 @defvr {Scheme Variable} qemu-binfmt-service-type
23871 This is the type of the QEMU/binfmt service for transparent emulation.
23872 Its value must be a @code{qemu-binfmt-configuration} object, which
23873 specifies the QEMU package to use as well as the architecture we want to
23877 (service qemu-binfmt-service-type
23878 (qemu-binfmt-configuration
23879 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23882 In this example, we enable transparent emulation for the ARM and aarch64
23883 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23884 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23885 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23888 @deftp {Data Type} qemu-binfmt-configuration
23889 This is the configuration for the @code{qemu-binfmt} service.
23892 @item @code{platforms} (default: @code{'()})
23893 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23894 object} as returned by @code{lookup-qemu-platforms} (see below).
23896 @item @code{guix-support?} (default: @code{#f})
23897 When it is true, QEMU and all its dependencies are added to the build
23898 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23899 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23900 handlers to be used within the build environment, which in turn means
23901 that you can transparently build programs for another architecture.
23903 For example, let's suppose you're on an x86_64 machine and you have this
23907 (service qemu-binfmt-service-type
23908 (qemu-binfmt-configuration
23909 (platforms (lookup-qemu-platforms "arm"))
23910 (guix-support? #t)))
23916 guix build -s armhf-linux inkscape
23920 and it will build Inkscape for ARMv7 @emph{as if it were a native
23921 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23922 if you'd like to test a package build for an architecture you don't have
23925 @item @code{qemu} (default: @code{qemu})
23926 The QEMU package to use.
23930 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23931 Return the list of QEMU platform objects corresponding to
23932 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23933 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23934 @code{"mips64el"}, and so on.
23937 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23938 Return true if @var{obj} is a platform object.
23941 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23942 Return the name of @var{platform}---a string such as @code{"arm"}.
23945 @node Version Control Services
23946 @subsection Version Control Services
23948 The @code{(gnu services version-control)} module provides a service to
23949 allow remote access to local Git repositories. There are three options:
23950 the @code{git-daemon-service}, which provides access to repositories via
23951 the @code{git://} unsecured TCP-based protocol, extending the
23952 @code{nginx} web server to proxy some requests to
23953 @code{git-http-backend}, or providing a web interface with
23954 @code{cgit-service-type}.
23956 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23958 Return a service that runs @command{git daemon}, a simple TCP server to
23959 expose repositories over the Git protocol for anonymous access.
23961 The optional @var{config} argument should be a
23962 @code{<git-daemon-configuration>} object, by default it allows read-only
23963 access to exported@footnote{By creating the magic file
23964 "git-daemon-export-ok" in the repository directory.} repositories under
23969 @deftp {Data Type} git-daemon-configuration
23970 Data type representing the configuration for @code{git-daemon-service}.
23973 @item @code{package} (default: @var{git})
23974 Package object of the Git distributed version control system.
23976 @item @code{export-all?} (default: @var{#f})
23977 Whether to allow access for all Git repositories, even if they do not
23978 have the @file{git-daemon-export-ok} file.
23980 @item @code{base-path} (default: @file{/srv/git})
23981 Whether to remap all the path requests as relative to the given path.
23982 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23983 then if you later try to pull @code{git://example.com/hello.git}, git
23984 daemon will interpret the path as @code{/srv/git/hello.git}.
23986 @item @code{user-path} (default: @var{#f})
23987 Whether to allow @code{~user} notation to be used in requests. When
23988 specified with empty string, requests to @code{git://host/~alice/foo} is
23989 taken as a request to access @code{foo} repository in the home directory
23990 of user @code{alice}. If @var{(user-path "path")} is specified, the
23991 same request is taken as a request to access @code{path/foo} repository
23992 in the home directory of user @code{alice}.
23994 @item @code{listen} (default: @var{'()})
23995 Whether to listen on specific IP addresses or hostnames, defaults to
23998 @item @code{port} (default: @var{#f})
23999 Whether to listen on an alternative port, which defaults to 9418.
24001 @item @code{whitelist} (default: @var{'()})
24002 If not empty, only allow access to this list of directories.
24004 @item @code{extra-options} (default: @var{'()})
24005 Extra options will be passed to @code{git daemon}, please run
24006 @command{man git-daemon} for more information.
24011 The @code{git://} protocol lacks authentication. When you pull from a
24012 repository fetched via @code{git://}, you don't know whether the data you
24013 receive was modified or is even coming from the specified host, and your
24014 connection is subject to eavesdropping. It's better to use an authenticated
24015 and encrypted transport, such as @code{https}. Although Git allows you
24016 to serve repositories using unsophisticated file-based web servers,
24017 there is a faster protocol implemented by the @code{git-http-backend}
24018 program. This program is the back-end of a proper Git web service. It
24019 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
24020 on running the necessary @code{fcgiwrap} daemon.
24022 Guix has a separate configuration data type for serving Git repositories
24025 @deftp {Data Type} git-http-configuration
24026 Data type representing the configuration for @code{git-http-service}.
24029 @item @code{package} (default: @var{git})
24030 Package object of the Git distributed version control system.
24032 @item @code{git-root} (default: @file{/srv/git})
24033 Directory containing the Git repositories to expose to the world.
24035 @item @code{export-all?} (default: @var{#f})
24036 Whether to expose access for all Git repositories in @var{git-root},
24037 even if they do not have the @file{git-daemon-export-ok} file.
24039 @item @code{uri-path} (default: @file{/git/})
24040 Path prefix for Git access. With the default @code{/git/} prefix, this
24041 will map @code{http://@var{server}/git/@var{repo}.git} to
24042 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
24043 with this prefix are not passed on to this Git instance.
24045 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
24046 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
24051 There is no @code{git-http-service-type}, currently; instead you can
24052 create an @code{nginx-location-configuration} from a
24053 @code{git-http-configuration} and then add that location to a web
24056 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
24057 [config=(git-http-configuration)]
24058 Compute an @code{nginx-location-configuration} that corresponds to the
24059 given Git http configuration. An example nginx service definition to
24060 serve the default @file{/srv/git} over HTTPS might be:
24063 (service nginx-service-type
24064 (nginx-configuration
24067 (nginx-server-configuration
24068 (listen '("443 ssl"))
24069 (server-name "git.my-host.org")
24071 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
24072 (ssl-certificate-key
24073 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
24076 (git-http-nginx-location-configuration
24077 (git-http-configuration (uri-path "/"))))))))))
24080 This example assumes that you are using Let's Encrypt to get your TLS
24081 certificate. @xref{Certificate Services}. The default @code{certbot}
24082 service will redirect all HTTP traffic on @code{git.my-host.org} to
24083 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
24084 system services. @xref{Web Services}.
24087 @subsubheading Cgit Service
24089 @cindex Cgit service
24090 @cindex Git, web interface
24091 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
24092 repositories written in C.
24094 The following example will configure the service with default values.
24095 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
24098 (service cgit-service-type)
24101 The @code{file-object} type designates either a file-like object
24102 (@pxref{G-Expressions, file-like objects}) or a string.
24104 @c %start of fragment
24106 Available @code{cgit-configuration} fields are:
24108 @deftypevr {@code{cgit-configuration} parameter} package package
24113 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
24114 NGINX configuration.
24118 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
24119 Specifies a command which will be invoked to format the content of about
24120 pages (both top-level and for each repository).
24122 Defaults to @samp{""}.
24126 @deftypevr {@code{cgit-configuration} parameter} string agefile
24127 Specifies a path, relative to each repository path, which can be used to
24128 specify the date and time of the youngest commit in the repository.
24130 Defaults to @samp{""}.
24134 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
24135 Specifies a command that will be invoked for authenticating repository
24138 Defaults to @samp{""}.
24142 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
24143 Flag which, when set to @samp{age}, enables date ordering in the branch
24144 ref list, and when set @samp{name} enables ordering by branch name.
24146 Defaults to @samp{"name"}.
24150 @deftypevr {@code{cgit-configuration} parameter} string cache-root
24151 Path used to store the cgit cache entries.
24153 Defaults to @samp{"/var/cache/cgit"}.
24157 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
24158 Number which specifies the time-to-live, in minutes, for the cached
24159 version of repository pages accessed with a fixed SHA1.
24161 Defaults to @samp{-1}.
24165 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
24166 Number which specifies the time-to-live, in minutes, for the cached
24167 version of repository pages accessed without a fixed SHA1.
24169 Defaults to @samp{5}.
24173 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
24174 Number which specifies the time-to-live, in minutes, for the cached
24175 version of the repository summary page.
24177 Defaults to @samp{5}.
24181 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
24182 Number which specifies the time-to-live, in minutes, for the cached
24183 version of the repository index page.
24185 Defaults to @samp{5}.
24189 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
24190 Number which specifies the time-to-live, in minutes, for the result of
24191 scanning a path for Git repositories.
24193 Defaults to @samp{15}.
24197 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
24198 Number which specifies the time-to-live, in minutes, for the cached
24199 version of the repository about page.
24201 Defaults to @samp{15}.
24205 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
24206 Number which specifies the time-to-live, in minutes, for the cached
24207 version of snapshots.
24209 Defaults to @samp{5}.
24213 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
24214 The maximum number of entries in the cgit cache. When set to @samp{0},
24215 caching is disabled.
24217 Defaults to @samp{0}.
24221 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24222 Sort items in the repo list case sensitively.
24224 Defaults to @samp{#t}.
24228 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24229 List of common prefixes which, when combined with a repository URL,
24230 generates valid clone URLs for the repository.
24232 Defaults to @samp{()}.
24236 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24237 List of @code{clone-url} templates.
24239 Defaults to @samp{()}.
24243 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24244 Command which will be invoked to format commit messages.
24246 Defaults to @samp{""}.
24250 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24251 Flag which, when set to @samp{date}, enables strict date ordering in the
24252 commit log, and when set to @samp{topo} enables strict topological
24255 Defaults to @samp{"git log"}.
24259 @deftypevr {@code{cgit-configuration} parameter} file-object css
24260 URL which specifies the css document to include in all cgit pages.
24262 Defaults to @samp{"/share/cgit/cgit.css"}.
24266 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24267 Specifies a command which will be invoked to format names and email
24268 address of committers, authors, and taggers, as represented in various
24269 places throughout the cgit interface.
24271 Defaults to @samp{""}.
24275 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24276 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24277 fragment suitable for embedding in other HTML pages.
24279 Defaults to @samp{#f}.
24283 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24284 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24285 commit history graph to the left of the commit messages in the
24286 repository log page.
24288 Defaults to @samp{#f}.
24292 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24293 Flag which, when set to @samp{#t}, allows all filter settings to be
24294 overridden in repository-specific cgitrc files.
24296 Defaults to @samp{#f}.
24300 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24301 Flag which, when set to @samp{#t}, allows users to follow a file in the
24304 Defaults to @samp{#f}.
24308 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24309 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24312 Defaults to @samp{#t}.
24316 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24317 Flag which, when set to @samp{#t}, will make cgit generate extra links
24318 "summary", "commit", "tree" for each repo in the repository index.
24320 Defaults to @samp{#f}.
24324 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24325 Flag which, when set to @samp{#t}, will make cgit display the owner of
24326 each repo in the repository index.
24328 Defaults to @samp{#t}.
24332 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24333 Flag which, when set to @samp{#t}, will make cgit print the number of
24334 modified files for each commit on the repository log page.
24336 Defaults to @samp{#f}.
24340 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24341 Flag which, when set to @samp{#t}, will make cgit print the number of
24342 added and removed lines for each commit on the repository log page.
24344 Defaults to @samp{#f}.
24348 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24349 Flag which, when set to @code{#t}, will make cgit display remote
24350 branches in the summary and refs views.
24352 Defaults to @samp{#f}.
24356 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24357 Flag which, when set to @code{1}, will make cgit use the subject of the
24358 parent commit as link text when generating links to parent commits in
24361 Defaults to @samp{#f}.
24365 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24366 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24367 parent commit as link text when generating links to parent commits in
24370 Defaults to @samp{#f}.
24374 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24375 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24376 links for plaintext blobs printed in the tree view.
24378 Defaults to @samp{#t}.
24382 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24383 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24384 set any repo specific settings.
24386 Defaults to @samp{#f}.
24390 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24391 URL used as link to a shortcut icon for cgit.
24393 Defaults to @samp{"/favicon.ico"}.
24397 @deftypevr {@code{cgit-configuration} parameter} string footer
24398 The content of the file specified with this option will be included
24399 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24400 "generated by..."@: message).
24402 Defaults to @samp{""}.
24406 @deftypevr {@code{cgit-configuration} parameter} string head-include
24407 The content of the file specified with this option will be included
24408 verbatim in the HTML HEAD section on all pages.
24410 Defaults to @samp{""}.
24414 @deftypevr {@code{cgit-configuration} parameter} string header
24415 The content of the file specified with this option will be included
24416 verbatim at the top of all pages.
24418 Defaults to @samp{""}.
24422 @deftypevr {@code{cgit-configuration} parameter} file-object include
24423 Name of a configfile to include before the rest of the current config-
24426 Defaults to @samp{""}.
24430 @deftypevr {@code{cgit-configuration} parameter} string index-header
24431 The content of the file specified with this option will be included
24432 verbatim above the repository index.
24434 Defaults to @samp{""}.
24438 @deftypevr {@code{cgit-configuration} parameter} string index-info
24439 The content of the file specified with this option will be included
24440 verbatim below the heading on the repository index page.
24442 Defaults to @samp{""}.
24446 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24447 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24448 in the servers timezone.
24450 Defaults to @samp{#f}.
24454 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24455 URL which specifies the source of an image which will be used as a logo
24458 Defaults to @samp{"/share/cgit/cgit.png"}.
24462 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24463 URL loaded when clicking on the cgit logo image.
24465 Defaults to @samp{""}.
24469 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24470 Command which will be invoked to format the Owner column of the main
24473 Defaults to @samp{""}.
24477 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24478 Number of items to display in atom feeds view.
24480 Defaults to @samp{10}.
24484 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24485 Number of entries to list per page in "log" view.
24487 Defaults to @samp{50}.
24491 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24492 Number of commit message characters to display in "log" view.
24494 Defaults to @samp{80}.
24498 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24499 Specifies the number of entries to list per page on the repository index
24502 Defaults to @samp{50}.
24506 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24507 Specifies the maximum number of repo description characters to display
24508 on the repository index page.
24510 Defaults to @samp{80}.
24514 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24515 Specifies the maximum size of a blob to display HTML for in KBytes.
24517 Defaults to @samp{0}.
24521 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24522 Maximum statistics period. Valid values are @samp{week},@samp{month},
24523 @samp{quarter} and @samp{year}.
24525 Defaults to @samp{""}.
24529 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24530 Mimetype for the specified filename extension.
24532 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24533 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24534 "image/png") (svg "image/svg+xml"))}.
24538 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24539 Specifies the file to use for automatic mimetype lookup.
24541 Defaults to @samp{""}.
24545 @deftypevr {@code{cgit-configuration} parameter} string module-link
24546 Text which will be used as the formatstring for a hyperlink when a
24547 submodule is printed in a directory listing.
24549 Defaults to @samp{""}.
24553 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24554 If set to the value @samp{#t} caching will be disabled.
24556 Defaults to @samp{#f}.
24560 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24561 If set to @samp{#t} showing full author email addresses will be
24564 Defaults to @samp{#f}.
24568 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24569 Flag which, when set to @samp{#t}, will make cgit omit the standard
24570 header on all pages.
24572 Defaults to @samp{#f}.
24576 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24577 A list of subdirectories inside of @code{repository-directory}, relative
24578 to it, that should loaded as Git repositories. An empty list means that
24579 all subdirectories will be loaded.
24581 Defaults to @samp{()}.
24585 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24586 Text which will be used as default value for @code{cgit-repo-readme}.
24588 Defaults to @samp{""}.
24592 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24593 If set to @code{#t} and @code{repository-directory} is enabled, if any
24594 repositories are found with a suffix of @code{.git}, this suffix will be
24595 removed for the URL and name.
24597 Defaults to @samp{#f}.
24601 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24602 Maximum number of files to consider when detecting renames.
24604 Defaults to @samp{-1}.
24608 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24609 The way in which repositories in each section are sorted.
24611 Defaults to @samp{""}.
24615 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24616 Text used as content for the @code{robots} meta-tag.
24618 Defaults to @samp{("noindex" "nofollow")}.
24622 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24623 Text printed below the heading on the repository index page.
24625 Defaults to @samp{"a fast webinterface for the git dscm"}.
24629 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24630 The content of the file specified with this option will be included
24631 verbatim below the "about" link on the repository index page.
24633 Defaults to @samp{""}.
24637 @deftypevr {@code{cgit-configuration} parameter} string root-title
24638 Text printed as heading on the repository index page.
24640 Defaults to @samp{""}.
24644 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24645 If set to @samp{#t} and repository-directory is enabled,
24646 repository-directory will recurse into directories whose name starts
24647 with a period. Otherwise, repository-directory will stay away from such
24648 directories, considered as "hidden". Note that this does not apply to
24649 the ".git" directory in non-bare repos.
24651 Defaults to @samp{#f}.
24655 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24656 Text which specifies the default set of snapshot formats that cgit
24657 generates links for.
24659 Defaults to @samp{()}.
24663 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24664 Name of the directory to scan for repositories (represents
24667 Defaults to @samp{"/srv/git"}.
24671 @deftypevr {@code{cgit-configuration} parameter} string section
24672 The name of the current repository section - all repositories defined
24673 after this option will inherit the current section name.
24675 Defaults to @samp{""}.
24679 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24680 Flag which, when set to @samp{1}, will sort the sections on the
24681 repository listing by name.
24683 Defaults to @samp{""}.
24687 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24688 A number which, if defined prior to repository-directory, specifies how
24689 many path elements from each repo path to use as a default section name.
24691 Defaults to @samp{0}.
24695 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24696 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24699 Defaults to @samp{#f}.
24703 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24704 Specifies a command which will be invoked to format plaintext blobs in
24707 Defaults to @samp{""}.
24711 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24712 Specifies the number of branches to display in the repository "summary"
24715 Defaults to @samp{10}.
24719 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24720 Specifies the number of log entries to display in the repository
24723 Defaults to @samp{10}.
24727 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24728 Specifies the number of tags to display in the repository "summary"
24731 Defaults to @samp{10}.
24735 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24736 Filename which, if specified, needs to be present within the repository
24737 for cgit to allow access to that repository.
24739 Defaults to @samp{""}.
24743 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24744 URL which, if specified, will be used as root for all cgit links.
24746 Defaults to @samp{"/"}.
24750 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24751 A list of @dfn{cgit-repo} records to use with config.
24753 Defaults to @samp{()}.
24755 Available @code{repository-cgit-configuration} fields are:
24757 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24758 A mask of snapshot formats for this repo that cgit generates links for,
24759 restricted by the global @code{snapshots} setting.
24761 Defaults to @samp{()}.
24765 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24766 Override the default @code{source-filter}.
24768 Defaults to @samp{""}.
24772 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24773 The relative URL used to access the repository.
24775 Defaults to @samp{""}.
24779 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24780 Override the default @code{about-filter}.
24782 Defaults to @samp{""}.
24786 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24787 Flag which, when set to @samp{age}, enables date ordering in the branch
24788 ref list, and when set to @samp{name} enables ordering by branch name.
24790 Defaults to @samp{""}.
24794 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24795 A list of URLs which can be used to clone repo.
24797 Defaults to @samp{()}.
24801 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24802 Override the default @code{commit-filter}.
24804 Defaults to @samp{""}.
24808 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24809 Flag which, when set to @samp{date}, enables strict date ordering in the
24810 commit log, and when set to @samp{topo} enables strict topological
24813 Defaults to @samp{""}.
24817 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24818 The name of the default branch for this repository. If no such branch
24819 exists in the repository, the first branch name (when sorted) is used as
24820 default instead. By default branch pointed to by HEAD, or "master" if
24821 there is no suitable HEAD.
24823 Defaults to @samp{""}.
24827 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24828 The value to show as repository description.
24830 Defaults to @samp{""}.
24834 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24835 The value to show as repository homepage.
24837 Defaults to @samp{""}.
24841 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24842 Override the default @code{email-filter}.
24844 Defaults to @samp{""}.
24848 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24849 A flag which can be used to disable the global setting
24850 @code{enable-commit-graph?}.
24852 Defaults to @samp{disabled}.
24856 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24857 A flag which can be used to disable the global setting
24858 @code{enable-log-filecount?}.
24860 Defaults to @samp{disabled}.
24864 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24865 A flag which can be used to disable the global setting
24866 @code{enable-log-linecount?}.
24868 Defaults to @samp{disabled}.
24872 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24873 Flag which, when set to @code{#t}, will make cgit display remote
24874 branches in the summary and refs views.
24876 Defaults to @samp{disabled}.
24880 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24881 A flag which can be used to override the global setting
24882 @code{enable-subject-links?}.
24884 Defaults to @samp{disabled}.
24888 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24889 A flag which can be used to override the global setting
24890 @code{enable-html-serving?}.
24892 Defaults to @samp{disabled}.
24896 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24897 Flag which, when set to @code{#t}, hides the repository from the
24900 Defaults to @samp{#f}.
24904 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24905 Flag which, when set to @samp{#t}, ignores the repository.
24907 Defaults to @samp{#f}.
24911 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24912 URL which specifies the source of an image which will be used as a logo
24913 on this repo’s pages.
24915 Defaults to @samp{""}.
24919 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24920 URL loaded when clicking on the cgit logo image.
24922 Defaults to @samp{""}.
24926 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24927 Override the default @code{owner-filter}.
24929 Defaults to @samp{""}.
24933 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24934 Text which will be used as the formatstring for a hyperlink when a
24935 submodule is printed in a directory listing. The arguments for the
24936 formatstring are the path and SHA1 of the submodule commit.
24938 Defaults to @samp{""}.
24942 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24943 Text which will be used as the formatstring for a hyperlink when a
24944 submodule with the specified subdirectory path is printed in a directory
24947 Defaults to @samp{()}.
24951 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24952 Override the default maximum statistics period.
24954 Defaults to @samp{""}.
24958 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24959 The value to show as repository name.
24961 Defaults to @samp{""}.
24965 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24966 A value used to identify the owner of the repository.
24968 Defaults to @samp{""}.
24972 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24973 An absolute path to the repository directory.
24975 Defaults to @samp{""}.
24979 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24980 A path (relative to repo) which specifies a file to include verbatim as
24981 the "About" page for this repo.
24983 Defaults to @samp{""}.
24987 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24988 The name of the current repository section - all repositories defined
24989 after this option will inherit the current section name.
24991 Defaults to @samp{""}.
24995 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24996 Extra options will be appended to cgitrc file.
24998 Defaults to @samp{()}.
25004 @deftypevr {@code{cgit-configuration} parameter} list extra-options
25005 Extra options will be appended to cgitrc file.
25007 Defaults to @samp{()}.
25012 @c %end of fragment
25014 However, it could be that you just want to get a @code{cgitrc} up and
25015 running. In that case, you can pass an @code{opaque-cgit-configuration}
25016 as a record to @code{cgit-service-type}. As its name indicates, an
25017 opaque configuration does not have easy reflective capabilities.
25019 Available @code{opaque-cgit-configuration} fields are:
25021 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
25025 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
25026 The contents of the @code{cgitrc}, as a string.
25029 For example, if your @code{cgitrc} is just the empty string, you
25030 could instantiate a cgit service like this:
25033 (service cgit-service-type
25034 (opaque-cgit-configuration
25038 @subsubheading Gitolite Service
25040 @cindex Gitolite service
25041 @cindex Git, hosting
25042 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
25043 repositories on a central server.
25045 Gitolite can handle multiple repositories and users, and supports flexible
25046 configuration of the permissions for the users on the repositories.
25048 The following example will configure Gitolite using the default @code{git}
25049 user, and the provided SSH public key.
25052 (service gitolite-service-type
25053 (gitolite-configuration
25054 (admin-pubkey (plain-file
25056 "ssh-rsa AAAA... guix@@example.com"))))
25059 Gitolite is configured through a special admin repository which you can clone,
25060 for example, if you setup Gitolite on @code{example.com}, you would run the
25061 following command to clone the admin repository.
25064 git clone git@@example.com:gitolite-admin
25067 When the Gitolite service is activated, the provided @code{admin-pubkey} will
25068 be inserted in to the @file{keydir} directory in the gitolite-admin
25069 repository. If this results in a change in the repository, it will be
25070 committed using the message ``gitolite setup by GNU Guix''.
25072 @deftp {Data Type} gitolite-configuration
25073 Data type representing the configuration for @code{gitolite-service-type}.
25076 @item @code{package} (default: @var{gitolite})
25077 Gitolite package to use.
25079 @item @code{user} (default: @var{git})
25080 User to use for Gitolite. This will be user that you use when accessing
25083 @item @code{group} (default: @var{git})
25084 Group to use for Gitolite.
25086 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
25087 Directory in which to store the Gitolite configuration and repositories.
25089 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
25090 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
25091 representing the configuration for Gitolite.
25093 @item @code{admin-pubkey} (default: @var{#f})
25094 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
25095 setup Gitolite. This will be inserted in to the @file{keydir} directory
25096 within the gitolite-admin repository.
25098 To specify the SSH key as a string, use the @code{plain-file} function.
25101 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
25107 @deftp {Data Type} gitolite-rc-file
25108 Data type representing the Gitolite RC file.
25111 @item @code{umask} (default: @code{#o0077})
25112 This controls the permissions Gitolite sets on the repositories and their
25115 A value like @code{#o0027} will give read access to the group used by Gitolite
25116 (by default: @code{git}). This is necessary when using Gitolite with software
25117 like cgit or gitweb.
25119 @item @code{git-config-keys} (default: @code{""})
25120 Gitolite allows you to set git config values using the "config" keyword. This
25121 setting allows control over the config keys to accept.
25123 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
25124 Set the role names allowed to be used by users running the perms command.
25126 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
25127 This setting controls the commands and features to enable within Gitolite.
25133 @node Game Services
25134 @subsection Game Services
25136 @subsubheading The Battle for Wesnoth Service
25138 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
25139 based tactical strategy game, with several single player campaigns, and
25140 multiplayer games (both networked and local).
25142 @defvar {Scheme Variable} wesnothd-service-type
25143 Service type for the wesnothd service. Its value must be a
25144 @code{wesnothd-configuration} object. To run wesnothd in the default
25145 configuration, instantiate it as:
25148 (service wesnothd-service-type)
25152 @deftp {Data Type} wesnothd-configuration
25153 Data type representing the configuration of @command{wesnothd}.
25156 @item @code{package} (default: @code{wesnoth-server})
25157 The wesnoth server package to use.
25159 @item @code{port} (default: @code{15000})
25160 The port to bind the server to.
25165 @node PAM Mount Service
25166 @subsection PAM Mount Service
25169 The @code{(gnu services pam-mount)} module provides a service allowing
25170 users to mount volumes when they log in. It should be able to mount any
25171 volume format supported by the system.
25173 @defvar {Scheme Variable} pam-mount-service-type
25174 Service type for PAM Mount support.
25177 @deftp {Data Type} pam-mount-configuration
25178 Data type representing the configuration of PAM Mount.
25180 It takes the following parameters:
25184 The configuration rules that will be used to generate
25185 @file{/etc/security/pam_mount.conf.xml}.
25187 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
25188 Guile Reference Manual}), and the the default ones don't mount anything
25189 for anyone at login:
25192 `((debug (@@ (enable "0")))
25193 (mntoptions (@@ (allow ,(string-join
25194 '("nosuid" "nodev" "loop"
25195 "encryption" "fsck" "nonempty"
25196 "allow_root" "allow_other")
25198 (mntoptions (@@ (require "nosuid,nodev")))
25199 (logout (@@ (wait "0")
25203 (mkmountpoint (@@ (enable "1")
25207 Some @code{volume} elements must be added to automatically mount volumes
25208 at login. Here's an example allowing the user @code{alice} to mount her
25209 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
25210 the partition where he stores his data:
25213 (define pam-mount-rules
25214 `((debug (@@ (enable "0")))
25215 (volume (@@ (user "alice")
25218 (mountpoint "/home/alice")))
25219 (volume (@@ (user "bob")
25222 (mountpoint "/home/bob/data")
25223 (options "defaults,autodefrag,compress")))
25224 (mntoptions (@@ (allow ,(string-join
25225 '("nosuid" "nodev" "loop"
25226 "encryption" "fsck" "nonempty"
25227 "allow_root" "allow_other")
25229 (mntoptions (@@ (require "nosuid,nodev")))
25230 (logout (@@ (wait "0")
25234 (mkmountpoint (@@ (enable "1")
25235 (remove "true")))))
25237 (service pam-mount-service-type
25238 (pam-mount-configuration
25239 (rules pam-mount-rules)))
25242 The complete list of possible options can be found in the man page for
25243 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25248 @node Guix Services
25249 @subsection Guix Services
25251 @subsubheading Guix Data Service
25252 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25253 and provides data about GNU Guix. This includes information about
25254 packages, derivations and lint warnings.
25256 The data is stored in a PostgreSQL database, and available through a web
25259 @defvar {Scheme Variable} guix-data-service-type
25260 Service type for the Guix Data Service. Its value must be a
25261 @code{guix-data-service-configuration} object. The service optionally
25262 extends the getmail service, as the guix-commits mailing list is used to
25263 find out about changes in the Guix git repository.
25266 @deftp {Data Type} guix-data-service-configuration
25267 Data type representing the configuration of the Guix Data Service.
25270 @item @code{package} (default: @code{guix-data-service})
25271 The Guix Data Service package to use.
25273 @item @code{user} (default: @code{"guix-data-service"})
25274 The system user to run the service as.
25276 @item @code{group} (default: @code{"guix-data-service"})
25277 The system group to run the service as.
25279 @item @code{port} (default: @code{8765})
25280 The port to bind the web service to.
25282 @item @code{host} (default: @code{"127.0.0.1"})
25283 The host to bind the web service to.
25285 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25286 If set, this is the list of mailboxes that the getmail service will be
25287 configured to listen to.
25289 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25290 If set, this is the @code{getmail-retriever-configuration} object with
25291 which to configure getmail to fetch mail from the guix-commits mailing
25294 @item @code{extra-options} (default: @var{'()})
25295 Extra command line options for @code{guix-data-service}.
25297 @item @code{extra-process-jobs-options} (default: @var{'()})
25298 Extra command line options for @code{guix-data-service-process-jobs}.
25303 @node Linux Services
25304 @subsubheading Linux Services
25307 @cindex out of memory killer
25309 @cindex early out of memory daemon
25310 @subsection Early OOM Service
25312 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
25313 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
25314 space and provides a more responsive and configurable alternative to the
25315 in-kernel OOM killer. It is useful to prevent the system from becoming
25316 unresponsive when it runs out of memory.
25318 @deffn {Scheme Variable} earlyoom-service-type
25319 The service type for running @command{earlyoom}, the Early OOM daemon.
25320 Its value must be a @code{earlyoom-configuration} object, described
25321 below. The service can be instantiated in its default configuration
25325 (service earlyoom-service-type)
25329 @deftp {Data Type} earlyoom-configuration
25330 This is the configuration record for the @code{earlyoom-service-type}.
25333 @item @code{earlyoom} (default: @var{earlyoom})
25334 The Earlyoom package to use.
25336 @item @code{minimum-available-memory} (default: @code{10})
25337 The threshold for the minimum @emph{available} memory, in percentages.
25339 @item @code{minimum-free-swap} (default: @code{10})
25340 The threshold for the minimum free swap memory, in percentages.
25342 @item @code{prefer-regexp} (default: @code{#f})
25343 A regular expression (as a string) to match the names of the processes
25344 that should be preferably killed.
25346 @item @code{avoid-regexp} (default: @code{#f})
25347 A regular expression (as a string) to match the names of the processes
25348 that should @emph{not} be killed.
25350 @item @code{memory-report-interval} (default: @code{0})
25351 The interval in seconds at which a memory report is printed. It is
25352 disabled by default.
25354 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
25355 A boolean indicating whether the positive adjustments set in
25356 @file{/proc/*/oom_score_adj}.
25358 @item @code{show-debug-messages?} (default: @code{#f})
25359 A boolean indicating whether debug messages should be printed. The logs
25360 are saved at @file{/var/log/earlyoom.log}.
25362 @item @code{send-notification-command} (default: @code{#f})
25363 This can be used to provide a custom command used for sending
25369 @node Miscellaneous Services
25370 @subsection Miscellaneous Services
25372 @cindex fingerprint
25373 @subsubheading Fingerprint Service
25375 The @code{(gnu services authentication)} module provides a DBus service to
25376 read and identify fingerprints via a fingerprint sensor.
25378 @defvr {Scheme Variable} fprintd-service-type
25379 The service type for @command{fprintd}, which provides the fingerprint
25380 reading capability.
25383 (service fprintd-service-type)
25388 @subsubheading System Control Service
25390 The @code{(gnu services sysctl)} provides a service to configure kernel
25391 parameters at boot.
25393 @defvr {Scheme Variable} sysctl-service-type
25394 The service type for @command{sysctl}, which modifies kernel parameters
25395 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25399 (service sysctl-service-type
25400 (sysctl-configuration
25401 (settings '(("net.ipv4.ip_forward" . "1")))))
25405 @deftp {Data Type} sysctl-configuration
25406 The data type representing the configuration of @command{sysctl}.
25409 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25410 The @command{sysctl} executable to use.
25412 @item @code{settings} (default: @code{'()})
25413 An association list specifies kernel parameters and their values.
25418 @subsubheading PC/SC Smart Card Daemon Service
25420 The @code{(gnu services security-token)} module provides the following service
25421 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25422 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25423 manager that coordinates communications with smart card readers, smart cards
25424 and cryptographic tokens that are connected to the system.
25426 @defvr {Scheme Variable} pcscd-service-type
25427 Service type for the @command{pcscd} service. Its value must be a
25428 @code{pcscd-configuration} object. To run pcscd in the default
25429 configuration, instantiate it as:
25432 (service pcscd-service-type)
25436 @deftp {Data Type} pcscd-configuration
25437 The data type representing the configuration of @command{pcscd}.
25440 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25441 The pcsc-lite package that provides pcscd.
25442 @item @code{usb-drivers} (default: @code{(list ccid)})
25443 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25444 under @file{pcsc/drivers} in the store directory of the package.
25449 @subsubheading Lirc Service
25451 The @code{(gnu services lirc)} module provides the following service.
25453 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25454 [#:device #f] [#:driver #f] [#:config-file #f] @
25455 [#:extra-options '()]
25456 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25457 decodes infrared signals from remote controls.
25459 Optionally, @var{device}, @var{driver} and @var{config-file}
25460 (configuration file name) may be specified. See @command{lircd} manual
25463 Finally, @var{extra-options} is a list of additional command-line options
25464 passed to @command{lircd}.
25468 @subsubheading Spice Service
25470 The @code{(gnu services spice)} module provides the following service.
25472 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25473 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25474 that enables sharing the clipboard with a vm and setting the guest display
25475 resolution when the graphical console window resizes.
25478 @cindex inputattach
25479 @subsubheading inputattach Service
25481 @cindex tablet input, for Xorg
25482 @cindex touchscreen input, for Xorg
25483 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25484 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25485 Xorg display server.
25487 @deffn {Scheme Variable} inputattach-service-type
25488 Type of a service that runs @command{inputattach} on a device and
25489 dispatches events from it.
25492 @deftp {Data Type} inputattach-configuration
25494 @item @code{device-type} (default: @code{"wacom"})
25495 The type of device to connect to. Run @command{inputattach --help}, from the
25496 @code{inputattach} package, to see the list of supported device types.
25498 @item @code{device} (default: @code{"/dev/ttyS0"})
25499 The device file to connect to the device.
25501 @item @code{baud-rate} (default: @code{#f})
25502 Baud rate to use for the serial connection.
25503 Should be a number or @code{#f}.
25505 @item @code{log-file} (default: @code{#f})
25506 If true, this must be the name of a file to log messages to.
25510 @subsection Dictionary Services
25512 The @code{(gnu services dict)} module provides the following service:
25514 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25515 Return a service that runs the @command{dicod} daemon, an implementation
25516 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25518 The optional @var{config} argument specifies the configuration for
25519 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25520 default it serves the GNU Collaborative International Dictionary of English.
25522 You can add @command{open localhost} to your @file{~/.dico} file to make
25523 @code{localhost} the default server for @command{dico} client
25524 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25527 @deftp {Data Type} dicod-configuration
25528 Data type representing the configuration of dicod.
25531 @item @code{dico} (default: @var{dico})
25532 Package object of the GNU Dico dictionary server.
25534 @item @code{interfaces} (default: @var{'("localhost")})
25535 This is the list of IP addresses and ports and possibly socket file
25536 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25537 dico, GNU Dico Manual}).
25539 @item @code{handlers} (default: @var{'()})
25540 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25542 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25543 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25547 @deftp {Data Type} dicod-handler
25548 Data type representing a dictionary handler (module instance).
25552 Name of the handler (module instance).
25554 @item @code{module} (default: @var{#f})
25555 Name of the dicod module of the handler (instance). If it is @code{#f},
25556 the module has the same name as the handler.
25557 (@pxref{Modules,,, dico, GNU Dico Manual}).
25559 @item @code{options}
25560 List of strings or gexps representing the arguments for the module handler
25564 @deftp {Data Type} dicod-database
25565 Data type representing a dictionary database.
25569 Name of the database, will be used in DICT commands.
25571 @item @code{handler}
25572 Name of the dicod handler (module instance) used by this database
25573 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25575 @item @code{complex?} (default: @var{#f})
25576 Whether the database configuration complex. The complex configuration
25577 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25579 @item @code{options}
25580 List of strings or gexps representing the arguments for the database
25581 (@pxref{Databases,,, dico, GNU Dico Manual}).
25585 @defvr {Scheme Variable} %dicod-database:gcide
25586 A @code{<dicod-database>} object serving the GNU Collaborative International
25587 Dictionary of English using the @code{gcide} package.
25590 The following is an example @code{dicod-service} configuration.
25593 (dicod-service #:config
25594 (dicod-configuration
25595 (handlers (list (dicod-handler
25599 (list #~(string-append "dbdir=" #$wordnet))))))
25600 (databases (list (dicod-database
25603 (handler "wordnet")
25604 (options '("database=wn")))
25605 %dicod-database:gcide))))
25609 @subsubheading Docker Service
25611 The @code{(gnu services docker)} module provides the following services.
25613 @defvr {Scheme Variable} docker-service-type
25615 This is the type of the service that runs @url{https://www.docker.com,Docker},
25616 a daemon that can execute application bundles (sometimes referred to as
25617 ``containers'') in isolated environments.
25621 @deftp {Data Type} docker-configuration
25622 This is the data type representing the configuration of Docker and Containerd.
25626 @item @code{package} (default: @code{docker})
25627 The Docker package to use.
25629 @item @code{containerd} (default: @var{containerd})
25630 The Containerd package to use.
25636 @subsubheading Auditd Service
25638 The @code{(gnu services auditd)} module provides the following service.
25640 @defvr {Scheme Variable} auditd-service-type
25642 This is the type of the service that runs
25643 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25644 a daemon that tracks security-relevant information on your system.
25646 Examples of things that can be tracked:
25656 Failed login attempts
25663 @command{auditctl} from the @code{audit} package can be used in order
25664 to add or remove events to be tracked (until the next reboot).
25665 In order to permanently track events, put the command line arguments
25666 of auditctl into @file{/etc/audit/audit.rules}.
25667 @command{aureport} from the @code{audit} package can be used in order
25668 to view a report of all recorded events.
25669 The audit daemon usually logs into the directory @file{/var/log/audit}.
25673 @deftp {Data Type} auditd-configuration
25674 This is the data type representing the configuration of auditd.
25678 @item @code{audit} (default: @code{audit})
25679 The audit package to use.
25684 @defvr {Scheme Variable} singularity-service-type
25685 This is the type of the service that allows you to run
25686 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25687 create and run application bundles (aka. ``containers''). The value for this
25688 service is the Singularity package to use.
25690 The service does not install a daemon; instead, it installs helper programs as
25691 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25692 @command{singularity run} and similar commands.
25696 @subsubheading Nix service
25698 The @code{(gnu services nix)} module provides the following service.
25700 @defvr {Scheme Variable} nix-service-type
25702 This is the type of the service that runs build daemon of the
25703 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25707 (use-modules (gnu))
25708 (use-service-modules nix)
25709 (use-package-modules package-management)
25713 (packages (append (list nix)
25716 (services (append (list (service nix-service-type))
25720 After @command{guix system reconfigure} configure Nix for your user:
25723 @item Add a Nix channel and update it. See
25724 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25726 @item Create a symlink to your profile and activate Nix profile:
25730 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25731 $ source /run/current-system/profile/etc/profile.d/nix.sh
25736 @node Setuid Programs
25737 @section Setuid Programs
25739 @cindex setuid programs
25740 Some programs need to run with ``root'' privileges, even when they are
25741 launched by unprivileged users. A notorious example is the
25742 @command{passwd} program, which users can run to change their
25743 password, and which needs to access the @file{/etc/passwd} and
25744 @file{/etc/shadow} files---something normally restricted to root, for
25745 obvious security reasons. To address that, these executables are
25746 @dfn{setuid-root}, meaning that they always run with root privileges
25747 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25748 for more info about the setuid mechanism.)
25750 The store itself @emph{cannot} contain setuid programs: that would be a
25751 security issue since any user on the system can write derivations that
25752 populate the store (@pxref{The Store}). Thus, a different mechanism is
25753 used: instead of changing the setuid bit directly on files that are in
25754 the store, we let the system administrator @emph{declare} which programs
25755 should be setuid root.
25757 The @code{setuid-programs} field of an @code{operating-system}
25758 declaration contains a list of G-expressions denoting the names of
25759 programs to be setuid-root (@pxref{Using the Configuration System}).
25760 For instance, the @command{passwd} program, which is part of the Shadow
25761 package, can be designated by this G-expression (@pxref{G-Expressions}):
25764 #~(string-append #$shadow "/bin/passwd")
25767 A default set of setuid programs is defined by the
25768 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25770 @defvr {Scheme Variable} %setuid-programs
25771 A list of G-expressions denoting common programs that are setuid-root.
25773 The list includes commands such as @command{passwd}, @command{ping},
25774 @command{su}, and @command{sudo}.
25777 Under the hood, the actual setuid programs are created in the
25778 @file{/run/setuid-programs} directory at system activation time. The
25779 files in this directory refer to the ``real'' binaries, which are in the
25782 @node X.509 Certificates
25783 @section X.509 Certificates
25785 @cindex HTTPS, certificates
25786 @cindex X.509 certificates
25788 Web servers available over HTTPS (that is, HTTP over the transport-layer
25789 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25790 that the client can then use to @emph{authenticate} the server. To do
25791 that, clients verify that the server's certificate is signed by a
25792 so-called @dfn{certificate authority} (CA). But to verify the CA's
25793 signature, clients must have first acquired the CA's certificate.
25795 Web browsers such as GNU@tie{}IceCat include their own set of CA
25796 certificates, such that they are able to verify CA signatures
25799 However, most other programs that can talk HTTPS---@command{wget},
25800 @command{git}, @command{w3m}, etc.---need to be told where CA
25801 certificates can be found.
25803 @cindex @code{nss-certs}
25804 In Guix, this is done by adding a package that provides certificates
25805 to the @code{packages} field of the @code{operating-system} declaration
25806 (@pxref{operating-system Reference}). Guix includes one such package,
25807 @code{nss-certs}, which is a set of CA certificates provided as part of
25808 Mozilla's Network Security Services.
25810 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25811 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25812 most applications and libraries look for certificates by default, points
25813 to the certificates installed globally.
25815 Unprivileged users, including users of Guix on a foreign distro,
25816 can also install their own certificate package in
25817 their profile. A number of environment variables need to be defined so
25818 that applications and libraries know where to find them. Namely, the
25819 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25820 variables. Some applications add their own environment variables; for
25821 instance, the Git version control system honors the certificate bundle
25822 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25823 would typically run something like:
25826 $ guix install nss-certs
25827 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25828 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25829 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25832 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25833 variable to point to a certificate bundle, so you would have to run
25834 something like this:
25837 $ guix install nss-certs
25838 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25841 For other applications you may want to look up the required environment
25842 variable in the relevant documentation.
25845 @node Name Service Switch
25846 @section Name Service Switch
25848 @cindex name service switch
25850 The @code{(gnu system nss)} module provides bindings to the
25851 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25852 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25853 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25854 extended with new ``name'' lookup methods for system databases, which
25855 includes host names, service names, user accounts, and more (@pxref{Name
25856 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25857 C Library Reference Manual}).
25859 The NSS configuration specifies, for each system database, which lookup
25860 method is to be used, and how the various methods are chained
25861 together---for instance, under which circumstances NSS should try the
25862 next method in the list. The NSS configuration is given in the
25863 @code{name-service-switch} field of @code{operating-system} declarations
25864 (@pxref{operating-system Reference, @code{name-service-switch}}).
25867 @cindex .local, host name lookup
25868 As an example, the declaration below configures the NSS to use the
25869 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25870 back-end}, which supports host name lookups over multicast DNS (mDNS)
25871 for host names ending in @code{.local}:
25874 (name-service-switch
25875 (hosts (list %files ;first, check /etc/hosts
25877 ;; If the above did not succeed, try
25878 ;; with 'mdns_minimal'.
25880 (name "mdns_minimal")
25882 ;; 'mdns_minimal' is authoritative for
25883 ;; '.local'. When it returns "not found",
25884 ;; no need to try the next methods.
25885 (reaction (lookup-specification
25886 (not-found => return))))
25888 ;; Then fall back to DNS.
25892 ;; Finally, try with the "full" 'mdns'.
25897 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25898 contains this configuration, so you will not have to type it if all you
25899 want is to have @code{.local} host lookup working.
25901 Note that, in this case, in addition to setting the
25902 @code{name-service-switch} of the @code{operating-system} declaration,
25903 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25904 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25905 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25906 to the name service cache daemon (@pxref{Base Services,
25907 @code{nscd-service}}).
25909 For convenience, the following variables provide typical NSS
25912 @defvr {Scheme Variable} %default-nss
25913 This is the default name service switch configuration, a
25914 @code{name-service-switch} object.
25917 @defvr {Scheme Variable} %mdns-host-lookup-nss
25918 This is the name service switch configuration with support for host name
25919 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25922 The reference for name service switch configuration is given below. It
25923 is a direct mapping of the configuration file format of the C library , so
25924 please refer to the C library manual for more information (@pxref{NSS
25925 Configuration File,,, libc, The GNU C Library Reference Manual}).
25926 Compared to the configuration file format of libc NSS, it has the advantage
25927 not only of adding this warm parenthetic feel that we like, but also
25928 static checks: you will know about syntax errors and typos as soon as you
25929 run @command{guix system}.
25931 @deftp {Data Type} name-service-switch
25933 This is the data type representation the configuration of libc's name
25934 service switch (NSS). Each field below represents one of the supported
25951 The system databases handled by the NSS. Each of these fields must be a
25952 list of @code{<name-service>} objects (see below).
25956 @deftp {Data Type} name-service
25958 This is the data type representing an actual name service and the
25959 associated lookup action.
25963 A string denoting the name service (@pxref{Services in the NSS
25964 configuration,,, libc, The GNU C Library Reference Manual}).
25966 Note that name services listed here must be visible to nscd. This is
25967 achieved by passing the @code{#:name-services} argument to
25968 @code{nscd-service} the list of packages providing the needed name
25969 services (@pxref{Base Services, @code{nscd-service}}).
25972 An action specified using the @code{lookup-specification} macro
25973 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25974 Reference Manual}). For example:
25977 (lookup-specification (unavailable => continue)
25978 (success => return))
25983 @node Initial RAM Disk
25984 @section Initial RAM Disk
25987 @cindex initial RAM disk
25988 For bootstrapping purposes, the Linux-Libre kernel is passed an
25989 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25990 root file system as well as an initialization script. The latter is
25991 responsible for mounting the real root file system, and for loading any
25992 kernel modules that may be needed to achieve that.
25994 The @code{initrd-modules} field of an @code{operating-system}
25995 declaration allows you to specify Linux-libre kernel modules that must
25996 be available in the initrd. In particular, this is where you would list
25997 modules needed to actually drive the hard disk where your root partition
25998 is---although the default value of @code{initrd-modules} should cover
25999 most use cases. For example, assuming you need the @code{megaraid_sas}
26000 module in addition to the default modules to be able to access your root
26001 file system, you would write:
26006 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
26009 @defvr {Scheme Variable} %base-initrd-modules
26010 This is the list of kernel modules included in the initrd by default.
26013 Furthermore, if you need lower-level customization, the @code{initrd}
26014 field of an @code{operating-system} declaration allows
26015 you to specify which initrd you would like to use. The @code{(gnu
26016 system linux-initrd)} module provides three ways to build an initrd: the
26017 high-level @code{base-initrd} procedure and the low-level
26018 @code{raw-initrd} and @code{expression->initrd} procedures.
26020 The @code{base-initrd} procedure is intended to cover most common uses.
26021 For example, if you want to add a bunch of kernel modules to be loaded
26022 at boot time, you can define the @code{initrd} field of the operating
26023 system declaration like this:
26026 (initrd (lambda (file-systems . rest)
26027 ;; Create a standard initrd but set up networking
26028 ;; with the parameters QEMU expects by default.
26029 (apply base-initrd file-systems
26030 #:qemu-networking? #t
26034 The @code{base-initrd} procedure also handles common use cases that
26035 involves using the system as a QEMU guest, or as a ``live'' system with
26036 volatile root file system.
26038 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
26039 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
26040 such as trying to guess which kernel modules and packages should be included
26041 to the initrd. An example use of @code{raw-initrd} is when a user has
26042 a custom Linux kernel configuration and default kernel modules included by
26043 @code{base-initrd} are not available.
26045 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
26046 honors several options passed on the Linux kernel command line
26047 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
26048 @code{-append} option of QEMU), notably:
26051 @item --load=@var{boot}
26052 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
26053 program, once it has mounted the root file system.
26055 Guix uses this option to yield control to a boot program that runs the
26056 service activation programs and then spawns the GNU@tie{}Shepherd, the
26057 initialization system.
26059 @item --root=@var{root}
26060 Mount @var{root} as the root file system. @var{root} can be a
26061 device name like @code{/dev/sda1}, a file system label, or a file system
26064 @item --system=@var{system}
26065 Have @file{/run/booted-system} and @file{/run/current-system} point to
26068 @item modprobe.blacklist=@var{modules}@dots{}
26069 @cindex module, black-listing
26070 @cindex black list, of kernel modules
26071 Instruct the initial RAM disk as well as the @command{modprobe} command
26072 (from the kmod package) to refuse to load @var{modules}. @var{modules}
26073 must be a comma-separated list of module names---e.g.,
26074 @code{usbkbd,9pnet}.
26077 Start a read-eval-print loop (REPL) from the initial RAM disk before it
26078 tries to load kernel modules and to mount the root file system. Our
26079 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
26080 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
26081 Manual}, for more information on Guile's REPL.
26085 Now that you know all the features that initial RAM disks produced by
26086 @code{base-initrd} and @code{raw-initrd} provide,
26087 here is how to use it and customize it further.
26090 @cindex initial RAM disk
26091 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
26092 [#:linux-modules '()] [#:mapped-devices '()] @
26093 [#:keyboard-layout #f] @
26094 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
26095 Return a derivation that builds a raw initrd. @var{file-systems} is
26096 a list of file systems to be mounted by the initrd, possibly in addition to
26097 the root file system specified on the kernel command line via @code{--root}.
26098 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
26099 @var{mapped-devices} is a list of device mappings to realize before
26100 @var{file-systems} are mounted (@pxref{Mapped Devices}).
26101 @var{helper-packages} is a list of packages to be copied in the initrd. It may
26102 include @code{e2fsck/static} or other packages needed by the initrd to check
26103 the root file system.
26105 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26106 the desired console keyboard layout. This is done before @var{mapped-devices}
26107 are set up and before @var{file-systems} are mounted such that, should the
26108 user need to enter a passphrase or use the REPL, this happens using the
26109 intended keyboard layout.
26111 When @var{qemu-networking?} is true, set up networking with the standard QEMU
26112 parameters. When @var{virtio?} is true, load additional modules so that the
26113 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
26115 When @var{volatile-root?} is true, the root file system is writable but any changes
26119 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
26120 [#:mapped-devices '()] [#:keyboard-layout #f] @
26121 [#:qemu-networking? #f] [#:volatile-root? #f] @
26122 [#:linux-modules '()]
26123 Return as a file-like object a generic initrd, with kernel
26124 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
26125 mounted by the initrd, possibly in addition to the root file system specified
26126 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
26127 mappings to realize before @var{file-systems} are mounted.
26129 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26130 the desired console keyboard layout. This is done before @var{mapped-devices}
26131 are set up and before @var{file-systems} are mounted such that, should the
26132 user need to enter a passphrase or use the REPL, this happens using the
26133 intended keyboard layout.
26135 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
26137 The initrd is automatically populated with all the kernel modules necessary
26138 for @var{file-systems} and for the given options. Additional kernel
26139 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
26140 loaded at boot time in the order in which they appear.
26143 Needless to say, the initrds we produce and use embed a
26144 statically-linked Guile, and the initialization program is a Guile
26145 program. That gives a lot of flexibility. The
26146 @code{expression->initrd} procedure builds such an initrd, given the
26147 program to run in that initrd.
26149 @deffn {Scheme Procedure} expression->initrd @var{exp} @
26150 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
26151 Return as a file-like object a Linux initrd (a gzipped cpio archive)
26152 containing @var{guile} and that evaluates @var{exp}, a G-expression,
26153 upon booting. All the derivations referenced by @var{exp} are
26154 automatically copied to the initrd.
26157 @node Bootloader Configuration
26158 @section Bootloader Configuration
26161 @cindex boot loader
26163 The operating system supports multiple bootloaders. The bootloader is
26164 configured using @code{bootloader-configuration} declaration. All the
26165 fields of this structure are bootloader agnostic except for one field,
26166 @code{bootloader} that indicates the bootloader to be configured and
26169 Some of the bootloaders do not honor every field of
26170 @code{bootloader-configuration}. For instance, the extlinux
26171 bootloader does not support themes and thus ignores the @code{theme}
26174 @deftp {Data Type} bootloader-configuration
26175 The type of a bootloader configuration declaration.
26179 @item @code{bootloader}
26180 @cindex EFI, bootloader
26181 @cindex UEFI, bootloader
26182 @cindex BIOS, bootloader
26183 The bootloader to use, as a @code{bootloader} object. For now
26184 @code{grub-bootloader}, @code{grub-efi-bootloader},
26185 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
26187 @vindex grub-efi-bootloader
26188 @code{grub-efi-bootloader} allows to boot on modern systems using the
26189 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
26190 use if the installation image contains a @file{/sys/firmware/efi} directory
26191 when you boot it on your system.
26193 @vindex grub-bootloader
26194 @code{grub-bootloader} allows you to boot in particular Intel-based machines
26195 in ``legacy'' BIOS mode.
26197 @cindex ARM, bootloaders
26198 @cindex AArch64, bootloaders
26199 Available bootloaders are described in @code{(gnu bootloader @dots{})}
26200 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
26201 of bootloaders for a wide range of ARM and AArch64 systems, using the
26202 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
26204 @item @code{target}
26205 This is a string denoting the target onto which to install the
26208 The interpretation depends on the bootloader in question. For
26209 @code{grub-bootloader}, for example, it should be a device name understood by
26210 the bootloader @command{installer} command, such as @code{/dev/sda} or
26211 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
26212 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
26213 system, usually @file{/boot/efi}.
26215 @item @code{menu-entries} (default: @code{()})
26216 A possibly empty list of @code{menu-entry} objects (see below), denoting
26217 entries to appear in the bootloader menu, in addition to the current
26218 system entry and the entry pointing to previous system generations.
26220 @item @code{default-entry} (default: @code{0})
26221 The index of the default boot menu entry. Index 0 is for the entry of the
26224 @item @code{timeout} (default: @code{5})
26225 The number of seconds to wait for keyboard input before booting. Set to
26226 0 to boot immediately, and to -1 to wait indefinitely.
26228 @cindex keyboard layout, for the bootloader
26229 @item @code{keyboard-layout} (default: @code{#f})
26230 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
26231 layout, usually US@tie{}English (``qwerty'').
26233 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
26237 This option is currently ignored by bootloaders other than @code{grub} and
26241 @item @code{theme} (default: @var{#f})
26242 The bootloader theme object describing the theme to use. If no theme
26243 is provided, some bootloaders might use a default theme, that's true
26246 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
26247 The output terminals used for the bootloader boot menu, as a list of
26248 symbols. GRUB accepts the values: @code{console}, @code{serial},
26249 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
26250 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
26251 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
26252 configuration,,, grub,GNU GRUB manual}).
26254 @item @code{terminal-inputs} (default: @code{'()})
26255 The input terminals used for the bootloader boot menu, as a list of
26256 symbols. For GRUB, the default is the native platform terminal as
26257 determined at run-time. GRUB accepts the values: @code{console},
26258 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
26259 @code{usb_keyboard}. This field corresponds to the GRUB variable
26260 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
26263 @item @code{serial-unit} (default: @code{#f})
26264 The serial unit used by the bootloader, as an integer from 0 to 3.
26265 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
26266 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26268 @item @code{serial-speed} (default: @code{#f})
26269 The speed of the serial interface, as an integer. For GRUB, the
26270 default value is chosen at run-time; currently GRUB chooses
26271 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26278 Should you want to list additional boot menu entries @i{via} the
26279 @code{menu-entries} field above, you will need to create them with the
26280 @code{menu-entry} form. For example, imagine you want to be able to
26281 boot another distro (hard to imagine!), you can define a menu entry
26286 (label "The Other Distro")
26287 (linux "/boot/old/vmlinux-2.6.32")
26288 (linux-arguments '("root=/dev/sda2"))
26289 (initrd "/boot/old/initrd"))
26294 @deftp {Data Type} menu-entry
26295 The type of an entry in the bootloader menu.
26300 The label to show in the menu---e.g., @code{"GNU"}.
26303 The Linux kernel image to boot, for example:
26306 (file-append linux-libre "/bzImage")
26309 For GRUB, it is also possible to specify a device explicitly in the
26310 file path using GRUB's device naming convention (@pxref{Naming
26311 convention,,, grub, GNU GRUB manual}), for example:
26314 "(hd0,msdos1)/boot/vmlinuz"
26317 If the device is specified explicitly as above, then the @code{device}
26318 field is ignored entirely.
26320 @item @code{linux-arguments} (default: @code{()})
26321 The list of extra Linux kernel command-line arguments---e.g.,
26322 @code{("console=ttyS0")}.
26324 @item @code{initrd}
26325 A G-Expression or string denoting the file name of the initial RAM disk
26326 to use (@pxref{G-Expressions}).
26327 @item @code{device} (default: @code{#f})
26328 The device where the kernel and initrd are to be found---i.e., for GRUB,
26329 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26331 This may be a file system label (a string), a file system UUID (a
26332 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26333 the bootloader will search the device containing the file specified by
26334 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26335 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26343 @c FIXME: Write documentation once it's stable.
26344 For now only GRUB has theme support. GRUB themes are created using
26345 the @code{grub-theme} form, which is not fully documented yet.
26347 @deftp {Data Type} grub-theme
26348 Data type representing the configuration of the GRUB theme.
26351 @item @code{gfxmode} (default: @code{'("auto")})
26352 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
26353 @pxref{gfxmode,,, grub, GNU GRUB manual}).
26357 @defvr {Scheme Variable} %default-theme
26358 This is the default GRUB theme used by the operating system if no
26359 @code{theme} field is specified in @code{bootloader-configuration}
26362 It comes with a fancy background image displaying the GNU and Guix
26366 For example, to override the default resolution, you may use something
26371 (grub-configuration
26374 (inherit %default-theme)
26375 (gfxmode '("1024x786x32" "auto"))))))
26378 @node Invoking guix system
26379 @section Invoking @code{guix system}
26381 Once you have written an operating system declaration as seen in the
26382 previous section, it can be @dfn{instantiated} using the @command{guix
26383 system} command. The synopsis is:
26386 guix system @var{options}@dots{} @var{action} @var{file}
26389 @var{file} must be the name of a file containing an
26390 @code{operating-system} declaration. @var{action} specifies how the
26391 operating system is instantiated. Currently the following values are
26396 Display available service type definitions that match the given regular
26397 expressions, sorted by relevance:
26403 $ guix system search console
26404 name: console-fonts
26405 location: gnu/services/base.scm:806:2
26406 extends: shepherd-root
26407 description: Install the given fonts on the specified ttys (fonts are per
26408 + virtual console on GNU/Linux). The value of this service is a list of
26409 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26410 + package or any valid argument to `setfont', as in this example:
26412 + '(("tty1" . "LatGrkCyr-8x16")
26413 + ("tty2" . (file-append
26415 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26416 + ("tty3" . (file-append
26418 + "/share/consolefonts/ter-132n"))) ; for HDPI
26422 location: gnu/services/base.scm:1190:2
26423 extends: shepherd-root
26424 description: Provide console login using the `mingetty' program.
26428 location: gnu/services/base.scm:860:2
26430 description: Provide a console log-in service as specified by its
26431 + configuration value, a `login-configuration' object.
26437 As for @command{guix package --search}, the result is written in
26438 @code{recutils} format, which makes it easy to filter the output
26439 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26442 Build the operating system described in @var{file}, activate it, and
26443 switch to it@footnote{This action (and the related actions
26444 @code{switch-generation} and @code{roll-back}) are usable only on
26445 systems already running Guix System.}.
26448 @c The paragraph below refers to the problem discussed at
26449 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26450 It is highly recommended to run @command{guix pull} once before you run
26451 @command{guix system reconfigure} for the first time (@pxref{Invoking
26452 guix pull}). Failing to do that you would see an older version of Guix
26453 once @command{reconfigure} has completed.
26456 This effects all the configuration specified in @var{file}: user
26457 accounts, system services, global package list, setuid programs, etc.
26458 The command starts system services specified in @var{file} that are not
26459 currently running; if a service is currently running this command will
26460 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26461 @code{herd stop X} or @code{herd restart X}).
26463 This command creates a new generation whose number is one greater than
26464 the current generation (as reported by @command{guix system
26465 list-generations}). If that generation already exists, it will be
26466 overwritten. This behavior mirrors that of @command{guix package}
26467 (@pxref{Invoking guix package}).
26469 It also adds a bootloader menu entry for the new OS configuration,
26470 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26471 entries for older configurations to a submenu, allowing you to choose
26472 an older system generation at boot time should you need it.
26474 @cindex provenance tracking, of the operating system
26475 Upon completion, the new system is deployed under
26476 @file{/run/current-system}. This directory contains @dfn{provenance
26477 meta-data}: the list of channels in use (@pxref{Channels}) and
26478 @var{file} itself, when available. This information is useful should
26479 you later want to inspect how this particular generation was built.
26481 In fact, assuming @var{file} is self-contained, you can later rebuild
26482 generation @var{n} of your operating system with:
26485 guix time-machine \
26486 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26487 system reconfigure \
26488 /var/guix/profiles/system-@var{n}-link/configuration.scm
26491 You can think of it as some sort of built-in version control! Your
26492 system is not just a binary artifact: @emph{it carries its own source}.
26493 @xref{Service Reference, @code{provenance-service-type}}, for more
26494 information on provenance tracking.
26496 @item switch-generation
26497 @cindex generations
26498 Switch to an existing system generation. This action atomically
26499 switches the system profile to the specified system generation. It
26500 also rearranges the system's existing bootloader menu entries. It
26501 makes the menu entry for the specified system generation the default,
26502 and it moves the entries for the other generations to a submenu, if
26503 supported by the bootloader being used. The next time the system
26504 boots, it will use the specified system generation.
26506 The bootloader itself is not being reinstalled when using this
26507 command. Thus, the installed bootloader is used with an updated
26508 configuration file.
26510 The target generation can be specified explicitly by its generation
26511 number. For example, the following invocation would switch to system
26515 guix system switch-generation 7
26518 The target generation can also be specified relative to the current
26519 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26520 ``3 generations ahead of the current generation,'' and @code{-1} means
26521 ``1 generation prior to the current generation.'' When specifying a
26522 negative value such as @code{-1}, you must precede it with @code{--} to
26523 prevent it from being parsed as an option. For example:
26526 guix system switch-generation -- -1
26529 Currently, the effect of invoking this action is @emph{only} to switch
26530 the system profile to an existing generation and rearrange the
26531 bootloader menu entries. To actually start using the target system
26532 generation, you must reboot after running this action. In the future,
26533 it will be updated to do the same things as @command{reconfigure},
26534 like activating and deactivating services.
26536 This action will fail if the specified generation does not exist.
26539 @cindex rolling back
26540 Switch to the preceding system generation. The next time the system
26541 boots, it will use the preceding system generation. This is the inverse
26542 of @command{reconfigure}, and it is exactly the same as invoking
26543 @command{switch-generation} with an argument of @code{-1}.
26545 Currently, as with @command{switch-generation}, you must reboot after
26546 running this action to actually start using the preceding system
26549 @item delete-generations
26550 @cindex deleting system generations
26551 @cindex saving space
26552 Delete system generations, making them candidates for garbage collection
26553 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
26556 This works in the same way as @command{guix package --delete-generations}
26557 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
26558 arguments, all system generations but the current one are deleted:
26561 guix system delete-generations
26564 You can also select the generations you want to delete. The example below
26565 deletes all the system generations that are more than two month old:
26568 guix system delete-generations 2m
26571 Running this command automatically reinstalls the bootloader with an updated
26572 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26573 longer lists the generations that have been deleted.
26576 Build the derivation of the operating system, which includes all the
26577 configuration files and programs needed to boot and run the system.
26578 This action does not actually install anything.
26581 Populate the given directory with all the files necessary to run the
26582 operating system specified in @var{file}. This is useful for first-time
26583 installations of Guix System. For instance:
26586 guix system init my-os-config.scm /mnt
26589 copies to @file{/mnt} all the store items required by the configuration
26590 specified in @file{my-os-config.scm}. This includes configuration
26591 files, packages, and so on. It also creates other essential files
26592 needed for the system to operate correctly---e.g., the @file{/etc},
26593 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
26595 This command also installs bootloader on the target specified in
26596 @file{my-os-config}, unless the @option{--no-bootloader} option was
26600 @cindex virtual machine
26602 @anchor{guix system vm}
26603 Build a virtual machine that contains the operating system declared in
26604 @var{file}, and return a script to run that virtual machine (VM).
26607 The @code{vm} action and others below
26608 can use KVM support in the Linux-libre kernel. Specifically, if the
26609 machine has hardware virtualization support, the corresponding
26610 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
26611 must exist and be readable and writable by the user and by the
26612 build users of the daemon (@pxref{Build Environment Setup}).
26615 Arguments given to the script are passed to QEMU as in the example
26616 below, which enables networking and requests 1@tie{}GiB of RAM for the
26620 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
26623 The VM shares its store with the host system.
26625 Additional file systems can be shared between the host and the VM using
26626 the @code{--share} and @code{--expose} command-line options: the former
26627 specifies a directory to be shared with write access, while the latter
26628 provides read-only access to the shared directory.
26630 The example below creates a VM in which the user's home directory is
26631 accessible read-only, and where the @file{/exchange} directory is a
26632 read-write mapping of @file{$HOME/tmp} on the host:
26635 guix system vm my-config.scm \
26636 --expose=$HOME --share=$HOME/tmp=/exchange
26639 On GNU/Linux, the default is to boot directly to the kernel; this has
26640 the advantage of requiring only a very tiny root disk image since the
26641 store of the host can then be mounted.
26643 The @code{--full-boot} option forces a complete boot sequence, starting
26644 with the bootloader. This requires more disk space since a root image
26645 containing at least the kernel, initrd, and bootloader data files must
26646 be created. The @code{--image-size} option can be used to specify the
26649 @cindex System images, creation in various formats
26650 @cindex Creating system images in various formats
26653 @itemx docker-image
26654 Return a virtual machine, disk image, or Docker image of the operating
26655 system declared in @var{file} that stands alone. By default,
26656 @command{guix system} estimates the size of the image needed to store
26657 the system, but you can use the @option{--image-size} option to specify
26658 a value. Docker images are built to contain exactly what they need, so
26659 the @option{--image-size} option is ignored in the case of
26660 @code{docker-image}.
26662 You can specify the root file system type by using the
26663 @option{--file-system-type} option. It defaults to @code{ext4}.
26665 When using @code{vm-image}, the returned image is in qcow2 format, which
26666 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
26667 for more information on how to run the image in a virtual machine.
26669 When using @code{disk-image}, a raw disk image is produced; it can be
26670 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
26671 the device corresponding to a USB stick, one can copy the image to it
26672 using the following command:
26675 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
26678 When using @code{docker-image}, a Docker image is produced. Guix builds
26679 the image from scratch, not from a pre-existing Docker base image. As a
26680 result, it contains @emph{exactly} what you define in the operating
26681 system configuration file. You can then load the image and launch a
26682 Docker container using commands like the following:
26685 image_id="`docker load < guix-system-docker-image.tar.gz`"
26686 container_id="`docker create $image_id`"
26687 docker start $container_id
26690 This command starts a new Docker container from the specified image. It
26691 will boot the Guix system in the usual manner, which means it will
26692 start any services you have defined in the operating system
26693 configuration. You can get an interactive shell running in the container
26694 using @command{docker exec}:
26697 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
26700 Depending on what you run in the Docker container, it
26701 may be necessary to give the container additional permissions. For
26702 example, if you intend to build software using Guix inside of the Docker
26703 container, you may need to pass the @option{--privileged} option to
26704 @code{docker create}.
26707 Return a script to run the operating system declared in @var{file}
26708 within a container. Containers are a set of lightweight isolation
26709 mechanisms provided by the kernel Linux-libre. Containers are
26710 substantially less resource-demanding than full virtual machines since
26711 the kernel, shared objects, and other resources can be shared with the
26712 host system; this also means they provide thinner isolation.
26714 Currently, the script must be run as root in order to support more than
26715 a single user and group. The container shares its store with the host
26718 As with the @code{vm} action (@pxref{guix system vm}), additional file
26719 systems to be shared between the host and container can be specified
26720 using the @option{--share} and @option{--expose} options:
26723 guix system container my-config.scm \
26724 --expose=$HOME --share=$HOME/tmp=/exchange
26728 This option requires Linux-libre 3.19 or newer.
26733 @var{options} can contain any of the common build options (@pxref{Common
26734 Build Options}). In addition, @var{options} can contain one of the
26738 @item --expression=@var{expr}
26739 @itemx -e @var{expr}
26740 Consider the operating-system @var{expr} evaluates to.
26741 This is an alternative to specifying a file which evaluates to an
26743 This is used to generate the Guix system installer @pxref{Building the
26744 Installation Image}).
26746 @item --system=@var{system}
26747 @itemx -s @var{system}
26748 Attempt to build for @var{system} instead of the host system type.
26749 This works as per @command{guix build} (@pxref{Invoking guix build}).
26753 Return the derivation file name of the given operating system without
26756 @cindex provenance tracking, of the operating system
26757 @item --save-provenance
26758 As discussed above, @command{guix system init} and @command{guix system
26759 reconfigure} always save provenance information @i{via} a dedicated
26760 service (@pxref{Service Reference, @code{provenance-service-type}}).
26761 However, other commands don't do that by default. If you wish to, say,
26762 create a virtual machine image that contains provenance information, you
26766 guix system vm-image --save-provenance config.scm
26769 That way, the resulting image will effectively ``embed its own source''
26770 in the form of meta-data in @file{/run/current-system}. With that
26771 information, one can rebuild the image to make sure it really contains
26772 what it pretends to contain; or they could use that to derive a variant
26775 @item --file-system-type=@var{type}
26776 @itemx -t @var{type}
26777 For the @code{disk-image} action, create a file system of the given
26778 @var{type} on the image.
26780 When this option is omitted, @command{guix system} uses @code{ext4}.
26782 @cindex ISO-9660 format
26783 @cindex CD image format
26784 @cindex DVD image format
26785 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26786 for burning on CDs and DVDs.
26788 @item --image-size=@var{size}
26789 For the @code{vm-image} and @code{disk-image} actions, create an image
26790 of the given @var{size}. @var{size} may be a number of bytes, or it may
26791 include a unit as a suffix (@pxref{Block size, size specifications,,
26792 coreutils, GNU Coreutils}).
26794 When this option is omitted, @command{guix system} computes an estimate
26795 of the image size as a function of the size of the system declared in
26800 For the @code{container} action, allow containers to access the host network,
26801 that is, do not create a network namespace.
26803 @item --root=@var{file}
26804 @itemx -r @var{file}
26805 Make @var{file} a symlink to the result, and register it as a garbage
26808 @item --skip-checks
26809 Skip pre-installation safety checks.
26811 By default, @command{guix system init} and @command{guix system
26812 reconfigure} perform safety checks: they make sure the file systems that
26813 appear in the @code{operating-system} declaration actually exist
26814 (@pxref{File Systems}), and that any Linux kernel modules that may be
26815 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26816 RAM Disk}). Passing this option skips these tests altogether.
26819 @cindex on-error strategy
26820 @cindex error strategy
26821 @item --on-error=@var{strategy}
26822 Apply @var{strategy} when an error occurs when reading @var{file}.
26823 @var{strategy} may be one of the following:
26826 @item nothing-special
26827 Report the error concisely and exit. This is the default strategy.
26830 Likewise, but also display a backtrace.
26833 Report the error and enter Guile's debugger. From there, you can run
26834 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26835 display local variable values, and more generally inspect the state of the
26836 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26837 a list of available debugging commands.
26841 Once you have built, configured, re-configured, and re-re-configured
26842 your Guix installation, you may find it useful to list the operating
26843 system generations available on disk---and that you can choose from the
26844 bootloader boot menu:
26849 Describe the current system generation: its file name, the kernel and
26850 bootloader used, etc., as well as provenance information when available.
26852 @item list-generations
26853 List a summary of each generation of the operating system available on
26854 disk, in a human-readable way. This is similar to the
26855 @option{--list-generations} option of @command{guix package}
26856 (@pxref{Invoking guix package}).
26858 Optionally, one can specify a pattern, with the same syntax that is used
26859 in @command{guix package --list-generations}, to restrict the list of
26860 generations displayed. For instance, the following command displays
26861 generations that are up to 10 days old:
26864 $ guix system list-generations 10d
26869 The @command{guix system} command has even more to offer! The following
26870 sub-commands allow you to visualize how your system services relate to
26873 @anchor{system-extension-graph}
26876 @item extension-graph
26877 Emit in Dot/Graphviz format to standard output the @dfn{service
26878 extension graph} of the operating system defined in @var{file}
26879 (@pxref{Service Composition}, for more information on service
26885 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26888 produces a PDF file showing the extension relations among services.
26890 @anchor{system-shepherd-graph}
26891 @item shepherd-graph
26892 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26893 graph} of shepherd services of the operating system defined in
26894 @var{file}. @xref{Shepherd Services}, for more information and for an
26899 @node Invoking guix deploy
26900 @section Invoking @code{guix deploy}
26902 We've already seen @code{operating-system} declarations used to manage a
26903 machine's configuration locally. Suppose you need to configure multiple
26904 machines, though---perhaps you're managing a service on the web that's
26905 comprised of several servers. @command{guix deploy} enables you to use those
26906 same @code{operating-system} declarations to manage multiple remote hosts at
26907 once as a logical ``deployment''.
26910 The functionality described in this section is still under development
26911 and is subject to change. Get in touch with us on
26912 @email{guix-devel@@gnu.org}!
26916 guix deploy @var{file}
26919 Such an invocation will deploy the machines that the code within @var{file}
26920 evaluates to. As an example, @var{file} might contain a definition like this:
26923 ;; This is a Guix deployment of a "bare bones" setup, with
26924 ;; no X11 display server, to a machine with an SSH daemon
26925 ;; listening on localhost:2222. A configuration such as this
26926 ;; may be appropriate for virtual machine with ports
26927 ;; forwarded to the host's loopback interface.
26929 (use-service-modules networking ssh)
26930 (use-package-modules bootloaders)
26934 (host-name "gnu-deployed")
26935 (timezone "Etc/UTC")
26936 (bootloader (bootloader-configuration
26937 (bootloader grub-bootloader)
26938 (target "/dev/vda")
26939 (terminal-outputs '(console))))
26940 (file-systems (cons (file-system
26942 (device "/dev/vda1")
26944 %base-file-systems))
26946 (append (list (service dhcp-client-service-type)
26947 (service openssh-service-type
26948 (openssh-configuration
26949 (permit-root-login #t)
26950 (allow-empty-passwords? #t))))
26954 (operating-system %system)
26955 (environment managed-host-environment-type)
26956 (configuration (machine-ssh-configuration
26957 (host-name "localhost")
26958 (system "x86_64-linux")
26960 (identity "./id_rsa")
26964 The file should evaluate to a list of @var{machine} objects. This example,
26965 upon being deployed, will create a new generation on the remote system
26966 realizing the @code{operating-system} declaration @var{%system}.
26967 @var{environment} and @var{configuration} specify how the machine should be
26968 provisioned---that is, how the computing resources should be created and
26969 managed. The above example does not create any resources, as a
26970 @code{'managed-host} is a machine that is already running the Guix system and
26971 available over the network. This is a particularly simple case; a more
26972 complex deployment may involve, for example, starting virtual machines through
26973 a Virtual Private Server (VPS) provider. In such a case, a different
26974 @var{environment} type would be used.
26976 Do note that you first need to generate a key pair on the coordinator machine
26977 to allow the daemon to export signed archives of files from the store
26978 (@pxref{Invoking guix archive}).
26981 # guix archive --generate-key
26985 Each target machine must authorize the key of the master machine so that it
26986 accepts store items it receives from the coordinator:
26989 # guix archive --authorize < coordinator-public-key.txt
26992 @code{user}, in this example, specifies the name of the user account to log in
26993 as to perform the deployment. Its default value is @code{root}, but root
26994 login over SSH may be forbidden in some cases. To work around this,
26995 @command{guix deploy} can log in as an unprivileged user and employ
26996 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26997 currently installed on the remote and can be invoked non-interactively as
26998 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
26999 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
27000 be accomplished with the following operating system configuration snippet:
27004 (gnu system)) ;for %sudoers-specification
27006 (define %user "username")
27011 (plain-file "sudoers"
27012 (string-append (plain-file-content %sudoers-specification)
27013 (format #f "~a ALL = NOPASSWD: ALL~%"
27018 For more information regarding the format of the @file{sudoers} file,
27019 consult @command{man sudoers}.
27021 @deftp {Data Type} machine
27022 This is the data type representing a single machine in a heterogeneous Guix
27026 @item @code{operating-system}
27027 The object of the operating system configuration to deploy.
27029 @item @code{environment}
27030 An @code{environment-type} describing how the machine should be provisioned.
27032 @item @code{configuration} (default: @code{#f})
27033 An object describing the configuration for the machine's @code{environment}.
27034 If the @code{environment} has a default configuration, @code{#f} may be used.
27035 If @code{#f} is used for an environment with no default configuration,
27036 however, an error will be thrown.
27040 @deftp {Data Type} machine-ssh-configuration
27041 This is the data type representing the SSH client parameters for a machine
27042 with an @code{environment} of @code{managed-host-environment-type}.
27045 @item @code{host-name}
27046 @item @code{build-locally?} (default: @code{#t})
27047 If false, system derivations will be built on the machine being deployed to.
27048 @item @code{system}
27049 The system type describing the architecture of the machine being deployed
27050 to---e.g., @code{"x86_64-linux"}.
27051 @item @code{authorize?} (default: @code{#t})
27052 If true, the coordinator's signing key will be added to the remote's ACL
27054 @item @code{port} (default: @code{22})
27055 @item @code{user} (default: @code{"root"})
27056 @item @code{identity} (default: @code{#f})
27057 If specified, the path to the SSH private key to use to authenticate with the
27060 @item @code{host-key} (default: @code{#f})
27061 This should be the SSH host key of the machine, which looks like this:
27064 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
27067 When @code{host-key} is @code{#f}, the server is authenticated against
27068 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
27074 @deftp {Data Type} digital-ocean-configuration
27075 This is the data type describing the Droplet that should be created for a
27076 machine with an @code{environment} of @code{digital-ocean-environment-type}.
27079 @item @code{ssh-key}
27080 The path to the SSH private key to use to authenticate with the remote
27081 host. In the future, this field may not exist.
27083 A list of string ``tags'' that uniquely identify the machine. Must be given
27084 such that no two machines in the deployment have the same set of tags.
27085 @item @code{region}
27086 A Digital Ocean region slug, such as @code{"nyc3"}.
27088 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
27089 @item @code{enable-ipv6?}
27090 Whether or not the droplet should be created with IPv6 networking.
27094 @node Running Guix in a VM
27095 @section Running Guix in a Virtual Machine
27097 @cindex virtual machine
27098 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
27100 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
27101 This image is a compressed image in QCOW format. You will first need to
27102 decompress with @command{xz -d}, and then you can pass it to an emulator such
27103 as QEMU (see below for details).
27105 This image boots the Xfce graphical environment and it contains some
27106 commonly-used tools. You can install more software in the image by running
27107 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
27108 also reconfigure the system based on its initial configuration file available
27109 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
27111 Instead of using this pre-built image, one can also build their own virtual
27112 machine image using @command{guix system vm-image} (@pxref{Invoking guix
27113 system}). The returned image is in qcow2 format, which the
27114 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
27117 If you built your own image, you must copy it out of the store
27118 (@pxref{The Store}) and give yourself permission to write to the copy
27119 before you can use it. When invoking QEMU, you must choose a system
27120 emulator that is suitable for your hardware platform. Here is a minimal
27121 QEMU invocation that will boot the result of @command{guix system
27122 vm-image} on x86_64 hardware:
27125 $ qemu-system-x86_64 \
27126 -nic user,model=virtio-net-pci \
27127 -enable-kvm -m 1024 \
27128 -device virtio-blk,drive=myhd \
27129 -drive if=none,file=/tmp/qemu-image,id=myhd
27132 Here is what each of these options means:
27135 @item qemu-system-x86_64
27136 This specifies the hardware platform to emulate. This should match the
27139 @item -nic user,model=virtio-net-pci
27140 Enable the unprivileged user-mode network stack. The guest OS can
27141 access the host but not vice versa. This is the simplest way to get the
27142 guest OS online. @code{model} specifies which network device to emulate:
27143 @code{virtio-net-pci} is a special device made for virtualized operating
27144 systems and recommended for most uses. Assuming your hardware platform is
27145 x86_64, you can get a list of available NIC models by running
27146 @command{qemu-system-x86_64 -nic model=help}.
27149 If your system has hardware virtualization extensions, enabling the
27150 virtual machine support (KVM) of the Linux kernel will make things run
27153 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
27155 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
27156 which may be insufficient for some operations.
27158 @item -device virtio-blk,drive=myhd
27159 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
27160 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
27161 better performance than if it were emulating a complete disk drive. See the
27162 QEMU and KVM documentation for more info.
27164 @item -drive if=none,file=/tmp/qemu-image,id=myhd
27165 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
27166 the ``myhd'' drive.
27169 The default @command{run-vm.sh} script that is returned by an invocation of
27170 @command{guix system vm} does not add a @command{-nic user} flag by default.
27171 To get network access from within the vm add the @code{(dhcp-client-service)}
27172 to your system definition and start the VM using
27173 @command{`guix system vm config.scm` -nic user}. An important caveat of using
27174 @command{-nic user} for networking is that @command{ping} will not work, because
27175 it uses the ICMP protocol. You'll have to use a different command to check for
27176 network connectivity, for example @command{guix download}.
27178 @subsection Connecting Through SSH
27182 To enable SSH inside a VM you need to add an SSH server like
27183 @code{openssh-service-type} to your VM (@pxref{Networking Services,
27184 @code{openssh-service-type}}). In addition you need to forward the SSH port,
27185 22 by default, to the host. You can do this with
27188 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
27191 To connect to the VM you can run
27194 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
27197 The @command{-p} tells @command{ssh} the port you want to connect to.
27198 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
27199 every time you modify your @command{config.scm} file and the
27200 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
27201 connection to an unknown host every time you connect.
27203 @subsection Using @command{virt-viewer} with Spice
27205 As an alternative to the default @command{qemu} graphical client you can
27206 use the @command{remote-viewer} from the @command{virt-viewer} package. To
27207 connect pass the @command{-spice port=5930,disable-ticketing} flag to
27208 @command{qemu}. See previous section for further information on how to do this.
27210 Spice also allows you to do some nice stuff like share your clipboard with your
27211 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
27214 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
27215 -chardev spicevmc,name=vdagent,id=vdagent
27216 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
27217 name=com.redhat.spice.0
27220 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
27222 @node Defining Services
27223 @section Defining Services
27225 The previous sections show the available services and how one can combine
27226 them in an @code{operating-system} declaration. But how do we define
27227 them in the first place? And what is a service anyway?
27230 * Service Composition:: The model for composing services.
27231 * Service Types and Services:: Types and services.
27232 * Service Reference:: API reference.
27233 * Shepherd Services:: A particular type of service.
27236 @node Service Composition
27237 @subsection Service Composition
27241 Here we define a @dfn{service} as, broadly, something that extends the
27242 functionality of the operating system. Often a service is a process---a
27243 @dfn{daemon}---started when the system boots: a secure shell server, a
27244 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
27245 whose execution can be triggered by another daemon---e.g., an FTP server
27246 started by @command{inetd} or a D-Bus service activated by
27247 @command{dbus-daemon}. Occasionally, a service does not map to a
27248 daemon. For instance, the ``account'' service collects user accounts
27249 and makes sure they exist when the system runs; the ``udev'' service
27250 collects device management rules and makes them available to the eudev
27251 daemon; the @file{/etc} service populates the @file{/etc} directory
27254 @cindex service extensions
27255 Guix system services are connected by @dfn{extensions}. For instance, the
27256 secure shell service @emph{extends} the Shepherd---the
27257 initialization system, running as PID@tie{}1---by giving it the command
27258 lines to start and stop the secure shell daemon (@pxref{Networking
27259 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
27260 service by passing it its @file{.service} specification, and extends the
27261 udev service by passing it device management rules (@pxref{Desktop
27262 Services, @code{upower-service}}); the Guix daemon service extends the
27263 Shepherd by passing it the command lines to start and stop the daemon,
27264 and extends the account service by passing it a list of required build
27265 user accounts (@pxref{Base Services}).
27267 All in all, services and their ``extends'' relations form a directed
27268 acyclic graph (DAG). If we represent services as boxes and extensions
27269 as arrows, a typical system might provide something like this:
27271 @image{images/service-graph,,5in,Typical service extension graph.}
27273 @cindex system service
27274 At the bottom, we see the @dfn{system service}, which produces the
27275 directory containing everything to run and boot the system, as returned
27276 by the @command{guix system build} command. @xref{Service Reference},
27277 to learn about the other service types shown here.
27278 @xref{system-extension-graph, the @command{guix system extension-graph}
27279 command}, for information on how to generate this representation for a
27280 particular operating system definition.
27282 @cindex service types
27283 Technically, developers can define @dfn{service types} to express these
27284 relations. There can be any number of services of a given type on the
27285 system---for instance, a system running two instances of the GNU secure
27286 shell server (lsh) has two instances of @code{lsh-service-type}, with
27287 different parameters.
27289 The following section describes the programming interface for service
27290 types and services.
27292 @node Service Types and Services
27293 @subsection Service Types and Services
27295 A @dfn{service type} is a node in the DAG described above. Let us start
27296 with a simple example, the service type for the Guix build daemon
27297 (@pxref{Invoking guix-daemon}):
27300 (define guix-service-type
27304 (list (service-extension shepherd-root-service-type guix-shepherd-service)
27305 (service-extension account-service-type guix-accounts)
27306 (service-extension activation-service-type guix-activation)))
27307 (default-value (guix-configuration))))
27311 It defines three things:
27315 A name, whose sole purpose is to make inspection and debugging easier.
27318 A list of @dfn{service extensions}, where each extension designates the
27319 target service type and a procedure that, given the parameters of the
27320 service, returns a list of objects to extend the service of that type.
27322 Every service type has at least one service extension. The only
27323 exception is the @dfn{boot service type}, which is the ultimate service.
27326 Optionally, a default value for instances of this type.
27329 In this example, @code{guix-service-type} extends three services:
27332 @item shepherd-root-service-type
27333 The @code{guix-shepherd-service} procedure defines how the Shepherd
27334 service is extended. Namely, it returns a @code{<shepherd-service>}
27335 object that defines how @command{guix-daemon} is started and stopped
27336 (@pxref{Shepherd Services}).
27338 @item account-service-type
27339 This extension for this service is computed by @code{guix-accounts},
27340 which returns a list of @code{user-group} and @code{user-account}
27341 objects representing the build user accounts (@pxref{Invoking
27344 @item activation-service-type
27345 Here @code{guix-activation} is a procedure that returns a gexp, which is
27346 a code snippet to run at ``activation time''---e.g., when the service is
27350 A service of this type is instantiated like this:
27353 (service guix-service-type
27354 (guix-configuration
27356 (use-substitutes? #f)))
27359 The second argument to the @code{service} form is a value representing
27360 the parameters of this specific service instance.
27361 @xref{guix-configuration-type, @code{guix-configuration}}, for
27362 information about the @code{guix-configuration} data type. When the
27363 value is omitted, the default value specified by
27364 @code{guix-service-type} is used:
27367 (service guix-service-type)
27370 @code{guix-service-type} is quite simple because it extends other
27371 services but is not extensible itself.
27373 @c @subsubsubsection Extensible Service Types
27375 The service type for an @emph{extensible} service looks like this:
27378 (define udev-service-type
27379 (service-type (name 'udev)
27381 (list (service-extension shepherd-root-service-type
27382 udev-shepherd-service)))
27384 (compose concatenate) ;concatenate the list of rules
27385 (extend (lambda (config rules)
27387 (($ <udev-configuration> udev initial-rules)
27388 (udev-configuration
27389 (udev udev) ;the udev package to use
27390 (rules (append initial-rules rules)))))))))
27393 This is the service type for the
27394 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27395 management daemon}. Compared to the previous example, in addition to an
27396 extension of @code{shepherd-root-service-type}, we see two new fields:
27400 This is the procedure to @dfn{compose} the list of extensions to
27401 services of this type.
27403 Services can extend the udev service by passing it lists of rules; we
27404 compose those extensions simply by concatenating them.
27407 This procedure defines how the value of the service is @dfn{extended} with
27408 the composition of the extensions.
27410 Udev extensions are composed into a list of rules, but the udev service
27411 value is itself a @code{<udev-configuration>} record. So here, we
27412 extend that record by appending the list of rules it contains to the
27413 list of contributed rules.
27416 This is a string giving an overview of the service type. The string can
27417 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27418 @command{guix system search} command searches these strings and displays
27419 them (@pxref{Invoking guix system}).
27422 There can be only one instance of an extensible service type such as
27423 @code{udev-service-type}. If there were more, the
27424 @code{service-extension} specifications would be ambiguous.
27426 Still here? The next section provides a reference of the programming
27427 interface for services.
27429 @node Service Reference
27430 @subsection Service Reference
27432 We have seen an overview of service types (@pxref{Service Types and
27433 Services}). This section provides a reference on how to manipulate
27434 services and service types. This interface is provided by the
27435 @code{(gnu services)} module.
27437 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27438 Return a new service of @var{type}, a @code{<service-type>} object (see
27439 below.) @var{value} can be any object; it represents the parameters of
27440 this particular service instance.
27442 When @var{value} is omitted, the default value specified by @var{type}
27443 is used; if @var{type} does not specify a default value, an error is
27446 For instance, this:
27449 (service openssh-service-type)
27453 is equivalent to this:
27456 (service openssh-service-type
27457 (openssh-configuration))
27460 In both cases the result is an instance of @code{openssh-service-type}
27461 with the default configuration.
27464 @deffn {Scheme Procedure} service? @var{obj}
27465 Return true if @var{obj} is a service.
27468 @deffn {Scheme Procedure} service-kind @var{service}
27469 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27472 @deffn {Scheme Procedure} service-value @var{service}
27473 Return the value associated with @var{service}. It represents its
27477 Here is an example of how a service is created and manipulated:
27481 (service nginx-service-type
27482 (nginx-configuration
27484 (log-directory log-directory)
27485 (run-directory run-directory)
27486 (file config-file))))
27491 (eq? (service-kind s) nginx-service-type)
27495 The @code{modify-services} form provides a handy way to change the
27496 parameters of some of the services of a list such as
27497 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27498 evaluates to a list of services. Of course, you could always use
27499 standard list combinators such as @code{map} and @code{fold} to do that
27500 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27501 @code{modify-services} simply provides a more concise form for this
27504 @deffn {Scheme Syntax} modify-services @var{services} @
27505 (@var{type} @var{variable} => @var{body}) @dots{}
27507 Modify the services listed in @var{services} according to the given
27508 clauses. Each clause has the form:
27511 (@var{type} @var{variable} => @var{body})
27514 where @var{type} is a service type---e.g.,
27515 @code{guix-service-type}---and @var{variable} is an identifier that is
27516 bound within the @var{body} to the service parameters---e.g., a
27517 @code{guix-configuration} instance---of the original service of that
27520 The @var{body} should evaluate to the new service parameters, which will
27521 be used to configure the new service. This new service will replace the
27522 original in the resulting list. Because a service's service parameters
27523 are created using @code{define-record-type*}, you can write a succinct
27524 @var{body} that evaluates to the new service parameters by using the
27525 @code{inherit} feature that @code{define-record-type*} provides.
27527 @xref{Using the Configuration System}, for example usage.
27531 Next comes the programming interface for service types. This is
27532 something you want to know when writing new service definitions, but not
27533 necessarily when simply looking for ways to customize your
27534 @code{operating-system} declaration.
27536 @deftp {Data Type} service-type
27537 @cindex service type
27538 This is the representation of a @dfn{service type} (@pxref{Service Types
27543 This is a symbol, used only to simplify inspection and debugging.
27545 @item @code{extensions}
27546 A non-empty list of @code{<service-extension>} objects (see below).
27548 @item @code{compose} (default: @code{#f})
27549 If this is @code{#f}, then the service type denotes services that cannot
27550 be extended---i.e., services that do not receive ``values'' from other
27553 Otherwise, it must be a one-argument procedure. The procedure is called
27554 by @code{fold-services} and is passed a list of values collected from
27555 extensions. It may return any single value.
27557 @item @code{extend} (default: @code{#f})
27558 If this is @code{#f}, services of this type cannot be extended.
27560 Otherwise, it must be a two-argument procedure: @code{fold-services}
27561 calls it, passing it the initial value of the service as the first
27562 argument and the result of applying @code{compose} to the extension
27563 values as the second argument. It must return a value that is a valid
27564 parameter value for the service instance.
27567 @xref{Service Types and Services}, for examples.
27570 @deffn {Scheme Procedure} service-extension @var{target-type} @
27572 Return a new extension for services of type @var{target-type}.
27573 @var{compute} must be a one-argument procedure: @code{fold-services}
27574 calls it, passing it the value associated with the service that provides
27575 the extension; it must return a valid value for the target service.
27578 @deffn {Scheme Procedure} service-extension? @var{obj}
27579 Return true if @var{obj} is a service extension.
27582 Occasionally, you might want to simply extend an existing service. This
27583 involves creating a new service type and specifying the extension of
27584 interest, which can be verbose; the @code{simple-service} procedure
27585 provides a shorthand for this.
27587 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
27588 Return a service that extends @var{target} with @var{value}. This works
27589 by creating a singleton service type @var{name}, of which the returned
27590 service is an instance.
27592 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
27596 (simple-service 'my-mcron-job mcron-service-type
27597 #~(job '(next-hour (3)) "guix gc -F 2G"))
27601 At the core of the service abstraction lies the @code{fold-services}
27602 procedure, which is responsible for ``compiling'' a list of services
27603 down to a single directory that contains everything needed to boot and
27604 run the system---the directory shown by the @command{guix system build}
27605 command (@pxref{Invoking guix system}). In essence, it propagates
27606 service extensions down the service graph, updating each node parameters
27607 on the way, until it reaches the root node.
27609 @deffn {Scheme Procedure} fold-services @var{services} @
27610 [#:target-type @var{system-service-type}]
27611 Fold @var{services} by propagating their extensions down to the root of
27612 type @var{target-type}; return the root service adjusted accordingly.
27615 Lastly, the @code{(gnu services)} module also defines several essential
27616 service types, some of which are listed below.
27618 @defvr {Scheme Variable} system-service-type
27619 This is the root of the service graph. It produces the system directory
27620 as returned by the @command{guix system build} command.
27623 @defvr {Scheme Variable} boot-service-type
27624 The type of the ``boot service'', which produces the @dfn{boot script}.
27625 The boot script is what the initial RAM disk runs when booting.
27628 @defvr {Scheme Variable} etc-service-type
27629 The type of the @file{/etc} service. This service is used to create
27630 files under @file{/etc} and can be extended by
27631 passing it name/file tuples such as:
27634 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
27637 In this example, the effect would be to add an @file{/etc/issue} file
27638 pointing to the given file.
27641 @defvr {Scheme Variable} setuid-program-service-type
27642 Type for the ``setuid-program service''. This service collects lists of
27643 executable file names, passed as gexps, and adds them to the set of
27644 setuid-root programs on the system (@pxref{Setuid Programs}).
27647 @defvr {Scheme Variable} profile-service-type
27648 Type of the service that populates the @dfn{system profile}---i.e., the
27649 programs under @file{/run/current-system/profile}. Other services can
27650 extend it by passing it lists of packages to add to the system profile.
27653 @cindex provenance tracking, of the operating system
27654 @defvr {Scheme Variable} provenance-service-type
27655 This is the type of the service that records @dfn{provenance meta-data}
27656 in the system itself. It creates several files under
27657 @file{/run/current-system}:
27661 This is a ``channel file'' that can be passed to @command{guix pull -C}
27662 or @command{guix time-machine -C}, and which describes the channels used
27663 to build the system, if that information was available
27664 (@pxref{Channels}).
27666 @item configuration.scm
27667 This is the file that was passed as the value for this
27668 @code{provenance-service-type} service. By default, @command{guix
27669 system reconfigure} automatically passes the OS configuration file it
27670 received on the command line.
27673 This contains the same information as the two other files but in a
27674 format that is more readily processable.
27677 In general, these two pieces of information (channels and configuration
27678 file) are enough to reproduce the operating system ``from source''.
27681 This information is necessary to rebuild your operating system, but it
27682 is not always sufficient. In particular, @file{configuration.scm}
27683 itself is insufficient if it is not self-contained---if it refers to
27684 external Guile modules or to extra files. If you want
27685 @file{configuration.scm} to be self-contained, we recommend that modules
27686 or files it refers to be part of a channel.
27688 Besides, provenance meta-data is ``silent'' in the sense that it does
27689 not change the bits contained in your system, @emph{except for the
27690 meta-data bits themselves}. Two different OS configurations or sets of
27691 channels can lead to the same system, bit-for-bit; when
27692 @code{provenance-service-type} is used, these two systems will have
27693 different meta-data and thus different store file names, which makes
27694 comparison less trivial.
27697 This service is automatically added to your operating system
27698 configuration when you use @command{guix system reconfigure},
27699 @command{guix system init}, or @command{guix deploy}.
27702 @node Shepherd Services
27703 @subsection Shepherd Services
27705 @cindex shepherd services
27707 @cindex init system
27708 The @code{(gnu services shepherd)} module provides a way to define
27709 services managed by the GNU@tie{}Shepherd, which is the
27710 initialization system---the first process that is started when the
27711 system boots, also known as PID@tie{}1
27712 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
27714 Services in the Shepherd can depend on each other. For instance, the
27715 SSH daemon may need to be started after the syslog daemon has been
27716 started, which in turn can only happen once all the file systems have
27717 been mounted. The simple operating system defined earlier (@pxref{Using
27718 the Configuration System}) results in a service graph like this:
27720 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
27722 You can actually generate such a graph for any operating system
27723 definition using the @command{guix system shepherd-graph} command
27724 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
27726 The @code{%shepherd-root-service} is a service object representing
27727 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
27728 by passing it lists of @code{<shepherd-service>} objects.
27730 @deftp {Data Type} shepherd-service
27731 The data type representing a service managed by the Shepherd.
27734 @item @code{provision}
27735 This is a list of symbols denoting what the service provides.
27737 These are the names that may be passed to @command{herd start},
27738 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
27739 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
27740 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
27742 @item @code{requirement} (default: @code{'()})
27743 List of symbols denoting the Shepherd services this one depends on.
27745 @cindex one-shot services, for the Shepherd
27746 @item @code{one-shot?} (default: @code{#f})
27747 Whether this service is @dfn{one-shot}. One-shot services stop immediately
27748 after their @code{start} action has completed. @xref{Slots of services,,,
27749 shepherd, The GNU Shepherd Manual}, for more info.
27751 @item @code{respawn?} (default: @code{#t})
27752 Whether to restart the service when it stops, for instance when the
27753 underlying process dies.
27756 @itemx @code{stop} (default: @code{#~(const #f)})
27757 The @code{start} and @code{stop} fields refer to the Shepherd's
27758 facilities to start and stop processes (@pxref{Service De- and
27759 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
27760 G-expressions that get expanded in the Shepherd configuration file
27761 (@pxref{G-Expressions}).
27763 @item @code{actions} (default: @code{'()})
27764 @cindex actions, of Shepherd services
27765 This is a list of @code{shepherd-action} objects (see below) defining
27766 @dfn{actions} supported by the service, in addition to the standard
27767 @code{start} and @code{stop} actions. Actions listed here become available as
27768 @command{herd} sub-commands:
27771 herd @var{action} @var{service} [@var{arguments}@dots{}]
27774 @item @code{auto-start?} (default: @code{#t})
27775 Whether this service should be started automatically by the Shepherd. If it
27776 is @code{#f} the service has to be started manually with @code{herd start}.
27778 @item @code{documentation}
27779 A documentation string, as shown when running:
27782 herd doc @var{service-name}
27785 where @var{service-name} is one of the symbols in @code{provision}
27786 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
27788 @item @code{modules} (default: @code{%default-modules})
27789 This is the list of modules that must be in scope when @code{start} and
27790 @code{stop} are evaluated.
27795 @deftp {Data Type} shepherd-action
27796 This is the data type that defines additional actions implemented by a
27797 Shepherd service (see above).
27801 Symbol naming the action.
27803 @item documentation
27804 This is a documentation string for the action. It can be viewed by running:
27807 herd doc @var{service} action @var{action}
27811 This should be a gexp that evaluates to a procedure of at least one argument,
27812 which is the ``running value'' of the service (@pxref{Slots of services,,,
27813 shepherd, The GNU Shepherd Manual}).
27816 The following example defines an action called @code{say-hello} that kindly
27822 (documentation "Say hi!")
27823 (procedure #~(lambda (running . args)
27824 (format #t "Hello, friend! arguments: ~s\n"
27829 Assuming this action is added to the @code{example} service, then you can do:
27832 # herd say-hello example
27833 Hello, friend! arguments: ()
27834 # herd say-hello example a b c
27835 Hello, friend! arguments: ("a" "b" "c")
27838 This, as you can see, is a fairly sophisticated way to say hello.
27839 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27843 @defvr {Scheme Variable} shepherd-root-service-type
27844 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27846 This is the service type that extensions target when they want to create
27847 shepherd services (@pxref{Service Types and Services}, for an example).
27848 Each extension must pass a list of @code{<shepherd-service>}.
27851 @defvr {Scheme Variable} %shepherd-root-service
27852 This service represents PID@tie{}1.
27856 @node Documentation
27857 @chapter Documentation
27859 @cindex documentation, searching for
27860 @cindex searching for documentation
27861 @cindex Info, documentation format
27863 @cindex manual pages
27864 In most cases packages installed with Guix come with documentation.
27865 There are two main documentation formats: ``Info'', a browseable
27866 hypertext format used for GNU software, and ``manual pages'' (or ``man
27867 pages''), the linear documentation format traditionally found on Unix.
27868 Info manuals are accessed with the @command{info} command or with Emacs,
27869 and man pages are accessed using @command{man}.
27871 You can look for documentation of software installed on your system by
27872 keyword. For example, the following command searches for information
27873 about ``TLS'' in Info manuals:
27877 "(emacs)Network Security" -- STARTTLS
27878 "(emacs)Network Security" -- TLS
27879 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27880 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27885 The command below searches for the same keyword in man pages:
27889 SSL (7) - OpenSSL SSL/TLS library
27890 certtool (1) - GnuTLS certificate tool
27894 These searches are purely local to your computer so you have the
27895 guarantee that documentation you find corresponds to what you have
27896 actually installed, you can access it off-line, and your privacy is
27899 Once you have these results, you can view the relevant documentation by
27903 $ info "(gnutls)Core TLS API"
27913 Info manuals contain sections and indices as well as hyperlinks like
27914 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27915 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27916 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27917 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27918 Introduction}, for an introduction to Info navigation.
27920 @node Installing Debugging Files
27921 @chapter Installing Debugging Files
27923 @cindex debugging files
27924 Program binaries, as produced by the GCC compilers for instance, are
27925 typically written in the ELF format, with a section containing
27926 @dfn{debugging information}. Debugging information is what allows the
27927 debugger, GDB, to map binary code to source code; it is required to
27928 debug a compiled program in good conditions.
27930 The problem with debugging information is that is takes up a fair amount
27931 of disk space. For example, debugging information for the GNU C Library
27932 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27933 debugging info of all the installed programs is usually not an option.
27934 Yet, space savings should not come at the cost of an impediment to
27935 debugging---especially in the GNU system, which should make it easier
27936 for users to exert their computing freedom (@pxref{GNU Distribution}).
27938 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27939 mechanism that allows users to get the best of both worlds: debugging
27940 information can be stripped from the binaries and stored in separate
27941 files. GDB is then able to load debugging information from those files,
27942 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27945 The GNU distribution takes advantage of this by storing debugging
27946 information in the @code{lib/debug} sub-directory of a separate package
27947 output unimaginatively called @code{debug} (@pxref{Packages with
27948 Multiple Outputs}). Users can choose to install the @code{debug} output
27949 of a package when they need it. For instance, the following command
27950 installs the debugging information for the GNU C Library and for GNU
27954 guix install glibc:debug guile:debug
27957 GDB must then be told to look for debug files in the user's profile, by
27958 setting the @code{debug-file-directory} variable (consider setting it
27959 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27963 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27966 From there on, GDB will pick up debugging information from the
27967 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27969 In addition, you will most likely want GDB to be able to show the source
27970 code being debugged. To do that, you will have to unpack the source
27971 code of the package of interest (obtained with @code{guix build
27972 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27973 directory using the @code{directory} command (@pxref{Source Path,
27974 @code{directory},, gdb, Debugging with GDB}).
27976 @c XXX: keep me up-to-date
27977 The @code{debug} output mechanism in Guix is implemented by the
27978 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27979 opt-in---debugging information is available only for the packages
27980 with definitions explicitly declaring a @code{debug} output. This may be
27981 changed to opt-out in the future if our build farm servers can handle
27982 the load. To check whether a package has a @code{debug} output, use
27983 @command{guix package --list-available} (@pxref{Invoking guix package}).
27986 @node Security Updates
27987 @chapter Security Updates
27989 @cindex security updates
27990 @cindex security vulnerabilities
27991 Occasionally, important security vulnerabilities are discovered in software
27992 packages and must be patched. Guix developers try hard to keep track of
27993 known vulnerabilities and to apply fixes as soon as possible in the
27994 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27995 containing only security updates.) The @command{guix lint} tool helps
27996 developers find out about vulnerable versions of software packages in the
28001 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
28002 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
28003 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
28007 @xref{Invoking guix lint}, for more information.
28009 Guix follows a functional
28010 package management discipline (@pxref{Introduction}), which implies
28011 that, when a package is changed, @emph{every package that depends on it}
28012 must be rebuilt. This can significantly slow down the deployment of
28013 fixes in core packages such as libc or Bash, since basically the whole
28014 distribution would need to be rebuilt. Using pre-built binaries helps
28015 (@pxref{Substitutes}), but deployment may still take more time than
28019 To address this, Guix implements @dfn{grafts}, a mechanism that allows
28020 for fast deployment of critical updates without the costs associated
28021 with a whole-distribution rebuild. The idea is to rebuild only the
28022 package that needs to be patched, and then to ``graft'' it onto packages
28023 explicitly installed by the user and that were previously referring to
28024 the original package. The cost of grafting is typically very low, and
28025 order of magnitudes lower than a full rebuild of the dependency chain.
28027 @cindex replacements of packages, for grafts
28028 For instance, suppose a security update needs to be applied to Bash.
28029 Guix developers will provide a package definition for the ``fixed''
28030 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
28031 Packages}). Then, the original package definition is augmented with a
28032 @code{replacement} field pointing to the package containing the bug fix:
28039 (replacement bash-fixed)))
28042 From there on, any package depending directly or indirectly on Bash---as
28043 reported by @command{guix gc --requisites} (@pxref{Invoking guix
28044 gc})---that is installed is automatically ``rewritten'' to refer to
28045 @code{bash-fixed} instead of @code{bash}. This grafting process takes
28046 time proportional to the size of the package, usually less than a
28047 minute for an ``average'' package on a recent machine. Grafting is
28048 recursive: when an indirect dependency requires grafting, then grafting
28049 ``propagates'' up to the package that the user is installing.
28051 Currently, the length of the name and version of the graft and that of
28052 the package it replaces (@code{bash-fixed} and @code{bash} in the example
28053 above) must be equal. This restriction mostly comes from the fact that
28054 grafting works by patching files, including binary files, directly.
28055 Other restrictions may apply: for instance, when adding a graft to a
28056 package providing a shared library, the original shared library and its
28057 replacement must have the same @code{SONAME} and be binary-compatible.
28059 The @option{--no-grafts} command-line option allows you to forcefully
28060 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
28064 guix build bash --no-grafts
28068 returns the store file name of the original Bash, whereas:
28075 returns the store file name of the ``fixed'', replacement Bash. This
28076 allows you to distinguish between the two variants of Bash.
28078 To verify which Bash your whole profile refers to, you can run
28079 (@pxref{Invoking guix gc}):
28082 guix gc -R `readlink -f ~/.guix-profile` | grep bash
28086 @dots{} and compare the store file names that you get with those above.
28087 Likewise for a complete Guix system generation:
28090 guix gc -R `guix system build my-config.scm` | grep bash
28093 Lastly, to check which Bash running processes are using, you can use the
28094 @command{lsof} command:
28097 lsof | grep /gnu/store/.*bash
28101 @node Bootstrapping
28102 @chapter Bootstrapping
28104 @c Adapted from the ELS 2013 paper.
28106 @cindex bootstrapping
28108 Bootstrapping in our context refers to how the distribution gets built
28109 ``from nothing''. Remember that the build environment of a derivation
28110 contains nothing but its declared inputs (@pxref{Introduction}). So
28111 there's an obvious chicken-and-egg problem: how does the first package
28112 get built? How does the first compiler get compiled? Note that this is
28113 a question of interest only to the curious hacker, not to the regular
28114 user, so you can shamelessly skip this section if you consider yourself
28115 a ``regular user''.
28117 @cindex bootstrap binaries
28118 The GNU system is primarily made of C code, with libc at its core. The
28119 GNU build system itself assumes the availability of a Bourne shell and
28120 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
28121 `grep'. Furthermore, build programs---programs that run
28122 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
28123 (@pxref{Derivations}). Consequently, to be able to build anything at
28124 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
28125 Binutils, libc, and the other packages mentioned above---the
28126 @dfn{bootstrap binaries}.
28128 These bootstrap binaries are ``taken for granted'', though we can also
28129 re-create them if needed (more on that later).
28131 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
28132 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
28135 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
28136 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
28139 @node Reduced Binary Seed Bootstrap
28140 @section The Reduced Binary Seed Bootstrap
28142 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
28143 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
28144 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
28145 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
28146 ``taken for granted.''
28148 Taking these binaries for granted means that we consider them to be a correct
28149 and trustworthy `seed' for building the complete system. Therein lies a
28150 problem: the current combined size of these bootstrap binaries is about 250MB
28151 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
28152 these is next to impossible.
28154 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
28155 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
28156 Bootstrap'' and while we are working towards that goal it would be hyperbole
28157 to use that term for what we do now.}.
28159 The Reduced Binary Seed bootstrap removes the most critical tools---from a
28160 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
28161 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
28162 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
28163 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
28164 these new binary seeds and a new set of
28166 packages@footnote{@c
28181 gcc-mesboot1-wrapper,
28182 glibc-headers-mesboot,
28186 gcc-mesboot-wrapper.
28189 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
28190 From here on the more traditional bootstrap process resumes. This approach
28191 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
28192 reduce this further. If you are interested, join us on @code{#bootstrappable}
28193 on the Freenode IRC network.
28195 @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
28196 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
28198 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
28199 compiler used to build the rest of GuixSD.
28201 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
28203 @node Preparing to Use the Bootstrap Binaries
28204 @section Preparing to Use the Bootstrap Binaries
28206 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
28207 @c large image, it's hard to scroll. Oh well.
28208 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
28210 The figure above shows the very beginning of the dependency graph of the
28211 distribution, corresponding to the package definitions of the @code{(gnu
28212 packages bootstrap)} module. A similar figure can be generated with
28213 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
28216 guix graph -t derivation \
28217 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
28218 | dot -Tps > gcc.ps
28221 or, for the Reduced Binary Seed bootstrap
28224 guix graph -t derivation \
28225 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
28226 | dot -Tps > mes.ps
28229 At this level of detail, things are
28230 slightly complex. First, Guile itself consists of an ELF executable,
28231 along with many source and compiled Scheme files that are dynamically
28232 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
28233 tarball shown in this graph. This tarball is part of Guix's ``source''
28234 distribution, and gets inserted into the store with @code{add-to-store}
28235 (@pxref{The Store}).
28237 But how do we write a derivation that unpacks this tarball and adds it
28238 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
28239 derivation---the first one that gets built---uses @code{bash} as its
28240 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
28241 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
28242 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
28243 the Guix source distribution, whose sole purpose is to allow the Guile
28244 tarball to be unpacked.
28246 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
28247 Guile that can be used to run subsequent build programs. Its first task
28248 is to download tarballs containing the other pre-built binaries---this
28249 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
28250 @code{ftp-client.scm} are used for this purpose. The
28251 @code{module-import.drv} derivations import those modules in a directory
28252 in the store, using the original layout. The
28253 @code{module-import-compiled.drv} derivations compile those modules, and
28254 write them in an output directory with the right layout. This
28255 corresponds to the @code{#:modules} argument of
28256 @code{build-expression->derivation} (@pxref{Derivations}).
28258 Finally, the various tarballs are unpacked by the derivations
28259 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
28260 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
28261 point we have a working C tool chain.
28263 @unnumberedsec Building the Build Tools
28265 Bootstrapping is complete when we have a full tool chain that does not
28266 depend on the pre-built bootstrap tools discussed above. This
28267 no-dependency requirement is verified by checking whether the files of
28268 the final tool chain contain references to the @file{/gnu/store}
28269 directories of the bootstrap inputs. The process that leads to this
28270 ``final'' tool chain is described by the package definitions found in
28271 the @code{(gnu packages commencement)} module.
28273 The @command{guix graph} command allows us to ``zoom out'' compared to
28274 the graph above, by looking at the level of package objects instead of
28275 individual derivations---remember that a package may translate to
28276 several derivations, typically one derivation to download its source,
28277 one to build the Guile modules it needs, and one to actually build the
28278 package from source. The command:
28281 guix graph -t bag \
28282 -e '(@@@@ (gnu packages commencement)
28283 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
28287 produces the dependency graph leading to the ``final'' C
28288 library@footnote{You may notice the @code{glibc-intermediate} label,
28289 suggesting that it is not @emph{quite} final, but as a good
28290 approximation, we will consider it final.}, depicted below.
28292 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
28294 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
28295 The first tool that gets built with the bootstrap binaries is
28296 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
28297 for all the following packages. From there Findutils and Diffutils get
28300 Then come the first-stage Binutils and GCC, built as pseudo cross
28301 tools---i.e., with @code{--target} equal to @code{--host}. They are
28302 used to build libc. Thanks to this cross-build trick, this libc is
28303 guaranteed not to hold any reference to the initial tool chain.
28305 From there the final Binutils and GCC (not shown above) are built.
28307 from the final Binutils, and links programs against the just-built libc.
28308 This tool chain is used to build the other packages used by Guix and by
28309 the GNU Build System: Guile, Bash, Coreutils, etc.
28311 And voilà! At this point we have the complete set of build tools that
28312 the GNU Build System expects. These are in the @code{%final-inputs}
28313 variable of the @code{(gnu packages commencement)} module, and are
28314 implicitly used by any package that uses @code{gnu-build-system}
28315 (@pxref{Build Systems, @code{gnu-build-system}}).
28318 @unnumberedsec Building the Bootstrap Binaries
28320 @cindex bootstrap binaries
28321 Because the final tool chain does not depend on the bootstrap binaries,
28322 those rarely need to be updated. Nevertheless, it is useful to have an
28323 automated way to produce them, should an update occur, and this is what
28324 the @code{(gnu packages make-bootstrap)} module provides.
28326 The following command builds the tarballs containing the bootstrap binaries
28327 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
28328 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
28329 and Guile, and a tarball containing a mixture of Coreutils and other basic
28330 command-line tools):
28333 guix build bootstrap-tarballs
28336 The generated tarballs are those that should be referred to in the
28337 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28340 Still here? Then perhaps by now you've started to wonder: when do we
28341 reach a fixed point? That is an interesting question! The answer is
28342 unknown, but if you would like to investigate further (and have
28343 significant computational and storage resources to do so), then let us
28346 @unnumberedsec Reducing the Set of Bootstrap Binaries
28348 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28349 binary code! Why is that a problem? It's a problem because these big chunks
28350 of binary code are practically non-auditable, which makes it hard to establish
28351 what source code produced them. Every unauditable binary also leaves us
28352 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28353 paper @emph{Reflections on Trusting Trust}.
28355 This is mitigated by the fact that our bootstrap binaries were generated
28356 from an earlier Guix revision. Nevertheless it lacks the level of
28357 transparency that we get in the rest of the package dependency graph,
28358 where Guix always gives us a source-to-binary mapping. Thus, our goal
28359 is to reduce the set of bootstrap binaries to the bare minimum.
28361 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
28362 on-going projects to do that. One of these is about replacing the
28363 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28364 of increasing complexity, which could be built from source starting from
28365 a simple and auditable assembler.
28367 Our first major achievement is the replacement of of GCC, the GNU C Library
28368 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28369 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28370 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28371 bootstrapped yet and thus we inject them as binary seeds. We call this the
28372 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28373 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28374 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28376 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28377 also looking at any other bootstrap binaries. Your help is welcome!
28380 @chapter Porting to a New Platform
28382 As discussed above, the GNU distribution is self-contained, and
28383 self-containment is achieved by relying on pre-built ``bootstrap
28384 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28385 operating system kernel, CPU architecture, and application binary
28386 interface (ABI). Thus, to port the distribution to a platform that is
28387 not yet supported, one must build those bootstrap binaries, and update
28388 the @code{(gnu packages bootstrap)} module to use them on that platform.
28390 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28391 When everything goes well, and assuming the GNU tool chain supports the
28392 target platform, this can be as simple as running a command like this
28396 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28399 For this to work, the @code{glibc-dynamic-linker} procedure in
28400 @code{(gnu packages bootstrap)} must be augmented to return the right
28401 file name for libc's dynamic linker on that platform; likewise,
28402 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28403 taught about the new platform.
28405 Once these are built, the @code{(gnu packages bootstrap)} module needs
28406 to be updated to refer to these binaries on the target platform. That
28407 is, the hashes and URLs of the bootstrap tarballs for the new platform
28408 must be added alongside those of the currently supported platforms. The
28409 bootstrap Guile tarball is treated specially: it is expected to be
28410 available locally, and @file{gnu/local.mk} has rules to download it for
28411 the supported architectures; a rule for the new platform must be added
28414 In practice, there may be some complications. First, it may be that the
28415 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28416 above) is not recognized by all the GNU tools. Typically, glibc
28417 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
28418 configure flag (see @code{gcc.scm} for examples of how to handle this).
28419 Second, some of the required packages could fail to build for that
28420 platform. Lastly, the generated binaries could be broken for some
28423 @c *********************************************************************
28424 @include contributing.texi
28426 @c *********************************************************************
28427 @node Acknowledgments
28428 @chapter Acknowledgments
28430 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28431 which was designed and
28432 implemented by Eelco Dolstra, with contributions from other people (see
28433 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28434 management, and promoted unprecedented features, such as transactional
28435 package upgrades and rollbacks, per-user profiles, and referentially
28436 transparent build processes. Without this work, Guix would not exist.
28438 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28439 an inspiration for Guix.
28441 GNU@tie{}Guix itself is a collective work with contributions from a
28442 number of people. See the @file{AUTHORS} file in Guix for more
28443 information on these fine people. The @file{THANKS} file lists people
28444 who have helped by reporting bugs, taking care of the infrastructure,
28445 providing artwork and themes, making suggestions, and more---thank you!
28448 @c *********************************************************************
28449 @node GNU Free Documentation License
28450 @appendix GNU Free Documentation License
28451 @cindex license, GNU Free Documentation License
28452 @include fdl-1.3.texi
28454 @c *********************************************************************
28455 @node Concept Index
28456 @unnumbered Concept Index
28459 @node Programming Index
28460 @unnumbered Programming Index
28461 @syncodeindex tp fn
28462 @syncodeindex vr fn
28467 @c Local Variables:
28468 @c ispell-local-dictionary: "american";