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 Nikita Gillmann@*
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, 2020 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@*
78 Copyright @copyright{} 2020 Naga Malleswari@*
79 Copyright @copyright{} 2020 Brice Waegeneire@*
80 Copyright @copyright{} 2020 R Veera Kumar@*
81 Copyright @copyright{} 2020 Pierre Langlois@*
82 Copyright @copyright{} 2020 pinoaffe@*
84 Permission is granted to copy, distribute and/or modify this document
85 under the terms of the GNU Free Documentation License, Version 1.3 or
86 any later version published by the Free Software Foundation; with no
87 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
88 copy of the license is included in the section entitled ``GNU Free
89 Documentation License''.
92 @dircategory System administration
94 * Guix: (guix). Manage installed software and system configuration.
95 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
96 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
97 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
98 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
99 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
102 @dircategory Software development
104 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
105 * guix build: (guix)Invoking guix build. Building packages.
106 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
110 @title GNU Guix Reference Manual
111 @subtitle Using the GNU Guix Functional Package Manager
112 @author The GNU Guix Developers
115 @vskip 0pt plus 1filll
116 Edition @value{EDITION} @*
124 @c *********************************************************************
128 This document describes GNU Guix version @value{VERSION}, a functional
129 package management tool written for the GNU system.
131 @c TRANSLATORS: You can replace the following paragraph with information on
132 @c how to join your own translation team and how to report issues with the
134 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
135 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
136 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
137 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
138 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
139 would like to translate it in your native language, consider joining the
140 @uref{https://translationproject.org/domain/guix-manual.html, Translation
144 * Introduction:: What is Guix about?
145 * Installation:: Installing Guix.
146 * System Installation:: Installing the whole operating system.
147 * Package Management:: Package installation, upgrade, etc.
148 * Development:: Guix-aided software development.
149 * Programming Interface:: Using Guix in Scheme.
150 * Utilities:: Package management commands.
151 * System Configuration:: Configuring the operating system.
152 * Documentation:: Browsing software user manuals.
153 * Installing Debugging Files:: Feeding the debugger.
154 * Security Updates:: Deploying security fixes quickly.
155 * Bootstrapping:: GNU/Linux built from scratch.
156 * Porting:: Targeting another platform or kernel.
157 * Contributing:: Your help needed!
159 * Acknowledgments:: Thanks!
160 * GNU Free Documentation License:: The license of this manual.
161 * Concept Index:: Concepts.
162 * Programming Index:: Data types, functions, and variables.
165 --- The Detailed Node Listing ---
169 * Managing Software the Guix Way:: What's special.
170 * GNU Distribution:: The packages and tools.
174 * Binary Installation:: Getting Guix running in no time!
175 * Requirements:: Software needed to build and run Guix.
176 * Running the Test Suite:: Testing Guix.
177 * Setting Up the Daemon:: Preparing the build daemon's environment.
178 * Invoking guix-daemon:: Running the build daemon.
179 * Application Setup:: Application-specific setup.
181 Setting Up the Daemon
183 * Build Environment Setup:: Preparing the isolated build environment.
184 * Daemon Offload Setup:: Offloading builds to remote machines.
185 * SELinux Support:: Using an SELinux policy for the daemon.
189 * Limitations:: What you can expect.
190 * Hardware Considerations:: Supported hardware.
191 * USB Stick and DVD Installation:: Preparing the installation medium.
192 * Preparing for Installation:: Networking, partitioning, etc.
193 * Guided Graphical Installation:: Easy graphical installation.
194 * Manual Installation:: Manual installation for wizards.
195 * After System Installation:: When installation succeeded.
196 * Installing Guix in a VM:: Guix System playground.
197 * Building the Installation Image:: How this comes to be.
201 * Keyboard Layout and Networking and Partitioning:: Initial setup.
202 * Proceeding with the Installation:: Installing.
206 * Features:: How Guix will make your life brighter.
207 * Invoking guix package:: Package installation, removal, etc.
208 * Substitutes:: Downloading pre-built binaries.
209 * Packages with Multiple Outputs:: Single source package, multiple outputs.
210 * Invoking guix gc:: Running the garbage collector.
211 * Invoking guix pull:: Fetching the latest Guix and distribution.
212 * Channels:: Customizing the package collection.
213 * Invoking guix time-machine:: Running an older revision of Guix.
214 * Inferiors:: Interacting with another revision of Guix.
215 * Invoking guix describe:: Display information about your Guix revision.
216 * Invoking guix archive:: Exporting and importing store files.
220 * Official Substitute Server:: One particular source of substitutes.
221 * Substitute Server Authorization:: How to enable or disable substitutes.
222 * Substitute Authentication:: How Guix verifies substitutes.
223 * Proxy Settings:: How to get substitutes via proxy.
224 * Substitution Failure:: What happens when substitution fails.
225 * On Trusting Binaries:: How can you trust that binary blob?
229 * Invoking guix environment:: Setting up development environments.
230 * Invoking guix pack:: Creating software bundles.
232 Programming Interface
234 * Package Modules:: Packages from the programmer's viewpoint.
235 * Defining Packages:: Defining new packages.
236 * Build Systems:: Specifying how packages are built.
237 * The Store:: Manipulating the package store.
238 * Derivations:: Low-level interface to package derivations.
239 * The Store Monad:: Purely functional interface to the store.
240 * G-Expressions:: Manipulating build expressions.
241 * Invoking guix repl:: Fiddling with Guix interactively.
245 * package Reference:: The package data type.
246 * origin Reference:: The origin data type.
250 * Invoking guix build:: Building packages from the command line.
251 * Invoking guix edit:: Editing package definitions.
252 * Invoking guix download:: Downloading a file and printing its hash.
253 * Invoking guix hash:: Computing the cryptographic hash of a file.
254 * Invoking guix import:: Importing package definitions.
255 * Invoking guix refresh:: Updating package definitions.
256 * Invoking guix lint:: Finding errors in package definitions.
257 * Invoking guix size:: Profiling disk usage.
258 * Invoking guix graph:: Visualizing the graph of packages.
259 * Invoking guix publish:: Sharing substitutes.
260 * Invoking guix challenge:: Challenging substitute servers.
261 * Invoking guix copy:: Copying to and from a remote store.
262 * Invoking guix container:: Process isolation.
263 * Invoking guix weather:: Assessing substitute availability.
264 * Invoking guix processes:: Listing client processes.
266 Invoking @command{guix build}
268 * Common Build Options:: Build options for most commands.
269 * Package Transformation Options:: Creating variants of packages.
270 * Additional Build Options:: Options specific to 'guix build'.
271 * Debugging Build Failures:: Real life packaging experience.
275 * Using the Configuration System:: Customizing your GNU system.
276 * operating-system Reference:: Detail of operating-system declarations.
277 * File Systems:: Configuring file system mounts.
278 * Mapped Devices:: Block device extra processing.
279 * User Accounts:: Specifying user accounts.
280 * Keyboard Layout:: How the system interprets key strokes.
281 * Locales:: Language and cultural convention settings.
282 * Services:: Specifying system services.
283 * Setuid Programs:: Programs running with root privileges.
284 * X.509 Certificates:: Authenticating HTTPS servers.
285 * Name Service Switch:: Configuring libc's name service switch.
286 * Initial RAM Disk:: Linux-Libre bootstrapping.
287 * Bootloader Configuration:: Configuring the boot loader.
288 * Invoking guix system:: Instantiating a system configuration.
289 * Invoking guix deploy:: Deploying a system configuration to a remote host.
290 * Running Guix in a VM:: How to run Guix System in a virtual machine.
291 * Defining Services:: Adding new service definitions.
295 * Base Services:: Essential system services.
296 * Scheduled Job Execution:: The mcron service.
297 * Log Rotation:: The rottlog service.
298 * Networking Services:: Network setup, SSH daemon, etc.
299 * X Window:: Graphical display.
300 * Printing Services:: Local and remote printer support.
301 * Desktop Services:: D-Bus and desktop services.
302 * Sound Services:: ALSA and Pulseaudio services.
303 * Database Services:: SQL databases, key-value stores, etc.
304 * Mail Services:: IMAP, POP3, SMTP, and all that.
305 * Messaging Services:: Messaging services.
306 * Telephony Services:: Telephony services.
307 * Monitoring Services:: Monitoring services.
308 * Kerberos Services:: Kerberos services.
309 * Web Services:: Web servers.
310 * Certificate Services:: TLS certificates via Let's Encrypt.
311 * DNS Services:: DNS daemons.
312 * VPN Services:: VPN daemons.
313 * Network File System:: NFS related services.
314 * Continuous Integration:: The Cuirass service.
315 * Power Management Services:: Extending battery life.
316 * Audio Services:: The MPD.
317 * Virtualization Services:: Virtualization services.
318 * Version Control Services:: Providing remote access to Git repositories.
319 * Game Services:: Game servers.
320 * PAM Mount Service:: Service to mount volumes when logging in.
321 * Linux Services:: Services tied to the Linux kernel.
322 * Miscellaneous Services:: Other services.
326 * Service Composition:: The model for composing services.
327 * Service Types and Services:: Types and services.
328 * Service Reference:: API reference.
329 * Shepherd Services:: A particular type of service.
334 @c *********************************************************************
336 @chapter Introduction
339 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
340 using the international phonetic alphabet (IPA).} is a package
341 management tool for and distribution of the GNU system.
342 Guix makes it easy for unprivileged
343 users to install, upgrade, or remove software packages, to roll back to a
344 previous package set, to build packages from source, and generally
345 assists with the creation and maintenance of software environments.
348 @cindex GuixSD, now Guix System
349 @cindex Guix System Distribution, now Guix System
350 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
351 complements the available tools without interference (@pxref{Installation}),
352 or you can use it as a standalone operating system distribution,
353 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
354 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
355 group everything under the ``Guix'' banner since, after all, Guix System is
356 readily available through the @command{guix system} command, even if you're
357 using a different distro underneath!}. @xref{GNU Distribution}.
360 * Managing Software the Guix Way:: What's special.
361 * GNU Distribution:: The packages and tools.
364 @node Managing Software the Guix Way
365 @section Managing Software the Guix Way
367 @cindex user interfaces
368 Guix provides a command-line package management interface
369 (@pxref{Package Management}), tools to help with software development
370 (@pxref{Development}), command-line utilities for more advanced usage,
371 (@pxref{Utilities}), as well as Scheme programming interfaces
372 (@pxref{Programming Interface}).
374 Its @dfn{build daemon} is responsible for building packages on behalf of
375 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
376 binaries from authorized sources (@pxref{Substitutes}).
378 @cindex extensibility of the distribution
379 @cindex customization, of packages
380 Guix includes package definitions for many GNU and non-GNU packages, all
381 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
382 user's computing freedom}. It is @emph{extensible}: users can write
383 their own package definitions (@pxref{Defining Packages}) and make them
384 available as independent package modules (@pxref{Package Modules}). It
385 is also @emph{customizable}: users can @emph{derive} specialized package
386 definitions from existing ones, including from the command line
387 (@pxref{Package Transformation Options}).
389 @cindex functional package management
391 Under the hood, Guix implements the @dfn{functional package management}
392 discipline pioneered by Nix (@pxref{Acknowledgments}).
393 In Guix, the package build and installation process is seen
394 as a @emph{function}, in the mathematical sense. That function takes inputs,
395 such as build scripts, a compiler, and libraries, and
396 returns an installed package. As a pure function, its result depends
397 solely on its inputs---for instance, it cannot refer to software or
398 scripts that were not explicitly passed as inputs. A build function
399 always produces the same result when passed a given set of inputs. It
400 cannot alter the environment of the running system in
401 any way; for instance, it cannot create, modify, or delete files outside
402 of its build and installation directories. This is achieved by running
403 build processes in isolated environments (or @dfn{containers}), where only their
404 explicit inputs are visible.
407 The result of package build functions is @dfn{cached} in the file
408 system, in a special directory called @dfn{the store} (@pxref{The
409 Store}). Each package is installed in a directory of its own in the
410 store---by default under @file{/gnu/store}. The directory name contains
411 a hash of all the inputs used to build that package; thus, changing an
412 input yields a different directory name.
414 This approach is the foundation for the salient features of Guix: support
415 for transactional package upgrade and rollback, per-user installation, and
416 garbage collection of packages (@pxref{Features}).
419 @node GNU Distribution
420 @section GNU Distribution
423 Guix comes with a distribution of the GNU system consisting entirely of
424 free software@footnote{The term ``free'' here refers to the
425 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
426 users of that software}.}. The
427 distribution can be installed on its own (@pxref{System Installation}),
428 but it is also possible to install Guix as a package manager on top of
429 an installed GNU/Linux system (@pxref{Installation}). When we need to
430 distinguish between the two, we refer to the standalone distribution as
433 The distribution provides core GNU packages such as GNU libc, GCC, and
434 Binutils, as well as many GNU and non-GNU applications. The complete
435 list of available packages can be browsed
436 @url{https://www.gnu.org/software/guix/packages,on-line} or by
437 running @command{guix package} (@pxref{Invoking guix package}):
440 guix package --list-available
443 Our goal is to provide a practical 100% free software distribution of
444 Linux-based and other variants of GNU, with a focus on the promotion and
445 tight integration of GNU components, and an emphasis on programs and
446 tools that help users exert that freedom.
448 Packages are currently available on the following platforms:
453 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
456 Intel 32-bit architecture (IA32), Linux-Libre kernel;
459 ARMv7-A architecture with hard float, Thumb-2 and NEON,
460 using the EABI hard-float application binary interface (ABI),
461 and Linux-Libre kernel.
464 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
467 little-endian 64-bit MIPS processors, specifically the Loongson series,
468 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
469 supported; in particular, the project's build farms no longer provide
470 substitutes for this architecture.
474 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
475 configuration and Guix takes care of instantiating the configuration in a
476 transactional, reproducible, and stateless fashion (@pxref{System
477 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
478 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
479 Manual}), the well-known GNU utilities and tool chain, as well as the
480 graphical environment or system services of your choice.
482 Guix System is available on all the above platforms except
483 @code{mips64el-linux}.
486 For information on porting to other architectures or kernels,
489 Building this distribution is a cooperative effort, and you are invited
490 to join! @xref{Contributing}, for information about how you can help.
493 @c *********************************************************************
495 @chapter Installation
497 @cindex installing Guix
500 We recommend the use of this
501 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
502 shell installer script} to install Guix on top of a running GNU/Linux system,
503 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
504 with the installation of the package manager, which can be done on top of a
505 running GNU/Linux system. If, instead, you want to install the complete GNU
506 operating system, @pxref{System Installation}.} The script automates the
507 download, installation, and initial configuration of Guix. It should be run
511 @cindex foreign distro
512 @cindex directories related to foreign distro
513 When installed on a foreign distro, GNU@tie{}Guix complements the available
514 tools without interference. Its data lives exclusively in two directories,
515 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
516 such as @file{/etc}, are left untouched.
518 Once installed, Guix can be updated by running @command{guix pull}
519 (@pxref{Invoking guix pull}).
521 If you prefer to perform the installation steps manually or want to tweak
522 them, you may find the following subsections useful. They describe the
523 software requirements of Guix, as well as how to install it manually and get
527 * Binary Installation:: Getting Guix running in no time!
528 * Requirements:: Software needed to build and run Guix.
529 * Running the Test Suite:: Testing Guix.
530 * Setting Up the Daemon:: Preparing the build daemon's environment.
531 * Invoking guix-daemon:: Running the build daemon.
532 * Application Setup:: Application-specific setup.
533 * Upgrading Guix:: Upgrading Guix and its build daemon.
536 @node Binary Installation
537 @section Binary Installation
539 @cindex installing Guix from binaries
540 @cindex installer script
541 This section describes how to install Guix on an arbitrary system from a
542 self-contained tarball providing binaries for Guix and for all its
543 dependencies. This is often quicker than installing from source, which
544 is described in the next sections. The only requirement is to have
547 @c Note duplicated from the ``Installation'' node.
549 We recommend the use of this
550 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
551 shell installer script}. The script automates the download, installation, and
552 initial configuration steps described below. It should be run as the root
553 user. As root, you can thus run this:
557 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
558 chmod +x guix-install.sh
563 Installing goes along these lines:
567 @cindex downloading Guix binary
568 Download the binary tarball from
569 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
570 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
571 already running the kernel Linux, and so on.
573 @c The following is somewhat duplicated in ``System Installation''.
574 Make sure to download the associated @file{.sig} file and to verify the
575 authenticity of the tarball against it, along these lines:
578 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
579 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
582 If that command fails because you do not have the required public key,
583 then run this command to import it:
586 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
587 -qO - | gpg --import -
591 and rerun the @code{gpg --verify} command.
593 Take note that a warning like ``This key is not certified with a trusted
594 signature!'' is normal.
596 @c end authentication part
599 Now, you need to become the @code{root} user. Depending on your distribution,
600 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
604 # tar --warning=no-timestamp -xf \
605 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
606 # mv var/guix /var/ && mv gnu /
609 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
610 The latter contains a ready-to-use profile for @code{root} (see next
613 Do @emph{not} unpack the tarball on a working Guix system since that
614 would overwrite its own essential files.
616 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
617 not emit warnings about ``implausibly old time stamps'' (such
618 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
620 They stem from the fact that all the
621 files in the archive have their modification time set to zero (which
622 means January 1st, 1970.) This is done on purpose to make sure the
623 archive content is independent of its creation time, thus making it
627 Make the profile available under @file{~root/.config/guix/current}, which is
628 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
631 # mkdir -p ~root/.config/guix
632 # ln -sf /var/guix/profiles/per-user/root/current-guix \
633 ~root/.config/guix/current
636 Source @file{etc/profile} to augment @env{PATH} and other relevant
637 environment variables:
640 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
641 source $GUIX_PROFILE/etc/profile
645 Create the group and user accounts for build users as explained below
646 (@pxref{Build Environment Setup}).
649 Run the daemon, and set it to automatically start on boot.
651 If your host distro uses the systemd init system, this can be achieved
654 @c Versions of systemd that supported symlinked service files are not
655 @c yet widely deployed, so we should suggest that users copy the service
658 @c See this thread for more information:
659 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
662 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
664 # systemctl enable --now guix-daemon
667 If your host distro uses the Upstart init system:
670 # initctl reload-configuration
671 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
676 Otherwise, you can still start the daemon manually with:
679 # ~root/.config/guix/current/bin/guix-daemon \
680 --build-users-group=guixbuild
684 Make the @command{guix} command available to other users on the machine,
688 # mkdir -p /usr/local/bin
690 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
693 It is also a good idea to make the Info version of this manual available
697 # mkdir -p /usr/local/share/info
698 # cd /usr/local/share/info
699 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
703 That way, assuming @file{/usr/local/share/info} is in the search path,
704 running @command{info guix} will open this manual (@pxref{Other Info
705 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
709 @cindex substitutes, authorization thereof
710 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
711 (@pxref{Substitutes}), authorize them:
714 # guix archive --authorize < \
715 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
719 Each user may need to perform a few additional steps to make their Guix
720 environment ready for use, @pxref{Application Setup}.
723 Voilà, the installation is complete!
725 You can confirm that Guix is working by installing a sample package into
732 The binary installation tarball can be (re)produced and verified simply
733 by running the following command in the Guix source tree:
736 make guix-binary.@var{system}.tar.xz
740 ...@: which, in turn, runs:
743 guix pack -s @var{system} --localstatedir \
744 --profile-name=current-guix guix
747 @xref{Invoking guix pack}, for more info on this handy tool.
750 @section Requirements
752 This section lists requirements when building Guix from source. The
753 build procedure for Guix is the same as for other GNU software, and is
754 not covered here. Please see the files @file{README} and @file{INSTALL}
755 in the Guix source tree for additional details.
757 @cindex official website
758 GNU Guix is available for download from its website at
759 @url{https://www.gnu.org/software/guix/}.
761 GNU Guix depends on the following packages:
764 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
766 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
769 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
770 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
771 Guile,, gnutls-guile, GnuTLS-Guile});
773 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
776 @c FIXME: Specify a version number once a release has been made.
777 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
779 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
780 @item @url{https://zlib.net, zlib};
781 @item @url{https://www.gnu.org/software/make/, GNU Make}.
784 The following dependencies are optional:
788 @c Note: We need at least 0.12.0 for 'userauth-gssapi!'.
789 Support for build offloading (@pxref{Daemon Offload Setup}) and
790 @command{guix copy} (@pxref{Invoking guix copy}) depends on
791 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
792 version 0.12.0 or later.
795 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
796 substitutes can be used and @command{guix publish} can compress substitutes
800 When @url{http://www.bzip.org, libbz2} is available,
801 @command{guix-daemon} can use it to compress build logs.
804 Unless @option{--disable-daemon} was passed to @command{configure}, the
805 following packages are also needed:
808 @item @url{https://gnupg.org/, GNU libgcrypt};
809 @item @url{https://sqlite.org, SQLite 3};
810 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
814 @cindex state directory
815 When configuring Guix on a system that already has a Guix installation,
816 be sure to specify the same state directory as the existing installation
817 using the @option{--localstatedir} option of the @command{configure}
818 script (@pxref{Directory Variables, @code{localstatedir},, standards,
819 GNU Coding Standards}). Usually, this @var{localstatedir} option is
820 set to the value @file{/var}. The @command{configure} script protects
821 against unintended misconfiguration of @var{localstatedir} so you do not
822 inadvertently corrupt your store (@pxref{The Store}).
824 @node Running the Test Suite
825 @section Running the Test Suite
828 After a successful @command{configure} and @code{make} run, it is a good
829 idea to run the test suite. It can help catch issues with the setup or
830 environment, or bugs in Guix itself---and really, reporting test
831 failures is a good way to help improve the software. To run the test
838 Test cases can run in parallel: you can use the @code{-j} option of
839 GNU@tie{}make to speed things up. The first run may take a few minutes
840 on a recent machine; subsequent runs will be faster because the store
841 that is created for test purposes will already have various things in
844 It is also possible to run a subset of the tests by defining the
845 @code{TESTS} makefile variable as in this example:
848 make check TESTS="tests/store.scm tests/cpio.scm"
851 By default, tests results are displayed at a file level. In order to
852 see the details of every individual test cases, it is possible to define
853 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
856 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
859 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
860 @file{test-suite.log} file. Please specify the Guix version being used
861 as well as version numbers of the dependencies (@pxref{Requirements}) in
864 Guix also comes with a whole-system test suite that tests complete
865 Guix System instances. It can only run on systems where
866 Guix is already installed, using:
873 or, again, by defining @code{TESTS} to select a subset of tests to run:
876 make check-system TESTS="basic mcron"
879 These system tests are defined in the @code{(gnu tests @dots{})}
880 modules. They work by running the operating systems under test with
881 lightweight instrumentation in a virtual machine (VM). They can be
882 computationally intensive or rather cheap, depending on whether
883 substitutes are available for their dependencies (@pxref{Substitutes}).
884 Some of them require a lot of storage space to hold VM images.
886 Again in case of test failures, please send @email{bug-guix@@gnu.org}
889 @node Setting Up the Daemon
890 @section Setting Up the Daemon
893 Operations such as building a package or running the garbage collector
894 are all performed by a specialized process, the @dfn{build daemon}, on
895 behalf of clients. Only the daemon may access the store and its
896 associated database. Thus, any operation that manipulates the store
897 goes through the daemon. For instance, command-line tools such as
898 @command{guix package} and @command{guix build} communicate with the
899 daemon (@i{via} remote procedure calls) to instruct it what to do.
901 The following sections explain how to prepare the build daemon's
902 environment. See also @ref{Substitutes}, for information on how to allow
903 the daemon to download pre-built binaries.
906 * Build Environment Setup:: Preparing the isolated build environment.
907 * Daemon Offload Setup:: Offloading builds to remote machines.
908 * SELinux Support:: Using an SELinux policy for the daemon.
911 @node Build Environment Setup
912 @subsection Build Environment Setup
914 @cindex build environment
915 In a standard multi-user setup, Guix and its daemon---the
916 @command{guix-daemon} program---are installed by the system
917 administrator; @file{/gnu/store} is owned by @code{root} and
918 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
919 Guix tools to build packages or otherwise access the store, and the
920 daemon will do it on their behalf, ensuring that the store is kept in a
921 consistent state, and allowing built packages to be shared among users.
924 When @command{guix-daemon} runs as @code{root}, you may not want package
925 build processes themselves to run as @code{root} too, for obvious
926 security reasons. To avoid that, a special pool of @dfn{build users}
927 should be created for use by build processes started by the daemon.
928 These build users need not have a shell and a home directory: they will
929 just be used when the daemon drops @code{root} privileges in build
930 processes. Having several such users allows the daemon to launch
931 distinct build processes under separate UIDs, which guarantees that they
932 do not interfere with each other---an essential feature since builds are
933 regarded as pure functions (@pxref{Introduction}).
935 On a GNU/Linux system, a build user pool may be created like this (using
936 Bash syntax and the @code{shadow} commands):
938 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
939 @c for why `-G' is needed.
941 # groupadd --system guixbuild
942 # for i in `seq -w 1 10`;
944 useradd -g guixbuild -G guixbuild \
945 -d /var/empty -s `which nologin` \
946 -c "Guix build user $i" --system \
952 The number of build users determines how many build jobs may run in
953 parallel, as specified by the @option{--max-jobs} option
954 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
955 @command{guix system vm} and related commands, you may need to add the
956 build users to the @code{kvm} group so they can access @file{/dev/kvm},
957 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
958 (@pxref{Invoking guix system}).
960 The @code{guix-daemon} program may then be run as @code{root} with the
961 following command@footnote{If your machine uses the systemd init system,
962 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
963 file in @file{/etc/systemd/system} will ensure that
964 @command{guix-daemon} is automatically started. Similarly, if your
965 machine uses the Upstart init system, drop the
966 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
967 file in @file{/etc/init}.}:
970 # guix-daemon --build-users-group=guixbuild
975 This way, the daemon starts build processes in a chroot, under one of
976 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
977 environment contains nothing but:
979 @c Keep this list in sync with libstore/build.cc! -----------------------
982 a minimal @code{/dev} directory, created mostly independently from the
983 host @code{/dev}@footnote{``Mostly'', because while the set of files
984 that appear in the chroot's @code{/dev} is fixed, most of these files
985 can only be created if the host has them.};
988 the @code{/proc} directory; it only shows the processes of the container
989 since a separate PID name space is used;
992 @file{/etc/passwd} with an entry for the current user and an entry for
996 @file{/etc/group} with an entry for the user's group;
999 @file{/etc/hosts} with an entry that maps @code{localhost} to
1003 a writable @file{/tmp} directory.
1006 You can influence the directory where the daemon stores build trees
1007 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1008 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1009 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1010 This way, the value of @env{TMPDIR} does not leak inside build
1011 environments, which avoids discrepancies in cases where build processes
1012 capture the name of their build tree.
1015 The daemon also honors the @env{http_proxy} environment variable for
1016 HTTP downloads it performs, be it for fixed-output derivations
1017 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1019 If you are installing Guix as an unprivileged user, it is still possible
1020 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1021 However, build processes will not be isolated from one another, and not
1022 from the rest of the system. Thus, build processes may interfere with
1023 each other, and may access programs, libraries, and other files
1024 available on the system---making it much harder to view them as
1025 @emph{pure} functions.
1028 @node Daemon Offload Setup
1029 @subsection Using the Offload Facility
1033 When desired, the build daemon can @dfn{offload} derivation builds to
1034 other machines running Guix, using the @code{offload} @dfn{build
1035 hook}@footnote{This feature is available only when
1036 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1037 present.}. When that
1038 feature is enabled, a list of user-specified build machines is read from
1039 @file{/etc/guix/machines.scm}; every time a build is requested, for
1040 instance via @code{guix build}, the daemon attempts to offload it to one
1041 of the machines that satisfy the constraints of the derivation, in
1042 particular its system type---e.g., @file{x86_64-linux}. Missing
1043 prerequisites for the build are copied over SSH to the target machine,
1044 which then proceeds with the build; upon success the output(s) of the
1045 build are copied back to the initial machine.
1047 The @file{/etc/guix/machines.scm} file typically looks like this:
1050 (list (build-machine
1051 (name "eightysix.example.org")
1052 (system "x86_64-linux")
1053 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1055 (speed 2.)) ;incredibly fast!
1058 (name "meeps.example.org")
1059 (system "mips64el-linux")
1060 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1063 (string-append (getenv "HOME")
1064 "/.ssh/identity-for-guix"))))
1068 In the example above we specify a list of two build machines, one for
1069 the @code{x86_64} architecture and one for the @code{mips64el}
1072 In fact, this file is---not surprisingly!---a Scheme file that is
1073 evaluated when the @code{offload} hook is started. Its return value
1074 must be a list of @code{build-machine} objects. While this example
1075 shows a fixed list of build machines, one could imagine, say, using
1076 DNS-SD to return a list of potential build machines discovered in the
1077 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1078 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1081 @deftp {Data Type} build-machine
1082 This data type represents build machines to which the daemon may offload
1083 builds. The important fields are:
1088 The host name of the remote machine.
1091 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1094 The user account to use when connecting to the remote machine over SSH.
1095 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1096 allow non-interactive logins.
1099 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1100 This is used to authenticate the machine when we connect to it. It is a
1101 long string that looks like this:
1104 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1107 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1108 key can be found in a file such as
1109 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1111 If the machine is running the SSH daemon of GNU@tie{}lsh,
1112 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1113 similar file. It can be converted to the OpenSSH format using
1114 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1117 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1118 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1123 A number of optional fields may be specified:
1127 @item @code{port} (default: @code{22})
1128 Port number of SSH server on the machine.
1130 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1131 The SSH private key file to use when connecting to the machine, in
1132 OpenSSH format. This key must not be protected with a passphrase.
1134 Note that the default value is the private key @emph{of the root
1135 account}. Make sure it exists if you use the default.
1137 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1138 @itemx @code{compression-level} (default: @code{3})
1139 The SSH-level compression methods and compression level requested.
1141 Note that offloading relies on SSH compression to reduce bandwidth usage
1142 when transferring files to and from build machines.
1144 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1145 File name of the Unix-domain socket @command{guix-daemon} is listening
1148 @item @code{parallel-builds} (default: @code{1})
1149 The number of builds that may run in parallel on the machine.
1151 @item @code{speed} (default: @code{1.0})
1152 A ``relative speed factor''. The offload scheduler will tend to prefer
1153 machines with a higher speed factor.
1155 @item @code{features} (default: @code{'()})
1156 A list of strings denoting specific features supported by the machine.
1157 An example is @code{"kvm"} for machines that have the KVM Linux modules
1158 and corresponding hardware support. Derivations can request features by
1159 name, and they will be scheduled on matching build machines.
1164 The @command{guix} command must be in the search path on the build
1165 machines. You can check whether this is the case by running:
1168 ssh build-machine guix repl --version
1171 There is one last thing to do once @file{machines.scm} is in place. As
1172 explained above, when offloading, files are transferred back and forth
1173 between the machine stores. For this to work, you first need to
1174 generate a key pair on each machine to allow the daemon to export signed
1175 archives of files from the store (@pxref{Invoking guix archive}):
1178 # guix archive --generate-key
1182 Each build machine must authorize the key of the master machine so that
1183 it accepts store items it receives from the master:
1186 # guix archive --authorize < master-public-key.txt
1190 Likewise, the master machine must authorize the key of each build machine.
1192 All the fuss with keys is here to express pairwise mutual trust
1193 relations between the master and the build machines. Concretely, when
1194 the master receives files from a build machine (and @i{vice versa}), its
1195 build daemon can make sure they are genuine, have not been tampered
1196 with, and that they are signed by an authorized key.
1198 @cindex offload test
1199 To test whether your setup is operational, run this command on the
1206 This will attempt to connect to each of the build machines specified in
1207 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1208 available on each machine, attempt to export to the machine and import
1209 from it, and report any error in the process.
1211 If you want to test a different machine file, just specify it on the
1215 # guix offload test machines-qualif.scm
1218 Last, you can test the subset of the machines whose name matches a
1219 regular expression like this:
1222 # guix offload test machines.scm '\.gnu\.org$'
1225 @cindex offload status
1226 To display the current load of all build hosts, run this command on the
1230 # guix offload status
1234 @node SELinux Support
1235 @subsection SELinux Support
1237 @cindex SELinux, daemon policy
1238 @cindex mandatory access control, SELinux
1239 @cindex security, guix-daemon
1240 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1241 can be installed on a system where SELinux is enabled, in order to label
1242 Guix files and to specify the expected behavior of the daemon. Since
1243 Guix System does not provide an SELinux base policy, the daemon policy cannot
1244 be used on Guix System.
1246 @subsubsection Installing the SELinux policy
1247 @cindex SELinux, policy installation
1248 To install the policy run this command as root:
1251 semodule -i etc/guix-daemon.cil
1254 Then relabel the file system with @code{restorecon} or by a different
1255 mechanism provided by your system.
1257 Once the policy is installed, the file system has been relabeled, and
1258 the daemon has been restarted, it should be running in the
1259 @code{guix_daemon_t} context. You can confirm this with the following
1263 ps -Zax | grep guix-daemon
1266 Monitor the SELinux log files as you run a command like @code{guix build
1267 hello} to convince yourself that SELinux permits all necessary
1270 @subsubsection Limitations
1271 @cindex SELinux, limitations
1273 This policy is not perfect. Here is a list of limitations or quirks
1274 that should be considered when deploying the provided SELinux policy for
1279 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1280 operations involve contexts that have anything to do with
1281 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1282 but it would be preferrable to define socket rules for only this label.
1285 @code{guix gc} cannot access arbitrary links to profiles. By design,
1286 the file label of the destination of a symlink is independent of the
1287 file label of the link itself. Although all profiles under
1288 $localstatedir are labelled, the links to these profiles inherit the
1289 label of the directory they are in. For links in the user’s home
1290 directory this will be @code{user_home_t}. But for links from the root
1291 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1292 directory, etc, this won’t work. @code{guix gc} would be prevented from
1293 reading and following these links.
1296 The daemon’s feature to listen for TCP connections might no longer work.
1297 This might require extra rules, because SELinux treats network sockets
1298 differently from files.
1301 Currently all files with a name matching the regular expression
1302 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1303 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1304 that name in any profile would be permitted to run in the
1305 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1306 build a package that provides this executable and convince a user to
1307 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1308 At that point SELinux could not prevent it from accessing files that are
1309 allowed for processes in that domain.
1311 We could generate a much more restrictive policy at installation time,
1312 so that only the @emph{exact} file name of the currently installed
1313 @code{guix-daemon} executable would be labelled with
1314 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1315 The downside is that root would have to install or upgrade the policy at
1316 installation time whenever the Guix package that provides the
1317 effectively running @code{guix-daemon} executable is upgraded.
1320 @node Invoking guix-daemon
1321 @section Invoking @command{guix-daemon}
1323 The @command{guix-daemon} program implements all the functionality to
1324 access the store. This includes launching build processes, running the
1325 garbage collector, querying the availability of a build result, etc. It
1326 is normally run as @code{root} like this:
1329 # guix-daemon --build-users-group=guixbuild
1333 For details on how to set it up, @pxref{Setting Up the Daemon}.
1336 @cindex container, build environment
1337 @cindex build environment
1338 @cindex reproducible builds
1339 By default, @command{guix-daemon} launches build processes under
1340 different UIDs, taken from the build group specified with
1341 @option{--build-users-group}. In addition, each build process is run in a
1342 chroot environment that only contains the subset of the store that the
1343 build process depends on, as specified by its derivation
1344 (@pxref{Programming Interface, derivation}), plus a set of specific
1345 system directories. By default, the latter contains @file{/dev} and
1346 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1347 @dfn{container}: in addition to having its own file system tree, it has
1348 a separate mount name space, its own PID name space, network name space,
1349 etc. This helps achieve reproducible builds (@pxref{Features}).
1351 When the daemon performs a build on behalf of the user, it creates a
1352 build directory under @file{/tmp} or under the directory specified by
1353 its @env{TMPDIR} environment variable. This directory is shared with
1354 the container for the duration of the build, though within the container,
1355 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1357 The build directory is automatically deleted upon completion, unless the
1358 build failed and the client specified @option{--keep-failed}
1359 (@pxref{Invoking guix build, @option{--keep-failed}}).
1361 The daemon listens for connections and spawns one sub-process for each session
1362 started by a client (one of the @command{guix} sub-commands.) The
1363 @command{guix processes} command allows you to get an overview of the activity
1364 on your system by viewing each of the active sessions and clients.
1365 @xref{Invoking guix processes}, for more information.
1367 The following command-line options are supported:
1370 @item --build-users-group=@var{group}
1371 Take users from @var{group} to run build processes (@pxref{Setting Up
1372 the Daemon, build users}).
1374 @item --no-substitutes
1376 Do not use substitutes for build products. That is, always build things
1377 locally instead of allowing downloads of pre-built binaries
1378 (@pxref{Substitutes}).
1380 When the daemon runs with @option{--no-substitutes}, clients can still
1381 explicitly enable substitution @i{via} the @code{set-build-options}
1382 remote procedure call (@pxref{The Store}).
1384 @item --substitute-urls=@var{urls}
1385 @anchor{daemon-substitute-urls}
1386 Consider @var{urls} the default whitespace-separated list of substitute
1387 source URLs. When this option is omitted,
1388 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1390 This means that substitutes may be downloaded from @var{urls}, as long
1391 as they are signed by a trusted signature (@pxref{Substitutes}).
1395 Do not use offload builds to other machines (@pxref{Daemon Offload
1396 Setup}). That is, always build things locally instead of offloading
1397 builds to remote machines.
1399 @item --cache-failures
1400 Cache build failures. By default, only successful builds are cached.
1402 When this option is used, @command{guix gc --list-failures} can be used
1403 to query the set of store items marked as failed; @command{guix gc
1404 --clear-failures} removes store items from the set of cached failures.
1405 @xref{Invoking guix gc}.
1407 @item --cores=@var{n}
1409 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1412 The default value is @code{0}, but it may be overridden by clients, such
1413 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1416 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1417 in the build process, which can then use it to exploit internal
1418 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1420 @item --max-jobs=@var{n}
1422 Allow at most @var{n} build jobs in parallel. The default value is
1423 @code{1}. Setting it to @code{0} means that no builds will be performed
1424 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1425 Setup}), or simply fail.
1427 @item --max-silent-time=@var{seconds}
1428 When the build or substitution process remains silent for more than
1429 @var{seconds}, terminate it and report a build failure.
1431 The default value is @code{0}, which disables the timeout.
1433 The value specified here can be overridden by clients (@pxref{Common
1434 Build Options, @option{--max-silent-time}}).
1436 @item --timeout=@var{seconds}
1437 Likewise, when the build or substitution process lasts for more than
1438 @var{seconds}, terminate it and report a build failure.
1440 The default value is @code{0}, which disables the timeout.
1442 The value specified here can be overridden by clients (@pxref{Common
1443 Build Options, @option{--timeout}}).
1445 @item --rounds=@var{N}
1446 Build each derivation @var{n} times in a row, and raise an error if
1447 consecutive build results are not bit-for-bit identical. Note that this
1448 setting can be overridden by clients such as @command{guix build}
1449 (@pxref{Invoking guix build}).
1451 When used in conjunction with @option{--keep-failed}, the differing
1452 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1453 This makes it easy to look for differences between the two results.
1456 Produce debugging output.
1458 This is useful to debug daemon start-up issues, but then it may be
1459 overridden by clients, for example the @option{--verbosity} option of
1460 @command{guix build} (@pxref{Invoking guix build}).
1462 @item --chroot-directory=@var{dir}
1463 Add @var{dir} to the build chroot.
1465 Doing this may change the result of build processes---for instance if
1466 they use optional dependencies found in @var{dir} when it is available,
1467 and not otherwise. For that reason, it is not recommended to do so.
1468 Instead, make sure that each derivation declares all the inputs that it
1471 @item --disable-chroot
1472 Disable chroot builds.
1474 Using this option is not recommended since, again, it would allow build
1475 processes to gain access to undeclared dependencies. It is necessary,
1476 though, when @command{guix-daemon} is running under an unprivileged user
1479 @item --log-compression=@var{type}
1480 Compress build logs according to @var{type}, one of @code{gzip},
1481 @code{bzip2}, or @code{none}.
1483 Unless @option{--lose-logs} is used, all the build logs are kept in the
1484 @var{localstatedir}. To save space, the daemon automatically compresses
1485 them with Bzip2 by default.
1487 @item --disable-deduplication
1488 @cindex deduplication
1489 Disable automatic file ``deduplication'' in the store.
1491 By default, files added to the store are automatically ``deduplicated'':
1492 if a newly added file is identical to another one found in the store,
1493 the daemon makes the new file a hard link to the other file. This can
1494 noticeably reduce disk usage, at the expense of slightly increased
1495 input/output load at the end of a build process. This option disables
1498 @item --gc-keep-outputs[=yes|no]
1499 Tell whether the garbage collector (GC) must keep outputs of live
1503 @cindex garbage collector roots
1504 When set to @code{yes}, the GC will keep the outputs of any live
1505 derivation available in the store---the @file{.drv} files. The default
1506 is @code{no}, meaning that derivation outputs are kept only if they are
1507 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1510 @item --gc-keep-derivations[=yes|no]
1511 Tell whether the garbage collector (GC) must keep derivations
1512 corresponding to live outputs.
1514 When set to @code{yes}, as is the case by default, the GC keeps
1515 derivations---i.e., @file{.drv} files---as long as at least one of their
1516 outputs is live. This allows users to keep track of the origins of
1517 items in their store. Setting it to @code{no} saves a bit of disk
1520 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1521 liveness to flow from outputs to derivations, and setting
1522 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1523 derivations to outputs. When both are set to @code{yes}, the effect is
1524 to keep all the build prerequisites (the sources, compiler, libraries,
1525 and other build-time tools) of live objects in the store, regardless of
1526 whether these prerequisites are reachable from a GC root. This is
1527 convenient for developers since it saves rebuilds or downloads.
1529 @item --impersonate-linux-2.6
1530 On Linux-based systems, impersonate Linux 2.6. This means that the
1531 kernel's @command{uname} system call will report 2.6 as the release number.
1533 This might be helpful to build programs that (usually wrongfully) depend
1534 on the kernel version number.
1537 Do not keep build logs. By default they are kept under
1538 @file{@var{localstatedir}/guix/log}.
1540 @item --system=@var{system}
1541 Assume @var{system} as the current system type. By default it is the
1542 architecture/kernel pair found at configure time, such as
1543 @code{x86_64-linux}.
1545 @item --listen=@var{endpoint}
1546 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1547 as the file name of a Unix-domain socket if it starts with
1548 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1549 host name or host name and port to listen to. Here are a few examples:
1552 @item --listen=/gnu/var/daemon
1553 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1554 creating it if needed.
1556 @item --listen=localhost
1557 @cindex daemon, remote access
1558 @cindex remote access to the daemon
1559 @cindex daemon, cluster setup
1560 @cindex clusters, daemon setup
1561 Listen for TCP connections on the network interface corresponding to
1562 @code{localhost}, on port 44146.
1564 @item --listen=128.0.0.42:1234
1565 Listen for TCP connections on the network interface corresponding to
1566 @code{128.0.0.42}, on port 1234.
1569 This option can be repeated multiple times, in which case
1570 @command{guix-daemon} accepts connections on all the specified
1571 endpoints. Users can tell client commands what endpoint to connect to
1572 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1573 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1576 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1577 @option{--listen=@var{host}} is suitable on local networks, such as
1578 clusters, where only trusted nodes may connect to the build daemon. In
1579 other cases where remote access to the daemon is needed, we recommend
1580 using Unix-domain sockets along with SSH.
1583 When @option{--listen} is omitted, @command{guix-daemon} listens for
1584 connections on the Unix-domain socket located at
1585 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1589 @node Application Setup
1590 @section Application Setup
1592 @cindex foreign distro
1593 When using Guix on top of GNU/Linux distribution other than Guix System---a
1594 so-called @dfn{foreign distro}---a few additional steps are needed to
1595 get everything in place. Here are some of them.
1599 @anchor{locales-and-locpath}
1600 @cindex locales, when not on Guix System
1602 @vindex GUIX_LOCPATH
1603 Packages installed @i{via} Guix will not use the locale data of the
1604 host system. Instead, you must first install one of the locale packages
1605 available with Guix and then define the @env{GUIX_LOCPATH} environment
1609 $ guix install glibc-locales
1610 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1613 Note that the @code{glibc-locales} package contains data for all the
1614 locales supported by the GNU@tie{}libc and weighs in at around
1615 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1616 limited to a few UTF-8 locales.
1618 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1619 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1620 Manual}). There are two important differences though:
1624 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1625 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1626 to make sure the programs of the foreign distro will not end up loading
1627 incompatible locale data.
1630 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1631 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1632 should your Guix profile contain a mixture of programs linked against
1633 different libc version, each libc version will only try to load locale
1634 data in the right format.
1637 This is important because the locale data format used by different libc
1638 versions may be incompatible.
1640 @subsection Name Service Switch
1642 @cindex name service switch, glibc
1643 @cindex NSS (name service switch), glibc
1644 @cindex nscd (name service caching daemon)
1645 @cindex name service caching daemon (nscd)
1646 When using Guix on a foreign distro, we @emph{strongly recommend} that
1647 the system run the GNU C library's @dfn{name service cache daemon},
1648 @command{nscd}, which should be listening on the
1649 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1650 installed with Guix may fail to look up host names or user accounts, or
1651 may even crash. The next paragraphs explain why.
1653 @cindex @file{nsswitch.conf}
1654 The GNU C library implements a @dfn{name service switch} (NSS), which is
1655 an extensible mechanism for ``name lookups'' in general: host name
1656 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1657 The GNU C Library Reference Manual}).
1659 @cindex Network information service (NIS)
1660 @cindex NIS (Network information service)
1661 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1662 lookup implementations: for example, the @code{nss-mdns} plugin allow
1663 resolution of @code{.local} host names, the @code{nis} plugin allows
1664 user account lookup using the Network information service (NIS), and so
1665 on. These extra ``lookup services'' are configured system-wide in
1666 @file{/etc/nsswitch.conf}, and all the programs running on the system
1667 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1670 When they perform a name lookup---for instance by calling the
1671 @code{getaddrinfo} function in C---applications first try to connect to
1672 the nscd; on success, nscd performs name lookups on their behalf. If
1673 the nscd is not running, then they perform the name lookup by
1674 themselves, by loading the name lookup services into their own address
1675 space and running it. These name lookup services---the
1676 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1677 the host system's C library, rather than from the C library the
1678 application is linked against (the C library coming from Guix).
1680 And this is where the problem is: if your application is linked against
1681 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1682 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1683 likely crash or have its name lookups fail unexpectedly.
1685 Running @command{nscd} on the system, among other advantages, eliminates
1686 this binary incompatibility problem because those @code{libnss_*.so}
1687 files are loaded in the @command{nscd} process, not in applications
1690 @subsection X11 Fonts
1693 The majority of graphical applications use Fontconfig to locate and
1694 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1695 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1696 by default. Thus, to allow graphical applications installed with Guix
1697 to display fonts, you have to install fonts with Guix as well.
1698 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1699 @code{font-gnu-freefont}.
1701 @cindex @code{fc-cache}
1703 Once you have installed or removed fonts, or when you notice an
1704 application that does not find fonts, you may need to install Fontconfig
1705 and to force an update of its font cache by running:
1708 guix install fontconfig
1712 To display text written in Chinese languages, Japanese, or Korean in
1713 graphical applications, consider installing
1714 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1715 has multiple outputs, one per language family (@pxref{Packages with
1716 Multiple Outputs}). For instance, the following command installs fonts
1717 for Chinese languages:
1720 guix install font-adobe-source-han-sans:cn
1723 @cindex @code{xterm}
1724 Older programs such as @command{xterm} do not use Fontconfig and instead
1725 rely on server-side font rendering. Such programs require to specify a
1726 full name of a font using XLFD (X Logical Font Description), like this:
1729 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1732 To be able to use such full names for the TrueType fonts installed in
1733 your Guix profile, you need to extend the font path of the X server:
1735 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1736 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1738 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1741 @cindex @code{xlsfonts}
1742 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1743 to make sure your TrueType fonts are listed there.
1746 @subsection X.509 Certificates
1748 @cindex @code{nss-certs}
1749 The @code{nss-certs} package provides X.509 certificates, which allow
1750 programs to authenticate Web servers accessed over HTTPS.
1752 When using Guix on a foreign distro, you can install this package and
1753 define the relevant environment variables so that packages know where to
1754 look for certificates. @xref{X.509 Certificates}, for detailed
1757 @subsection Emacs Packages
1759 @cindex @code{emacs}
1760 When you install Emacs packages with Guix, the Elisp files are placed
1761 under the @file{share/emacs/site-lisp/} directory of the profile in
1762 which they are installed. The Elisp libraries are made available to
1763 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1764 set when installing Emacs itself.
1766 Additionally, autoload definitions are automatically evaluated at the
1767 initialization of Emacs, by the Guix-specific
1768 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1769 want to avoid auto-loading the Emacs packages installed with Guix, you
1770 can do so by running Emacs with the @option{--no-site-file} option
1771 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1773 @subsection The GCC toolchain
1775 @c XXX: The contents of this section were moved under
1776 @c ``Development'', since it makes more sense there and is not specific
1777 @c foreign distros. Remove it from here eventually?
1778 @xref{Packages for C Development}, for information on packages for C/C++
1781 @node Upgrading Guix
1782 @section Upgrading Guix
1784 @cindex Upgrading Guix, on a foreign distro
1786 To upgrade Guix, run:
1792 @xref{Invoking guix pull}, for more information.
1794 @cindex upgrading Guix for the root user, on a foreign distro
1795 @cindex upgrading the Guix daemon, on a foreign distro
1796 @cindex @command{guix pull} for the root user, on a foreign distro
1798 On a foreign distro, you can upgrade the build daemon by running:
1805 followed by (assuming your distro uses the systemd service management
1809 systemctl restart guix-daemon.service
1812 On Guix System, upgrading the daemon is achieved by reconfiguring the
1813 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1817 @c *********************************************************************
1818 @node System Installation
1819 @chapter System Installation
1821 @cindex installing Guix System
1822 @cindex Guix System, installation
1823 This section explains how to install Guix System
1824 on a machine. Guix, as a package manager, can
1825 also be installed on top of a running GNU/Linux system,
1826 @pxref{Installation}.
1830 @c This paragraph is for people reading this from tty2 of the
1831 @c installation image.
1832 You are reading this documentation with an Info reader. For details on
1833 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1834 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1835 Info}. Hit @kbd{l} afterwards to come back here.
1837 Alternately, run @command{info info} in another tty to keep the manual
1843 * Limitations:: What you can expect.
1844 * Hardware Considerations:: Supported hardware.
1845 * USB Stick and DVD Installation:: Preparing the installation medium.
1846 * Preparing for Installation:: Networking, partitioning, etc.
1847 * Guided Graphical Installation:: Easy graphical installation.
1848 * Manual Installation:: Manual installation for wizards.
1849 * After System Installation:: When installation succeeded.
1850 * Installing Guix in a VM:: Guix System playground.
1851 * Building the Installation Image:: How this comes to be.
1855 @section Limitations
1857 We consider Guix System to be ready for a wide range of ``desktop'' and server
1858 use cases. The reliability guarantees it provides---transactional upgrades
1859 and rollbacks, reproducibility---make it a solid foundation.
1861 Nevertheless, before you proceed with the installation, be aware of the
1862 following noteworthy limitations applicable to version @value{VERSION}:
1866 Support for the Logical Volume Manager (LVM) is missing.
1869 More and more system services are provided (@pxref{Services}), but some
1873 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1874 as well as a number of X11 window managers. However, KDE is currently
1878 More than a disclaimer, this is an invitation to report issues (and success
1879 stories!), and to join us in improving it. @xref{Contributing}, for more
1883 @node Hardware Considerations
1884 @section Hardware Considerations
1886 @cindex hardware support on Guix System
1887 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1888 builds around the kernel Linux-libre, which means that only hardware for
1889 which free software drivers and firmware exist is supported. Nowadays,
1890 a wide range of off-the-shelf hardware is supported on
1891 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1892 Ethernet controllers. Unfortunately, there are still areas where
1893 hardware vendors deny users control over their own computing, and such
1894 hardware is not supported on Guix System.
1896 @cindex WiFi, hardware support
1897 One of the main areas where free drivers or firmware are lacking is WiFi
1898 devices. WiFi devices known to work include those using Atheros chips
1899 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1900 driver, and those using Broadcom/AirForce chips (BCM43xx with
1901 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1902 Linux-libre driver. Free firmware exists for both and is available
1903 out-of-the-box on Guix System, as part of @code{%base-firmware}
1904 (@pxref{operating-system Reference, @code{firmware}}).
1906 @cindex RYF, Respects Your Freedom
1907 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1908 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1909 certification program for hardware products that respect your freedom
1910 and your privacy and ensure that you have control over your device. We
1911 encourage you to check the list of RYF-certified devices.
1913 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1914 web site. It contains a catalog of hardware devices with information
1915 about their support in GNU/Linux.
1918 @node USB Stick and DVD Installation
1919 @section USB Stick and DVD Installation
1921 An ISO-9660 installation image that can be written to a USB stick or
1922 burnt to a DVD can be downloaded from
1923 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1924 where @var{system} is one of:
1928 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1931 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1934 @c start duplication of authentication part from ``Binary Installation''
1935 Make sure to download the associated @file{.sig} file and to verify the
1936 authenticity of the image against it, along these lines:
1939 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1940 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1943 If that command fails because you do not have the required public key,
1944 then run this command to import it:
1947 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1948 -qO - | gpg --import -
1952 and rerun the @code{gpg --verify} command.
1954 Take note that a warning like ``This key is not certified with a trusted
1955 signature!'' is normal.
1959 This image contains the tools necessary for an installation.
1960 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1962 @unnumberedsubsec Copying to a USB Stick
1964 To copy the image to a USB stick, follow these steps:
1968 Decompress the image using the @command{xz} command:
1971 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1975 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1976 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1977 copy the image with:
1980 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1984 Access to @file{/dev/sdX} usually requires root privileges.
1987 @unnumberedsubsec Burning on a DVD
1989 To copy the image to a DVD, follow these steps:
1993 Decompress the image using the @command{xz} command:
1996 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
2000 Insert a blank DVD into your machine, and determine
2001 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2002 copy the image with:
2005 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
2008 Access to @file{/dev/srX} usually requires root privileges.
2011 @unnumberedsubsec Booting
2013 Once this is done, you should be able to reboot the system and boot from
2014 the USB stick or DVD. The latter usually requires you to get in the
2015 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2016 In order to boot from Libreboot, switch to the command mode by pressing
2017 the @kbd{c} key and type @command{search_grub usb}.
2019 @xref{Installing Guix in a VM}, if, instead, you would like to install
2020 Guix System in a virtual machine (VM).
2023 @node Preparing for Installation
2024 @section Preparing for Installation
2026 Once you have booted, you can use the guided graphical installer, which makes
2027 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2028 if you are already familiar with GNU/Linux and if you want more control than
2029 what the graphical installer provides, you can choose the ``manual''
2030 installation process (@pxref{Manual Installation}).
2032 The graphical installer is available on TTY1. You can obtain root shells on
2033 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2034 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2035 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2036 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2037 which allows you to select text with the left mouse button and to paste it
2038 with the middle button.
2041 Installation requires access to the Internet so that any missing
2042 dependencies of your system configuration can be downloaded. See the
2043 ``Networking'' section below.
2046 @node Guided Graphical Installation
2047 @section Guided Graphical Installation
2049 The graphical installer is a text-based user interface. It will guide you,
2050 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2052 The first dialog boxes allow you to set up the system as you use it during the
2053 installation: you can choose the language, keyboard layout, and set up
2054 networking, which will be used during the installation. The image below shows
2055 the networking dialog.
2057 @image{images/installer-network,5in,, networking setup with the graphical installer}
2059 Later steps allow you to partition your hard disk, as shown in the image
2060 below, to choose whether or not to use encrypted file systems, to enter the
2061 host name and root password, and to create an additional account, among other
2064 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2066 Note that, at any time, the installer allows you to exit the current
2067 installation step and resume at a previous step, as show in the image below.
2069 @image{images/installer-resume,5in,, resuming the installation process}
2071 Once you're done, the installer produces an operating system configuration and
2072 displays it (@pxref{Using the Configuration System}). At that point you can
2073 hit ``OK'' and installation will proceed. On success, you can reboot into the
2074 new system and enjoy. @xref{After System Installation}, for what's next!
2077 @node Manual Installation
2078 @section Manual Installation
2080 This section describes how you would ``manually'' install GNU@tie{}Guix System
2081 on your machine. This option requires familiarity with GNU/Linux, with the
2082 shell, and with common administration tools. If you think this is not for
2083 you, consider using the guided graphical installer (@pxref{Guided Graphical
2086 The installation system provides root shells on TTYs 3 to 6; press
2087 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2088 many common tools needed to install the system. But it is also a full-blown
2089 Guix System, which means that you can install additional packages, should you
2090 need it, using @command{guix package} (@pxref{Invoking guix package}).
2093 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2094 * Proceeding with the Installation:: Installing.
2097 @node Keyboard Layout and Networking and Partitioning
2098 @subsection Keyboard Layout, Networking, and Partitioning
2100 Before you can install the system, you may want to adjust the keyboard layout,
2101 set up networking, and partition your target hard disk. This section will
2102 guide you through this.
2104 @subsubsection Keyboard Layout
2106 @cindex keyboard layout
2107 The installation image uses the US qwerty keyboard layout. If you want
2108 to change it, you can use the @command{loadkeys} command. For example,
2109 the following command selects the Dvorak keyboard layout:
2115 See the files under @file{/run/current-system/profile/share/keymaps} for
2116 a list of available keyboard layouts. Run @command{man loadkeys} for
2119 @subsubsection Networking
2121 Run the following command to see what your network interfaces are called:
2128 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2134 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2135 Wired interfaces have a name starting with @samp{e}; for example, the
2136 interface corresponding to the first on-board Ethernet controller is
2137 called @samp{eno1}. Wireless interfaces have a name starting with
2138 @samp{w}, like @samp{w1p2s0}.
2141 @item Wired connection
2142 To configure a wired network run the following command, substituting
2143 @var{interface} with the name of the wired interface you want to use.
2146 ifconfig @var{interface} up
2150 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2153 ip link set @var{interface} up
2156 @item Wireless connection
2159 To configure wireless networking, you can create a configuration file
2160 for the @command{wpa_supplicant} configuration tool (its location is not
2161 important) using one of the available text editors such as
2165 nano wpa_supplicant.conf
2168 As an example, the following stanza can go to this file and will work
2169 for many wireless networks, provided you give the actual SSID and
2170 passphrase for the network you are connecting to:
2174 ssid="@var{my-ssid}"
2176 psk="the network's secret passphrase"
2180 Start the wireless service and run it in the background with the
2181 following command (substitute @var{interface} with the name of the
2182 network interface you want to use):
2185 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2188 Run @command{man wpa_supplicant} for more information.
2192 At this point, you need to acquire an IP address. On a network where IP
2193 addresses are automatically assigned @i{via} DHCP, you can run:
2196 dhclient -v @var{interface}
2199 Try to ping a server to see if networking is up and running:
2205 Setting up network access is almost always a requirement because the
2206 image does not contain all the software and tools that may be needed.
2208 @cindex proxy, during system installation
2209 If you need HTTP and HTTPS access to go through a proxy, run the
2213 herd set-http-proxy guix-daemon @var{URL}
2217 where @var{URL} is the proxy URL, for example
2218 @code{http://example.org:8118}.
2220 @cindex installing over SSH
2221 If you want to, you can continue the installation remotely by starting
2225 herd start ssh-daemon
2228 Make sure to either set a password with @command{passwd}, or configure
2229 OpenSSH public key authentication before logging in.
2231 @subsubsection Disk Partitioning
2233 Unless this has already been done, the next step is to partition, and
2234 then format the target partition(s).
2236 The installation image includes several partitioning tools, including
2237 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2238 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2239 the partition layout you want:
2245 If your disk uses the GUID Partition Table (GPT) format and you plan to
2246 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2247 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2250 @cindex EFI, installation
2251 @cindex UEFI, installation
2252 @cindex ESP, EFI system partition
2253 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2254 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2255 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2258 parted /dev/sda set 1 esp on
2262 @vindex grub-bootloader
2263 @vindex grub-efi-bootloader
2264 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2265 @file{/sys/firmware/efi} exists in the installation image, then you should
2266 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2267 Otherwise you should use the BIOS-based GRUB, known as
2268 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2272 Once you are done partitioning the target hard disk drive, you have to
2273 create a file system on the relevant partition(s)@footnote{Currently
2274 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2275 code that reads file system UUIDs and labels only works for these file system
2276 types.}. For the ESP, if you have one and assuming it is
2277 @file{/dev/sda1}, run:
2280 mkfs.fat -F32 /dev/sda1
2283 Preferably, assign file systems a label so that you can easily and
2284 reliably refer to them in @code{file-system} declarations (@pxref{File
2285 Systems}). This is typically done using the @code{-L} option of
2286 @command{mkfs.ext4} and related commands. So, assuming the target root
2287 partition lives at @file{/dev/sda2}, a file system with the label
2288 @code{my-root} can be created with:
2291 mkfs.ext4 -L my-root /dev/sda2
2294 @cindex encrypted disk
2295 If you are instead planning to encrypt the root partition, you can use
2296 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2297 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2298 @code{man cryptsetup}} for more information.) Assuming you want to
2299 store the root partition on @file{/dev/sda2}, the command sequence would
2300 be along these lines:
2303 cryptsetup luksFormat /dev/sda2
2304 cryptsetup open --type luks /dev/sda2 my-partition
2305 mkfs.ext4 -L my-root /dev/mapper/my-partition
2308 Once that is done, mount the target file system under @file{/mnt}
2309 with a command like (again, assuming @code{my-root} is the label of the
2313 mount LABEL=my-root /mnt
2316 Also mount any other file systems you would like to use on the target
2317 system relative to this path. If you have opted for @file{/boot/efi} as an
2318 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2319 found by @code{guix system init} afterwards.
2321 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2322 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2323 sure to initialize them with @command{mkswap}. Assuming you have one
2324 swap partition on @file{/dev/sda3}, you would run:
2331 Alternatively, you may use a swap file. For example, assuming that in
2332 the new system you want to use the file @file{/swapfile} as a swap file,
2333 you would run@footnote{This example will work for many types of file
2334 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2335 btrfs), the required steps may be different. For details, see the
2336 manual pages for @command{mkswap} and @command{swapon}.}:
2339 # This is 10 GiB of swap space. Adjust "count" to change the size.
2340 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2341 # For security, make the file readable and writable only by root.
2342 chmod 600 /mnt/swapfile
2343 mkswap /mnt/swapfile
2344 swapon /mnt/swapfile
2347 Note that if you have encrypted the root partition and created a swap
2348 file in its file system as described above, then the encryption also
2349 protects the swap file, just like any other file in that file system.
2351 @node Proceeding with the Installation
2352 @subsection Proceeding with the Installation
2354 With the target partitions ready and the target root mounted on
2355 @file{/mnt}, we're ready to go. First, run:
2358 herd start cow-store /mnt
2361 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2362 during the installation phase are written to the target disk on @file{/mnt}
2363 rather than kept in memory. This is necessary because the first phase of
2364 the @command{guix system init} command (see below) entails downloads or
2365 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2367 Next, you have to edit a file and
2368 provide the declaration of the operating system to be installed. To
2369 that end, the installation system comes with three text editors. We
2370 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2371 supports syntax highlighting and parentheses matching; other editors
2372 include GNU Zile (an Emacs clone), and
2373 nvi (a clone of the original BSD @command{vi} editor).
2374 We strongly recommend storing that file on the target root file system, say,
2375 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2376 configuration file once you have rebooted into the newly-installed system.
2378 @xref{Using the Configuration System}, for an overview of the
2379 configuration file. The example configurations discussed in that
2380 section are available under @file{/etc/configuration} in the
2381 installation image. Thus, to get started with a system configuration
2382 providing a graphical display server (a ``desktop'' system), you can run
2383 something along these lines:
2387 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2388 # nano /mnt/etc/config.scm
2391 You should pay attention to what your configuration file contains, and
2396 Make sure the @code{bootloader-configuration} form refers to the target
2397 you want to install GRUB on. It should mention @code{grub-bootloader} if
2398 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2399 for newer UEFI systems. For legacy systems, the @code{target} field
2400 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2401 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2402 currently mounted and a @code{file-system} entry is specified in your
2406 Be sure that your file system labels match the value of their respective
2407 @code{device} fields in your @code{file-system} configuration, assuming
2408 your @code{file-system} configuration uses the @code{file-system-label}
2409 procedure in its @code{device} field.
2412 If there are encrypted or RAID partitions, make sure to add a
2413 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2416 Once you are done preparing the configuration file, the new system must
2417 be initialized (remember that the target root file system is mounted
2421 guix system init /mnt/etc/config.scm /mnt
2425 This copies all the necessary files and installs GRUB on
2426 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2427 more information, @pxref{Invoking guix system}. This command may trigger
2428 downloads or builds of missing packages, which can take some time.
2430 Once that command has completed---and hopefully succeeded!---you can run
2431 @command{reboot} and boot into the new system. The @code{root} password
2432 in the new system is initially empty; other users' passwords need to be
2433 initialized by running the @command{passwd} command as @code{root},
2434 unless your configuration specifies otherwise
2435 (@pxref{user-account-password, user account passwords}).
2436 @xref{After System Installation}, for what's next!
2439 @node After System Installation
2440 @section After System Installation
2442 Success, you've now booted into Guix System! From then on, you can update the
2443 system whenever you want by running, say:
2447 sudo guix system reconfigure /etc/config.scm
2451 This builds a new system generation with the latest packages and services
2452 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2453 your system includes the latest security updates (@pxref{Security Updates}).
2455 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2457 @cindex sudo vs. @command{guix pull}
2458 Note that @command{sudo guix} runs your user's @command{guix} command and
2459 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2460 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2462 The difference matters here, because @command{guix pull} updates
2463 the @command{guix} command and package definitions only for the user it is ran
2464 as. This means that if you choose to use @command{guix system reconfigure} in
2465 root's login shell, you'll need to @command{guix pull} separately.
2468 Join us on @code{#guix} on the Freenode IRC network or on
2469 @email{guix-devel@@gnu.org} to share your experience!
2472 @node Installing Guix in a VM
2473 @section Installing Guix in a Virtual Machine
2475 @cindex virtual machine, Guix System installation
2476 @cindex virtual private server (VPS)
2477 @cindex VPS (virtual private server)
2478 If you'd like to install Guix System in a virtual machine (VM) or on a
2479 virtual private server (VPS) rather than on your beloved machine, this
2482 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2483 disk image, follow these steps:
2487 First, retrieve and decompress the Guix system installation image as
2488 described previously (@pxref{USB Stick and DVD Installation}).
2491 Create a disk image that will hold the installed system. To make a
2492 qcow2-formatted disk image, use the @command{qemu-img} command:
2495 qemu-img create -f qcow2 guix-system.img 50G
2498 The resulting file will be much smaller than 50 GB (typically less than
2499 1 MB), but it will grow as the virtualized storage device is filled up.
2502 Boot the USB installation image in an VM:
2505 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2506 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2507 -drive file=guix-system.img \
2508 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2511 @code{-enable-kvm} is optional, but significantly improves performance,
2512 @pxref{Running Guix in a VM}.
2515 You're now root in the VM, proceed with the installation process.
2516 @xref{Preparing for Installation}, and follow the instructions.
2519 Once installation is complete, you can boot the system that's on your
2520 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2523 @node Building the Installation Image
2524 @section Building the Installation Image
2526 @cindex installation image
2527 The installation image described above was built using the @command{guix
2528 system} command, specifically:
2531 guix system disk-image --file-system-type=iso9660 \
2532 gnu/system/install.scm
2535 Have a look at @file{gnu/system/install.scm} in the source tree,
2536 and see also @ref{Invoking guix system} for more information
2537 about the installation image.
2539 @section Building the Installation Image for ARM Boards
2541 Many ARM boards require a specific variant of the
2542 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2544 If you build a disk image and the bootloader is not available otherwise
2545 (on another boot drive etc), it's advisable to build an image that
2546 includes the bootloader, specifically:
2549 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2552 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2553 board, a list of possible boards will be printed.
2555 @c *********************************************************************
2556 @node Package Management
2557 @chapter Package Management
2560 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2561 remove software packages, without having to know about their build
2562 procedures or dependencies. Guix also goes beyond this obvious set of
2565 This chapter describes the main features of Guix, as well as the
2566 package management tools it provides. Along with the command-line
2567 interface described below (@pxref{Invoking guix package, @code{guix
2568 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2569 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2570 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2574 guix install emacs-guix
2578 * Features:: How Guix will make your life brighter.
2579 * Invoking guix package:: Package installation, removal, etc.
2580 * Substitutes:: Downloading pre-built binaries.
2581 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2582 * Invoking guix gc:: Running the garbage collector.
2583 * Invoking guix pull:: Fetching the latest Guix and distribution.
2584 * Channels:: Customizing the package collection.
2585 * Invoking guix time-machine:: Running an older revision of Guix.
2586 * Inferiors:: Interacting with another revision of Guix.
2587 * Invoking guix describe:: Display information about your Guix revision.
2588 * Invoking guix archive:: Exporting and importing store files.
2594 When using Guix, each package ends up in the @dfn{package store}, in its
2595 own directory---something that resembles
2596 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2598 Instead of referring to these directories, users have their own
2599 @dfn{profile}, which points to the packages that they actually want to
2600 use. These profiles are stored within each user's home directory, at
2601 @code{$HOME/.guix-profile}.
2603 For example, @code{alice} installs GCC 4.7.2. As a result,
2604 @file{/home/alice/.guix-profile/bin/gcc} points to
2605 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2606 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2607 simply continues to point to
2608 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2609 coexist on the same system without any interference.
2611 The @command{guix package} command is the central tool to manage
2612 packages (@pxref{Invoking guix package}). It operates on the per-user
2613 profiles, and can be used @emph{with normal user privileges}.
2615 @cindex transactions
2616 The command provides the obvious install, remove, and upgrade
2617 operations. Each invocation is actually a @emph{transaction}: either
2618 the specified operation succeeds, or nothing happens. Thus, if the
2619 @command{guix package} process is terminated during the transaction,
2620 or if a power outage occurs during the transaction, then the user's
2621 profile remains in its previous state, and remains usable.
2623 In addition, any package transaction may be @emph{rolled back}. So, if,
2624 for example, an upgrade installs a new version of a package that turns
2625 out to have a serious bug, users may roll back to the previous instance
2626 of their profile, which was known to work well. Similarly, the global
2627 system configuration on Guix is subject to
2628 transactional upgrades and roll-back
2629 (@pxref{Using the Configuration System}).
2631 All packages in the package store may be @emph{garbage-collected}.
2632 Guix can determine which packages are still referenced by user
2633 profiles, and remove those that are provably no longer referenced
2634 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2635 generations of their profile so that the packages they refer to can be
2638 @cindex reproducibility
2639 @cindex reproducible builds
2640 Guix takes a @dfn{purely functional} approach to package
2641 management, as described in the introduction (@pxref{Introduction}).
2642 Each @file{/gnu/store} package directory name contains a hash of all the
2643 inputs that were used to build that package---compiler, libraries, build
2644 scripts, etc. This direct correspondence allows users to make sure a
2645 given package installation matches the current state of their
2646 distribution. It also helps maximize @dfn{build reproducibility}:
2647 thanks to the isolated build environments that are used, a given build
2648 is likely to yield bit-identical files when performed on different
2649 machines (@pxref{Invoking guix-daemon, container}).
2652 This foundation allows Guix to support @dfn{transparent binary/source
2653 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2654 available from an external source---a @dfn{substitute}, Guix just
2655 downloads it and unpacks it;
2656 otherwise, it builds the package from source, locally
2657 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2658 reproducible, users do not have to trust servers that provide
2659 substitutes: they can force a local build and @emph{challenge} providers
2660 (@pxref{Invoking guix challenge}).
2662 Control over the build environment is a feature that is also useful for
2663 developers. The @command{guix environment} command allows developers of
2664 a package to quickly set up the right development environment for their
2665 package, without having to manually install the dependencies of the
2666 package into their profile (@pxref{Invoking guix environment}).
2668 @cindex replication, of software environments
2669 @cindex provenance tracking, of software artifacts
2670 All of Guix and its package definitions is version-controlled, and
2671 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2672 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2673 Guix instance on a different machine or at a later point in time, which in
2674 turn allows you to @emph{replicate complete software environments}, while
2675 retaining precise @dfn{provenance tracking} of the software.
2677 @node Invoking guix package
2678 @section Invoking @command{guix package}
2680 @cindex installing packages
2681 @cindex removing packages
2682 @cindex package installation
2683 @cindex package removal
2684 The @command{guix package} command is the tool that allows users to
2685 install, upgrade, and remove packages, as well as rolling back to
2686 previous configurations. It operates only on the user's own profile,
2687 and works with normal user privileges (@pxref{Features}). Its syntax
2691 guix package @var{options}
2694 @cindex transactions
2695 Primarily, @var{options} specifies the operations to be performed during
2696 the transaction. Upon completion, a new profile is created, but
2697 previous @dfn{generations} of the profile remain available, should the user
2700 For example, to remove @code{lua} and install @code{guile} and
2701 @code{guile-cairo} in a single transaction:
2704 guix package -r lua -i guile guile-cairo
2707 @cindex aliases, for @command{guix package}
2708 For your convenience, we also provide the following aliases:
2712 @command{guix search} is an alias for @command{guix package -s},
2714 @command{guix install} is an alias for @command{guix package -i},
2716 @command{guix remove} is an alias for @command{guix package -r},
2718 @command{guix upgrade} is an alias for @command{guix package -u},
2720 and @command{guix show} is an alias for @command{guix package --show=}.
2723 These aliases are less expressive than @command{guix package} and provide
2724 fewer options, so in some cases you'll probably want to use @command{guix
2727 @command{guix package} also supports a @dfn{declarative approach}
2728 whereby the user specifies the exact set of packages to be available and
2729 passes it @i{via} the @option{--manifest} option
2730 (@pxref{profile-manifest, @option{--manifest}}).
2733 For each user, a symlink to the user's default profile is automatically
2734 created in @file{$HOME/.guix-profile}. This symlink always points to the
2735 current generation of the user's default profile. Thus, users can add
2736 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2737 variable, and so on.
2738 @cindex search paths
2739 If you are not using Guix System, consider adding the
2740 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2741 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2742 shells get all the right environment variable definitions:
2745 GUIX_PROFILE="$HOME/.guix-profile" ; \
2746 source "$HOME/.guix-profile/etc/profile"
2749 In a multi-user setup, user profiles are stored in a place registered as
2750 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2751 to (@pxref{Invoking guix gc}). That directory is normally
2752 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2753 @var{localstatedir} is the value passed to @code{configure} as
2754 @option{--localstatedir}, and @var{user} is the user name. The
2755 @file{per-user} directory is created when @command{guix-daemon} is
2756 started, and the @var{user} sub-directory is created by @command{guix
2759 The @var{options} can be among the following:
2763 @item --install=@var{package} @dots{}
2764 @itemx -i @var{package} @dots{}
2765 Install the specified @var{package}s.
2767 Each @var{package} may specify either a simple package name, such as
2768 @code{guile}, or a package name followed by an at-sign and version number,
2769 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2770 case, the newest version prefixed by @code{1.8} is selected.)
2772 If no version number is specified, the
2773 newest available version will be selected. In addition, @var{package}
2774 may contain a colon, followed by the name of one of the outputs of the
2775 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2776 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2777 name (and optionally version) are searched for among the GNU
2778 distribution modules (@pxref{Package Modules}).
2780 @cindex propagated inputs
2781 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2782 that automatically get installed along with the required package
2783 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2784 @code{package} objects}, for information about propagated inputs in
2785 package definitions).
2787 @anchor{package-cmd-propagated-inputs}
2788 An example is the GNU MPC library: its C header files refer to those of
2789 the GNU MPFR library, which in turn refer to those of the GMP library.
2790 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2791 in the profile; removing MPC also removes MPFR and GMP---unless they had
2792 also been explicitly installed by the user.
2794 Besides, packages sometimes rely on the definition of environment
2795 variables for their search paths (see explanation of
2796 @option{--search-paths} below). Any missing or possibly incorrect
2797 environment variable definitions are reported here.
2799 @item --install-from-expression=@var{exp}
2801 Install the package @var{exp} evaluates to.
2803 @var{exp} must be a Scheme expression that evaluates to a
2804 @code{<package>} object. This option is notably useful to disambiguate
2805 between same-named variants of a package, with expressions such as
2806 @code{(@@ (gnu packages base) guile-final)}.
2808 Note that this option installs the first output of the specified
2809 package, which may be insufficient when needing a specific output of a
2810 multiple-output package.
2812 @item --install-from-file=@var{file}
2813 @itemx -f @var{file}
2814 Install the package that the code within @var{file} evaluates to.
2816 As an example, @var{file} might contain a definition like this
2817 (@pxref{Defining Packages}):
2820 @include package-hello.scm
2823 Developers may find it useful to include such a @file{guix.scm} file
2824 in the root of their project source tree that can be used to test
2825 development snapshots and create reproducible development environments
2826 (@pxref{Invoking guix environment}).
2828 The @var{file} may also contain a JSON representation of one or more
2829 package definitions. Running @code{guix package -f} on
2830 @file{hello.json} with the following contents would result in installing
2831 the package @code{greeter} after building @code{myhello}:
2834 @verbatiminclude package-hello.json
2837 @item --remove=@var{package} @dots{}
2838 @itemx -r @var{package} @dots{}
2839 Remove the specified @var{package}s.
2841 As for @option{--install}, each @var{package} may specify a version number
2842 and/or output name in addition to the package name. For instance,
2843 @samp{-r glibc:debug} would remove the @code{debug} output of
2846 @item --upgrade[=@var{regexp} @dots{}]
2847 @itemx -u [@var{regexp} @dots{}]
2848 @cindex upgrading packages
2849 Upgrade all the installed packages. If one or more @var{regexp}s are
2850 specified, upgrade only installed packages whose name matches a
2851 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
2853 Note that this upgrades package to the latest version of packages found
2854 in the distribution currently installed. To update your distribution,
2855 you should regularly run @command{guix pull} (@pxref{Invoking guix
2858 @item --do-not-upgrade[=@var{regexp} @dots{}]
2859 When used together with the @option{--upgrade} option, do @emph{not}
2860 upgrade any packages whose name matches a @var{regexp}. For example, to
2861 upgrade all packages in the current profile except those containing the
2862 substring ``emacs'':
2865 $ guix package --upgrade . --do-not-upgrade emacs
2868 @item @anchor{profile-manifest}--manifest=@var{file}
2869 @itemx -m @var{file}
2870 @cindex profile declaration
2871 @cindex profile manifest
2872 Create a new generation of the profile from the manifest object
2873 returned by the Scheme code in @var{file}. This option can be repeated
2874 several times, in which case the manifests are concatenated.
2876 This allows you to @emph{declare} the profile's contents rather than
2877 constructing it through a sequence of @option{--install} and similar
2878 commands. The advantage is that @var{file} can be put under version
2879 control, copied to different machines to reproduce the same profile, and
2882 @c FIXME: Add reference to (guix profile) documentation when available.
2883 @var{file} must return a @dfn{manifest} object, which is roughly a list
2886 @findex packages->manifest
2888 (use-package-modules guile emacs)
2893 ;; Use a specific package output.
2894 (list guile-2.0 "debug")))
2897 @findex specifications->manifest
2898 In this example we have to know which modules define the @code{emacs}
2899 and @code{guile-2.0} variables to provide the right
2900 @code{use-package-modules} line, which can be cumbersome. We can
2901 instead provide regular package specifications and let
2902 @code{specifications->manifest} look up the corresponding package
2906 (specifications->manifest
2907 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2911 @cindex rolling back
2912 @cindex undoing transactions
2913 @cindex transactions, undoing
2914 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2915 the last transaction.
2917 When combined with options such as @option{--install}, roll back occurs
2918 before any other actions.
2920 When rolling back from the first generation that actually contains
2921 installed packages, the profile is made to point to the @dfn{zeroth
2922 generation}, which contains no files apart from its own metadata.
2924 After having rolled back, installing, removing, or upgrading packages
2925 overwrites previous future generations. Thus, the history of the
2926 generations in a profile is always linear.
2928 @item --switch-generation=@var{pattern}
2929 @itemx -S @var{pattern}
2931 Switch to a particular generation defined by @var{pattern}.
2933 @var{pattern} may be either a generation number or a number prefixed
2934 with ``+'' or ``-''. The latter means: move forward/backward by a
2935 specified number of generations. For example, if you want to return to
2936 the latest generation after @option{--roll-back}, use
2937 @option{--switch-generation=+1}.
2939 The difference between @option{--roll-back} and
2940 @option{--switch-generation=-1} is that @option{--switch-generation} will
2941 not make a zeroth generation, so if a specified generation does not
2942 exist, the current generation will not be changed.
2944 @item --search-paths[=@var{kind}]
2945 @cindex search paths
2946 Report environment variable definitions, in Bash syntax, that may be
2947 needed in order to use the set of installed packages. These environment
2948 variables are used to specify @dfn{search paths} for files used by some
2949 of the installed packages.
2951 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
2952 environment variables to be defined so it can look for headers and
2953 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2954 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2955 library are installed in the profile, then @option{--search-paths} will
2956 suggest setting these variables to @file{@var{profile}/include} and
2957 @file{@var{profile}/lib}, respectively.
2959 The typical use case is to define these environment variables in the
2963 $ eval `guix package --search-paths`
2966 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2967 meaning that the returned environment variable definitions will either
2968 be exact settings, or prefixes or suffixes of the current value of these
2969 variables. When omitted, @var{kind} defaults to @code{exact}.
2971 This option can also be used to compute the @emph{combined} search paths
2972 of several profiles. Consider this example:
2975 $ guix package -p foo -i guile
2976 $ guix package -p bar -i guile-json
2977 $ guix package -p foo -p bar --search-paths
2980 The last command above reports about the @env{GUILE_LOAD_PATH}
2981 variable, even though, taken individually, neither @file{foo} nor
2982 @file{bar} would lead to that recommendation.
2985 @item --profile=@var{profile}
2986 @itemx -p @var{profile}
2987 Use @var{profile} instead of the user's default profile.
2989 @var{profile} must be the name of a file that will be created upon
2990 completion. Concretely, @var{profile} will be a mere symbolic link
2991 (``symlink'') pointing to the actual profile where packages are
2995 $ guix install hello -p ~/code/my-profile
2997 $ ~/code/my-profile/bin/hello
3001 All it takes to get rid of the profile is to remove this symlink and its
3002 siblings that point to specific generations:
3005 $ rm ~/code/my-profile ~/code/my-profile-*-link
3008 @item --list-profiles
3009 List all the user's profiles:
3012 $ guix package --list-profiles
3013 /home/charlie/.guix-profile
3014 /home/charlie/code/my-profile
3015 /home/charlie/code/devel-profile
3016 /home/charlie/tmp/test
3019 When running as root, list all the profiles of all the users.
3021 @cindex collisions, in a profile
3022 @cindex colliding packages in profiles
3023 @cindex profile collisions
3024 @item --allow-collisions
3025 Allow colliding packages in the new profile. Use at your own risk!
3027 By default, @command{guix package} reports as an error @dfn{collisions}
3028 in the profile. Collisions happen when two or more different versions
3029 or variants of a given package end up in the profile.
3032 Use the bootstrap Guile to build the profile. This option is only
3033 useful to distribution developers.
3037 In addition to these actions, @command{guix package} supports the
3038 following options to query the current state of a profile, or the
3039 availability of packages:
3043 @item --search=@var{regexp}
3044 @itemx -s @var{regexp}
3045 @cindex searching for packages
3046 List the available packages whose name, synopsis, or description matches
3047 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3048 Print all the metadata of matching packages in
3049 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3050 GNU recutils manual}).
3052 This allows specific fields to be extracted using the @command{recsel}
3053 command, for instance:
3056 $ guix package -s malloc | recsel -p name,version,relevance
3070 Similarly, to show the name of all the packages available under the
3071 terms of the GNU@tie{}LGPL version 3:
3074 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3081 It is also possible to refine search results using several @code{-s} flags to
3082 @command{guix package}, or several arguments to @command{guix search}. For
3083 example, the following command returns a list of board games (this time using
3084 the @command{guix search} alias):
3087 $ guix search '\<board\>' game | recsel -p name
3092 If we were to omit @code{-s game}, we would also get software packages
3093 that deal with printed circuit boards; removing the angle brackets
3094 around @code{board} would further add packages that have to do with
3097 And now for a more elaborate example. The following command searches
3098 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3099 libraries, and prints the name and synopsis of the matching packages:
3102 $ guix search crypto library | \
3103 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3107 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3108 information on @dfn{selection expressions} for @code{recsel -e}.
3110 @item --show=@var{package}
3111 Show details about @var{package}, taken from the list of available packages, in
3112 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3116 $ guix package --show=python | recsel -p name,version
3124 You may also specify the full name of a package to only get details about a
3125 specific version of it (this time using the @command{guix show} alias):
3127 $ guix show python@@3.4 | recsel -p name,version
3134 @item --list-installed[=@var{regexp}]
3135 @itemx -I [@var{regexp}]
3136 List the currently installed packages in the specified profile, with the
3137 most recently installed packages shown last. When @var{regexp} is
3138 specified, list only installed packages whose name matches @var{regexp}.
3140 For each installed package, print the following items, separated by
3141 tabs: the package name, its version string, the part of the package that
3142 is installed (for instance, @code{out} for the default output,
3143 @code{include} for its headers, etc.), and the path of this package in
3146 @item --list-available[=@var{regexp}]
3147 @itemx -A [@var{regexp}]
3148 List packages currently available in the distribution for this system
3149 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3150 available packages whose name matches @var{regexp}.
3152 For each package, print the following items separated by tabs: its name,
3153 its version string, the parts of the package (@pxref{Packages with
3154 Multiple Outputs}), and the source location of its definition.
3156 @item --list-generations[=@var{pattern}]
3157 @itemx -l [@var{pattern}]
3159 Return a list of generations along with their creation dates; for each
3160 generation, show the installed packages, with the most recently
3161 installed packages shown last. Note that the zeroth generation is never
3164 For each installed package, print the following items, separated by
3165 tabs: the name of a package, its version string, the part of the package
3166 that is installed (@pxref{Packages with Multiple Outputs}), and the
3167 location of this package in the store.
3169 When @var{pattern} is used, the command returns only matching
3170 generations. Valid patterns include:
3173 @item @emph{Integers and comma-separated integers}. Both patterns denote
3174 generation numbers. For instance, @option{--list-generations=1} returns
3177 And @option{--list-generations=1,8,2} outputs three generations in the
3178 specified order. Neither spaces nor trailing commas are allowed.
3180 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3181 specified generations and everything in between. Note that the start of
3182 a range must be smaller than its end.
3184 It is also possible to omit the endpoint. For example,
3185 @option{--list-generations=2..}, returns all generations starting from the
3188 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3189 or months by passing an integer along with the first letter of the
3190 duration. For example, @option{--list-generations=20d} lists generations
3191 that are up to 20 days old.
3194 @item --delete-generations[=@var{pattern}]
3195 @itemx -d [@var{pattern}]
3196 When @var{pattern} is omitted, delete all generations except the current
3199 This command accepts the same patterns as @option{--list-generations}.
3200 When @var{pattern} is specified, delete the matching generations. When
3201 @var{pattern} specifies a duration, generations @emph{older} than the
3202 specified duration match. For instance, @option{--delete-generations=1m}
3203 deletes generations that are more than one month old.
3205 If the current generation matches, it is @emph{not} deleted. Also, the
3206 zeroth generation is never deleted.
3208 Note that deleting generations prevents rolling back to them.
3209 Consequently, this command must be used with care.
3213 Finally, since @command{guix package} may actually start build
3214 processes, it supports all the common build options (@pxref{Common Build
3215 Options}). It also supports package transformation options, such as
3216 @option{--with-source} (@pxref{Package Transformation Options}).
3217 However, note that package transformations are lost when upgrading; to
3218 preserve transformations across upgrades, you should define your own
3219 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3220 (@pxref{Defining Packages}).
3223 @section Substitutes
3226 @cindex pre-built binaries
3227 Guix supports transparent source/binary deployment, which means that it
3228 can either build things locally, or download pre-built items from a
3229 server, or both. We call these pre-built items @dfn{substitutes}---they
3230 are substitutes for local build results. In many cases, downloading a
3231 substitute is much faster than building things locally.
3233 Substitutes can be anything resulting from a derivation build
3234 (@pxref{Derivations}). Of course, in the common case, they are
3235 pre-built package binaries, but source tarballs, for instance, which
3236 also result from derivation builds, can be available as substitutes.
3239 * Official Substitute Server:: One particular source of substitutes.
3240 * Substitute Server Authorization:: How to enable or disable substitutes.
3241 * Substitute Authentication:: How Guix verifies substitutes.
3242 * Proxy Settings:: How to get substitutes via proxy.
3243 * Substitution Failure:: What happens when substitution fails.
3244 * On Trusting Binaries:: How can you trust that binary blob?
3247 @node Official Substitute Server
3248 @subsection Official Substitute Server
3251 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3252 that builds packages from Guix continuously for some
3253 architectures, and makes them available as substitutes. This is the
3254 default source of substitutes; it can be overridden by passing the
3255 @option{--substitute-urls} option either to @command{guix-daemon}
3256 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3257 or to client tools such as @command{guix package}
3258 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3261 Substitute URLs can be either HTTP or HTTPS.
3262 HTTPS is recommended because communications are encrypted; conversely,
3263 using HTTP makes all communications visible to an eavesdropper, who
3264 could use the information gathered to determine, for instance, whether
3265 your system has unpatched security vulnerabilities.
3267 Substitutes from the official build farm are enabled by default when
3268 using Guix System (@pxref{GNU Distribution}). However,
3269 they are disabled by default when using Guix on a foreign distribution,
3270 unless you have explicitly enabled them via one of the recommended
3271 installation steps (@pxref{Installation}). The following paragraphs
3272 describe how to enable or disable substitutes for the official build
3273 farm; the same procedure can also be used to enable substitutes for any
3274 other substitute server.
3276 @node Substitute Server Authorization
3277 @subsection Substitute Server Authorization
3280 @cindex substitutes, authorization thereof
3281 @cindex access control list (ACL), for substitutes
3282 @cindex ACL (access control list), for substitutes
3283 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3285 must add its public key to the access control list (ACL) of archive
3286 imports, using the @command{guix archive} command (@pxref{Invoking guix
3287 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3288 be compromised and to serve genuine substitutes.
3290 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3291 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3292 the installation prefix of Guix. If you installed Guix from source,
3293 make sure you checked the GPG signature of
3294 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3295 Then, you can run something like this:
3298 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3301 Once this is in place, the output of a command like @code{guix build}
3302 should change from something like:
3305 $ guix build emacs --dry-run
3306 The following derivations would be built:
3307 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3308 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3309 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3310 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3318 $ guix build emacs --dry-run
3319 112.3 MB would be downloaded:
3320 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3321 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3322 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3323 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3328 The text changed from ``The following derivations would be built'' to
3329 ``112.3 MB would be downloaded''. This indicates that substitutes from
3330 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3331 possible, for future builds.
3333 @cindex substitutes, how to disable
3334 The substitute mechanism can be disabled globally by running
3335 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3336 guix-daemon}). It can also be disabled temporarily by passing the
3337 @option{--no-substitutes} option to @command{guix package},
3338 @command{guix build}, and other command-line tools.
3340 @node Substitute Authentication
3341 @subsection Substitute Authentication
3343 @cindex digital signatures
3344 Guix detects and raises an error when attempting to use a substitute
3345 that has been tampered with. Likewise, it ignores substitutes that are
3346 not signed, or that are not signed by one of the keys listed in the ACL.
3348 There is one exception though: if an unauthorized server provides
3349 substitutes that are @emph{bit-for-bit identical} to those provided by
3350 an authorized server, then the unauthorized server becomes eligible for
3351 downloads. For example, assume we have chosen two substitute servers
3355 --substitute-urls="https://a.example.org https://b.example.org"
3359 @cindex reproducible builds
3360 If the ACL contains only the key for @samp{b.example.org}, and if
3361 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3362 then Guix will download substitutes from @samp{a.example.org} because it
3363 comes first in the list and can be considered a mirror of
3364 @samp{b.example.org}. In practice, independent build machines usually
3365 produce the same binaries, thanks to bit-reproducible builds (see
3368 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3369 (in other words, the server is not authenticated), contrary to what
3370 HTTPS clients such as Web browsers usually do. This is because Guix
3371 authenticates substitute information itself, as explained above, which
3372 is what we care about (whereas X.509 certificates are about
3373 authenticating bindings between domain names and public keys.)
3375 @node Proxy Settings
3376 @subsection Proxy Settings
3379 Substitutes are downloaded over HTTP or HTTPS.
3380 The @env{http_proxy} environment
3381 variable can be set in the environment of @command{guix-daemon} and is
3382 honored for downloads of substitutes. Note that the value of
3383 @env{http_proxy} in the environment where @command{guix build},
3384 @command{guix package}, and other client commands are run has
3385 @emph{absolutely no effect}.
3387 @node Substitution Failure
3388 @subsection Substitution Failure
3390 Even when a substitute for a derivation is available, sometimes the
3391 substitution attempt will fail. This can happen for a variety of
3392 reasons: the substitute server might be offline, the substitute may
3393 recently have been deleted, the connection might have been interrupted,
3396 When substitutes are enabled and a substitute for a derivation is
3397 available, but the substitution attempt fails, Guix will attempt to
3398 build the derivation locally depending on whether or not
3399 @option{--fallback} was given (@pxref{fallback-option,, common build
3400 option @option{--fallback}}). Specifically, if @option{--fallback} was
3401 omitted, then no local build will be performed, and the derivation is
3402 considered to have failed. However, if @option{--fallback} was given,
3403 then Guix will attempt to build the derivation locally, and the success
3404 or failure of the derivation depends on the success or failure of the
3405 local build. Note that when substitutes are disabled or no substitute
3406 is available for the derivation in question, a local build will
3407 @emph{always} be performed, regardless of whether or not
3408 @option{--fallback} was given.
3410 To get an idea of how many substitutes are available right now, you can
3411 try running the @command{guix weather} command (@pxref{Invoking guix
3412 weather}). This command provides statistics on the substitutes provided
3415 @node On Trusting Binaries
3416 @subsection On Trusting Binaries
3418 @cindex trust, of pre-built binaries
3419 Today, each individual's control over their own computing is at the
3420 mercy of institutions, corporations, and groups with enough power and
3421 determination to subvert the computing infrastructure and exploit its
3422 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3423 convenient, we encourage users to also build on their own, or even run
3424 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3425 interesting target. One way to help is by publishing the software you
3426 build using @command{guix publish} so that others have one more choice
3427 of server to download substitutes from (@pxref{Invoking guix publish}).
3429 Guix has the foundations to maximize build reproducibility
3430 (@pxref{Features}). In most cases, independent builds of a given
3431 package or derivation should yield bit-identical results. Thus, through
3432 a diverse set of independent package builds, we can strengthen the
3433 integrity of our systems. The @command{guix challenge} command aims to
3434 help users assess substitute servers, and to assist developers in
3435 finding out about non-deterministic package builds (@pxref{Invoking guix
3436 challenge}). Similarly, the @option{--check} option of @command{guix
3437 build} allows users to check whether previously-installed substitutes
3438 are genuine by rebuilding them locally (@pxref{build-check,
3439 @command{guix build --check}}).
3441 In the future, we want Guix to have support to publish and retrieve
3442 binaries to/from other users, in a peer-to-peer fashion. If you would
3443 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3445 @node Packages with Multiple Outputs
3446 @section Packages with Multiple Outputs
3448 @cindex multiple-output packages
3449 @cindex package outputs
3452 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3453 source package leads to exactly one directory in the store. When running
3454 @command{guix install glibc}, one installs the default output of the
3455 GNU libc package; the default output is called @code{out}, but its name
3456 can be omitted as shown in this command. In this particular case, the
3457 default output of @code{glibc} contains all the C header files, shared
3458 libraries, static libraries, Info documentation, and other supporting
3461 Sometimes it is more appropriate to separate the various types of files
3462 produced from a single source package into separate outputs. For
3463 instance, the GLib C library (used by GTK+ and related packages)
3464 installs more than 20 MiB of reference documentation as HTML pages.
3465 To save space for users who do not need it, the documentation goes to a
3466 separate output, called @code{doc}. To install the main GLib output,
3467 which contains everything but the documentation, one would run:
3473 @cindex documentation
3474 The command to install its documentation is:
3477 guix install glib:doc
3480 Some packages install programs with different ``dependency footprints''.
3481 For instance, the WordNet package installs both command-line tools and
3482 graphical user interfaces (GUIs). The former depend solely on the C
3483 library, whereas the latter depend on Tcl/Tk and the underlying X
3484 libraries. In this case, we leave the command-line tools in the default
3485 output, whereas the GUIs are in a separate output. This allows users
3486 who do not need the GUIs to save space. The @command{guix size} command
3487 can help find out about such situations (@pxref{Invoking guix size}).
3488 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3490 There are several such multiple-output packages in the GNU distribution.
3491 Other conventional output names include @code{lib} for libraries and
3492 possibly header files, @code{bin} for stand-alone programs, and
3493 @code{debug} for debugging information (@pxref{Installing Debugging
3494 Files}). The outputs of a packages are listed in the third column of
3495 the output of @command{guix package --list-available} (@pxref{Invoking
3499 @node Invoking guix gc
3500 @section Invoking @command{guix gc}
3502 @cindex garbage collector
3504 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3505 The @command{guix gc} command allows users to explicitly run the garbage
3506 collector to reclaim space from the @file{/gnu/store} directory. It is
3507 the @emph{only} way to remove files from @file{/gnu/store}---removing
3508 files or directories manually may break it beyond repair!
3511 @cindex garbage collector roots
3512 The garbage collector has a set of known @dfn{roots}: any file under
3513 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3514 cannot be deleted; any other file is considered @dfn{dead} and may be
3515 deleted. The set of garbage collector roots (``GC roots'' for short)
3516 includes default user profiles; by default, the symlinks under
3517 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3518 added with @command{guix build --root}, for example (@pxref{Invoking
3519 guix build}). The @command{guix gc --list-roots} command lists them.
3521 Prior to running @code{guix gc --collect-garbage} to make space, it is
3522 often useful to remove old generations from user profiles; that way, old
3523 package builds referenced by those generations can be reclaimed. This
3524 is achieved by running @code{guix package --delete-generations}
3525 (@pxref{Invoking guix package}).
3527 Our recommendation is to run a garbage collection periodically, or when
3528 you are short on disk space. For instance, to guarantee that at least
3529 5@tie{}GB are available on your disk, simply run:
3535 It is perfectly safe to run as a non-interactive periodic job
3536 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3537 Running @command{guix gc} with no arguments will collect as
3538 much garbage as it can, but that is often inconvenient: you may find
3539 yourself having to rebuild or re-download software that is ``dead'' from
3540 the GC viewpoint but that is necessary to build other pieces of
3541 software---e.g., the compiler tool chain.
3543 The @command{guix gc} command has three modes of operation: it can be
3544 used to garbage-collect any dead files (the default), to delete specific
3545 files (the @option{--delete} option), to print garbage-collector
3546 information, or for more advanced queries. The garbage collection
3547 options are as follows:
3550 @item --collect-garbage[=@var{min}]
3551 @itemx -C [@var{min}]
3552 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3553 sub-directories. This is the default operation when no option is
3556 When @var{min} is given, stop once @var{min} bytes have been collected.
3557 @var{min} may be a number of bytes, or it may include a unit as a
3558 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3559 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3561 When @var{min} is omitted, collect all the garbage.
3563 @item --free-space=@var{free}
3564 @itemx -F @var{free}
3565 Collect garbage until @var{free} space is available under
3566 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3567 as @code{500MiB}, as described above.
3569 When @var{free} or more is already available in @file{/gnu/store}, do
3570 nothing and exit immediately.
3572 @item --delete-generations[=@var{duration}]
3573 @itemx -d [@var{duration}]
3574 Before starting the garbage collection process, delete all the generations
3575 older than @var{duration}, for all the user profiles; when run as root, this
3576 applies to all the profiles @emph{of all the users}.
3578 For example, this command deletes all the generations of all your profiles
3579 that are older than 2 months (except generations that are current), and then
3580 proceeds to free space until at least 10 GiB are available:
3583 guix gc -d 2m -F 10G
3588 Attempt to delete all the store files and directories specified as
3589 arguments. This fails if some of the files are not in the store, or if
3590 they are still live.
3592 @item --list-failures
3593 List store items corresponding to cached build failures.
3595 This prints nothing unless the daemon was started with
3596 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3597 @option{--cache-failures}}).
3600 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3604 List store items in use by currently running processes. These store
3605 items are effectively considered GC roots: they cannot be deleted.
3607 @item --clear-failures
3608 Remove the specified store items from the failed-build cache.
3610 Again, this option only makes sense when the daemon is started with
3611 @option{--cache-failures}. Otherwise, it does nothing.
3614 Show the list of dead files and directories still present in the
3615 store---i.e., files and directories no longer reachable from any root.
3618 Show the list of live store files and directories.
3622 In addition, the references among existing store files can be queried:
3628 @cindex package dependencies
3629 List the references (respectively, the referrers) of store files given
3635 List the requisites of the store files passed as arguments. Requisites
3636 include the store files themselves, their references, and the references
3637 of these, recursively. In other words, the returned list is the
3638 @dfn{transitive closure} of the store files.
3640 @xref{Invoking guix size}, for a tool to profile the size of the closure
3641 of an element. @xref{Invoking guix graph}, for a tool to visualize
3642 the graph of references.
3646 Return the derivation(s) leading to the given store items
3647 (@pxref{Derivations}).
3649 For example, this command:
3652 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3656 returns the @file{.drv} file(s) leading to the @code{emacs} package
3657 installed in your profile.
3659 Note that there may be zero matching @file{.drv} files, for instance
3660 because these files have been garbage-collected. There can also be more
3661 than one matching @file{.drv} due to fixed-output derivations.
3664 Lastly, the following options allow you to check the integrity of the
3665 store and to control disk usage.
3669 @item --verify[=@var{options}]
3670 @cindex integrity, of the store
3671 @cindex integrity checking
3672 Verify the integrity of the store.
3674 By default, make sure that all the store items marked as valid in the
3675 database of the daemon actually exist in @file{/gnu/store}.
3677 When provided, @var{options} must be a comma-separated list containing one
3678 or more of @code{contents} and @code{repair}.
3680 When passing @option{--verify=contents}, the daemon computes the
3681 content hash of each store item and compares it against its hash in the
3682 database. Hash mismatches are reported as data corruptions. Because it
3683 traverses @emph{all the files in the store}, this command can take a
3684 long time, especially on systems with a slow disk drive.
3686 @cindex repairing the store
3687 @cindex corruption, recovering from
3688 Using @option{--verify=repair} or @option{--verify=contents,repair}
3689 causes the daemon to try to repair corrupt store items by fetching
3690 substitutes for them (@pxref{Substitutes}). Because repairing is not
3691 atomic, and thus potentially dangerous, it is available only to the
3692 system administrator. A lightweight alternative, when you know exactly
3693 which items in the store are corrupt, is @command{guix build --repair}
3694 (@pxref{Invoking guix build}).
3697 @cindex deduplication
3698 Optimize the store by hard-linking identical files---this is
3699 @dfn{deduplication}.
3701 The daemon performs deduplication after each successful build or archive
3702 import, unless it was started with @option{--disable-deduplication}
3703 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3704 this option is primarily useful when the daemon was running with
3705 @option{--disable-deduplication}.
3709 @node Invoking guix pull
3710 @section Invoking @command{guix pull}
3712 @cindex upgrading Guix
3713 @cindex updating Guix
3714 @cindex @command{guix pull}
3716 Packages are installed or upgraded to the latest version available in
3717 the distribution currently available on your local machine. To update
3718 that distribution, along with the Guix tools, you must run @command{guix
3719 pull}: the command downloads the latest Guix source code and package
3720 descriptions, and deploys it. Source code is downloaded from a
3721 @uref{https://git-scm.com, Git} repository, by default the official
3722 GNU@tie{}Guix repository, though this can be customized.
3724 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3725 (@pxref{Channels}) specified by one of the followings, in this order:
3729 the @option{--channels} option;
3731 the user's @file{~/.config/guix/channels.scm} file;
3733 the system-wide @file{/etc/guix/channels.scm} file;
3735 the built-in default channels specified in the @code{%default-channels}
3739 On completion, @command{guix package} will use packages and package
3740 versions from this just-retrieved copy of Guix. Not only that, but all
3741 the Guix commands and Scheme modules will also be taken from that latest
3742 version. New @command{guix} sub-commands added by the update also
3745 Any user can update their Guix copy using @command{guix pull}, and the
3746 effect is limited to the user who ran @command{guix pull}. For
3747 instance, when user @code{root} runs @command{guix pull}, this has no
3748 effect on the version of Guix that user @code{alice} sees, and vice
3751 The result of running @command{guix pull} is a @dfn{profile} available
3752 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3753 make sure to add it to the beginning of your search path so that you use
3754 the latest version, and similarly for the Info manual
3755 (@pxref{Documentation}):
3758 export PATH="$HOME/.config/guix/current/bin:$PATH"
3759 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3762 The @option{--list-generations} or @option{-l} option lists past generations
3763 produced by @command{guix pull}, along with details about their provenance:
3767 Generation 1 Jun 10 2018 00:18:18
3769 repository URL: https://git.savannah.gnu.org/git/guix.git
3770 branch: origin/master
3771 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3773 Generation 2 Jun 11 2018 11:02:49
3775 repository URL: https://git.savannah.gnu.org/git/guix.git
3776 branch: origin/master
3777 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3778 2 new packages: keepalived, libnfnetlink
3779 6 packages upgraded: emacs-nix-mode@@2.0.4,
3780 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3781 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3783 Generation 3 Jun 13 2018 23:31:07 (current)
3785 repository URL: https://git.savannah.gnu.org/git/guix.git
3786 branch: origin/master
3787 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3788 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3789 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3792 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3793 describe the current status of Guix.
3795 This @code{~/.config/guix/current} profile works exactly like the profiles
3796 created by @command{guix package} (@pxref{Invoking guix package}). That
3797 is, you can list generations, roll back to the previous
3798 generation---i.e., the previous Guix---and so on:
3801 $ guix pull --roll-back
3802 switched from generation 3 to 2
3803 $ guix pull --delete-generations=1
3804 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3807 You can also use @command{guix package} (@pxref{Invoking guix package})
3808 to manage the profile by naming it explicitly:
3810 $ guix package -p ~/.config/guix/current --roll-back
3811 switched from generation 3 to 2
3812 $ guix package -p ~/.config/guix/current --delete-generations=1
3813 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3816 The @command{guix pull} command is usually invoked with no arguments,
3817 but it supports the following options:
3820 @item --url=@var{url}
3821 @itemx --commit=@var{commit}
3822 @itemx --branch=@var{branch}
3823 Download code for the @code{guix} channel from the specified @var{url}, at the
3824 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3825 string), or @var{branch}.
3827 @cindex @file{channels.scm}, configuration file
3828 @cindex configuration file for channels
3829 These options are provided for convenience, but you can also specify your
3830 configuration in the @file{~/.config/guix/channels.scm} file or using the
3831 @option{--channels} option (see below).
3833 @item --channels=@var{file}
3834 @itemx -C @var{file}
3835 Read the list of channels from @var{file} instead of
3836 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3837 @var{file} must contain Scheme code that
3838 evaluates to a list of channel objects. @xref{Channels}, for more
3841 @cindex channel news
3844 Display the list of packages added or upgraded since the previous
3845 generation, as well as, occasionally, news written by channel authors
3846 for their users (@pxref{Channels, Writing Channel News}).
3848 The package information is the same as displayed upon @command{guix
3849 pull} completion, but without ellipses; it is also similar to the output
3850 of @command{guix pull -l} for the last generation (see below).
3852 @item --list-generations[=@var{pattern}]
3853 @itemx -l [@var{pattern}]
3854 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3855 is provided, the subset of generations that match @var{pattern}.
3856 The syntax of @var{pattern} is the same as with @code{guix package
3857 --list-generations} (@pxref{Invoking guix package}).
3860 @cindex rolling back
3861 @cindex undoing transactions
3862 @cindex transactions, undoing
3863 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3864 undo the last transaction.
3866 @item --switch-generation=@var{pattern}
3867 @itemx -S @var{pattern}
3869 Switch to a particular generation defined by @var{pattern}.
3871 @var{pattern} may be either a generation number or a number prefixed
3872 with ``+'' or ``-''. The latter means: move forward/backward by a
3873 specified number of generations. For example, if you want to return to
3874 the latest generation after @option{--roll-back}, use
3875 @option{--switch-generation=+1}.
3877 @item --delete-generations[=@var{pattern}]
3878 @itemx -d [@var{pattern}]
3879 When @var{pattern} is omitted, delete all generations except the current
3882 This command accepts the same patterns as @option{--list-generations}.
3883 When @var{pattern} is specified, delete the matching generations. When
3884 @var{pattern} specifies a duration, generations @emph{older} than the
3885 specified duration match. For instance, @option{--delete-generations=1m}
3886 deletes generations that are more than one month old.
3888 If the current generation matches, it is @emph{not} deleted.
3890 Note that deleting generations prevents rolling back to them.
3891 Consequently, this command must be used with care.
3893 @xref{Invoking guix describe}, for a way to display information about the
3894 current generation only.
3896 @item --profile=@var{profile}
3897 @itemx -p @var{profile}
3898 Use @var{profile} instead of @file{~/.config/guix/current}.
3902 Show which channel commit(s) would be used and what would be built or
3903 substituted but do not actually do it.
3905 @item --system=@var{system}
3906 @itemx -s @var{system}
3907 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3908 the system type of the build host.
3911 Produce verbose output, writing build logs to the standard error output.
3914 Use the bootstrap Guile to build the latest Guix. This option is only
3915 useful to Guix developers.
3918 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3919 repository and branch to pull from, as well as @emph{additional} repositories
3920 containing package modules that should be deployed. @xref{Channels}, for more
3923 In addition, @command{guix pull} supports all the common build options
3924 (@pxref{Common Build Options}).
3930 @cindex @file{channels.scm}, configuration file
3931 @cindex configuration file for channels
3932 @cindex @command{guix pull}, configuration file
3933 @cindex configuration of @command{guix pull}
3934 Guix and its package collection are updated by running @command{guix pull}
3935 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3936 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3937 customized by defining @dfn{channels} in the
3938 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3939 of a Git repository to be deployed, and @command{guix pull} can be instructed
3940 to pull from one or more channels. In other words, channels can be used to
3941 @emph{customize} and to @emph{extend} Guix, as we will see below.
3943 @subsection Using a Custom Guix Channel
3945 The channel called @code{guix} specifies where Guix itself---its command-line
3946 tools as well as its package collection---should be downloaded. For instance,
3947 suppose you want to update from your own copy of the Guix repository at
3948 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3949 write in @code{~/.config/guix/channels.scm} this specification:
3952 ;; Tell 'guix pull' to use my own repo.
3955 (url "https://example.org/my-guix.git")
3956 (branch "super-hacks")))
3960 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3961 branch of the repository at @code{example.org}.
3963 @subsection Specifying Additional Channels
3965 @cindex extending the package collection (channels)
3966 @cindex personal packages (channels)
3967 @cindex channels, for personal packages
3968 You can also specify @emph{additional channels} to pull from. Let's say you
3969 have a bunch of custom package variants or personal packages that you think
3970 would make little sense to contribute to the Guix project, but would like to
3971 have these packages transparently available to you at the command line. You
3972 would first write modules containing those package definitions (@pxref{Package
3973 Modules}), maintain them in a Git repository, and then you and anyone else can
3974 use it as an additional channel to get packages from. Neat, no?
3976 @c What follows stems from discussions at
3977 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3978 @c earlier discussions on guix-devel@gnu.org.
3980 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3981 publish your personal channel to the world, we would like to share a few words
3986 Before publishing a channel, please consider contributing your package
3987 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3988 to free software of all sorts, and packages in Guix proper are readily
3989 available to all Guix users and benefit from the project's quality assurance
3993 When you maintain package definitions outside Guix, we, Guix developers,
3994 consider that @emph{the compatibility burden is on you}. Remember that
3995 package modules and package definitions are just Scheme code that uses various
3996 programming interfaces (APIs). We want to remain free to change these APIs to
3997 keep improving Guix, possibly in ways that break your channel. We never
3998 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4002 Corollary: if you're using an external channel and that channel breaks, please
4003 @emph{report the issue to the channel authors}, not to the Guix project.
4006 You've been warned! Having said this, we believe external channels are a
4007 practical way to exert your freedom to augment Guix' package collection and to
4008 share your improvements, which are basic tenets of
4009 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4010 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4013 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4014 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4017 @vindex %default-channels
4019 ;; Add my personal packages to those Guix provides.
4021 (name 'my-personal-packages)
4022 (url "https://example.org/personal-packages.git"))
4027 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4028 add a channel the list of channels that the variable @code{%default-channels}
4029 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4030 Manual}). With this file in place, @command{guix pull} builds not only Guix
4031 but also the package modules from your own repository. The result in
4032 @file{~/.config/guix/current} is the union of Guix with your own package
4036 $ guix pull --list-generations
4038 Generation 19 Aug 27 2018 16:20:48
4040 repository URL: https://git.savannah.gnu.org/git/guix.git
4042 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4043 my-personal-packages dd3df5e
4044 repository URL: https://example.org/personal-packages.git
4046 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4047 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4048 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4052 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4053 both Guix and packages from the @code{my-personal-packages} channel. Among
4054 the new and upgraded packages that are listed, some like @code{my-gimp} and
4055 @code{my-emacs-with-cool-features} might come from
4056 @code{my-personal-packages}, while others come from the Guix default channel.
4058 To create a channel, create a Git repository containing your own package
4059 modules and make it available. The repository can contain anything, but a
4060 useful channel will contain Guile modules that export packages. Once you
4061 start using a channel, Guix will behave as if the root directory of that
4062 channel's Git repository has been added to the Guile load path (@pxref{Load
4063 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4064 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4065 module, then the module will be available under the name @code{(my-packages
4066 my-tools)}, and you will be able to use it like any other module
4067 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4069 @cindex dependencies, channels
4070 @cindex meta-data, channels
4071 @subsection Declaring Channel Dependencies
4073 Channel authors may decide to augment a package collection provided by other
4074 channels. They can declare their channel to be dependent on other channels in
4075 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4076 the channel repository.
4078 The meta-data file should contain a simple S-expression like this:
4085 (name some-collection)
4086 (url "https://example.org/first-collection.git"))
4088 (name some-other-collection)
4089 (url "https://example.org/second-collection.git")
4090 (branch "testing"))))
4093 In the above example this channel is declared to depend on two other channels,
4094 which will both be fetched automatically. The modules provided by the channel
4095 will be compiled in an environment where the modules of all these declared
4096 channels are available.
4098 For the sake of reliability and maintainability, you should avoid dependencies
4099 on channels that you don't control, and you should aim to keep the number of
4100 dependencies to a minimum.
4102 @cindex subdirectory, channels
4103 @subsection Package Modules in a Sub-directory
4105 As a channel author, you may want to keep your channel modules in a
4106 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4107 add a meta-data file @file{.guix-channel} that contains:
4115 @cindex news, for channels
4116 @subsection Writing Channel News
4118 Channel authors may occasionally want to communicate to their users
4119 information about important changes in the channel. You'd send them all
4120 an email, but that's not convenient.
4122 Instead, channels can provide a @dfn{news file}; when the channel users
4123 run @command{guix pull}, that news file is automatically read and
4124 @command{guix pull --news} can display the announcements that correspond
4125 to the new commits that have been pulled, if any.
4127 To do that, channel authors must first declare the name of the news file
4128 in their @file{.guix-channel} file:
4133 (news-file "etc/news.txt"))
4136 The news file itself, @file{etc/news.txt} in this example, must look
4137 something like this:
4142 (entry (tag "the-bug-fix")
4143 (title (en "Fixed terrible bug")
4145 (body (en "@@emph@{Good news@}! It's fixed!")
4146 (eo "Certe ĝi pli bone funkcias nun!")))
4147 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4148 (title (en "Added a great package")
4149 (ca "Què vol dir guix?"))
4150 (body (en "Don't miss the @@code@{hello@} package!"))))
4153 The file consists of a list of @dfn{news entries}. Each entry is
4154 associated with a commit or tag: it describes changes made in this
4155 commit, possibly in preceding commits as well. Users see entries only
4156 the first time they obtain the commit the entry refers to.
4158 The @code{title} field should be a one-line summary while @code{body}
4159 can be arbitrarily long, and both can contain Texinfo markup
4160 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4161 a list of language tag/message tuples, which allows @command{guix pull}
4162 to display news in the language that corresponds to the user's locale.
4164 If you want to translate news using a gettext-based workflow, you can
4165 extract translatable strings with @command{xgettext} (@pxref{xgettext
4166 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4167 you write news entries in English first, the command below creates a PO
4168 file containing the strings to translate:
4171 xgettext -o news.po -l scheme -ken etc/news.scm
4174 To sum up, yes, you could use your channel as a blog. But beware, this
4175 is @emph{not quite} what your users might expect.
4177 @subsection Replicating Guix
4179 @cindex pinning, channels
4180 @cindex replicating Guix
4181 @cindex reproducibility, of Guix
4182 The @command{guix pull --list-generations} output above shows precisely which
4183 commits were used to build this instance of Guix. We can thus replicate it,
4184 say, on another machine, by providing a channel specification in
4185 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4188 ;; Deploy specific commits of my channels of interest.
4191 (url "https://git.savannah.gnu.org/git/guix.git")
4192 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4194 (name 'my-personal-packages)
4195 (url "https://example.org/personal-packages.git")
4196 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4199 The @command{guix describe --format=channels} command can even generate this
4200 list of channels directly (@pxref{Invoking guix describe}). The resulting
4201 file can be used with the -C options of @command{guix pull}
4202 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4203 (@pxref{Invoking guix time-machine}).
4205 At this point the two machines run the @emph{exact same Guix}, with access to
4206 the @emph{exact same packages}. The output of @command{guix build gimp} on
4207 one machine will be exactly the same, bit for bit, as the output of the same
4208 command on the other machine. It also means both machines have access to all
4209 the source code of Guix and, transitively, to all the source code of every
4212 This gives you super powers, allowing you to track the provenance of binary
4213 artifacts with very fine grain, and to reproduce software environments at
4214 will---some sort of ``meta reproducibility'' capabilities, if you will.
4215 @xref{Inferiors}, for another way to take advantage of these super powers.
4217 @node Invoking guix time-machine
4218 @section Invoking @command{guix time-machine}
4220 @cindex @command{guix time-machine}
4221 @cindex pinning, channels
4222 @cindex replicating Guix
4223 @cindex reproducibility, of Guix
4225 The @command{guix time-machine} command provides access to other
4226 revisions of Guix, for example to install older versions of packages,
4227 or to reproduce a computation in an identical environment. The revision
4228 of Guix to be used is defined by a commit or by a channel
4229 description file created by @command{guix describe}
4230 (@pxref{Invoking guix describe}).
4232 The general syntax is:
4235 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4238 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4239 @command{guix} command of the specified revision. The @var{options} that define
4240 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4243 @item --url=@var{url}
4244 @itemx --commit=@var{commit}
4245 @itemx --branch=@var{branch}
4246 Use the @code{guix} channel from the specified @var{url}, at the
4247 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4248 string), or @var{branch}.
4250 @item --channels=@var{file}
4251 @itemx -C @var{file}
4252 Read the list of channels from @var{file}. @var{file} must contain
4253 Scheme code that evaluates to a list of channel objects.
4254 @xref{Channels} for more information.
4257 As for @command{guix pull}, the absence of any options means that the
4258 the latest commit on the master branch will be used. The command
4261 guix time-machine -- build hello
4264 will thus build the package @code{hello} as defined in the master branch,
4265 which is in general a newer revision of Guix than you have installed.
4266 Time travel works in both directions!
4268 Note that @command{guix time-machine} can trigger builds of channels and
4269 their dependencies, and these are controlled by the standard build
4270 options (@pxref{Common Build Options}).
4275 @c TODO: Remove this once we're more confident about API stability.
4277 The functionality described here is a ``technology preview'' as of version
4278 @value{VERSION}. As such, the interface is subject to change.
4282 @cindex composition of Guix revisions
4283 Sometimes you might need to mix packages from the revision of Guix you're
4284 currently running with packages available in a different revision of Guix.
4285 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4286 revisions in arbitrary ways.
4288 @cindex inferior packages
4289 Technically, an ``inferior'' is essentially a separate Guix process connected
4290 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4291 @code{(guix inferior)} module allows you to create inferiors and to
4292 communicate with them. It also provides a high-level interface to browse and
4293 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4295 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4296 to interact with a separate revision of Guix. For example, let's assume you
4297 want to install in your profile the current @code{guile} package, along with
4298 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4299 because the newer @code{guile-json} has an incompatible API and you want to
4300 run your code against the old API@. To do that, you could write a manifest for
4301 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4302 manifest, you would create an inferior for that old Guix revision you care
4303 about, and you would look up the @code{guile-json} package in the inferior:
4306 (use-modules (guix inferior) (guix channels)
4307 (srfi srfi-1)) ;for 'first'
4310 ;; This is the old revision from which we want to
4311 ;; extract guile-json.
4314 (url "https://git.savannah.gnu.org/git/guix.git")
4316 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4319 ;; An inferior representing the above revision.
4320 (inferior-for-channels channels))
4322 ;; Now create a manifest with the current "guile" package
4323 ;; and the old "guile-json" package.
4325 (list (first (lookup-inferior-packages inferior "guile-json"))
4326 (specification->package "guile")))
4329 On its first run, @command{guix package --manifest} might have to build the
4330 channel you specified before it can create the inferior; subsequent runs will
4331 be much faster because the Guix revision will be cached.
4333 The @code{(guix inferior)} module provides the following procedures to open an
4336 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4337 [#:cache-directory] [#:ttl]
4338 Return an inferior for @var{channels}, a list of channels. Use the cache at
4339 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4340 This procedure opens a new connection to the build daemon.
4342 As a side effect, this procedure may build or substitute binaries for
4343 @var{channels}, which can take time.
4346 @deffn {Scheme Procedure} open-inferior @var{directory} @
4347 [#:command "bin/guix"]
4348 Open the inferior Guix in @var{directory}, running
4349 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4350 the inferior could not be launched.
4353 @cindex inferior packages
4354 The procedures listed below allow you to obtain and manipulate inferior
4357 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4358 Return the list of packages known to @var{inferior}.
4361 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4363 Return the sorted list of inferior packages matching @var{name} in
4364 @var{inferior}, with highest version numbers first. If @var{version} is true,
4365 return only packages with a version number prefixed by @var{version}.
4368 @deffn {Scheme Procedure} inferior-package? @var{obj}
4369 Return true if @var{obj} is an inferior package.
4372 @deffn {Scheme Procedure} inferior-package-name @var{package}
4373 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4374 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4375 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4376 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4377 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4378 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4379 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4380 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4381 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4382 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4383 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4384 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4385 These procedures are the counterpart of package record accessors
4386 (@pxref{package Reference}). Most of them work by querying the inferior
4387 @var{package} comes from, so the inferior must still be live when you call
4391 Inferior packages can be used transparently like any other package or
4392 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4393 transparently handled by the @code{packages->manifest} procedure, which is
4394 commonly use in manifests (@pxref{Invoking guix package, the
4395 @option{--manifest} option of @command{guix package}}). Thus you can insert
4396 an inferior package pretty much anywhere you would insert a regular package:
4397 in manifests, in the @code{packages} field of your @code{operating-system}
4398 declaration, and so on.
4400 @node Invoking guix describe
4401 @section Invoking @command{guix describe}
4403 @cindex reproducibility
4404 @cindex replicating Guix
4405 Often you may want to answer questions like: ``Which revision of Guix am I
4406 using?'' or ``Which channels am I using?'' This is useful information in many
4407 situations: if you want to @emph{replicate} an environment on a different
4408 machine or user account, if you want to report a bug or to determine what
4409 change in the channels you are using caused it, or if you want to record your
4410 system state for reproducibility purposes. The @command{guix describe}
4411 command answers these questions.
4413 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4414 displays the channel(s) that it was built from, including their repository URL
4415 and commit IDs (@pxref{Channels}):
4419 Generation 10 Sep 03 2018 17:32:44 (current)
4421 repository URL: https://git.savannah.gnu.org/git/guix.git
4423 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4426 If you're familiar with the Git version control system, this is similar in
4427 spirit to @command{git describe}; the output is also similar to that of
4428 @command{guix pull --list-generations}, but limited to the current generation
4429 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4430 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4431 information is all it takes to describe the revision of Guix you're using, and
4432 also to replicate it.
4434 To make it easier to replicate Guix, @command{guix describe} can also be asked
4435 to return a list of channels instead of the human-readable description above:
4438 $ guix describe -f channels
4441 (url "https://git.savannah.gnu.org/git/guix.git")
4443 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4447 You can save this to a file and feed it to @command{guix pull -C} on some
4448 other machine or at a later point in time, which will instantiate @emph{this
4449 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4450 From there on, since you're able to deploy the same revision of Guix, you can
4451 just as well @emph{replicate a complete software environment}. We humbly
4452 think that this is @emph{awesome}, and we hope you'll like it too!
4454 The details of the options supported by @command{guix describe} are as
4458 @item --format=@var{format}
4459 @itemx -f @var{format}
4460 Produce output in the specified @var{format}, one of:
4464 produce human-readable output;
4466 produce a list of channel specifications that can be passed to @command{guix
4467 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4471 produce a list of channel specifications in JSON format;
4473 produce a list of channel specifications in Recutils format.
4476 @item --profile=@var{profile}
4477 @itemx -p @var{profile}
4478 Display information about @var{profile}.
4481 @node Invoking guix archive
4482 @section Invoking @command{guix archive}
4484 @cindex @command{guix archive}
4486 The @command{guix archive} command allows users to @dfn{export} files
4487 from the store into a single archive, and to later @dfn{import} them on
4488 a machine that runs Guix.
4489 In particular, it allows store files to be transferred from one machine
4490 to the store on another machine.
4493 If you're looking for a way to produce archives in a format suitable for
4494 tools other than Guix, @pxref{Invoking guix pack}.
4497 @cindex exporting store items
4498 To export store files as an archive to standard output, run:
4501 guix archive --export @var{options} @var{specifications}...
4504 @var{specifications} may be either store file names or package
4505 specifications, as for @command{guix package} (@pxref{Invoking guix
4506 package}). For instance, the following command creates an archive
4507 containing the @code{gui} output of the @code{git} package and the main
4508 output of @code{emacs}:
4511 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4514 If the specified packages are not built yet, @command{guix archive}
4515 automatically builds them. The build process may be controlled with the
4516 common build options (@pxref{Common Build Options}).
4518 To transfer the @code{emacs} package to a machine connected over SSH,
4522 guix archive --export -r emacs | ssh the-machine guix archive --import
4526 Similarly, a complete user profile may be transferred from one machine
4527 to another like this:
4530 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4531 ssh the-machine guix archive --import
4535 However, note that, in both examples, all of @code{emacs} and the
4536 profile as well as all of their dependencies are transferred (due to
4537 @option{-r}), regardless of what is already available in the store on
4538 the target machine. The @option{--missing} option can help figure out
4539 which items are missing from the target store. The @command{guix copy}
4540 command simplifies and optimizes this whole process, so this is probably
4541 what you should use in this case (@pxref{Invoking guix copy}).
4543 @cindex nar, archive format
4544 @cindex normalized archive (nar)
4545 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4546 comparable in spirit to `tar', but with differences
4547 that make it more appropriate for our purposes. First, rather than
4548 recording all Unix metadata for each file, the nar format only mentions
4549 the file type (regular, directory, or symbolic link); Unix permissions
4550 and owner/group are dismissed. Second, the order in which directory
4551 entries are stored always follows the order of file names according to
4552 the C locale collation order. This makes archive production fully
4555 When exporting, the daemon digitally signs the contents of the archive,
4556 and that digital signature is appended. When importing, the daemon
4557 verifies the signature and rejects the import in case of an invalid
4558 signature or if the signing key is not authorized.
4559 @c FIXME: Add xref to daemon doc about signatures.
4561 The main options are:
4565 Export the specified store files or packages (see below.) Write the
4566 resulting archive to the standard output.
4568 Dependencies are @emph{not} included in the output, unless
4569 @option{--recursive} is passed.
4573 When combined with @option{--export}, this instructs @command{guix archive}
4574 to include dependencies of the given items in the archive. Thus, the
4575 resulting archive is self-contained: it contains the closure of the
4576 exported store items.
4579 Read an archive from the standard input, and import the files listed
4580 therein into the store. Abort if the archive has an invalid digital
4581 signature, or if it is signed by a public key not among the authorized
4582 keys (see @option{--authorize} below.)
4585 Read a list of store file names from the standard input, one per line,
4586 and write on the standard output the subset of these files missing from
4589 @item --generate-key[=@var{parameters}]
4590 @cindex signing, archives
4591 Generate a new key pair for the daemon. This is a prerequisite before
4592 archives can be exported with @option{--export}. Note that this
4593 operation usually takes time, because it needs to gather enough entropy
4594 to generate the key pair.
4596 The generated key pair is typically stored under @file{/etc/guix}, in
4597 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4598 key, which must be kept secret.) When @var{parameters} is omitted,
4599 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4600 versions before 1.6.0, it is a 4096-bit RSA key.
4601 Alternatively, @var{parameters} can specify
4602 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4603 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4604 Libgcrypt Reference Manual}).
4607 @cindex authorizing, archives
4608 Authorize imports signed by the public key passed on standard input.
4609 The public key must be in ``s-expression advanced format''---i.e., the
4610 same format as the @file{signing-key.pub} file.
4612 The list of authorized keys is kept in the human-editable file
4613 @file{/etc/guix/acl}. The file contains
4614 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4615 s-expressions''} and is structured as an access-control list in the
4616 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4619 @item --extract=@var{directory}
4620 @itemx -x @var{directory}
4621 Read a single-item archive as served by substitute servers
4622 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4623 low-level operation needed in only very narrow use cases; see below.
4625 For example, the following command extracts the substitute for Emacs
4626 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4630 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4631 | gunzip | guix archive -x /tmp/emacs
4634 Single-item archives are different from multiple-item archives produced
4635 by @command{guix archive --export}; they contain a single store item,
4636 and they do @emph{not} embed a signature. Thus this operation does
4637 @emph{no} signature verification and its output should be considered
4640 The primary purpose of this operation is to facilitate inspection of
4641 archive contents coming from possibly untrusted substitute servers
4642 (@pxref{Invoking guix challenge}).
4646 Read a single-item archive as served by substitute servers
4647 (@pxref{Substitutes}) and print the list of files it contains, as in
4652 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4653 | lzip -d | guix archive -t
4659 @c *********************************************************************
4661 @chapter Development
4663 @cindex software development
4664 If you are a software developer, Guix provides tools that you should find
4665 helpful---independently of the language you're developing in. This is what
4666 this chapter is about.
4668 The @command{guix environment} command provides a convenient way to set up
4669 @dfn{development environments} containing all the dependencies and tools
4670 necessary to work on the software package of your choice. The @command{guix
4671 pack} command allows you to create @dfn{application bundles} that can be
4672 easily distributed to users who do not run Guix.
4675 * Invoking guix environment:: Setting up development environments.
4676 * Invoking guix pack:: Creating software bundles.
4677 * Packages for C Development:: Working with C code with Guix.
4680 @node Invoking guix environment
4681 @section Invoking @command{guix environment}
4683 @cindex reproducible build environments
4684 @cindex development environments
4685 @cindex @command{guix environment}
4686 @cindex environment, package build environment
4687 The purpose of @command{guix environment} is to assist hackers in
4688 creating reproducible development environments without polluting their
4689 package profile. The @command{guix environment} tool takes one or more
4690 packages, builds all of their inputs, and creates a shell
4691 environment to use them.
4693 The general syntax is:
4696 guix environment @var{options} @var{package}@dots{}
4699 The following example spawns a new shell set up for the development of
4703 guix environment guile
4706 If the needed dependencies are not built yet, @command{guix environment}
4707 automatically builds them. The environment of the new shell is an
4708 augmented version of the environment that @command{guix environment} was
4709 run in. It contains the necessary search paths for building the given
4710 package added to the existing environment variables. To create
4711 a ``pure'' environment, in which the original environment variables have
4712 been unset, use the @option{--pure} option@footnote{Users sometimes
4713 wrongfully augment environment variables such as @env{PATH} in their
4714 @file{~/.bashrc} file. As a consequence, when @command{guix
4715 environment} launches it, Bash may read @file{~/.bashrc}, thereby
4716 introducing ``impurities'' in these environment variables. It is an
4717 error to define such environment variables in @file{.bashrc}; instead,
4718 they should be defined in @file{.bash_profile}, which is sourced only by
4719 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
4720 Manual}, for details on Bash start-up files.}.
4722 @vindex GUIX_ENVIRONMENT
4723 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
4724 variable in the shell it spawns; its value is the file name of the
4725 profile of this environment. This allows users to, say, define a
4726 specific prompt for development environments in their @file{.bashrc}
4727 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4730 if [ -n "$GUIX_ENVIRONMENT" ]
4732 export PS1="\u@@\h \w [dev]\$ "
4737 ...@: or to browse the profile:
4740 $ ls "$GUIX_ENVIRONMENT/bin"
4743 Additionally, more than one package may be specified, in which case the
4744 union of the inputs for the given packages are used. For example, the
4745 command below spawns a shell where all of the dependencies of both Guile
4746 and Emacs are available:
4749 guix environment guile emacs
4752 Sometimes an interactive shell session is not desired. An arbitrary
4753 command may be invoked by placing the @code{--} token to separate the
4754 command from the rest of the arguments:
4757 guix environment guile -- make -j4
4760 In other situations, it is more convenient to specify the list of
4761 packages needed in the environment. For example, the following command
4762 runs @command{python} from an environment containing Python@tie{}2.7 and
4766 guix environment --ad-hoc python2-numpy python-2.7 -- python
4769 Furthermore, one might want the dependencies of a package and also some
4770 additional packages that are not build-time or runtime dependencies, but
4771 are useful when developing nonetheless. Because of this, the
4772 @option{--ad-hoc} flag is positional. Packages appearing before
4773 @option{--ad-hoc} are interpreted as packages whose dependencies will be
4774 added to the environment. Packages appearing after are interpreted as
4775 packages that will be added to the environment directly. For example,
4776 the following command creates a Guix development environment that
4777 additionally includes Git and strace:
4780 guix environment --pure guix --ad-hoc git strace
4784 Sometimes it is desirable to isolate the environment as much as
4785 possible, for maximal purity and reproducibility. In particular, when
4786 using Guix on a host distro that is not Guix System, it is desirable to
4787 prevent access to @file{/usr/bin} and other system-wide resources from
4788 the development environment. For example, the following command spawns
4789 a Guile REPL in a ``container'' where only the store and the current
4790 working directory are mounted:
4793 guix environment --ad-hoc --container guile -- guile
4797 The @option{--container} option requires Linux-libre 3.19 or newer.
4800 @cindex certificates
4801 Another typical use case for containers is to run security-sensitive
4802 applications such as a web browser. To run Eolie, we must expose and
4803 share some files and directories; we include @code{nss-certs} and expose
4804 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
4805 the @env{DISPLAY} environment variable since containerized graphical
4806 applications won't display without it.
4809 guix environment --preserve='^DISPLAY$' --container --network \
4810 --expose=/etc/machine-id \
4811 --expose=/etc/ssl/certs/ \
4812 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
4813 --ad-hoc eolie nss-certs dbus -- eolie
4816 The available options are summarized below.
4819 @item --root=@var{file}
4820 @itemx -r @var{file}
4821 @cindex persistent environment
4822 @cindex garbage collector root, for environments
4823 Make @var{file} a symlink to the profile for this environment, and
4824 register it as a garbage collector root.
4826 This is useful if you want to protect your environment from garbage
4827 collection, to make it ``persistent''.
4829 When this option is omitted, the environment is protected from garbage
4830 collection only for the duration of the @command{guix environment}
4831 session. This means that next time you recreate the same environment,
4832 you could have to rebuild or re-download packages. @xref{Invoking guix
4833 gc}, for more on GC roots.
4835 @item --expression=@var{expr}
4836 @itemx -e @var{expr}
4837 Create an environment for the package or list of packages that
4838 @var{expr} evaluates to.
4840 For example, running:
4843 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4846 starts a shell with the environment for this specific variant of the
4852 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4855 starts a shell with all the base system packages available.
4857 The above commands only use the default output of the given packages.
4858 To select other outputs, two element tuples can be specified:
4861 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4864 @item --load=@var{file}
4865 @itemx -l @var{file}
4866 Create an environment for the package or list of packages that the code
4867 within @var{file} evaluates to.
4869 As an example, @var{file} might contain a definition like this
4870 (@pxref{Defining Packages}):
4873 @verbatiminclude environment-gdb.scm
4876 @item --manifest=@var{file}
4877 @itemx -m @var{file}
4878 Create an environment for the packages contained in the manifest object
4879 returned by the Scheme code in @var{file}. This option can be repeated
4880 several times, in which case the manifests are concatenated.
4882 This is similar to the same-named option in @command{guix package}
4883 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4887 Include all specified packages in the resulting environment, as if an
4888 @i{ad hoc} package were defined with them as inputs. This option is
4889 useful for quickly creating an environment without having to write a
4890 package expression to contain the desired inputs.
4892 For instance, the command:
4895 guix environment --ad-hoc guile guile-sdl -- guile
4898 runs @command{guile} in an environment where Guile and Guile-SDL are
4901 Note that this example implicitly asks for the default output of
4902 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4903 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4904 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4906 This option may be composed with the default behavior of @command{guix
4907 environment}. Packages appearing before @option{--ad-hoc} are
4908 interpreted as packages whose dependencies will be added to the
4909 environment, the default behavior. Packages appearing after are
4910 interpreted as packages that will be added to the environment directly.
4913 Unset existing environment variables when building the new environment, except
4914 those specified with @option{--preserve} (see below.) This has the effect of
4915 creating an environment in which search paths only contain package inputs.
4917 @item --preserve=@var{regexp}
4918 @itemx -E @var{regexp}
4919 When used alongside @option{--pure}, preserve the environment variables
4920 matching @var{regexp}---in other words, put them on a ``white list'' of
4921 environment variables that must be preserved. This option can be repeated
4925 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4929 This example runs @command{mpirun} in a context where the only environment
4930 variables defined are @env{PATH}, environment variables whose name starts
4931 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
4934 @item --search-paths
4935 Display the environment variable definitions that make up the
4938 @item --system=@var{system}
4939 @itemx -s @var{system}
4940 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4945 Run @var{command} within an isolated container. The current working
4946 directory outside the container is mapped inside the container.
4947 Additionally, unless overridden with @option{--user}, a dummy home
4948 directory is created that matches the current user's home directory, and
4949 @file{/etc/passwd} is configured accordingly.
4951 The spawned process runs as the current user outside the container. Inside
4952 the container, it has the same UID and GID as the current user, unless
4953 @option{--user} is passed (see below.)
4957 For containers, share the network namespace with the host system.
4958 Containers created without this flag only have access to the loopback
4961 @item --link-profile
4963 For containers, link the environment profile to @file{~/.guix-profile}
4964 within the container. This is equivalent to running the command
4965 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
4966 Linking will fail and abort the environment if the directory already
4967 exists, which will certainly be the case if @command{guix environment}
4968 was invoked in the user's home directory.
4970 Certain packages are configured to look in @file{~/.guix-profile} for
4971 configuration files and data;@footnote{For example, the
4972 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
4973 for additional fonts.} @option{--link-profile} allows these programs to
4974 behave as expected within the environment.
4976 @item --user=@var{user}
4977 @itemx -u @var{user}
4978 For containers, use the username @var{user} in place of the current
4979 user. The generated @file{/etc/passwd} entry within the container will
4980 contain the name @var{user}, the home directory will be
4981 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4982 the UID and GID inside the container are 1000. @var{user}
4983 need not exist on the system.
4985 Additionally, any shared or exposed path (see @option{--share} and
4986 @option{--expose} respectively) whose target is within the current user's
4987 home directory will be remapped relative to @file{/home/USER}; this
4988 includes the automatic mapping of the current working directory.
4991 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4993 guix environment --container --user=foo \
4994 --expose=$HOME/test \
4995 --expose=/tmp/target=$HOME/target
4998 While this will limit the leaking of user identity through home paths
4999 and each of the user fields, this is only one useful component of a
5000 broader privacy/anonymity solution---not one in and of itself.
5003 For containers, the default behavior is to share the current working
5004 directory with the isolated container and immediately change to that
5005 directory within the container. If this is undesirable,
5006 @option{--no-cwd} will cause the current working directory to @emph{not}
5007 be automatically shared and will change to the user's home directory
5008 within the container instead. See also @option{--user}.
5010 @item --expose=@var{source}[=@var{target}]
5011 @itemx --share=@var{source}[=@var{target}]
5012 For containers, @option{--expose} (resp. @option{--share}) exposes the
5013 file system @var{source} from the host system as the read-only
5014 (resp. writable) file system @var{target} within the container. If
5015 @var{target} is not specified, @var{source} is used as the target mount
5016 point in the container.
5018 The example below spawns a Guile REPL in a container in which the user's
5019 home directory is accessible read-only via the @file{/exchange}
5023 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5028 @command{guix environment}
5029 also supports all of the common build options that @command{guix
5030 build} supports (@pxref{Common Build Options}) as well as package
5031 transformation options (@pxref{Package Transformation Options}).
5033 @node Invoking guix pack
5034 @section Invoking @command{guix pack}
5036 Occasionally you want to pass software to people who are not (yet!)
5037 lucky enough to be using Guix. You'd tell them to run @command{guix
5038 package -i @var{something}}, but that's not possible in this case. This
5039 is where @command{guix pack} comes in.
5042 If you are looking for ways to exchange binaries among machines that
5043 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5044 publish}, and @ref{Invoking guix archive}.
5049 @cindex application bundle
5050 @cindex software bundle
5051 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5052 @dfn{software bundle}: it creates a tarball or some other archive
5053 containing the binaries of the software you're interested in, and all
5054 its dependencies. The resulting archive can be used on any machine that
5055 does not have Guix, and people can run the exact same binaries as those
5056 you have with Guix. The pack itself is created in a bit-reproducible
5057 fashion, so anyone can verify that it really contains the build results
5058 that you pretend to be shipping.
5060 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5061 their dependencies, you can run:
5064 $ guix pack guile emacs geiser
5066 /gnu/store/@dots{}-pack.tar.gz
5069 The result here is a tarball containing a @file{/gnu/store} directory
5070 with all the relevant packages. The resulting tarball contains a
5071 @dfn{profile} with the three packages of interest; the profile is the
5072 same as would be created by @command{guix package -i}. It is this
5073 mechanism that is used to create Guix's own standalone binary tarball
5074 (@pxref{Binary Installation}).
5076 Users of this pack would have to run
5077 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5078 find inconvenient. To work around it, you can create, say, a
5079 @file{/opt/gnu/bin} symlink to the profile:
5082 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5086 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5088 @cindex relocatable binaries, with @command{guix pack}
5089 What if the recipient of your pack does not have root privileges on
5090 their machine, and thus cannot unpack it in the root file system? In
5091 that case, you will want to use the @option{--relocatable} option (see
5092 below). This option produces @dfn{relocatable binaries}, meaning they
5093 they can be placed anywhere in the file system hierarchy: in the example
5094 above, users can unpack your tarball in their home directory and
5095 directly run @file{./opt/gnu/bin/guile}.
5097 @cindex Docker, build an image with guix pack
5098 Alternatively, you can produce a pack in the Docker image format using
5099 the following command:
5102 guix pack -f docker -S /bin=bin guile guile-readline
5106 The result is a tarball that can be passed to the @command{docker load}
5107 command, followed by @code{docker run}:
5110 docker load < @var{file}
5111 docker run -ti guile-guile-readline /bin/guile
5115 where @var{file} is the image returned by @var{guix pack}, and
5116 @code{guile-guile-readline} is its ``image tag''. See the
5117 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5118 documentation} for more information.
5120 @cindex Singularity, build an image with guix pack
5121 @cindex SquashFS, build an image with guix pack
5122 Yet another option is to produce a SquashFS image with the following
5126 guix pack -f squashfs bash guile emacs geiser
5130 The result is a SquashFS file system image that can either be mounted or
5131 directly be used as a file system container image with the
5132 @uref{https://www.sylabs.io/docs/, Singularity container execution
5133 environment}, using commands like @command{singularity shell} or
5134 @command{singularity exec}.
5136 Several command-line options allow you to customize your pack:
5139 @item --format=@var{format}
5140 @itemx -f @var{format}
5141 Produce a pack in the given @var{format}.
5143 The available formats are:
5147 This is the default format. It produces a tarball containing all the
5148 specified binaries and symlinks.
5151 This produces a tarball that follows the
5152 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5153 Docker Image Specification}. The ``repository name'' as it appears in
5154 the output of the @command{docker images} command is computed from
5155 package names passed on the command line or in the manifest file.
5158 This produces a SquashFS image containing all the specified binaries and
5159 symlinks, as well as empty mount points for virtual file systems like
5163 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5164 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5165 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5166 with something like:
5169 guix pack -f squashfs bash @dots{}
5172 If you forget the @code{bash} (or similar) package, @command{singularity
5173 run} and @command{singularity exec} will fail with an unhelpful ``no
5174 such file or directory'' message.
5178 @cindex relocatable binaries
5181 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5182 anywhere in the file system hierarchy and run from there.
5184 When this option is passed once, the resulting binaries require support for
5185 @dfn{user namespaces} in the kernel Linux; when passed
5186 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5187 PRoot support, can be thought of as the abbreviation of ``Really
5188 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5189 if user namespaces are unavailable, and essentially work anywhere---see below
5190 for the implications.
5192 For example, if you create a pack containing Bash with:
5195 guix pack -RR -S /mybin=bin bash
5199 ...@: you can copy that pack to a machine that lacks Guix, and from your
5200 home directory as a normal user, run:
5208 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5209 @file{/gnu/store} shows up and contains all the dependencies of
5210 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5211 altogether! That is probably the simplest way to deploy Guix-built
5212 software on a non-Guix machine.
5215 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5216 the kernel Linux, which allows unprivileged users to mount or change root.
5217 Old versions of Linux did not support it, and some GNU/Linux distributions
5220 To produce relocatable binaries that work even in the absence of user
5221 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5222 case, binaries will try user namespace support and fall back to PRoot if user
5223 namespaces are not supported.
5225 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5226 support for file system virtualization. It achieves that by using the
5227 @code{ptrace} system call on the running program. This approach has the
5228 advantage to work without requiring special kernel support, but it incurs
5229 run-time overhead every time a system call is made.
5232 @cindex entry point, for Docker images
5233 @item --entry-point=@var{command}
5234 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5235 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5236 support it. @var{command} must be relative to the profile contained in the
5239 The entry point specifies the command that tools like @code{docker run} or
5240 @code{singularity run} automatically start by default. For example, you can
5244 guix pack -f docker --entry-point=bin/guile guile
5247 The resulting pack can easily be loaded and @code{docker run} with no extra
5248 arguments will spawn @code{bin/guile}:
5251 docker load -i pack.tar.gz
5252 docker run @var{image-id}
5255 @item --expression=@var{expr}
5256 @itemx -e @var{expr}
5257 Consider the package @var{expr} evaluates to.
5259 This has the same purpose as the same-named option in @command{guix
5260 build} (@pxref{Additional Build Options, @option{--expression} in
5261 @command{guix build}}).
5263 @item --manifest=@var{file}
5264 @itemx -m @var{file}
5265 Use the packages contained in the manifest object returned by the Scheme
5266 code in @var{file}. This option can be repeated several times, in which
5267 case the manifests are concatenated.
5269 This has a similar purpose as the same-named option in @command{guix
5270 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5271 same manifest files. It allows you to define a collection of packages
5272 once and use it both for creating profiles and for creating archives
5273 for use on machines that do not have Guix installed. Note that you can
5274 specify @emph{either} a manifest file @emph{or} a list of packages,
5277 @item --system=@var{system}
5278 @itemx -s @var{system}
5279 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5280 the system type of the build host.
5282 @item --target=@var{triplet}
5283 @cindex cross-compilation
5284 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5285 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5286 configuration triplets,, autoconf, Autoconf}).
5288 @item --compression=@var{tool}
5289 @itemx -C @var{tool}
5290 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5291 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5293 @item --symlink=@var{spec}
5294 @itemx -S @var{spec}
5295 Add the symlinks specified by @var{spec} to the pack. This option can
5296 appear several times.
5298 @var{spec} has the form @code{@var{source}=@var{target}}, where
5299 @var{source} is the symlink that will be created and @var{target} is the
5302 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5303 symlink pointing to the @file{bin} sub-directory of the profile.
5305 @item --save-provenance
5306 Save provenance information for the packages passed on the command line.
5307 Provenance information includes the URL and commit of the channels in use
5310 Provenance information is saved in the
5311 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5312 usual package metadata---the name and version of each package, their
5313 propagated inputs, and so on. It is useful information to the recipient of
5314 the pack, who then knows how the pack was (supposedly) obtained.
5316 This option is not enabled by default because, like timestamps, provenance
5317 information contributes nothing to the build process. In other words, there
5318 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5319 Recording such ``silent'' metadata in the output thus potentially breaks the
5320 source-to-binary bitwise reproducibility property.
5322 @item --root=@var{file}
5323 @itemx -r @var{file}
5324 @cindex garbage collector root, for packs
5325 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5328 @item --localstatedir
5329 @itemx --profile-name=@var{name}
5330 Include the ``local state directory'', @file{/var/guix}, in the resulting
5331 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5332 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5333 @file{~root/.guix-profile}.
5335 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5336 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5337 the pack means that the store is ``complete'' and manageable by Guix;
5338 not providing it pack means that the store is ``dead'': items cannot be
5339 added to it or removed from it after extraction of the pack.
5341 One use case for this is the Guix self-contained binary tarball
5342 (@pxref{Binary Installation}).
5346 Print the name of the derivation that builds the pack.
5349 Use the bootstrap binaries to build the pack. This option is only
5350 useful to Guix developers.
5353 In addition, @command{guix pack} supports all the common build options
5354 (@pxref{Common Build Options}) and all the package transformation
5355 options (@pxref{Package Transformation Options}).
5357 @node Packages for C Development
5358 @section Packages for C Development
5362 @cindex linker wrapper
5363 @cindex toolchain, for C development
5365 If you need a complete toolchain for compiling and linking C or C++
5366 source code, use the @code{gcc-toolchain} package. This package
5367 provides a complete GCC toolchain for C/C++ development, including GCC
5368 itself, the GNU C Library (headers and binaries, plus debugging symbols
5369 in the @code{debug} output), Binutils, and a linker wrapper.
5371 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5372 passed to the linker, add corresponding @code{-rpath} arguments, and
5373 invoke the actual linker with this new set of arguments. You can instruct the
5374 wrapper to refuse to link against libraries not in the store by setting the
5375 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5379 @c *********************************************************************
5380 @node Programming Interface
5381 @chapter Programming Interface
5383 GNU Guix provides several Scheme programming interfaces (APIs) to
5384 define, build, and query packages. The first interface allows users to
5385 write high-level package definitions. These definitions refer to
5386 familiar packaging concepts, such as the name and version of a package,
5387 its build system, and its dependencies. These definitions can then be
5388 turned into concrete build actions.
5390 Build actions are performed by the Guix daemon, on behalf of users. In a
5391 standard setup, the daemon has write access to the store---the
5392 @file{/gnu/store} directory---whereas users do not. The recommended
5393 setup also has the daemon perform builds in chroots, under a specific
5394 build users, to minimize interference with the rest of the system.
5397 Lower-level APIs are available to interact with the daemon and the
5398 store. To instruct the daemon to perform a build action, users actually
5399 provide it with a @dfn{derivation}. A derivation is a low-level
5400 representation of the build actions to be taken, and the environment in
5401 which they should occur---derivations are to package definitions what
5402 assembly is to C programs. The term ``derivation'' comes from the fact
5403 that build results @emph{derive} from them.
5405 This chapter describes all these APIs in turn, starting from high-level
5406 package definitions.
5409 * Package Modules:: Packages from the programmer's viewpoint.
5410 * Defining Packages:: Defining new packages.
5411 * Build Systems:: Specifying how packages are built.
5412 * The Store:: Manipulating the package store.
5413 * Derivations:: Low-level interface to package derivations.
5414 * The Store Monad:: Purely functional interface to the store.
5415 * G-Expressions:: Manipulating build expressions.
5416 * Invoking guix repl:: Fiddling with Guix interactively.
5419 @node Package Modules
5420 @section Package Modules
5422 From a programming viewpoint, the package definitions of the
5423 GNU distribution are provided by Guile modules in the @code{(gnu packages
5424 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5425 packages @dots{})} module name space are not necessarily ``GNU
5426 packages''. This module naming scheme follows the usual Guile module
5427 naming convention: @code{gnu} means that these modules are distributed
5428 as part of the GNU system, and @code{packages} identifies modules that
5429 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5430 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5431 module exports a variable named @code{emacs}, which is bound to a
5432 @code{<package>} object (@pxref{Defining Packages}).
5434 The @code{(gnu packages @dots{})} module name space is
5435 automatically scanned for packages by the command-line tools. For
5436 instance, when running @code{guix install emacs}, all the @code{(gnu
5437 packages @dots{})} modules are scanned until one that exports a package
5438 object whose name is @code{emacs} is found. This package search
5439 facility is implemented in the @code{(gnu packages)} module.
5441 @cindex customization, of packages
5442 @cindex package module search path
5443 Users can store package definitions in modules with different
5444 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5445 name and module name must match. For instance, the @code{(my-packages
5446 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5447 relative to the load path specified with @option{--load-path} or
5448 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5449 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5450 these package definitions visible to the user interfaces:
5454 By adding the directory containing your package modules to the search path
5455 with the @code{-L} flag of @command{guix package} and other commands
5456 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
5457 environment variable described below.
5460 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5461 pulls from it. A channel is essentially a Git repository containing package
5462 modules. @xref{Channels}, for more information on how to define and use
5466 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5468 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5469 This is a colon-separated list of directories to search for additional
5470 package modules. Directories listed in this variable take precedence
5471 over the own modules of the distribution.
5474 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5475 each package is built based solely on other packages in the
5476 distribution. The root of this dependency graph is a small set of
5477 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5478 bootstrap)} module. For more information on bootstrapping,
5479 @pxref{Bootstrapping}.
5481 @node Defining Packages
5482 @section Defining Packages
5484 The high-level interface to package definitions is implemented in the
5485 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5486 example, the package definition, or @dfn{recipe}, for the GNU Hello
5487 package looks like this:
5490 (define-module (gnu packages hello)
5491 #:use-module (guix packages)
5492 #:use-module (guix download)
5493 #:use-module (guix build-system gnu)
5494 #:use-module (guix licenses)
5495 #:use-module (gnu packages gawk))
5497 (define-public hello
5503 (uri (string-append "mirror://gnu/hello/hello-" version
5507 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5508 (build-system gnu-build-system)
5509 (arguments '(#:configure-flags '("--enable-silent-rules")))
5510 (inputs `(("gawk" ,gawk)))
5511 (synopsis "Hello, GNU world: An example GNU package")
5512 (description "Guess what GNU Hello prints!")
5513 (home-page "https://www.gnu.org/software/hello/")
5518 Without being a Scheme expert, the reader may have guessed the meaning
5519 of the various fields here. This expression binds the variable
5520 @code{hello} to a @code{<package>} object, which is essentially a record
5521 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5522 This package object can be inspected using procedures found in the
5523 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5524 returns---surprise!---@code{"hello"}.
5526 With luck, you may be able to import part or all of the definition of
5527 the package you are interested in from another repository, using the
5528 @code{guix import} command (@pxref{Invoking guix import}).
5530 In the example above, @var{hello} is defined in a module of its own,
5531 @code{(gnu packages hello)}. Technically, this is not strictly
5532 necessary, but it is convenient to do so: all the packages defined in
5533 modules under @code{(gnu packages @dots{})} are automatically known to
5534 the command-line tools (@pxref{Package Modules}).
5536 There are a few points worth noting in the above package definition:
5540 The @code{source} field of the package is an @code{<origin>} object
5541 (@pxref{origin Reference}, for the complete reference).
5542 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5543 meaning that the source is a file to be downloaded over FTP or HTTP.
5545 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5546 the GNU mirrors defined in @code{(guix download)}.
5548 The @code{sha256} field specifies the expected SHA256 hash of the file
5549 being downloaded. It is mandatory, and allows Guix to check the
5550 integrity of the file. The @code{(base32 @dots{})} form introduces the
5551 base32 representation of the hash. You can obtain this information with
5552 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5553 hash} (@pxref{Invoking guix hash}).
5556 When needed, the @code{origin} form can also have a @code{patches} field
5557 listing patches to be applied, and a @code{snippet} field giving a
5558 Scheme expression to modify the source code.
5561 @cindex GNU Build System
5562 The @code{build-system} field specifies the procedure to build the
5563 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5564 represents the familiar GNU Build System, where packages may be
5565 configured, built, and installed with the usual @code{./configure &&
5566 make && make check && make install} command sequence.
5569 The @code{arguments} field specifies options for the build system
5570 (@pxref{Build Systems}). Here it is interpreted by
5571 @var{gnu-build-system} as a request run @file{configure} with the
5572 @option{--enable-silent-rules} flag.
5578 What about these quote (@code{'}) characters? They are Scheme syntax to
5579 introduce a literal list; @code{'} is synonymous with @code{quote}.
5580 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5581 for details. Here the value of the @code{arguments} field is a list of
5582 arguments passed to the build system down the road, as with @code{apply}
5583 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5586 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5587 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5588 @code{#:configure-flags} is a keyword used to pass a keyword argument
5589 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5593 The @code{inputs} field specifies inputs to the build process---i.e.,
5594 build-time or run-time dependencies of the package. Here, we define an
5595 input called @code{"gawk"} whose value is that of the @var{gawk}
5596 variable; @var{gawk} is itself bound to a @code{<package>} object.
5598 @cindex backquote (quasiquote)
5601 @cindex comma (unquote)
5605 @findex unquote-splicing
5606 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5607 us to introduce a literal list in the @code{inputs} field, while
5608 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5609 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5612 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5613 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5614 of ensuring that they are present (@pxref{Build Systems}).
5616 However, any other dependencies need to be specified in the
5617 @code{inputs} field. Any dependency not specified here will simply be
5618 unavailable to the build process, possibly leading to a build failure.
5621 @xref{package Reference}, for a full description of possible fields.
5623 Once a package definition is in place, the
5624 package may actually be built using the @code{guix build} command-line
5625 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5626 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5627 package definition using the @command{guix edit} command
5628 (@pxref{Invoking guix edit}).
5629 @xref{Packaging Guidelines}, for
5630 more information on how to test package definitions, and
5631 @ref{Invoking guix lint}, for information on how to check a definition
5632 for style conformance.
5633 @vindex GUIX_PACKAGE_PATH
5634 Lastly, @pxref{Channels}, for information
5635 on how to extend the distribution by adding your own package definitions
5638 Finally, updating the package definition to a new upstream version
5639 can be partly automated by the @command{guix refresh} command
5640 (@pxref{Invoking guix refresh}).
5642 Behind the scenes, a derivation corresponding to the @code{<package>}
5643 object is first computed by the @code{package-derivation} procedure.
5644 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
5645 The build actions it prescribes may then be realized by using the
5646 @code{build-derivations} procedure (@pxref{The Store}).
5648 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5649 Return the @code{<derivation>} object of @var{package} for @var{system}
5650 (@pxref{Derivations}).
5652 @var{package} must be a valid @code{<package>} object, and @var{system}
5653 must be a string denoting the target system type---e.g.,
5654 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5655 must be a connection to the daemon, which operates on the store
5656 (@pxref{The Store}).
5660 @cindex cross-compilation
5661 Similarly, it is possible to compute a derivation that cross-builds a
5662 package for some other system:
5664 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5665 @var{package} @var{target} [@var{system}]
5666 Return the @code{<derivation>} object of @var{package} cross-built from
5667 @var{system} to @var{target}.
5669 @var{target} must be a valid GNU triplet denoting the target hardware
5670 and operating system, such as @code{"mips64el-linux-gnu"}
5671 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5674 @cindex package transformations
5675 @cindex input rewriting
5676 @cindex dependency tree rewriting
5677 Packages can be manipulated in arbitrary ways. An example of a useful
5678 transformation is @dfn{input rewriting}, whereby the dependency tree of
5679 a package is rewritten by replacing specific inputs by others:
5681 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5682 [@var{rewrite-name}]
5683 Return a procedure that, when passed a package, replaces its direct and
5684 indirect dependencies (but not its implicit inputs) according to
5685 @var{replacements}. @var{replacements} is a list of package pairs; the
5686 first element of each pair is the package to replace, and the second one
5689 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5690 the name of a package and returns its new name after rewrite.
5694 Consider this example:
5697 (define libressl-instead-of-openssl
5698 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5700 (package-input-rewriting `((,openssl . ,libressl))))
5702 (define git-with-libressl
5703 (libressl-instead-of-openssl git))
5707 Here we first define a rewriting procedure that replaces @var{openssl}
5708 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5709 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5710 This is exactly what the @option{--with-input} command-line option does
5711 (@pxref{Package Transformation Options, @option{--with-input}}).
5713 The following variant of @code{package-input-rewriting} can match packages to
5714 be replaced by name rather than by identity.
5716 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5717 Return a procedure that, given a package, applies the given @var{replacements} to
5718 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5719 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5720 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5721 replacement for that package.
5724 The example above could be rewritten this way:
5727 (define libressl-instead-of-openssl
5728 ;; Replace all the packages called "openssl" with LibreSSL.
5729 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5732 The key difference here is that, this time, packages are matched by spec and
5733 not by identity. In other words, any package in the graph that is called
5734 @code{openssl} will be replaced.
5736 A more generic procedure to rewrite a package dependency graph is
5737 @code{package-mapping}: it supports arbitrary changes to nodes in the
5740 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5741 Return a procedure that, given a package, applies @var{proc} to all the packages
5742 depended on and returns the resulting package. The procedure stops recursion
5743 when @var{cut?} returns true for a given package.
5747 * package Reference:: The package data type.
5748 * origin Reference:: The origin data type.
5752 @node package Reference
5753 @subsection @code{package} Reference
5755 This section summarizes all the options available in @code{package}
5756 declarations (@pxref{Defining Packages}).
5758 @deftp {Data Type} package
5759 This is the data type representing a package recipe.
5763 The name of the package, as a string.
5765 @item @code{version}
5766 The version of the package, as a string.
5769 An object telling how the source code for the package should be
5770 acquired. Most of the time, this is an @code{origin} object, which
5771 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5772 can also be any other ``file-like'' object such as a @code{local-file},
5773 which denotes a file from the local file system (@pxref{G-Expressions,
5774 @code{local-file}}).
5776 @item @code{build-system}
5777 The build system that should be used to build the package (@pxref{Build
5780 @item @code{arguments} (default: @code{'()})
5781 The arguments that should be passed to the build system. This is a
5782 list, typically containing sequential keyword-value pairs.
5784 @item @code{inputs} (default: @code{'()})
5785 @itemx @code{native-inputs} (default: @code{'()})
5786 @itemx @code{propagated-inputs} (default: @code{'()})
5787 @cindex inputs, of packages
5788 These fields list dependencies of the package. Each one is a list of
5789 tuples, where each tuple has a label for the input (a string) as its
5790 first element, a package, origin, or derivation as its second element,
5791 and optionally the name of the output thereof that should be used, which
5792 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5793 more on package outputs). For example, the list below specifies three
5797 `(("libffi" ,libffi)
5798 ("libunistring" ,libunistring)
5799 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5802 @cindex cross compilation, package dependencies
5803 The distinction between @code{native-inputs} and @code{inputs} is
5804 necessary when considering cross-compilation. When cross-compiling,
5805 dependencies listed in @code{inputs} are built for the @emph{target}
5806 architecture; conversely, dependencies listed in @code{native-inputs}
5807 are built for the architecture of the @emph{build} machine.
5809 @code{native-inputs} is typically used to list tools needed at
5810 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5811 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5812 this area (@pxref{Invoking guix lint}).
5814 @anchor{package-propagated-inputs}
5815 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5816 specified packages will be automatically installed alongside the package
5817 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5818 package}}, for information on how @command{guix package} deals with
5821 For example this is necessary when a C/C++ library needs headers of
5822 another library to compile, or when a pkg-config file refers to another
5823 one @i{via} its @code{Requires} field.
5825 Another example where @code{propagated-inputs} is useful is for languages
5826 that lack a facility to record the run-time search path akin to the
5827 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5828 more. To ensure that libraries written in those languages can find
5829 library code they depend on at run time, run-time dependencies must be
5830 listed in @code{propagated-inputs} rather than @code{inputs}.
5832 @item @code{outputs} (default: @code{'("out")})
5833 The list of output names of the package. @xref{Packages with Multiple
5834 Outputs}, for typical uses of additional outputs.
5836 @item @code{native-search-paths} (default: @code{'()})
5837 @itemx @code{search-paths} (default: @code{'()})
5838 A list of @code{search-path-specification} objects describing
5839 search-path environment variables honored by the package.
5841 @item @code{replacement} (default: @code{#f})
5842 This must be either @code{#f} or a package object that will be used as a
5843 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5846 @item @code{synopsis}
5847 A one-line description of the package.
5849 @item @code{description}
5850 A more elaborate description of the package.
5852 @item @code{license}
5853 @cindex license, of packages
5854 The license of the package; a value from @code{(guix licenses)},
5855 or a list of such values.
5857 @item @code{home-page}
5858 The URL to the home-page of the package, as a string.
5860 @item @code{supported-systems} (default: @code{%supported-systems})
5861 The list of systems supported by the package, as strings of the form
5862 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5864 @item @code{location} (default: source location of the @code{package} form)
5865 The source location of the package. It is useful to override this when
5866 inheriting from another package, in which case this field is not
5867 automatically corrected.
5871 @deffn {Scheme Syntax} this-package
5872 When used in the @emph{lexical scope} of a package field definition, this
5873 identifier resolves to the package being defined.
5875 The example below shows how to add a package as a native input of itself when
5883 ;; When cross-compiled, Guile, for example, depends on
5884 ;; a native version of itself. Add it here.
5885 (native-inputs (if (%current-target-system)
5886 `(("self" ,this-package))
5890 It is an error to refer to @code{this-package} outside a package definition.
5893 @node origin Reference
5894 @subsection @code{origin} Reference
5896 This section summarizes all the options available in @code{origin}
5897 declarations (@pxref{Defining Packages}).
5899 @deftp {Data Type} origin
5900 This is the data type representing a source code origin.
5904 An object containing the URI of the source. The object type depends on
5905 the @code{method} (see below). For example, when using the
5906 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5907 values are: a URL represented as a string, or a list thereof.
5910 A procedure that handles the URI.
5915 @item @var{url-fetch} from @code{(guix download)}
5916 download a file from the HTTP, HTTPS, or FTP URL specified in the
5920 @item @var{git-fetch} from @code{(guix git-download)}
5921 clone the Git version control repository, and check out the revision
5922 specified in the @code{uri} field as a @code{git-reference} object; a
5923 @code{git-reference} looks like this:
5927 (url "https://git.savannah.gnu.org/git/hello.git")
5933 A bytevector containing the SHA-256 hash of the source. Typically the
5934 @code{base32} form is used here to generate the bytevector from a
5937 You can obtain this information using @code{guix download}
5938 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5941 @item @code{file-name} (default: @code{#f})
5942 The file name under which the source code should be saved. When this is
5943 @code{#f}, a sensible default value will be used in most cases. In case
5944 the source is fetched from a URL, the file name from the URL will be
5945 used. For version control checkouts, it is recommended to provide the
5946 file name explicitly because the default is not very descriptive.
5948 @item @code{patches} (default: @code{'()})
5949 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5950 file-like objects}) pointing to patches to be applied to the source.
5952 This list of patches must be unconditional. In particular, it cannot
5953 depend on the value of @code{%current-system} or
5954 @code{%current-target-system}.
5956 @item @code{snippet} (default: @code{#f})
5957 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5958 in the source directory. This is a convenient way to modify the source,
5959 sometimes more convenient than a patch.
5961 @item @code{patch-flags} (default: @code{'("-p1")})
5962 A list of command-line flags that should be passed to the @code{patch}
5965 @item @code{patch-inputs} (default: @code{#f})
5966 Input packages or derivations to the patching process. When this is
5967 @code{#f}, the usual set of inputs necessary for patching are provided,
5968 such as GNU@tie{}Patch.
5970 @item @code{modules} (default: @code{'()})
5971 A list of Guile modules that should be loaded during the patching
5972 process and while running the code in the @code{snippet} field.
5974 @item @code{patch-guile} (default: @code{#f})
5975 The Guile package that should be used in the patching process. When
5976 this is @code{#f}, a sensible default is used.
5982 @section Build Systems
5984 @cindex build system
5985 Each package definition specifies a @dfn{build system} and arguments for
5986 that build system (@pxref{Defining Packages}). This @code{build-system}
5987 field represents the build procedure of the package, as well as implicit
5988 dependencies of that build procedure.
5990 Build systems are @code{<build-system>} objects. The interface to
5991 create and manipulate them is provided by the @code{(guix build-system)}
5992 module, and actual build systems are exported by specific modules.
5994 @cindex bag (low-level package representation)
5995 Under the hood, build systems first compile package objects to
5996 @dfn{bags}. A @dfn{bag} is like a package, but with less
5997 ornamentation---in other words, a bag is a lower-level representation of
5998 a package, which includes all the inputs of that package, including some
5999 that were implicitly added by the build system. This intermediate
6000 representation is then compiled to a derivation (@pxref{Derivations}).
6002 Build systems accept an optional list of @dfn{arguments}. In package
6003 definitions, these are passed @i{via} the @code{arguments} field
6004 (@pxref{Defining Packages}). They are typically keyword arguments
6005 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6006 Guile Reference Manual}). The value of these arguments is usually
6007 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6008 by the daemon (@pxref{Derivations}).
6010 The main build system is @code{gnu-build-system}, which implements the
6011 standard build procedure for GNU and many other packages. It
6012 is provided by the @code{(guix build-system gnu)} module.
6014 @defvr {Scheme Variable} gnu-build-system
6015 @code{gnu-build-system} represents the GNU Build System, and variants
6016 thereof (@pxref{Configuration, configuration and makefile conventions,,
6017 standards, GNU Coding Standards}).
6019 @cindex build phases
6020 In a nutshell, packages using it are configured, built, and installed with
6021 the usual @code{./configure && make && make check && make install}
6022 command sequence. In practice, a few additional steps are often needed.
6023 All these steps are split up in separate @dfn{phases},
6024 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6025 modules for more details about the build phases.}:
6029 Unpack the source tarball, and change the current directory to the
6030 extracted source tree. If the source is actually a directory, copy it
6031 to the build tree, and enter that directory.
6033 @item patch-source-shebangs
6034 Patch shebangs encountered in source files so they refer to the right
6035 store file names. For instance, this changes @code{#!/bin/sh} to
6036 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6039 Run the @file{configure} script with a number of default options, such
6040 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6041 by the @code{#:configure-flags} argument.
6044 Run @code{make} with the list of flags specified with
6045 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6046 (the default), build with @code{make -j}.
6049 Run @code{make check}, or some other target specified with
6050 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6051 @code{#:parallel-tests?} argument is true (the default), run @code{make
6055 Run @code{make install} with the flags listed in @code{#:make-flags}.
6057 @item patch-shebangs
6058 Patch shebangs on the installed executable files.
6061 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6062 is false), copying them to the @code{debug} output when available
6063 (@pxref{Installing Debugging Files}).
6066 @vindex %standard-phases
6067 The build-side module @code{(guix build gnu-build-system)} defines
6068 @code{%standard-phases} as the default list of build phases.
6069 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6070 procedure implements the actual phase.
6072 The list of phases used for a particular package can be changed with the
6073 @code{#:phases} parameter. For instance, passing:
6076 #:phases (modify-phases %standard-phases (delete 'configure))
6079 means that all the phases described above will be used, except the
6080 @code{configure} phase.
6082 In addition, this build system ensures that the ``standard'' environment
6083 for GNU packages is available. This includes tools such as GCC, libc,
6084 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6085 build-system gnu)} module for a complete list). We call these the
6086 @dfn{implicit inputs} of a package, because package definitions do not
6087 have to mention them.
6090 Other @code{<build-system>} objects are defined to support other
6091 conventions and tools used by free software packages. They inherit most
6092 of @code{gnu-build-system}, and differ mainly in the set of inputs
6093 implicitly added to the build process, and in the list of phases
6094 executed. Some of these build systems are listed below.
6096 @defvr {Scheme Variable} ant-build-system
6097 This variable is exported by @code{(guix build-system ant)}. It
6098 implements the build procedure for Java packages that can be built with
6099 @url{https://ant.apache.org/, Ant build tool}.
6101 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6102 provided by the @code{icedtea} package to the set of inputs. Different
6103 packages can be specified with the @code{#:ant} and @code{#:jdk}
6104 parameters, respectively.
6106 When the original package does not provide a suitable Ant build file,
6107 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6108 build file @file{build.xml} with tasks to build the specified jar
6109 archive. In this case the parameter @code{#:source-dir} can be used to
6110 specify the source sub-directory, defaulting to ``src''.
6112 The @code{#:main-class} parameter can be used with the minimal ant
6113 buildfile to specify the main class of the resulting jar. This makes the
6114 jar file executable. The @code{#:test-include} parameter can be used to
6115 specify the list of junit tests to run. It defaults to
6116 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6117 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6118 because abstract classes cannot be run as tests.
6120 The parameter @code{#:build-target} can be used to specify the Ant task
6121 that should be run during the @code{build} phase. By default the
6122 ``jar'' task will be run.
6126 @defvr {Scheme Variable} android-ndk-build-system
6127 @cindex Android distribution
6128 @cindex Android NDK build system
6129 This variable is exported by @code{(guix build-system android-ndk)}. It
6130 implements a build procedure for Android NDK (native development kit)
6131 packages using a Guix-specific build process.
6133 The build system assumes that packages install their public interface
6134 (header) files to the subdirectory @file{include} of the @code{out} output and
6135 their libraries to the subdirectory @file{lib} the @code{out} output.
6137 It's also assumed that the union of all the dependencies of a package
6138 has no conflicting files.
6140 For the time being, cross-compilation is not supported - so right now
6141 the libraries and header files are assumed to be host tools.
6145 @defvr {Scheme Variable} asdf-build-system/source
6146 @defvrx {Scheme Variable} asdf-build-system/sbcl
6147 @defvrx {Scheme Variable} asdf-build-system/ecl
6149 These variables, exported by @code{(guix build-system asdf)}, implement
6150 build procedures for Common Lisp packages using
6151 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6152 definition facility for Common Lisp programs and libraries.
6154 The @code{asdf-build-system/source} system installs the packages in
6155 source form, and can be loaded using any common lisp implementation, via
6156 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6157 systems in the format which a particular implementation understands.
6158 These build systems can also be used to produce executable programs, or
6159 lisp images which contain a set of packages pre-loaded.
6161 The build system uses naming conventions. For binary packages, the
6162 package name should be prefixed with the lisp implementation, such as
6163 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6165 Additionally, the corresponding source package should be labeled using
6166 the same convention as python packages (see @ref{Python Modules}), using
6167 the @code{cl-} prefix.
6169 For binary packages, each system should be defined as a Guix package.
6170 If one package @code{origin} contains several systems, package variants
6171 can be created in order to build all the systems. Source packages,
6172 which use @code{asdf-build-system/source}, may contain several systems.
6174 In order to create executable programs and images, the build-side
6175 procedures @code{build-program} and @code{build-image} can be used.
6176 They should be called in a build phase after the @code{create-symlinks}
6177 phase, so that the system which was just built can be used within the
6178 resulting image. @code{build-program} requires a list of Common Lisp
6179 expressions to be passed as the @code{#:entry-program} argument.
6181 If the system is not defined within its own @file{.asd} file of the same
6182 name, then the @code{#:asd-file} parameter should be used to specify
6183 which file the system is defined in. Furthermore, if the package
6184 defines a system for its tests in a separate file, it will be loaded
6185 before the tests are run if it is specified by the
6186 @code{#:test-asd-file} parameter. If it is not set, the files
6187 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6188 and @code{test.asd} will be tried if they exist.
6190 If for some reason the package must be named in a different way than the
6191 naming conventions suggest, the @code{#:asd-system-name} parameter can
6192 be used to specify the name of the system.
6196 @defvr {Scheme Variable} cargo-build-system
6197 @cindex Rust programming language
6198 @cindex Cargo (Rust build system)
6199 This variable is exported by @code{(guix build-system cargo)}. It
6200 supports builds of packages using Cargo, the build tool of the
6201 @uref{https://www.rust-lang.org, Rust programming language}.
6203 It adds @code{rustc} and @code{cargo} to the set of inputs.
6204 A different Rust package can be specified with the @code{#:rust} parameter.
6206 Regular cargo dependencies should be added to the package definition via the
6207 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6208 spec can be a package or a source definition. Note that the spec must
6209 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6210 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6211 should be added to the package definition via the
6212 @code{#:cargo-development-inputs} parameter.
6214 In its @code{configure} phase, this build system will make any source inputs
6215 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6216 parameters available to cargo. It will also remove an included
6217 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6218 @code{build} phase. The @code{install} phase installs any crate the binaries
6219 if they are defined by the crate.
6223 @defvr {Scheme Variable} copy-build-system
6224 This variable is exported by @code{(guix build-system copy)}. It
6225 supports builds of simple packages that don't require much compiling,
6226 mostly just moving files around.
6228 It adds much of the @code{gnu-build-system} packages to the set of
6229 inputs. Because of this, the @code{copy-build-system} does not require
6230 all the boilerplate code often needed for the
6231 @code{trivial-build-system}.
6233 To further simplify the file installation process, an
6234 @code{#:install-plan} argument is exposed to let the packager specify
6235 which files go where. The install plan is a list of @code{(@var{source}
6236 @var{target} [@var{filters}])}. @var{filters} are optional.
6239 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6241 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6242 @item Otherwise install @var{source} as @var{target}.
6245 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6246 the trailing slash of @var{target} is implied with the same meaning
6249 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6250 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6251 @code{#:exclude-regexp}, only select files are installed depending on
6252 the filters. Each filters is specified by a list of strings.
6254 @item With @code{#:include}, install all the files which the path suffix matches
6255 at least one of the elements in the given list.
6256 @item With @code{#:include-regexp}, install all the files which the
6257 subpaths match at least one of the regular expressions in the given
6259 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6260 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6261 install all files but those matching the exclusion filters.
6262 If both inclusions and exclusions are specified, the exclusions are done
6263 on top of the inclusions.
6266 In all cases, the paths relative to @var{source} are preserved within
6273 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6274 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6275 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6276 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6277 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6278 @file{share/my-app/sub/file}.
6279 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6280 @file{share/my-app/file}.
6285 @cindex Clojure (programming language)
6286 @cindex simple Clojure build system
6287 @defvr {Scheme Variable} clojure-build-system
6288 This variable is exported by @code{(guix build-system clojure)}. It implements
6289 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6290 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6293 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6294 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6295 @code{#:zip} parameters, respectively.
6297 A list of source directories, test directories and jar names can be specified
6298 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6299 parameters, respectively. Compile directory and main class can be specified
6300 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6301 Other parameters are documented below.
6303 This build system is an extension of @code{ant-build-system}, but with the
6304 following phases changed:
6309 This phase calls @code{compile} in Clojure to compile source files and runs
6310 @command{jar} to create jars from both source files and compiled files
6311 according to the include list and exclude list specified in
6312 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6313 has priority over the include list. These lists consist of symbols
6314 representing Clojure libraries or the special keyword @code{#:all} representing
6315 all Clojure libraries found under the source directories. The parameter
6316 @code{#:omit-source?} decides if source should be included into the jars.
6319 This phase runs tests according to the include list and exclude list specified
6320 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6321 meanings are analogous to that of @code{#:aot-include} and
6322 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6323 stands for all Clojure libraries found under the test directories. The
6324 parameter @code{#:tests?} decides if tests should be run.
6327 This phase installs all jars built previously.
6330 Apart from the above, this build system also contains an additional phase:
6335 This phase installs all top-level files with base name matching
6336 @code{%doc-regex}. A different regex can be specified with the
6337 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6338 directories specified in @code{#:doc-dirs} are installed as well.
6342 @defvr {Scheme Variable} cmake-build-system
6343 This variable is exported by @code{(guix build-system cmake)}. It
6344 implements the build procedure for packages using the
6345 @url{https://www.cmake.org, CMake build tool}.
6347 It automatically adds the @code{cmake} package to the set of inputs.
6348 Which package is used can be specified with the @code{#:cmake}
6351 The @code{#:configure-flags} parameter is taken as a list of flags
6352 passed to the @command{cmake} command. The @code{#:build-type}
6353 parameter specifies in abstract terms the flags passed to the compiler;
6354 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6355 debugging information''), which roughly means that code is compiled with
6356 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6359 @defvr {Scheme Variable} dune-build-system
6360 This variable is exported by @code{(guix build-system dune)}. It
6361 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6362 tool for the OCaml programming language. It is implemented as an extension
6363 of the @code{ocaml-build-system} which is described below. As such, the
6364 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6367 It automatically adds the @code{dune} package to the set of inputs.
6368 Which package is used can be specified with the @code{#:dune}
6371 There is no @code{configure} phase because dune packages typically don't
6372 need to be configured. The @code{#:build-flags} parameter is taken as a
6373 list of flags passed to the @code{dune} command during the build.
6375 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6376 command instead of the more recent @code{dune} command while building
6377 a package. Its default value is @code{#f}.
6379 The @code{#:package} parameter can be passed to specify a package name, which
6380 is useful when a package contains multiple packages and you want to build
6381 only one of them. This is equivalent to passing the @code{-p} argument to
6385 @defvr {Scheme Variable} go-build-system
6386 This variable is exported by @code{(guix build-system go)}. It
6387 implements a build procedure for Go packages using the standard
6388 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6389 Go build mechanisms}.
6391 The user is expected to provide a value for the key @code{#:import-path}
6392 and, in some cases, @code{#:unpack-path}. The
6393 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6394 corresponds to the file system path expected by the package's build
6395 scripts and any referring packages, and provides a unique way to
6396 refer to a Go package. It is typically based on a combination of the
6397 package source code's remote URI and file system hierarchy structure. In
6398 some cases, you will need to unpack the package's source code to a
6399 different directory structure than the one indicated by the import path,
6400 and @code{#:unpack-path} should be used in such cases.
6402 Packages that provide Go libraries should install their source code into
6403 the built output. The key @code{#:install-source?}, which defaults to
6404 @code{#t}, controls whether or not the source code is installed. It can
6405 be set to @code{#f} for packages that only provide executable files.
6408 @defvr {Scheme Variable} glib-or-gtk-build-system
6409 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6410 is intended for use with packages making use of GLib or GTK+.
6412 This build system adds the following two phases to the ones defined by
6413 @code{gnu-build-system}:
6416 @item glib-or-gtk-wrap
6417 The phase @code{glib-or-gtk-wrap} ensures that programs in
6418 @file{bin/} are able to find GLib ``schemas'' and
6419 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6420 modules}. This is achieved by wrapping the programs in launch scripts
6421 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
6422 environment variables.
6424 It is possible to exclude specific package outputs from that wrapping
6425 process by listing their names in the
6426 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6427 when an output is known not to contain any GLib or GTK+ binaries, and
6428 where wrapping would gratuitously add a dependency of that output on
6431 @item glib-or-gtk-compile-schemas
6432 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6433 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6434 GSettings schemas} of GLib are compiled. Compilation is performed by the
6435 @command{glib-compile-schemas} program. It is provided by the package
6436 @code{glib:bin} which is automatically imported by the build system.
6437 The @code{glib} package providing @command{glib-compile-schemas} can be
6438 specified with the @code{#:glib} parameter.
6441 Both phases are executed after the @code{install} phase.
6444 @defvr {Scheme Variable} guile-build-system
6445 This build system is for Guile packages that consist exclusively of Scheme
6446 code and that are so lean that they don't even have a makefile, let alone a
6447 @file{configure} script. It compiles Scheme code using @command{guild
6448 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6449 installs the @file{.scm} and @file{.go} files in the right place. It also
6450 installs documentation.
6452 This build system supports cross-compilation by using the
6453 @option{--target} option of @samp{guild compile}.
6455 Packages built with @code{guile-build-system} must provide a Guile package in
6456 their @code{native-inputs} field.
6459 @defvr {Scheme Variable} julia-build-system
6460 This variable is exported by @code{(guix build-system julia)}. It
6461 implements the build procedure used by @uref{https://julialang.org/,
6462 julia} packages, which essentially is similar to running @samp{julia -e
6463 'using Pkg; Pkg.add(package)'} in an environment where
6464 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
6465 Tests are run not run.
6467 Julia packages require the source @code{file-name} to be the real name of the
6468 package, correctly capitalized.
6470 For packages requiring shared library dependencies, you may need to write the
6471 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6472 variable = /gnu/store/library.so} for each dependency, plus a void function
6473 @code{check_deps() = nothing}.
6475 Some older packages that aren't using @file{Package.toml} yet, will require
6476 this file to be created, too. The function @code{julia-create-package-toml}
6477 helps creating the file. You need to pass the outputs and the source of the
6478 package, it's name (the same as the @code{file-name} parameter), the package
6479 uuid, the package version, and a list of dependencies specified by their name
6483 @defvr {Scheme Variable} minify-build-system
6484 This variable is exported by @code{(guix build-system minify)}. It
6485 implements a minification procedure for simple JavaScript packages.
6487 It adds @code{uglify-js} to the set of inputs and uses it to compress
6488 all JavaScript files in the @file{src} directory. A different minifier
6489 package can be specified with the @code{#:uglify-js} parameter, but it
6490 is expected that the package writes the minified code to the standard
6493 When the input JavaScript files are not all located in the @file{src}
6494 directory, the parameter @code{#:javascript-files} can be used to
6495 specify a list of file names to feed to the minifier.
6498 @defvr {Scheme Variable} ocaml-build-system
6499 This variable is exported by @code{(guix build-system ocaml)}. It implements
6500 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6501 of choosing the correct set of commands to run for each package. OCaml
6502 packages can expect many different commands to be run. This build system will
6505 When the package has a @file{setup.ml} file present at the top-level, it will
6506 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6507 @code{ocaml setup.ml -install}. The build system will assume that this file
6508 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6509 care of setting the prefix and enabling tests if they are not disabled. You
6510 can pass configure and build flags with the @code{#:configure-flags} and
6511 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6512 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6513 bypass this system in the build and install phases.
6515 When the package has a @file{configure} file, it is assumed that it is a
6516 hand-made configure script that requires a different argument format than
6517 in the @code{gnu-build-system}. You can add more flags with the
6518 @code{#:configure-flags} key.
6520 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6521 @code{#t}), it will be used and more flags can be passed to the build and
6522 install phases with the @code{#:make-flags} key.
6524 Finally, some packages do not have these files and use a somewhat standard
6525 location for its build system. In that case, the build system will run
6526 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6527 providing the path to the required findlib module. Additional flags can
6528 be passed via the @code{#:build-flags} key. Install is taken care of by
6529 @command{opam-installer}. In this case, the @code{opam} package must
6530 be added to the @code{native-inputs} field of the package definition.
6532 Note that most OCaml packages assume they will be installed in the same
6533 directory as OCaml, which is not what we want in guix. In particular, they
6534 will install @file{.so} files in their module's directory, which is usually
6535 fine because it is in the OCaml compiler directory. In guix though, these
6536 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
6537 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6538 @file{.so} libraries should be installed.
6541 @defvr {Scheme Variable} python-build-system
6542 This variable is exported by @code{(guix build-system python)}. It
6543 implements the more or less standard build procedure used by Python
6544 packages, which consists in running @code{python setup.py build} and
6545 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6547 For packages that install stand-alone Python programs under @code{bin/},
6548 it takes care of wrapping these programs so that their @env{PYTHONPATH}
6549 environment variable points to all the Python libraries they depend on.
6551 Which Python package is used to perform the build can be specified with
6552 the @code{#:python} parameter. This is a useful way to force a package
6553 to be built for a specific version of the Python interpreter, which
6554 might be necessary if the package is only compatible with a single
6555 interpreter version.
6557 By default guix calls @code{setup.py} under control of
6558 @code{setuptools}, much like @command{pip} does. Some packages are not
6559 compatible with setuptools (and pip), thus you can disable this by
6560 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6563 @defvr {Scheme Variable} perl-build-system
6564 This variable is exported by @code{(guix build-system perl)}. It
6565 implements the standard build procedure for Perl packages, which either
6566 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6567 followed by @code{Build} and @code{Build install}; or in running
6568 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6569 @code{make} and @code{make install}, depending on which of
6570 @code{Build.PL} or @code{Makefile.PL} is present in the package
6571 distribution. Preference is given to the former if both @code{Build.PL}
6572 and @code{Makefile.PL} exist in the package distribution. This
6573 preference can be reversed by specifying @code{#t} for the
6574 @code{#:make-maker?} parameter.
6576 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6577 passes flags specified by the @code{#:make-maker-flags} or
6578 @code{#:module-build-flags} parameter, respectively.
6580 Which Perl package is used can be specified with @code{#:perl}.
6583 @defvr {Scheme Variable} qt-build-system
6584 This variable is exported by @code{(guix build-system qt)}. It
6585 is intended for use with applications using Qt or KDE.
6587 This build system adds the following two phases to the ones defined by
6588 @code{cmake-build-system}:
6592 The phase @code{check-setup} prepares the environment for running
6593 the checks as commonly used by Qt test programs.
6594 For now this only sets some environment variables:
6595 @code{QT_QPA_PLATFORM=offscreen},
6596 @code{DBUS_FATAL_WARNINGS=0} and
6597 @code{CTEST_OUTPUT_ON_FAILURE=1}.
6599 This phase is added before the @code{check} phase.
6600 It's a separate phase to ease adjusting if necessary.
6603 The phase @code{qt-wrap}
6604 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6605 and output. In case some path is found, all programs in the output's
6606 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6607 are wrapped in scripts defining the necessary environment variables.
6609 It is possible to exclude specific package outputs from that wrapping process
6610 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6611 This is useful when an output is known not to contain any Qt binaries, and
6612 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6615 This phase is added after the @code{install} phase.
6619 @defvr {Scheme Variable} r-build-system
6620 This variable is exported by @code{(guix build-system r)}. It
6621 implements the build procedure used by @uref{https://r-project.org, R}
6622 packages, which essentially is little more than running @samp{R CMD
6623 INSTALL --library=/gnu/store/@dots{}} in an environment where
6624 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
6625 run after installation using the R function
6626 @code{tools::testInstalledPackage}.
6629 @defvr {Scheme Variable} rakudo-build-system
6630 This variable is exported by @code{(guix build-system rakudo)}. It
6631 implements the build procedure used by @uref{https://rakudo.org/,
6632 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6633 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6634 installs the binaries, library files and the resources, as well as wrap
6635 the files under the @code{bin/} directory. Tests can be skipped by
6636 passing @code{#f} to the @code{tests?} parameter.
6638 Which rakudo package is used can be specified with @code{rakudo}.
6639 Which perl6-tap-harness package used for the tests can be specified with
6640 @code{#:prove6} or removed by passing @code{#f} to the
6641 @code{with-prove6?} parameter.
6642 Which perl6-zef package used for tests and installing can be specified
6643 with @code{#:zef} or removed by passing @code{#f} to the
6644 @code{with-zef?} parameter.
6647 @defvr {Scheme Variable} texlive-build-system
6648 This variable is exported by @code{(guix build-system texlive)}. It is
6649 used to build TeX packages in batch mode with a specified engine. The
6650 build system sets the @env{TEXINPUTS} variable to find all TeX source
6651 files in the inputs.
6653 By default it runs @code{luatex} on all files ending on @code{ins}. A
6654 different engine and format can be specified with the
6655 @code{#:tex-format} argument. Different build targets can be specified
6656 with the @code{#:build-targets} argument, which expects a list of file
6657 names. The build system adds only @code{texlive-bin} and
6658 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6659 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6660 and @code{#:texlive-latex-base}, respectively.
6662 The @code{#:tex-directory} parameter tells the build system where to
6663 install the built files under the texmf tree.
6666 @defvr {Scheme Variable} ruby-build-system
6667 This variable is exported by @code{(guix build-system ruby)}. It
6668 implements the RubyGems build procedure used by Ruby packages, which
6669 involves running @code{gem build} followed by @code{gem install}.
6671 The @code{source} field of a package that uses this build system
6672 typically references a gem archive, since this is the format that Ruby
6673 developers use when releasing their software. The build system unpacks
6674 the gem archive, potentially patches the source, runs the test suite,
6675 repackages the gem, and installs it. Additionally, directories and
6676 tarballs may be referenced to allow building unreleased gems from Git or
6677 a traditional source release tarball.
6679 Which Ruby package is used can be specified with the @code{#:ruby}
6680 parameter. A list of additional flags to be passed to the @command{gem}
6681 command can be specified with the @code{#:gem-flags} parameter.
6684 @defvr {Scheme Variable} waf-build-system
6685 This variable is exported by @code{(guix build-system waf)}. It
6686 implements a build procedure around the @code{waf} script. The common
6687 phases---@code{configure}, @code{build}, and @code{install}---are
6688 implemented by passing their names as arguments to the @code{waf}
6691 The @code{waf} script is executed by the Python interpreter. Which
6692 Python package is used to run the script can be specified with the
6693 @code{#:python} parameter.
6696 @defvr {Scheme Variable} scons-build-system
6697 This variable is exported by @code{(guix build-system scons)}. It
6698 implements the build procedure used by the SCons software construction
6699 tool. This build system runs @code{scons} to build the package,
6700 @code{scons test} to run tests, and then @code{scons install} to install
6703 Additional flags to be passed to @code{scons} can be specified with the
6704 @code{#:scons-flags} parameter. The default build and install targets
6705 can be overridden with @code{#:build-targets} and
6706 @code{#:install-targets} respectively. The version of Python used to
6707 run SCons can be specified by selecting the appropriate SCons package
6708 with the @code{#:scons} parameter.
6711 @defvr {Scheme Variable} haskell-build-system
6712 This variable is exported by @code{(guix build-system haskell)}. It
6713 implements the Cabal build procedure used by Haskell packages, which
6714 involves running @code{runhaskell Setup.hs configure
6715 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6716 Instead of installing the package by running @code{runhaskell Setup.hs
6717 install}, to avoid trying to register libraries in the read-only
6718 compiler store directory, the build system uses @code{runhaskell
6719 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6720 addition, the build system generates the package documentation by
6721 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6722 is passed. Optional Haddock parameters can be passed with the help of
6723 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6724 not found, the build system looks for @code{Setup.lhs} instead.
6726 Which Haskell compiler is used can be specified with the @code{#:haskell}
6727 parameter which defaults to @code{ghc}.
6730 @defvr {Scheme Variable} dub-build-system
6731 This variable is exported by @code{(guix build-system dub)}. It
6732 implements the Dub build procedure used by D packages, which
6733 involves running @code{dub build} and @code{dub run}.
6734 Installation is done by copying the files manually.
6736 Which D compiler is used can be specified with the @code{#:ldc}
6737 parameter which defaults to @code{ldc}.
6740 @defvr {Scheme Variable} emacs-build-system
6741 This variable is exported by @code{(guix build-system emacs)}. It
6742 implements an installation procedure similar to the packaging system
6743 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6745 It first creates the @code{@code{package}-autoloads.el} file, then it
6746 byte compiles all Emacs Lisp files. Differently from the Emacs
6747 packaging system, the Info documentation files are moved to the standard
6748 documentation directory and the @file{dir} file is deleted. The Elisp
6749 package files are installed directly under @file{share/emacs/site-lisp}.
6752 @defvr {Scheme Variable} font-build-system
6753 This variable is exported by @code{(guix build-system font)}. It
6754 implements an installation procedure for font packages where upstream
6755 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6756 need to be copied into place. It copies font files to standard
6757 locations in the output directory.
6760 @defvr {Scheme Variable} meson-build-system
6761 This variable is exported by @code{(guix build-system meson)}. It
6762 implements the build procedure for packages that use
6763 @url{https://mesonbuild.com, Meson} as their build system.
6765 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6766 of inputs, and they can be changed with the parameters @code{#:meson}
6767 and @code{#:ninja} if needed. The default Meson is
6768 @code{meson-for-build}, which is special because it doesn't clear the
6769 @code{RUNPATH} of binaries and libraries when they are installed.
6771 This build system is an extension of @code{gnu-build-system}, but with the
6772 following phases changed to some specific for Meson:
6777 The phase runs @code{meson} with the flags specified in
6778 @code{#:configure-flags}. The flag @option{--build-type} is always set to
6779 @code{plain} unless something else is specified in @code{#:build-type}.
6782 The phase runs @code{ninja} to build the package in parallel by default, but
6783 this can be changed with @code{#:parallel-build?}.
6786 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6787 which is @code{"test"} by default.
6790 The phase runs @code{ninja install} and can not be changed.
6793 Apart from that, the build system also adds the following phases:
6798 This phase ensures that all binaries can find the libraries they need.
6799 It searches for required libraries in subdirectories of the package being
6800 built, and adds those to @code{RUNPATH} where needed. It also removes
6801 references to libraries left over from the build phase by
6802 @code{meson-for-build}, such as test dependencies, that aren't actually
6803 required for the program to run.
6805 @item glib-or-gtk-wrap
6806 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6807 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6809 @item glib-or-gtk-compile-schemas
6810 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6811 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6815 @defvr {Scheme Variable} linux-module-build-system
6816 @code{linux-module-build-system} allows building Linux kernel modules.
6818 @cindex build phases
6819 This build system is an extension of @code{gnu-build-system}, but with the
6820 following phases changed:
6825 This phase configures the environment so that the Linux kernel's Makefile
6826 can be used to build the external kernel module.
6829 This phase uses the Linux kernel's Makefile in order to build the external
6833 This phase uses the Linux kernel's Makefile in order to install the external
6837 It is possible and useful to specify the Linux kernel to use for building
6838 the module (in the @code{arguments} form of a package using the
6839 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
6842 @defvr {Scheme Variable} node-build-system
6843 This variable is exported by @code{(guix build-system node)}. It
6844 implements the build procedure used by @uref{https://nodejs.org,
6845 Node.js}, which implements an approximation of the @code{npm install}
6846 command, followed by an @code{npm test} command.
6848 Which Node.js package is used to interpret the @code{npm} commands can
6849 be specified with the @code{#:node} parameter which defaults to
6853 Lastly, for packages that do not need anything as sophisticated, a
6854 ``trivial'' build system is provided. It is trivial in the sense that
6855 it provides basically no support: it does not pull any implicit inputs,
6856 and does not have a notion of build phases.
6858 @defvr {Scheme Variable} trivial-build-system
6859 This variable is exported by @code{(guix build-system trivial)}.
6861 This build system requires a @code{#:builder} argument. This argument
6862 must be a Scheme expression that builds the package output(s)---as
6863 with @code{build-expression->derivation} (@pxref{Derivations,
6864 @code{build-expression->derivation}}).
6874 Conceptually, the @dfn{store} is the place where derivations that have
6875 been built successfully are stored---by default, @file{/gnu/store}.
6876 Sub-directories in the store are referred to as @dfn{store items} or
6877 sometimes @dfn{store paths}. The store has an associated database that
6878 contains information such as the store paths referred to by each store
6879 path, and the list of @emph{valid} store items---results of successful
6880 builds. This database resides in @file{@var{localstatedir}/guix/db},
6881 where @var{localstatedir} is the state directory specified @i{via}
6882 @option{--localstatedir} at configure time, usually @file{/var}.
6884 The store is @emph{always} accessed by the daemon on behalf of its clients
6885 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6886 connect to the daemon over a Unix-domain socket, send requests to it,
6887 and read the result---these are remote procedure calls, or RPCs.
6890 Users must @emph{never} modify files under @file{/gnu/store} directly.
6891 This would lead to inconsistencies and break the immutability
6892 assumptions of Guix's functional model (@pxref{Introduction}).
6894 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6895 how to check the integrity of the store and attempt recovery from
6896 accidental modifications.
6899 The @code{(guix store)} module provides procedures to connect to the
6900 daemon, and to perform RPCs. These are described below. By default,
6901 @code{open-connection}, and thus all the @command{guix} commands,
6902 connect to the local daemon or to the URI specified by the
6903 @env{GUIX_DAEMON_SOCKET} environment variable.
6905 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6906 When set, the value of this variable should be a file name or a URI
6907 designating the daemon endpoint. When it is a file name, it denotes a
6908 Unix-domain socket to connect to. In addition to file names, the
6909 supported URI schemes are:
6914 These are for Unix-domain sockets.
6915 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6916 @file{/var/guix/daemon-socket/socket}.
6919 @cindex daemon, remote access
6920 @cindex remote access to the daemon
6921 @cindex daemon, cluster setup
6922 @cindex clusters, daemon setup
6923 These URIs denote connections over TCP/IP, without encryption nor
6924 authentication of the remote host. The URI must specify the host name
6925 and optionally a port number (by default port 44146 is used):
6928 guix://master.guix.example.org:1234
6931 This setup is suitable on local networks, such as clusters, where only
6932 trusted nodes may connect to the build daemon at
6933 @code{master.guix.example.org}.
6935 The @option{--listen} option of @command{guix-daemon} can be used to
6936 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6937 @option{--listen}}).
6940 @cindex SSH access to build daemons
6941 These URIs allow you to connect to a remote daemon over SSH. This
6942 feature requires Guile-SSH (@pxref{Requirements}) and a working
6943 @command{guile} binary in @env{PATH} on the destination machine. It
6944 supports public key and GSSAPI authentication. A typical URL might look
6948 ssh://charlie@@guix.example.org:22
6951 As for @command{guix copy}, the usual OpenSSH client configuration files
6952 are honored (@pxref{Invoking guix copy}).
6955 Additional URI schemes may be supported in the future.
6957 @c XXX: Remove this note when the protocol incurs fewer round trips
6958 @c and when (guix derivations) no longer relies on file system access.
6960 The ability to connect to remote build daemons is considered
6961 experimental as of @value{VERSION}. Please get in touch with us to
6962 share any problems or suggestions you may have (@pxref{Contributing}).
6966 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6967 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6968 @var{reserve-space?} is true, instruct it to reserve a little bit of
6969 extra space on the file system so that the garbage collector can still
6970 operate should the disk become full. Return a server object.
6972 @var{file} defaults to @code{%default-socket-path}, which is the normal
6973 location given the options that were passed to @command{configure}.
6976 @deffn {Scheme Procedure} close-connection @var{server}
6977 Close the connection to @var{server}.
6980 @defvr {Scheme Variable} current-build-output-port
6981 This variable is bound to a SRFI-39 parameter, which refers to the port
6982 where build and error logs sent by the daemon should be written.
6985 Procedures that make RPCs all take a server object as their first
6988 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6989 @cindex invalid store items
6990 Return @code{#t} when @var{path} designates a valid store item and
6991 @code{#f} otherwise (an invalid item may exist on disk but still be
6992 invalid, for instance because it is the result of an aborted or failed
6995 A @code{&store-protocol-error} condition is raised if @var{path} is not
6996 prefixed by the store directory (@file{/gnu/store}).
6999 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7000 Add @var{text} under file @var{name} in the store, and return its store
7001 path. @var{references} is the list of store paths referred to by the
7002 resulting store path.
7005 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7007 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7008 file names, or derivation/output pairs, using the specified
7009 @var{mode}---@code{(build-mode normal)} by default.
7012 Note that the @code{(guix monads)} module provides a monad as well as
7013 monadic versions of the above procedures, with the goal of making it
7014 more convenient to work with code that accesses the store (@pxref{The
7018 @i{This section is currently incomplete.}
7021 @section Derivations
7024 Low-level build actions and the environment in which they are performed
7025 are represented by @dfn{derivations}. A derivation contains the
7026 following pieces of information:
7030 The outputs of the derivation---derivations produce at least one file or
7031 directory in the store, but may produce more.
7034 @cindex build-time dependencies
7035 @cindex dependencies, build-time
7036 The inputs of the derivations---i.e., its build-time dependencies---which may
7037 be other derivations or plain files in the store (patches, build scripts,
7041 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7044 The file name of a build script in the store, along with the arguments
7048 A list of environment variables to be defined.
7052 @cindex derivation path
7053 Derivations allow clients of the daemon to communicate build actions to
7054 the store. They exist in two forms: as an in-memory representation,
7055 both on the client- and daemon-side, and as files in the store whose
7056 name end in @file{.drv}---these files are referred to as @dfn{derivation
7057 paths}. Derivations paths can be passed to the @code{build-derivations}
7058 procedure to perform the build actions they prescribe (@pxref{The
7061 @cindex fixed-output derivations
7062 Operations such as file downloads and version-control checkouts for
7063 which the expected content hash is known in advance are modeled as
7064 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7065 of a fixed-output derivation are independent of its inputs---e.g., a
7066 source code download produces the same result regardless of the download
7067 method and tools being used.
7070 @cindex run-time dependencies
7071 @cindex dependencies, run-time
7072 The outputs of derivations---i.e., the build results---have a set of
7073 @dfn{references}, as reported by the @code{references} RPC or the
7074 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7075 are the set of run-time dependencies of the build results. References are a
7076 subset of the inputs of the derivation; this subset is automatically computed
7077 by the build daemon by scanning all the files in the outputs.
7079 The @code{(guix derivations)} module provides a representation of
7080 derivations as Scheme objects, along with procedures to create and
7081 otherwise manipulate derivations. The lowest-level primitive to create
7082 a derivation is the @code{derivation} procedure:
7084 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7085 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7086 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7087 [#:system (%current-system)] [#:references-graphs #f] @
7088 [#:allowed-references #f] [#:disallowed-references #f] @
7089 [#:leaked-env-vars #f] [#:local-build? #f] @
7090 [#:substitutable? #t] [#:properties '()]
7091 Build a derivation with the given arguments, and return the resulting
7092 @code{<derivation>} object.
7094 When @var{hash} and @var{hash-algo} are given, a
7095 @dfn{fixed-output derivation} is created---i.e., one whose result is
7096 known in advance, such as a file download. If, in addition,
7097 @var{recursive?} is true, then that fixed output may be an executable
7098 file or a directory and @var{hash} must be the hash of an archive
7099 containing this output.
7101 When @var{references-graphs} is true, it must be a list of file
7102 name/store path pairs. In that case, the reference graph of each store
7103 path is exported in the build environment in the corresponding file, in
7104 a simple text format.
7106 When @var{allowed-references} is true, it must be a list of store items
7107 or outputs that the derivation's output may refer to. Likewise,
7108 @var{disallowed-references}, if true, must be a list of things the
7109 outputs may @emph{not} refer to.
7111 When @var{leaked-env-vars} is true, it must be a list of strings
7112 denoting environment variables that are allowed to ``leak'' from the
7113 daemon's environment to the build environment. This is only applicable
7114 to fixed-output derivations---i.e., when @var{hash} is true. The main
7115 use is to allow variables such as @code{http_proxy} to be passed to
7116 derivations that download files.
7118 When @var{local-build?} is true, declare that the derivation is not a
7119 good candidate for offloading and should rather be built locally
7120 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7121 where the costs of data transfers would outweigh the benefits.
7123 When @var{substitutable?} is false, declare that substitutes of the
7124 derivation's output should not be used (@pxref{Substitutes}). This is
7125 useful, for instance, when building packages that capture details of the
7126 host CPU instruction set.
7128 @var{properties} must be an association list describing ``properties'' of the
7129 derivation. It is kept as-is, uninterpreted, in the derivation.
7133 Here's an example with a shell script as its builder, assuming
7134 @var{store} is an open connection to the daemon, and @var{bash} points
7135 to a Bash executable in the store:
7138 (use-modules (guix utils)
7142 (let ((builder ; add the Bash script to the store
7143 (add-text-to-store store "my-builder.sh"
7144 "echo hello world > $out\n" '())))
7145 (derivation store "foo"
7146 bash `("-e" ,builder)
7147 #:inputs `((,bash) (,builder))
7148 #:env-vars '(("HOME" . "/homeless"))))
7149 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7152 As can be guessed, this primitive is cumbersome to use directly. A
7153 better approach is to write build scripts in Scheme, of course! The
7154 best course of action for that is to write the build code as a
7155 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7156 information, @pxref{G-Expressions}.
7158 Once upon a time, @code{gexp->derivation} did not exist and constructing
7159 derivations with build code written in Scheme was achieved with
7160 @code{build-expression->derivation}, documented below. This procedure
7161 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7163 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7164 @var{name} @var{exp} @
7165 [#:system (%current-system)] [#:inputs '()] @
7166 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7167 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7168 [#:references-graphs #f] [#:allowed-references #f] @
7169 [#:disallowed-references #f] @
7170 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7171 Return a derivation that executes Scheme expression @var{exp} as a
7172 builder for derivation @var{name}. @var{inputs} must be a list of
7173 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7174 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7175 modules from the current search path to be copied in the store,
7176 compiled, and made available in the load path during the execution of
7177 @var{exp}---e.g., @code{((guix build utils) (guix build
7178 gnu-build-system))}.
7180 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7181 to a list of output/path pairs, and where @code{%build-inputs} is bound
7182 to a list of string/output-path pairs made from @var{inputs}.
7183 Optionally, @var{env-vars} is a list of string pairs specifying the name
7184 and value of environment variables visible to the builder. The builder
7185 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7186 @var{exp} returns @code{#f}, the build is considered to have failed.
7188 @var{exp} is built using @var{guile-for-build} (a derivation). When
7189 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7190 @code{%guile-for-build} fluid is used instead.
7192 See the @code{derivation} procedure for the meaning of
7193 @var{references-graphs}, @var{allowed-references},
7194 @var{disallowed-references}, @var{local-build?}, and
7195 @var{substitutable?}.
7199 Here's an example of a single-output derivation that creates a directory
7200 containing one file:
7203 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7204 (mkdir out) ; create /gnu/store/@dots{}-goo
7205 (call-with-output-file (string-append out "/test")
7207 (display '(hello guix) p))))))
7208 (build-expression->derivation store "goo" builder))
7210 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7214 @node The Store Monad
7215 @section The Store Monad
7219 The procedures that operate on the store described in the previous
7220 sections all take an open connection to the build daemon as their first
7221 argument. Although the underlying model is functional, they either have
7222 side effects or depend on the current state of the store.
7224 The former is inconvenient: the connection to the build daemon has to be
7225 carried around in all those functions, making it impossible to compose
7226 functions that do not take that parameter with functions that do. The
7227 latter can be problematic: since store operations have side effects
7228 and/or depend on external state, they have to be properly sequenced.
7230 @cindex monadic values
7231 @cindex monadic functions
7232 This is where the @code{(guix monads)} module comes in. This module
7233 provides a framework for working with @dfn{monads}, and a particularly
7234 useful monad for our uses, the @dfn{store monad}. Monads are a
7235 construct that allows two things: associating ``context'' with values
7236 (in our case, the context is the store), and building sequences of
7237 computations (here computations include accesses to the store). Values
7238 in a monad---values that carry this additional context---are called
7239 @dfn{monadic values}; procedures that return such values are called
7240 @dfn{monadic procedures}.
7242 Consider this ``normal'' procedure:
7245 (define (sh-symlink store)
7246 ;; Return a derivation that symlinks the 'bash' executable.
7247 (let* ((drv (package-derivation store bash))
7248 (out (derivation->output-path drv))
7249 (sh (string-append out "/bin/bash")))
7250 (build-expression->derivation store "sh"
7251 `(symlink ,sh %output))))
7254 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7255 as a monadic function:
7258 (define (sh-symlink)
7259 ;; Same, but return a monadic value.
7260 (mlet %store-monad ((drv (package->derivation bash)))
7261 (gexp->derivation "sh"
7262 #~(symlink (string-append #$drv "/bin/bash")
7266 There are several things to note in the second version: the @code{store}
7267 parameter is now implicit and is ``threaded'' in the calls to the
7268 @code{package->derivation} and @code{gexp->derivation} monadic
7269 procedures, and the monadic value returned by @code{package->derivation}
7270 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7272 As it turns out, the call to @code{package->derivation} can even be
7273 omitted since it will take place implicitly, as we will see later
7274 (@pxref{G-Expressions}):
7277 (define (sh-symlink)
7278 (gexp->derivation "sh"
7279 #~(symlink (string-append #$bash "/bin/bash")
7284 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7285 @c for the funny quote.
7286 Calling the monadic @code{sh-symlink} has no effect. As someone once
7287 said, ``you exit a monad like you exit a building on fire: by running''.
7288 So, to exit the monad and get the desired effect, one must use
7289 @code{run-with-store}:
7292 (run-with-store (open-connection) (sh-symlink))
7293 @result{} /gnu/store/...-sh-symlink
7296 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7297 new ``meta-commands'' to make it easier to deal with monadic procedures:
7298 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7299 to ``run'' a single monadic value through the store:
7302 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7303 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7306 The latter enters a recursive REPL, where all the return values are
7307 automatically run through the store:
7310 scheme@@(guile-user)> ,enter-store-monad
7311 store-monad@@(guile-user) [1]> (package->derivation hello)
7312 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7313 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7314 $3 = "/gnu/store/@dots{}-foo"
7315 store-monad@@(guile-user) [1]> ,q
7316 scheme@@(guile-user)>
7320 Note that non-monadic values cannot be returned in the
7321 @code{store-monad} REPL.
7323 The main syntactic forms to deal with monads in general are provided by
7324 the @code{(guix monads)} module and are described below.
7326 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7327 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7331 @deffn {Scheme Syntax} return @var{val}
7332 Return a monadic value that encapsulates @var{val}.
7335 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7336 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7337 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7338 referred to as ``bind'', but that name denotes an unrelated procedure in
7339 Guile. Thus we use this somewhat cryptic symbol inherited from the
7340 Haskell language.}. There can be one @var{mproc} or several of them, as
7345 (with-monad %state-monad
7347 (lambda (x) (return (+ 1 x)))
7348 (lambda (x) (return (* 2 x)))))
7352 @result{} some-state
7356 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7358 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7360 Bind the variables @var{var} to the monadic values @var{mval} in
7361 @var{body}, which is a sequence of expressions. As with the bind
7362 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7363 value ``contained'' in @var{mval} and making @var{var} refer to that
7364 raw, non-monadic value within the scope of the @var{body}. The form
7365 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7366 @var{val}, as per @code{let}. The binding operations occur in sequence
7367 from left to right. The last expression of @var{body} must be a monadic
7368 expression, and its result will become the result of the @code{mlet} or
7369 @code{mlet*} when run in the @var{monad}.
7371 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7372 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7375 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7376 Bind @var{mexp} and the following monadic expressions in sequence,
7377 returning the result of the last expression. Every expression in the
7378 sequence must be a monadic expression.
7380 This is akin to @code{mlet}, except that the return values of the
7381 monadic expressions are ignored. In that sense, it is analogous to
7382 @code{begin}, but applied to monadic expressions.
7385 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7386 When @var{condition} is true, evaluate the sequence of monadic
7387 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7388 @var{condition} is false, return @code{*unspecified*} in the current
7389 monad. Every expression in the sequence must be a monadic expression.
7392 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7393 When @var{condition} is false, evaluate the sequence of monadic
7394 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7395 @var{condition} is true, return @code{*unspecified*} in the current
7396 monad. Every expression in the sequence must be a monadic expression.
7400 The @code{(guix monads)} module provides the @dfn{state monad}, which
7401 allows an additional value---the state---to be @emph{threaded} through
7402 monadic procedure calls.
7404 @defvr {Scheme Variable} %state-monad
7405 The state monad. Procedures in the state monad can access and change
7406 the state that is threaded.
7408 Consider the example below. The @code{square} procedure returns a value
7409 in the state monad. It returns the square of its argument, but also
7410 increments the current state value:
7414 (mlet %state-monad ((count (current-state)))
7415 (mbegin %state-monad
7416 (set-current-state (+ 1 count))
7419 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7424 When ``run'' through @code{%state-monad}, we obtain that additional state
7425 value, which is the number of @code{square} calls.
7428 @deffn {Monadic Procedure} current-state
7429 Return the current state as a monadic value.
7432 @deffn {Monadic Procedure} set-current-state @var{value}
7433 Set the current state to @var{value} and return the previous state as a
7437 @deffn {Monadic Procedure} state-push @var{value}
7438 Push @var{value} to the current state, which is assumed to be a list,
7439 and return the previous state as a monadic value.
7442 @deffn {Monadic Procedure} state-pop
7443 Pop a value from the current state and return it as a monadic value.
7444 The state is assumed to be a list.
7447 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7448 Run monadic value @var{mval} starting with @var{state} as the initial
7449 state. Return two values: the resulting value, and the resulting state.
7452 The main interface to the store monad, provided by the @code{(guix
7453 store)} module, is as follows.
7455 @defvr {Scheme Variable} %store-monad
7456 The store monad---an alias for @code{%state-monad}.
7458 Values in the store monad encapsulate accesses to the store. When its
7459 effect is needed, a value of the store monad must be ``evaluated'' by
7460 passing it to the @code{run-with-store} procedure (see below.)
7463 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7464 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7465 open store connection.
7468 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7469 Return as a monadic value the absolute file name in the store of the file
7470 containing @var{text}, a string. @var{references} is a list of store items that the
7471 resulting text file refers to; it defaults to the empty list.
7474 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7475 Return as a monadic value the absolute file name in the store of the file
7476 containing @var{data}, a bytevector. @var{references} is a list of store
7477 items that the resulting binary file refers to; it defaults to the empty list.
7480 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7481 [#:recursive? #t] [#:select? (const #t)]
7482 Return the name of @var{file} once interned in the store. Use
7483 @var{name} as its store name, or the basename of @var{file} if
7484 @var{name} is omitted.
7486 When @var{recursive?} is true, the contents of @var{file} are added
7487 recursively; if @var{file} designates a flat file and @var{recursive?}
7488 is true, its contents are added, and its permission bits are kept.
7490 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7491 @var{stat})} for each directory entry, where @var{file} is the entry's
7492 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7493 entries for which @var{select?} does not return true.
7495 The example below adds a file to the store, under two different names:
7498 (run-with-store (open-connection)
7499 (mlet %store-monad ((a (interned-file "README"))
7500 (b (interned-file "README" "LEGU-MIN")))
7501 (return (list a b))))
7503 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7508 The @code{(guix packages)} module exports the following package-related
7511 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7512 [#:system (%current-system)] [#:target #f] @
7515 value in the absolute file name of @var{file} within the @var{output}
7516 directory of @var{package}. When @var{file} is omitted, return the name
7517 of the @var{output} directory of @var{package}. When @var{target} is
7518 true, use it as a cross-compilation target triplet.
7520 Note that this procedure does @emph{not} build @var{package}. Thus, the
7521 result might or might not designate an existing file. We recommend not
7522 using this procedure unless you know what you are doing.
7525 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7526 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7527 @var{target} [@var{system}]
7528 Monadic version of @code{package-derivation} and
7529 @code{package-cross-derivation} (@pxref{Defining Packages}).
7534 @section G-Expressions
7536 @cindex G-expression
7537 @cindex build code quoting
7538 So we have ``derivations'', which represent a sequence of build actions
7539 to be performed to produce an item in the store (@pxref{Derivations}).
7540 These build actions are performed when asking the daemon to actually
7541 build the derivations; they are run by the daemon in a container
7542 (@pxref{Invoking guix-daemon}).
7544 @cindex strata of code
7545 It should come as no surprise that we like to write these build actions
7546 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7547 code@footnote{The term @dfn{stratum} in this context was coined by
7548 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7549 Kiselyov, who has written insightful
7550 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7551 on this topic}, refers to this kind of code generation as
7552 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7553 to the daemon, etc.---and the ``build code''---code that actually
7554 performs build actions, such as making directories, invoking
7555 @command{make}, etc.
7557 To describe a derivation and its build actions, one typically needs to
7558 embed build code inside host code. It boils down to manipulating build
7559 code as data, and the homoiconicity of Scheme---code has a direct
7560 representation as data---comes in handy for that. But we need more than
7561 the normal @code{quasiquote} mechanism in Scheme to construct build
7564 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7565 S-expressions adapted to build expressions. G-expressions, or
7566 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7567 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7568 @code{#$}, and @code{#$@@}), which are comparable to
7569 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7570 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7571 GNU Guile Reference Manual}). However, there are major differences:
7575 Gexps are meant to be written to a file and run or manipulated by other
7579 When a high-level object such as a package or derivation is unquoted
7580 inside a gexp, the result is as if its output file name had been
7584 Gexps carry information about the packages or derivations they refer to,
7585 and these dependencies are automatically added as inputs to the build
7586 processes that use them.
7589 @cindex lowering, of high-level objects in gexps
7590 This mechanism is not limited to package and derivation
7591 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7592 derivations or files in the store can be defined,
7593 such that these objects can also be inserted
7594 into gexps. For example, a useful type of high-level objects that can be
7595 inserted in a gexp is ``file-like objects'', which make it easy to
7596 add files to the store and to refer to them in
7597 derivations and such (see @code{local-file} and @code{plain-file}
7600 To illustrate the idea, here is an example of a gexp:
7607 (symlink (string-append #$coreutils "/bin/ls")
7611 This gexp can be passed to @code{gexp->derivation}; we obtain a
7612 derivation that builds a directory containing exactly one symlink to
7613 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7616 (gexp->derivation "the-thing" build-exp)
7619 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7620 substituted to the reference to the @var{coreutils} package in the
7621 actual build code, and @var{coreutils} is automatically made an input to
7622 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7623 output)}) is replaced by a string containing the directory name of the
7624 output of the derivation.
7626 @cindex cross compilation
7627 In a cross-compilation context, it is useful to distinguish between
7628 references to the @emph{native} build of a package---that can run on the
7629 host---versus references to cross builds of a package. To that end, the
7630 @code{#+} plays the same role as @code{#$}, but is a reference to a
7631 native package build:
7634 (gexp->derivation "vi"
7637 (mkdir (string-append #$output "/bin"))
7638 (system* (string-append #+coreutils "/bin/ln")
7640 (string-append #$emacs "/bin/emacs")
7641 (string-append #$output "/bin/vi")))
7642 #:target "mips64el-linux-gnu")
7646 In the example above, the native build of @var{coreutils} is used, so
7647 that @command{ln} can actually run on the host; but then the
7648 cross-compiled build of @var{emacs} is referenced.
7650 @cindex imported modules, for gexps
7651 @findex with-imported-modules
7652 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7653 able to use certain Guile modules from the ``host environment'' in the
7654 gexp, so those modules should be imported in the ``build environment''.
7655 The @code{with-imported-modules} form allows you to express that:
7658 (let ((build (with-imported-modules '((guix build utils))
7660 (use-modules (guix build utils))
7661 (mkdir-p (string-append #$output "/bin"))))))
7662 (gexp->derivation "empty-dir"
7665 (display "success!\n")
7670 In this example, the @code{(guix build utils)} module is automatically
7671 pulled into the isolated build environment of our gexp, such that
7672 @code{(use-modules (guix build utils))} works as expected.
7674 @cindex module closure
7675 @findex source-module-closure
7676 Usually you want the @emph{closure} of the module to be imported---i.e.,
7677 the module itself and all the modules it depends on---rather than just
7678 the module; failing to do that, attempts to use the module will fail
7679 because of missing dependent modules. The @code{source-module-closure}
7680 procedure computes the closure of a module by looking at its source file
7681 headers, which comes in handy in this case:
7684 (use-modules (guix modules)) ;for 'source-module-closure'
7686 (with-imported-modules (source-module-closure
7687 '((guix build utils)
7689 (gexp->derivation "something-with-vms"
7691 (use-modules (guix build utils)
7696 @cindex extensions, for gexps
7697 @findex with-extensions
7698 In the same vein, sometimes you want to import not just pure-Scheme
7699 modules, but also ``extensions'' such as Guile bindings to C libraries
7700 or other ``full-blown'' packages. Say you need the @code{guile-json}
7701 package available on the build side, here's how you would do it:
7704 (use-modules (gnu packages guile)) ;for 'guile-json'
7706 (with-extensions (list guile-json)
7707 (gexp->derivation "something-with-json"
7709 (use-modules (json))
7713 The syntactic form to construct gexps is summarized below.
7715 @deffn {Scheme Syntax} #~@var{exp}
7716 @deffnx {Scheme Syntax} (gexp @var{exp})
7717 Return a G-expression containing @var{exp}. @var{exp} may contain one
7718 or more of the following forms:
7722 @itemx (ungexp @var{obj})
7723 Introduce a reference to @var{obj}. @var{obj} may have one of the
7724 supported types, for example a package or a
7725 derivation, in which case the @code{ungexp} form is replaced by its
7726 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7728 If @var{obj} is a list, it is traversed and references to supported
7729 objects are substituted similarly.
7731 If @var{obj} is another gexp, its contents are inserted and its
7732 dependencies are added to those of the containing gexp.
7734 If @var{obj} is another kind of object, it is inserted as is.
7736 @item #$@var{obj}:@var{output}
7737 @itemx (ungexp @var{obj} @var{output})
7738 This is like the form above, but referring explicitly to the
7739 @var{output} of @var{obj}---this is useful when @var{obj} produces
7740 multiple outputs (@pxref{Packages with Multiple Outputs}).
7743 @itemx #+@var{obj}:output
7744 @itemx (ungexp-native @var{obj})
7745 @itemx (ungexp-native @var{obj} @var{output})
7746 Same as @code{ungexp}, but produces a reference to the @emph{native}
7747 build of @var{obj} when used in a cross compilation context.
7749 @item #$output[:@var{output}]
7750 @itemx (ungexp output [@var{output}])
7751 Insert a reference to derivation output @var{output}, or to the main
7752 output when @var{output} is omitted.
7754 This only makes sense for gexps passed to @code{gexp->derivation}.
7757 @itemx (ungexp-splicing @var{lst})
7758 Like the above, but splices the contents of @var{lst} inside the
7762 @itemx (ungexp-native-splicing @var{lst})
7763 Like the above, but refers to native builds of the objects listed in
7768 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7769 of the @code{gexp?} type (see below.)
7772 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7773 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7774 in their execution environment.
7776 Each item in @var{modules} can be the name of a module, such as
7777 @code{(guix build utils)}, or it can be a module name, followed by an
7778 arrow, followed by a file-like object:
7781 `((guix build utils)
7783 ((guix config) => ,(scheme-file "config.scm"
7784 #~(define-module @dots{}))))
7788 In the example above, the first two modules are taken from the search
7789 path, and the last one is created from the given file-like object.
7791 This form has @emph{lexical} scope: it has an effect on the gexps
7792 directly defined in @var{body}@dots{}, but not on those defined, say, in
7793 procedures called from @var{body}@dots{}.
7796 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7797 Mark the gexps defined in @var{body}@dots{} as requiring
7798 @var{extensions} in their build and execution environment.
7799 @var{extensions} is typically a list of package objects such as those
7800 defined in the @code{(gnu packages guile)} module.
7802 Concretely, the packages listed in @var{extensions} are added to the
7803 load path while compiling imported modules in @var{body}@dots{}; they
7804 are also added to the load path of the gexp returned by
7808 @deffn {Scheme Procedure} gexp? @var{obj}
7809 Return @code{#t} if @var{obj} is a G-expression.
7812 G-expressions are meant to be written to disk, either as code building
7813 some derivation, or as plain files in the store. The monadic procedures
7814 below allow you to do that (@pxref{The Store Monad}, for more
7815 information about monads.)
7817 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7818 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7819 [#:hash #f] [#:hash-algo #f] @
7820 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7821 [#:module-path @code{%load-path}] @
7822 [#:effective-version "2.2"] @
7823 [#:references-graphs #f] [#:allowed-references #f] @
7824 [#:disallowed-references #f] @
7825 [#:leaked-env-vars #f] @
7826 [#:script-name (string-append @var{name} "-builder")] @
7827 [#:deprecation-warnings #f] @
7828 [#:local-build? #f] [#:substitutable? #t] @
7829 [#:properties '()] [#:guile-for-build #f]
7830 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7831 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7832 stored in a file called @var{script-name}. When @var{target} is true,
7833 it is used as the cross-compilation target triplet for packages referred
7836 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7838 make @var{modules} available in the evaluation context of @var{exp};
7839 @var{modules} is a list of names of Guile modules searched in
7840 @var{module-path} to be copied in the store, compiled, and made available in
7841 the load path during the execution of @var{exp}---e.g., @code{((guix
7842 build utils) (guix build gnu-build-system))}.
7844 @var{effective-version} determines the string to use when adding extensions of
7845 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7847 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7850 When @var{references-graphs} is true, it must be a list of tuples of one of the
7854 (@var{file-name} @var{package})
7855 (@var{file-name} @var{package} @var{output})
7856 (@var{file-name} @var{derivation})
7857 (@var{file-name} @var{derivation} @var{output})
7858 (@var{file-name} @var{store-item})
7861 The right-hand-side of each element of @var{references-graphs} is automatically made
7862 an input of the build process of @var{exp}. In the build environment, each
7863 @var{file-name} contains the reference graph of the corresponding item, in a simple
7866 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7867 In the latter case, the list denotes store items that the result is allowed to
7868 refer to. Any reference to another store item will lead to a build error.
7869 Similarly for @var{disallowed-references}, which can list items that must not be
7870 referenced by the outputs.
7872 @var{deprecation-warnings} determines whether to show deprecation warnings while
7873 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7875 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7878 @cindex file-like objects
7879 The @code{local-file}, @code{plain-file}, @code{computed-file},
7880 @code{program-file}, and @code{scheme-file} procedures below return
7881 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7882 these objects lead to a file in the store. Consider this G-expression:
7885 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7886 #$(local-file "/tmp/my-nscd.conf"))
7889 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7890 to the store. Once expanded, for instance @i{via}
7891 @code{gexp->derivation}, the G-expression refers to that copy under
7892 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7893 does not have any effect on what the G-expression does.
7894 @code{plain-file} can be used similarly; it differs in that the file
7895 content is directly passed as a string.
7897 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7898 [#:recursive? #f] [#:select? (const #t)]
7899 Return an object representing local file @var{file} to add to the store;
7900 this object can be used in a gexp. If @var{file} is a literal string
7901 denoting a relative file name, it is looked up relative to the source
7902 file where it appears; if @var{file} is not a literal string, it is
7903 looked up relative to the current working directory at run time.
7904 @var{file} will be added to the store under @var{name}--by default the
7905 base name of @var{file}.
7907 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7908 designates a flat file and @var{recursive?} is true, its contents are added, and its
7909 permission bits are kept.
7911 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7912 @var{stat})} for each directory entry, where @var{file} is the entry's
7913 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7914 entries for which @var{select?} does not return true.
7916 This is the declarative counterpart of the @code{interned-file} monadic
7917 procedure (@pxref{The Store Monad, @code{interned-file}}).
7920 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7921 Return an object representing a text file called @var{name} with the given
7922 @var{content} (a string or a bytevector) to be added to the store.
7924 This is the declarative counterpart of @code{text-file}.
7927 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7928 [#:options '(#:local-build? #t)]
7929 Return an object representing the store item @var{name}, a file or
7930 directory computed by @var{gexp}. @var{options}
7931 is a list of additional arguments to pass to @code{gexp->derivation}.
7933 This is the declarative counterpart of @code{gexp->derivation}.
7936 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7937 [#:guile (default-guile)] [#:module-path %load-path] @
7938 [#:system (%current-system)] [#:target #f]
7939 Return an executable script @var{name} that runs @var{exp} using
7940 @var{guile}, with @var{exp}'s imported modules in its search path.
7941 Look up @var{exp}'s modules in @var{module-path}.
7943 The example below builds a script that simply invokes the @command{ls}
7947 (use-modules (guix gexp) (gnu packages base))
7949 (gexp->script "list-files"
7950 #~(execl #$(file-append coreutils "/bin/ls")
7954 When ``running'' it through the store (@pxref{The Store Monad,
7955 @code{run-with-store}}), we obtain a derivation that produces an
7956 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7959 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7961 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7965 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7966 [#:guile #f] [#:module-path %load-path]
7967 Return an object representing the executable store item @var{name} that
7968 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7969 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7971 This is the declarative counterpart of @code{gexp->script}.
7974 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7975 [#:set-load-path? #t] [#:module-path %load-path] @
7977 [#:guile (default-guile)]
7978 Return a derivation that builds a file @var{name} containing @var{exp}.
7979 When @var{splice?} is true, @var{exp} is considered to be a list of
7980 expressions that will be spliced in the resulting file.
7982 When @var{set-load-path?} is true, emit code in the resulting file to
7983 set @code{%load-path} and @code{%load-compiled-path} to honor
7984 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7987 The resulting file holds references to all the dependencies of @var{exp}
7988 or a subset thereof.
7991 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
7992 [#:splice? #f] [#:set-load-path? #t]
7993 Return an object representing the Scheme file @var{name} that contains
7996 This is the declarative counterpart of @code{gexp->file}.
7999 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8000 Return as a monadic value a derivation that builds a text file
8001 containing all of @var{text}. @var{text} may list, in addition to
8002 strings, objects of any type that can be used in a gexp: packages,
8003 derivations, local file objects, etc. The resulting store file holds
8004 references to all these.
8006 This variant should be preferred over @code{text-file} anytime the file
8007 to create will reference items from the store. This is typically the
8008 case when building a configuration file that embeds store file names,
8012 (define (profile.sh)
8013 ;; Return the name of a shell script in the store that
8014 ;; initializes the 'PATH' environment variable.
8015 (text-file* "profile.sh"
8016 "export PATH=" coreutils "/bin:"
8017 grep "/bin:" sed "/bin\n"))
8020 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8021 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8022 preventing them from being garbage-collected during its lifetime.
8025 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8026 Return an object representing store file @var{name} containing
8027 @var{text}. @var{text} is a sequence of strings and file-like objects,
8031 (mixed-text-file "profile"
8032 "export PATH=" coreutils "/bin:" grep "/bin")
8035 This is the declarative counterpart of @code{text-file*}.
8038 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8039 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8040 Each item in @var{files} must be a two-element list where the first element is the
8041 file name to use in the new directory, and the second element is a gexp
8042 denoting the target file. Here's an example:
8046 `(("hosts" ,(plain-file "hosts"
8047 "127.0.0.1 localhost"))
8048 ("bashrc" ,(plain-file "bashrc"
8049 "alias ls='ls --color=auto'"))))
8052 This yields an @code{etc} directory containing these two files.
8055 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8056 Return a directory that is the union of @var{things}, where @var{things} is a list of
8057 file-like objects denoting directories. For example:
8060 (directory-union "guile+emacs" (list guile emacs))
8063 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8066 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8067 Return a file-like object that expands to the concatenation of @var{obj}
8068 and @var{suffix}, where @var{obj} is a lowerable object and each
8069 @var{suffix} is a string.
8071 As an example, consider this gexp:
8074 (gexp->script "run-uname"
8075 #~(system* #$(file-append coreutils
8079 The same effect could be achieved with:
8082 (gexp->script "run-uname"
8083 #~(system* (string-append #$coreutils
8087 There is one difference though: in the @code{file-append} case, the
8088 resulting script contains the absolute file name as a string, whereas in
8089 the second case, the resulting script contains a @code{(string-append
8090 @dots{})} expression to construct the file name @emph{at run time}.
8093 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8094 This macro is similar to the @code{parameterize} form for
8095 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8096 Guile Reference Manual}). The key difference is that it takes effect
8097 when the file-like object returned by @var{exp} is lowered to a
8098 derivation or store item.
8100 A typical use of @code{with-parameters} is to force the system in effect
8104 (with-parameters ((%current-system "i686-linux"))
8108 The example above returns an object that corresponds to the i686 build
8109 of Coreutils, regardless of the current value of @code{%current-system}.
8113 Of course, in addition to gexps embedded in ``host'' code, there are
8114 also modules containing build tools. To make it clear that they are
8115 meant to be used in the build stratum, these modules are kept in the
8116 @code{(guix build @dots{})} name space.
8118 @cindex lowering, of high-level objects in gexps
8119 Internally, high-level objects are @dfn{lowered}, using their compiler,
8120 to either derivations or store items. For instance, lowering a package
8121 yields a derivation, and lowering a @code{plain-file} yields a store
8122 item. This is achieved using the @code{lower-object} monadic procedure.
8124 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8126 Return as a value in @code{%store-monad} the derivation or store item
8127 corresponding to @var{obj} for @var{system}, cross-compiling for
8128 @var{target} if @var{target} is true. @var{obj} must be an object that
8129 has an associated gexp compiler, such as a @code{<package>}.
8132 @node Invoking guix repl
8133 @section Invoking @command{guix repl}
8135 @cindex REPL, read-eval-print loop
8136 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
8137 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
8138 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
8139 command, @command{guix repl} guarantees that all the Guix modules and all its
8140 dependencies are available in the search path. You can use it this way:
8144 scheme@@(guile-user)> ,use (gnu packages base)
8145 scheme@@(guile-user)> coreutils
8146 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8150 In addition, @command{guix repl} implements a simple machine-readable REPL
8151 protocol for use by @code{(guix inferior)}, a facility to interact with
8152 @dfn{inferiors}, separate processes running a potentially different revision
8155 The available options are as follows:
8158 @item --type=@var{type}
8159 @itemx -t @var{type}
8160 Start a REPL of the given @var{TYPE}, which can be one of the following:
8164 This is default, and it spawns a standard full-featured Guile REPL.
8166 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8167 that the @code{(guix inferior)} module speaks.
8170 @item --listen=@var{endpoint}
8171 By default, @command{guix repl} reads from standard input and writes to
8172 standard output. When this option is passed, it will instead listen for
8173 connections on @var{endpoint}. Here are examples of valid options:
8176 @item --listen=tcp:37146
8177 Accept connections on localhost on port 37146.
8179 @item --listen=unix:/tmp/socket
8180 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8183 @item --load-path=@var{directory}
8184 @itemx -L @var{directory}
8185 Add @var{directory} to the front of the package module search path
8186 (@pxref{Package Modules}).
8188 This allows users to define their own packages and make them visible to
8189 the command-line tool.
8192 Inhibit loading of the @file{~/.guile} file. By default, that
8193 configuration file is loaded when spawning a @code{guile} REPL.
8196 @c *********************************************************************
8200 This section describes Guix command-line utilities. Some of them are
8201 primarily targeted at developers and users who write new package
8202 definitions, while others are more generally useful. They complement
8203 the Scheme programming interface of Guix in a convenient way.
8206 * Invoking guix build:: Building packages from the command line.
8207 * Invoking guix edit:: Editing package definitions.
8208 * Invoking guix download:: Downloading a file and printing its hash.
8209 * Invoking guix hash:: Computing the cryptographic hash of a file.
8210 * Invoking guix import:: Importing package definitions.
8211 * Invoking guix refresh:: Updating package definitions.
8212 * Invoking guix lint:: Finding errors in package definitions.
8213 * Invoking guix size:: Profiling disk usage.
8214 * Invoking guix graph:: Visualizing the graph of packages.
8215 * Invoking guix publish:: Sharing substitutes.
8216 * Invoking guix challenge:: Challenging substitute servers.
8217 * Invoking guix copy:: Copying to and from a remote store.
8218 * Invoking guix container:: Process isolation.
8219 * Invoking guix weather:: Assessing substitute availability.
8220 * Invoking guix processes:: Listing client processes.
8223 @node Invoking guix build
8224 @section Invoking @command{guix build}
8226 @cindex package building
8227 @cindex @command{guix build}
8228 The @command{guix build} command builds packages or derivations and
8229 their dependencies, and prints the resulting store paths. Note that it
8230 does not modify the user's profile---this is the job of the
8231 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8232 it is mainly useful for distribution developers.
8234 The general syntax is:
8237 guix build @var{options} @var{package-or-derivation}@dots{}
8240 As an example, the following command builds the latest versions of Emacs
8241 and of Guile, displays their build logs, and finally displays the
8242 resulting directories:
8245 guix build emacs guile
8248 Similarly, the following command builds all the available packages:
8251 guix build --quiet --keep-going \
8252 `guix package -A | cut -f1,2 --output-delimiter=@@`
8255 @var{package-or-derivation} may be either the name of a package found in
8256 the software distribution such as @code{coreutils} or
8257 @code{coreutils@@8.20}, or a derivation such as
8258 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8259 package with the corresponding name (and optionally version) is searched
8260 for among the GNU distribution modules (@pxref{Package Modules}).
8262 Alternatively, the @option{--expression} option may be used to specify a
8263 Scheme expression that evaluates to a package; this is useful when
8264 disambiguating among several same-named packages or package variants is
8267 There may be zero or more @var{options}. The available options are
8268 described in the subsections below.
8271 * Common Build Options:: Build options for most commands.
8272 * Package Transformation Options:: Creating variants of packages.
8273 * Additional Build Options:: Options specific to 'guix build'.
8274 * Debugging Build Failures:: Real life packaging experience.
8277 @node Common Build Options
8278 @subsection Common Build Options
8280 A number of options that control the build process are common to
8281 @command{guix build} and other commands that can spawn builds, such as
8282 @command{guix package} or @command{guix archive}. These are the
8287 @item --load-path=@var{directory}
8288 @itemx -L @var{directory}
8289 Add @var{directory} to the front of the package module search path
8290 (@pxref{Package Modules}).
8292 This allows users to define their own packages and make them visible to
8293 the command-line tools.
8297 Keep the build tree of failed builds. Thus, if a build fails, its build
8298 tree is kept under @file{/tmp}, in a directory whose name is shown at
8299 the end of the build log. This is useful when debugging build issues.
8300 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8303 This option implies @option{--no-offload}, and it has no effect when
8304 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8305 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
8309 Keep going when some of the derivations fail to build; return only once
8310 all the builds have either completed or failed.
8312 The default behavior is to stop as soon as one of the specified
8313 derivations has failed.
8317 Do not build the derivations.
8319 @anchor{fallback-option}
8321 When substituting a pre-built binary fails, fall back to building
8322 packages locally (@pxref{Substitution Failure}).
8324 @item --substitute-urls=@var{urls}
8325 @anchor{client-substitute-urls}
8326 Consider @var{urls} the whitespace-separated list of substitute source
8327 URLs, overriding the default list of URLs of @command{guix-daemon}
8328 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8330 This means that substitutes may be downloaded from @var{urls}, provided
8331 they are signed by a key authorized by the system administrator
8332 (@pxref{Substitutes}).
8334 When @var{urls} is the empty string, substitutes are effectively
8337 @item --no-substitutes
8338 Do not use substitutes for build products. That is, always build things
8339 locally instead of allowing downloads of pre-built binaries
8340 (@pxref{Substitutes}).
8343 Do not ``graft'' packages. In practice, this means that package updates
8344 available as grafts are not applied. @xref{Security Updates}, for more
8345 information on grafts.
8347 @item --rounds=@var{n}
8348 Build each derivation @var{n} times in a row, and raise an error if
8349 consecutive build results are not bit-for-bit identical.
8351 This is a useful way to detect non-deterministic builds processes.
8352 Non-deterministic build processes are a problem because they make it
8353 practically impossible for users to @emph{verify} whether third-party
8354 binaries are genuine. @xref{Invoking guix challenge}, for more.
8356 Note that, currently, the differing build results are not kept around,
8357 so you will have to manually investigate in case of an error---e.g., by
8358 stashing one of the build results with @code{guix archive --export}
8359 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8363 Do not use offload builds to other machines (@pxref{Daemon Offload
8364 Setup}). That is, always build things locally instead of offloading
8365 builds to remote machines.
8367 @item --max-silent-time=@var{seconds}
8368 When the build or substitution process remains silent for more than
8369 @var{seconds}, terminate it and report a build failure.
8371 By default, the daemon's setting is honored (@pxref{Invoking
8372 guix-daemon, @option{--max-silent-time}}).
8374 @item --timeout=@var{seconds}
8375 Likewise, when the build or substitution process lasts for more than
8376 @var{seconds}, terminate it and report a build failure.
8378 By default, the daemon's setting is honored (@pxref{Invoking
8379 guix-daemon, @option{--timeout}}).
8381 @c Note: This option is actually not part of %standard-build-options but
8382 @c most programs honor it.
8383 @cindex verbosity, of the command-line tools
8384 @cindex build logs, verbosity
8385 @item -v @var{level}
8386 @itemx --verbosity=@var{level}
8387 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8388 output is produced, 1 is for quiet output, and 2 shows all the build log
8389 output on standard error.
8391 @item --cores=@var{n}
8393 Allow the use of up to @var{n} CPU cores for the build. The special
8394 value @code{0} means to use as many CPU cores as available.
8396 @item --max-jobs=@var{n}
8398 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8399 guix-daemon, @option{--max-jobs}}, for details about this option and the
8400 equivalent @command{guix-daemon} option.
8402 @item --debug=@var{level}
8403 Produce debugging output coming from the build daemon. @var{level} must be an
8404 integer between 0 and 5; higher means more verbose output. Setting a level of
8405 4 or more may be helpful when debugging setup issues with the build daemon.
8409 Behind the scenes, @command{guix build} is essentially an interface to
8410 the @code{package-derivation} procedure of the @code{(guix packages)}
8411 module, and to the @code{build-derivations} procedure of the @code{(guix
8412 derivations)} module.
8414 In addition to options explicitly passed on the command line,
8415 @command{guix build} and other @command{guix} commands that support
8416 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
8418 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8419 Users can define this variable to a list of command line options that
8420 will automatically be used by @command{guix build} and other
8421 @command{guix} commands that can perform builds, as in the example
8425 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8428 These options are parsed independently, and the result is appended to
8429 the parsed command-line options.
8433 @node Package Transformation Options
8434 @subsection Package Transformation Options
8436 @cindex package variants
8437 Another set of command-line options supported by @command{guix build}
8438 and also @command{guix package} are @dfn{package transformation
8439 options}. These are options that make it possible to define @dfn{package
8440 variants}---for instance, packages built from different source code.
8441 This is a convenient way to create customized packages on the fly
8442 without having to type in the definitions of package variants
8443 (@pxref{Defining Packages}).
8447 @item --with-source=@var{source}
8448 @itemx --with-source=@var{package}=@var{source}
8449 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8450 Use @var{source} as the source of @var{package}, and @var{version} as
8452 @var{source} must be a file name or a URL, as for @command{guix
8453 download} (@pxref{Invoking guix download}).
8455 When @var{package} is omitted,
8456 it is taken to be the package name specified on the
8457 command line that matches the base of @var{source}---e.g.,
8458 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8459 package is @code{guile}.
8461 Likewise, when @var{version} is omitted, the version string is inferred from
8462 @var{source}; in the previous example, it is @code{2.0.10}.
8464 This option allows users to try out versions of packages other than the
8465 one provided by the distribution. The example below downloads
8466 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8467 the @code{ed} package:
8470 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8473 As a developer, @option{--with-source} makes it easy to test release
8477 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8480 @dots{} or to build from a checkout in a pristine environment:
8483 $ git clone git://git.sv.gnu.org/guix.git
8484 $ guix build guix --with-source=guix@@1.0=./guix
8487 @item --with-input=@var{package}=@var{replacement}
8488 Replace dependency on @var{package} by a dependency on
8489 @var{replacement}. @var{package} must be a package name, and
8490 @var{replacement} must be a package specification such as @code{guile}
8491 or @code{guile@@1.8}.
8493 For instance, the following command builds Guix, but replaces its
8494 dependency on the current stable version of Guile with a dependency on
8495 the legacy version of Guile, @code{guile@@2.0}:
8498 guix build --with-input=guile=guile@@2.0 guix
8501 This is a recursive, deep replacement. So in this example, both
8502 @code{guix} and its dependency @code{guile-json} (which also depends on
8503 @code{guile}) get rebuilt against @code{guile@@2.0}.
8505 This is implemented using the @code{package-input-rewriting} Scheme
8506 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8508 @item --with-graft=@var{package}=@var{replacement}
8509 This is similar to @option{--with-input} but with an important difference:
8510 instead of rebuilding the whole dependency chain, @var{replacement} is
8511 built and then @dfn{grafted} onto the binaries that were initially
8512 referring to @var{package}. @xref{Security Updates}, for more
8513 information on grafts.
8515 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8516 and all its dependencies, replacing references to the version of GnuTLS
8517 they currently refer to:
8520 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8523 This has the advantage of being much faster than rebuilding everything.
8524 But there is a caveat: it works if and only if @var{package} and
8525 @var{replacement} are strictly compatible---for example, if they provide
8526 a library, the application binary interface (ABI) of those libraries
8527 must be compatible. If @var{replacement} is somehow incompatible with
8528 @var{package}, then the resulting package may be unusable. Use with
8531 @item --with-git-url=@var{package}=@var{url}
8532 @cindex Git, using the latest commit
8533 @cindex latest commit, building
8534 Build @var{package} from the latest commit of the @code{master} branch of the
8535 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8538 For example, the following command builds the NumPy Python library against the
8539 latest commit of the master branch of Python itself:
8542 guix build python-numpy \
8543 --with-git-url=python=https://github.com/python/cpython
8546 This option can also be combined with @option{--with-branch} or
8547 @option{--with-commit} (see below).
8549 @cindex continuous integration
8550 Obviously, since it uses the latest commit of the given branch, the result of
8551 such a command varies over time. Nevertheless it is a convenient way to
8552 rebuild entire software stacks against the latest commit of one or more
8553 packages. This is particularly useful in the context of continuous
8556 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8557 consecutive accesses to the same repository. You may want to clean it up once
8558 in a while to save disk space.
8560 @item --with-branch=@var{package}=@var{branch}
8561 Build @var{package} from the latest commit of @var{branch}. If the
8562 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8563 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8564 repository URL is taken from that @code{source}. Otherwise you have to use
8565 @option{--with-git-url} to specify the URL of the Git repository.
8567 For instance, the following command builds @code{guile-sqlite3} from the
8568 latest commit of its @code{master} branch, and then builds @code{guix} (which
8569 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8570 specific @code{guile-sqlite3} build:
8573 guix build --with-branch=guile-sqlite3=master cuirass
8576 @item --with-commit=@var{package}=@var{commit}
8577 This is similar to @option{--with-branch}, except that it builds from
8578 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8579 Git commit SHA1 identifier or a tag.
8582 @node Additional Build Options
8583 @subsection Additional Build Options
8585 The command-line options presented below are specific to @command{guix
8592 Build quietly, without displaying the build log; this is equivalent to
8593 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8594 (or similar) and can always be retrieved using the @option{--log-file} option.
8596 @item --file=@var{file}
8597 @itemx -f @var{file}
8598 Build the package, derivation, or other file-like object that the code within
8599 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8601 As an example, @var{file} might contain a package definition like this
8602 (@pxref{Defining Packages}):
8605 @include package-hello.scm
8608 The @var{file} may also contain a JSON representation of one or more
8609 package definitions. Running @code{guix build -f} on @file{hello.json}
8610 with the following contents would result in building the packages
8611 @code{myhello} and @code{greeter}:
8614 @verbatiminclude package-hello.json
8617 @item --manifest=@var{manifest}
8618 @itemx -m @var{manifest}
8619 Build all packages listed in the given @var{manifest}
8620 (@pxref{profile-manifest, @option{--manifest}}).
8622 @item --expression=@var{expr}
8623 @itemx -e @var{expr}
8624 Build the package or derivation @var{expr} evaluates to.
8626 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8627 guile-1.8)}, which unambiguously designates this specific variant of
8628 version 1.8 of Guile.
8630 Alternatively, @var{expr} may be a G-expression, in which case it is used
8631 as a build program passed to @code{gexp->derivation}
8632 (@pxref{G-Expressions}).
8634 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8635 (@pxref{The Store Monad}). The procedure must return a derivation as a
8636 monadic value, which is then passed through @code{run-with-store}.
8640 Build the source derivations of the packages, rather than the packages
8643 For instance, @code{guix build -S gcc} returns something like
8644 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8647 The returned source tarball is the result of applying any patches and
8648 code snippets specified in the package @code{origin} (@pxref{Defining
8651 Note that @command{guix build -S} compiles the sources only of the
8652 specified packages. They do not include the sources of statically
8653 linked dependencies and by themselves are insufficient for reproducing
8657 Fetch and return the source of @var{package-or-derivation} and all their
8658 dependencies, recursively. This is a handy way to obtain a local copy
8659 of all the source code needed to build @var{packages}, allowing you to
8660 eventually build them even without network access. It is an extension
8661 of the @option{--source} option and can accept one of the following
8662 optional argument values:
8666 This value causes the @option{--sources} option to behave in the same way
8667 as the @option{--source} option.
8670 Build the source derivations of all packages, including any source that
8671 might be listed as @code{inputs}. This is the default value.
8674 $ guix build --sources tzdata
8675 The following derivations will be built:
8676 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8677 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8681 Build the source derivations of all packages, as well of all transitive
8682 inputs to the packages. This can be used e.g.@: to
8683 prefetch package source for later offline building.
8686 $ guix build --sources=transitive tzdata
8687 The following derivations will be built:
8688 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8689 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8690 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8691 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8692 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8693 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8699 @item --system=@var{system}
8700 @itemx -s @var{system}
8701 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8702 the system type of the build host. The @command{guix build} command allows
8703 you to repeat this option several times, in which case it builds for all the
8704 specified systems; other commands ignore extraneous @option{-s} options.
8707 The @option{--system} flag is for @emph{native} compilation and must not
8708 be confused with cross-compilation. See @option{--target} below for
8709 information on cross-compilation.
8712 An example use of this is on Linux-based systems, which can emulate
8713 different personalities. For instance, passing
8714 @option{--system=i686-linux} on an @code{x86_64-linux} system or
8715 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
8716 you to build packages in a complete 32-bit environment.
8719 Building for an @code{armhf-linux} system is unconditionally enabled on
8720 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8721 allow for this functionality, notably the ThunderX.
8724 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8725 is enabled (@pxref{Virtualization Services,
8726 @code{qemu-binfmt-service-type}}), you can build for any system for
8727 which a QEMU @code{binfmt_misc} handler is installed.
8729 Builds for a system other than that of the machine you are using can
8730 also be offloaded to a remote machine of the right architecture.
8731 @xref{Daemon Offload Setup}, for more information on offloading.
8733 @item --target=@var{triplet}
8734 @cindex cross-compilation
8735 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8736 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8737 configuration triplets,, autoconf, Autoconf}).
8739 @anchor{build-check}
8741 @cindex determinism, checking
8742 @cindex reproducibility, checking
8743 Rebuild @var{package-or-derivation}, which are already available in the
8744 store, and raise an error if the build results are not bit-for-bit
8747 This mechanism allows you to check whether previously installed
8748 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8749 of a package is deterministic. @xref{Invoking guix challenge}, for more
8750 background information and tools.
8752 When used in conjunction with @option{--keep-failed}, the differing
8753 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8754 This makes it easy to look for differences between the two results.
8757 @cindex repairing store items
8758 @cindex corruption, recovering from
8759 Attempt to repair the specified store items, if they are corrupt, by
8760 re-downloading or rebuilding them.
8762 This operation is not atomic and thus restricted to @code{root}.
8766 Return the derivation paths, not the output paths, of the given
8769 @item --root=@var{file}
8770 @itemx -r @var{file}
8771 @cindex GC roots, adding
8772 @cindex garbage collector roots, adding
8773 Make @var{file} a symlink to the result, and register it as a garbage
8776 Consequently, the results of this @command{guix build} invocation are
8777 protected from garbage collection until @var{file} is removed. When
8778 that option is omitted, build results are eligible for garbage
8779 collection as soon as the build completes. @xref{Invoking guix gc}, for
8783 @cindex build logs, access
8784 Return the build log file names or URLs for the given
8785 @var{package-or-derivation}, or raise an error if build logs are
8788 This works regardless of how packages or derivations are specified. For
8789 instance, the following invocations are equivalent:
8792 guix build --log-file `guix build -d guile`
8793 guix build --log-file `guix build guile`
8794 guix build --log-file guile
8795 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8798 If a log is unavailable locally, and unless @option{--no-substitutes} is
8799 passed, the command looks for a corresponding log on one of the
8800 substitute servers (as specified with @option{--substitute-urls}.)
8802 So for instance, imagine you want to see the build log of GDB on MIPS,
8803 but you are actually on an @code{x86_64} machine:
8806 $ guix build --log-file gdb -s mips64el-linux
8807 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8810 You can freely access a huge library of build logs!
8813 @node Debugging Build Failures
8814 @subsection Debugging Build Failures
8816 @cindex build failures, debugging
8817 When defining a new package (@pxref{Defining Packages}), you will
8818 probably find yourself spending some time debugging and tweaking the
8819 build until it succeeds. To do that, you need to operate the build
8820 commands yourself in an environment as close as possible to the one the
8823 To that end, the first thing to do is to use the @option{--keep-failed}
8824 or @option{-K} option of @command{guix build}, which will keep the
8825 failed build tree in @file{/tmp} or whatever directory you specified as
8826 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
8828 From there on, you can @command{cd} to the failed build tree and source
8829 the @file{environment-variables} file, which contains all the
8830 environment variable definitions that were in place when the build
8831 failed. So let's say you're debugging a build failure in package
8832 @code{foo}; a typical session would look like this:
8836 @dots{} @i{build fails}
8837 $ cd /tmp/guix-build-foo.drv-0
8838 $ source ./environment-variables
8842 Now, you can invoke commands as if you were the daemon (almost) and
8843 troubleshoot your build process.
8845 Sometimes it happens that, for example, a package's tests pass when you
8846 run them manually but they fail when the daemon runs them. This can
8847 happen because the daemon runs builds in containers where, unlike in our
8848 environment above, network access is missing, @file{/bin/sh} does not
8849 exist, etc. (@pxref{Build Environment Setup}).
8851 In such cases, you may need to run inspect the build process from within
8852 a container similar to the one the build daemon creates:
8857 $ cd /tmp/guix-build-foo.drv-0
8858 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8859 [env]# source ./environment-variables
8863 Here, @command{guix environment -C} creates a container and spawns a new
8864 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8865 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8866 the container, which you may find handy while debugging. The
8867 @option{--no-grafts} option makes sure we get the exact same
8868 environment, with ungrafted packages (@pxref{Security Updates}, for more
8871 To get closer to a container like that used by the build daemon, we can
8872 remove @file{/bin/sh}:
8878 (Don't worry, this is harmless: this is all happening in the throw-away
8879 container created by @command{guix environment}.)
8881 The @command{strace} command is probably not in the search path, but we
8885 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8888 In this way, not only you will have reproduced the environment variables
8889 the daemon uses, you will also be running the build process in a container
8890 similar to the one the daemon uses.
8893 @node Invoking guix edit
8894 @section Invoking @command{guix edit}
8896 @cindex @command{guix edit}
8897 @cindex package definition, editing
8898 So many packages, so many source files! The @command{guix edit} command
8899 facilitates the life of users and packagers by pointing their editor at
8900 the source file containing the definition of the specified packages.
8904 guix edit gcc@@4.9 vim
8908 launches the program specified in the @env{VISUAL} or in the
8909 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8912 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8913 have created your own packages on @env{GUIX_PACKAGE_PATH}
8914 (@pxref{Package Modules}), you will be able to edit the package
8915 recipes. In other cases, you will be able to examine the read-only recipes
8916 for packages currently in the store.
8918 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
8919 @option{--load-path=@var{directory}} (or in short @option{-L
8920 @var{directory}}) allows you to add @var{directory} to the front of the
8921 package module search path and so make your own packages visible.
8923 @node Invoking guix download
8924 @section Invoking @command{guix download}
8926 @cindex @command{guix download}
8927 @cindex downloading package sources
8928 When writing a package definition, developers typically need to download
8929 a source tarball, compute its SHA256 hash, and write that
8930 hash in the package definition (@pxref{Defining Packages}). The
8931 @command{guix download} tool helps with this task: it downloads a file
8932 from the given URI, adds it to the store, and prints both its file name
8933 in the store and its SHA256 hash.
8935 The fact that the downloaded file is added to the store saves bandwidth:
8936 when the developer eventually tries to build the newly defined package
8937 with @command{guix build}, the source tarball will not have to be
8938 downloaded again because it is already in the store. It is also a
8939 convenient way to temporarily stash files, which may be deleted
8940 eventually (@pxref{Invoking guix gc}).
8942 The @command{guix download} command supports the same URIs as used in
8943 package definitions. In particular, it supports @code{mirror://} URIs.
8944 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8945 Guile bindings for GnuTLS are available in the user's environment; when
8946 they are not available, an error is raised. @xref{Guile Preparations,
8947 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8948 GnuTLS-Guile}, for more information.
8950 @command{guix download} verifies HTTPS server certificates by loading
8951 the certificates of X.509 authorities from the directory pointed to by
8952 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
8953 Certificates}), unless @option{--no-check-certificate} is used.
8955 The following options are available:
8958 @item --format=@var{fmt}
8960 Write the hash in the format specified by @var{fmt}. For more
8961 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8963 @item --no-check-certificate
8964 Do not validate the X.509 certificates of HTTPS servers.
8966 When using this option, you have @emph{absolutely no guarantee} that you
8967 are communicating with the authentic server responsible for the given
8968 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8970 @item --output=@var{file}
8971 @itemx -o @var{file}
8972 Save the downloaded file to @var{file} instead of adding it to the
8976 @node Invoking guix hash
8977 @section Invoking @command{guix hash}
8979 @cindex @command{guix hash}
8980 The @command{guix hash} command computes the SHA256 hash of a file.
8981 It is primarily a convenience tool for anyone contributing to the
8982 distribution: it computes the cryptographic hash of a file, which can be
8983 used in the definition of a package (@pxref{Defining Packages}).
8985 The general syntax is:
8988 guix hash @var{option} @var{file}
8991 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8992 hash of data read from standard input. @command{guix hash} has the
8997 @item --format=@var{fmt}
8999 Write the hash in the format specified by @var{fmt}.
9001 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
9002 (@code{hex} and @code{hexadecimal} can be used as well).
9004 If the @option{--format} option is not specified, @command{guix hash}
9005 will output the hash in @code{nix-base32}. This representation is used
9006 in the definitions of packages.
9010 Compute the hash on @var{file} recursively.
9012 In this case, the hash is computed on an archive containing @var{file},
9013 including its children if it is a directory. Some of the metadata of
9014 @var{file} is part of the archive; for instance, when @var{file} is a
9015 regular file, the hash is different depending on whether @var{file} is
9016 executable or not. Metadata such as time stamps has no impact on the
9017 hash (@pxref{Invoking guix archive}).
9018 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9023 When combined with @option{--recursive}, exclude version control system
9024 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
9027 As an example, here is how you would compute the hash of a Git checkout,
9028 which is useful when using the @code{git-fetch} method (@pxref{origin
9032 $ git clone http://example.org/foo.git
9038 @node Invoking guix import
9039 @section Invoking @command{guix import}
9041 @cindex importing packages
9042 @cindex package import
9043 @cindex package conversion
9044 @cindex Invoking @command{guix import}
9045 The @command{guix import} command is useful for people who would like to
9046 add a package to the distribution with as little work as
9047 possible---a legitimate demand. The command knows of a few
9048 repositories from which it can ``import'' package metadata. The result
9049 is a package definition, or a template thereof, in the format we know
9050 (@pxref{Defining Packages}).
9052 The general syntax is:
9055 guix import @var{importer} @var{options}@dots{}
9058 @var{importer} specifies the source from which to import package
9059 metadata, and @var{options} specifies a package identifier and other
9060 options specific to @var{importer}.
9062 Some of the importers rely on the ability to run the @command{gpgv} command.
9063 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9066 Currently, the available ``importers'' are:
9070 Import metadata for the given GNU package. This provides a template
9071 for the latest version of that GNU package, including the hash of its
9072 source tarball, and its canonical synopsis and description.
9074 Additional information such as the package dependencies and its
9075 license needs to be figured out manually.
9077 For example, the following command returns a package definition for
9081 guix import gnu hello
9084 Specific command-line options are:
9087 @item --key-download=@var{policy}
9088 As for @command{guix refresh}, specify the policy to handle missing
9089 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9090 refresh, @option{--key-download}}.
9095 Import metadata from the @uref{https://pypi.python.org/, Python Package
9096 Index}. Information is taken from the JSON-formatted description
9097 available at @code{pypi.python.org} and usually includes all the relevant
9098 information, including package dependencies. For maximum efficiency, it
9099 is recommended to install the @command{unzip} utility, so that the
9100 importer can unzip Python wheels and gather data from them.
9102 The command below imports metadata for the @code{itsdangerous} Python
9106 guix import pypi itsdangerous
9112 Traverse the dependency graph of the given upstream package recursively
9113 and generate package expressions for all those packages that are not yet
9119 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9120 is taken from the JSON-formatted description available at
9121 @code{rubygems.org} and includes most relevant information, including
9122 runtime dependencies. There are some caveats, however. The metadata
9123 doesn't distinguish between synopses and descriptions, so the same string
9124 is used for both fields. Additionally, the details of non-Ruby
9125 dependencies required to build native extensions is unavailable and left
9126 as an exercise to the packager.
9128 The command below imports metadata for the @code{rails} Ruby package:
9131 guix import gem rails
9137 Traverse the dependency graph of the given upstream package recursively
9138 and generate package expressions for all those packages that are not yet
9144 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9145 Information is taken from the JSON-formatted metadata provided through
9146 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9147 relevant information, such as module dependencies. License information
9148 should be checked closely. If Perl is available in the store, then the
9149 @code{corelist} utility will be used to filter core modules out of the
9150 list of dependencies.
9152 The command command below imports metadata for the Acme::Boolean Perl
9156 guix import cpan Acme::Boolean
9161 @cindex Bioconductor
9162 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9163 central repository for the @uref{https://r-project.org, GNU@tie{}R
9164 statistical and graphical environment}.
9166 Information is extracted from the @file{DESCRIPTION} file of the package.
9168 The command command below imports metadata for the Cairo R package:
9171 guix import cran Cairo
9174 When @option{--recursive} is added, the importer will traverse the
9175 dependency graph of the given upstream package recursively and generate
9176 package expressions for all those packages that are not yet in Guix.
9178 When @option{--archive=bioconductor} is added, metadata is imported from
9179 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9180 packages for for the analysis and comprehension of high-throughput
9181 genomic data in bioinformatics.
9183 Information is extracted from the @file{DESCRIPTION} file contained in the
9186 The command below imports metadata for the GenomicRanges R package:
9189 guix import cran --archive=bioconductor GenomicRanges
9192 Finally, you can also import R packages that have not yet been published on
9193 CRAN or Bioconductor as long as they are in a git repository. Use
9194 @option{--archive=git} followed by the URL of the git repository:
9197 guix import cran --archive=git https://github.com/immunogenomics/harmony
9203 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9204 comprehensive TeX archive network for TeX packages that are part of the
9205 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9207 Information about the package is obtained through the XML API provided
9208 by CTAN, while the source code is downloaded from the SVN repository of
9209 the Tex Live project. This is done because the CTAN does not keep
9212 The command command below imports metadata for the @code{fontspec}
9216 guix import texlive fontspec
9219 When @option{--archive=@var{directory}} is added, the source code is
9220 downloaded not from the @file{latex} sub-directory of the
9221 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9222 the specified sibling @var{directory} under the same root.
9224 The command below imports metadata for the @code{ifxetex} package from
9225 CTAN while fetching the sources from the directory
9226 @file{texmf/source/generic}:
9229 guix import texlive --archive=generic ifxetex
9233 @cindex JSON, import
9234 Import package metadata from a local JSON file. Consider the following
9235 example package definition in JSON format:
9241 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9242 "build-system": "gnu",
9243 "home-page": "https://www.gnu.org/software/hello/",
9244 "synopsis": "Hello, GNU world: An example GNU package",
9245 "description": "GNU Hello prints a greeting.",
9246 "license": "GPL-3.0+",
9247 "native-inputs": ["gettext"]
9251 The field names are the same as for the @code{<package>} record
9252 (@xref{Defining Packages}). References to other packages are provided
9253 as JSON lists of quoted package specification strings such as
9254 @code{guile} or @code{guile@@2.0}.
9256 The importer also supports a more explicit source definition using the
9257 common fields for @code{<origin>} records:
9263 "method": "url-fetch",
9264 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9266 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9273 The command below reads metadata from the JSON file @code{hello.json}
9274 and outputs a package expression:
9277 guix import json hello.json
9281 Import metadata from a local copy of the source of the
9282 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9283 relies on the @command{nix-instantiate} command of
9284 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9285 typically written in a mixture of Nix-language and Bash code. This
9286 command only imports the high-level package structure that is written in
9287 the Nix language. It normally includes all the basic fields of a
9290 When importing a GNU package, the synopsis and descriptions are replaced
9291 by their canonical upstream variant.
9293 Usually, you will first need to do:
9296 export NIX_REMOTE=daemon
9300 so that @command{nix-instantiate} does not try to open the Nix database.
9302 As an example, the command below imports the package definition of
9303 LibreOffice (more precisely, it imports the definition of the package
9304 bound to the @code{libreoffice} top-level attribute):
9307 guix import nix ~/path/to/nixpkgs libreoffice
9312 Import metadata from the Haskell community's central package archive
9313 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9314 Cabal files and includes all the relevant information, including package
9317 Specific command-line options are:
9322 Read a Cabal file from standard input.
9323 @item --no-test-dependencies
9325 Do not include dependencies required only by the test suites.
9326 @item --cabal-environment=@var{alist}
9327 @itemx -e @var{alist}
9328 @var{alist} is a Scheme alist defining the environment in which the
9329 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9330 @code{arch}, @code{impl} and a string representing the name of a flag.
9331 The value associated with a flag has to be either the symbol
9332 @code{true} or @code{false}. The value associated with other keys
9333 has to conform to the Cabal file format definition. The default value
9334 associated with the keys @code{os}, @code{arch} and @code{impl} is
9335 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9338 Traverse the dependency graph of the given upstream package recursively
9339 and generate package expressions for all those packages that are not yet
9343 The command below imports metadata for the latest version of the
9344 HTTP Haskell package without including test dependencies and
9345 specifying the value of the flag @samp{network-uri} as @code{false}:
9348 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9351 A specific package version may optionally be specified by following the
9352 package name by an at-sign and a version number as in the following example:
9355 guix import hackage mtl@@2.1.3.1
9360 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9361 It takes a package name, looks up the package version included in a
9362 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9363 release and uses the @code{hackage} importer to retrieve its metadata.
9364 Note that it is up to you to select an LTS release compatible with the
9365 GHC compiler used by Guix.
9367 Specific command-line options are:
9370 @item --no-test-dependencies
9372 Do not include dependencies required only by the test suites.
9373 @item --lts-version=@var{version}
9374 @itemx -l @var{version}
9375 @var{version} is the desired LTS release version. If omitted the latest
9379 Traverse the dependency graph of the given upstream package recursively
9380 and generate package expressions for all those packages that are not yet
9384 The command below imports metadata for the HTTP Haskell package
9385 included in the LTS Stackage release version 7.18:
9388 guix import stackage --lts-version=7.18 HTTP
9393 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9394 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9396 Specific command-line options are:
9399 @item --archive=@var{repo}
9400 @itemx -a @var{repo}
9401 @var{repo} identifies the archive repository from which to retrieve the
9402 information. Currently the supported repositories and their identifiers
9406 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9407 identifier. This is the default.
9409 Packages from @code{elpa.gnu.org} are signed with one of the keys
9410 contained in the GnuPG keyring at
9411 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9412 @code{emacs} package (@pxref{Package Installation, ELPA package
9413 signatures,, emacs, The GNU Emacs Manual}).
9416 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9417 @code{melpa-stable} identifier.
9420 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9426 Traverse the dependency graph of the given upstream package recursively
9427 and generate package expressions for all those packages that are not yet
9433 Import metadata from the crates.io Rust package repository
9434 @uref{https://crates.io, crates.io}, as in this example:
9437 guix import crate blake2-rfc
9440 The crate importer also allows you to specify a version string:
9443 guix import crate constant-time-eq@@0.1.0
9446 Additional options include:
9451 Traverse the dependency graph of the given upstream package recursively
9452 and generate package expressions for all those packages that are not yet
9459 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9460 repository used by the OCaml community.
9463 The structure of the @command{guix import} code is modular. It would be
9464 useful to have more importers for other package formats, and your help
9465 is welcome here (@pxref{Contributing}).
9467 @node Invoking guix refresh
9468 @section Invoking @command{guix refresh}
9470 @cindex @command {guix refresh}
9471 The primary audience of the @command{guix refresh} command is developers
9472 of the GNU software distribution. By default, it reports any packages
9473 provided by the distribution that are outdated compared to the latest
9474 upstream version, like this:
9478 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9479 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9482 Alternately, one can specify packages to consider, in which case a
9483 warning is emitted for packages that lack an updater:
9486 $ guix refresh coreutils guile guile-ssh
9487 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9488 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9491 @command{guix refresh} browses the upstream repository of each package and determines
9492 the highest version number of the releases therein. The command
9493 knows how to update specific types of packages: GNU packages, ELPA
9494 packages, etc.---see the documentation for @option{--type} below. There
9495 are many packages, though, for which it lacks a method to determine
9496 whether a new upstream release is available. However, the mechanism is
9497 extensible, so feel free to get in touch with us to add a new method!
9502 Consider the packages specified, and all the packages upon which they depend.
9505 $ guix refresh --recursive coreutils
9506 gnu/packages/acl.scm:35:2: warning: no updater for acl
9507 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9508 gnu/packages/xml.scm:68:2: warning: no updater for expat
9509 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9515 Sometimes the upstream name differs from the package name used in Guix,
9516 and @command{guix refresh} needs a little help. Most updaters honor the
9517 @code{upstream-name} property in package definitions, which can be used
9521 (define-public network-manager
9523 (name "network-manager")
9525 (properties '((upstream-name . "NetworkManager")))))
9528 When passed @option{--update}, it modifies distribution source files to
9529 update the version numbers and source tarball hashes of those package
9530 recipes (@pxref{Defining Packages}). This is achieved by downloading
9531 each package's latest source tarball and its associated OpenPGP
9532 signature, authenticating the downloaded tarball against its signature
9533 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9534 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9537 key used to sign the tarball is missing from the user's keyring, an
9538 attempt is made to automatically retrieve it from a public key server;
9539 when this is successful, the key is added to the user's keyring; otherwise,
9540 @command{guix refresh} reports an error.
9542 The following options are supported:
9546 @item --expression=@var{expr}
9547 @itemx -e @var{expr}
9548 Consider the package @var{expr} evaluates to.
9550 This is useful to precisely refer to a package, as in this example:
9553 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9556 This command lists the dependents of the ``final'' libc (essentially all
9561 Update distribution source files (package recipes) in place. This is
9562 usually run from a checkout of the Guix source tree (@pxref{Running
9563 Guix Before It Is Installed}):
9566 $ ./pre-inst-env guix refresh -s non-core -u
9569 @xref{Defining Packages}, for more information on package definitions.
9571 @item --select=[@var{subset}]
9572 @itemx -s @var{subset}
9573 Select all the packages in @var{subset}, one of @code{core} or
9576 The @code{core} subset refers to all the packages at the core of the
9577 distribution---i.e., packages that are used to build ``everything
9578 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9579 changing one of these packages in the distribution entails a rebuild of
9580 all the others. Thus, such updates are an inconvenience to users in
9581 terms of build time or bandwidth used to achieve the upgrade.
9583 The @code{non-core} subset refers to the remaining packages. It is
9584 typically useful in cases where an update of the core packages would be
9587 @item --manifest=@var{file}
9588 @itemx -m @var{file}
9589 Select all the packages from the manifest in @var{file}. This is useful to
9590 check if any packages of the user manifest can be updated.
9592 @item --type=@var{updater}
9593 @itemx -t @var{updater}
9594 Select only packages handled by @var{updater} (may be a comma-separated
9595 list of updaters). Currently, @var{updater} may be one of:
9599 the updater for GNU packages;
9601 the updater for GNOME packages;
9603 the updater for KDE packages;
9605 the updater for X.org packages;
9607 the updater for packages hosted on kernel.org;
9609 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9611 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9613 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9615 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9617 the updater for @uref{https://pypi.python.org, PyPI} packages.
9619 the updater for @uref{https://rubygems.org, RubyGems} packages.
9621 the updater for @uref{https://github.com, GitHub} packages.
9623 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9625 the updater for @uref{https://www.stackage.org, Stackage} packages.
9627 the updater for @uref{https://crates.io, Crates} packages.
9629 the updater for @uref{https://launchpad.net, Launchpad} packages.
9632 For instance, the following command only checks for updates of Emacs
9633 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9636 $ guix refresh --type=elpa,cran
9637 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9638 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9643 In addition, @command{guix refresh} can be passed one or more package
9644 names, as in this example:
9647 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9651 The command above specifically updates the @code{emacs} and
9652 @code{idutils} packages. The @option{--select} option would have no
9653 effect in this case.
9655 When considering whether to upgrade a package, it is sometimes
9656 convenient to know which packages would be affected by the upgrade and
9657 should be checked for compatibility. For this the following option may
9658 be used when passing @command{guix refresh} one or more package names:
9662 @item --list-updaters
9664 List available updaters and exit (see @option{--type} above.)
9666 For each updater, display the fraction of packages it covers; at the
9667 end, display the fraction of packages covered by all these updaters.
9669 @item --list-dependent
9671 List top-level dependent packages that would need to be rebuilt as a
9672 result of upgrading one or more packages.
9674 @xref{Invoking guix graph, the @code{reverse-package} type of
9675 @command{guix graph}}, for information on how to visualize the list of
9676 dependents of a package.
9680 Be aware that the @option{--list-dependent} option only
9681 @emph{approximates} the rebuilds that would be required as a result of
9682 an upgrade. More rebuilds might be required under some circumstances.
9685 $ guix refresh --list-dependent flex
9686 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9687 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9690 The command above lists a set of packages that could be built to check
9691 for compatibility with an upgraded @code{flex} package.
9695 @item --list-transitive
9696 List all the packages which one or more packages depend upon.
9699 $ guix refresh --list-transitive flex
9700 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9701 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{}
9706 The command above lists a set of packages which, when changed, would cause
9707 @code{flex} to be rebuilt.
9709 The following options can be used to customize GnuPG operation:
9713 @item --gpg=@var{command}
9714 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9715 for in @code{$PATH}.
9717 @item --keyring=@var{file}
9718 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9719 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9720 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9721 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9722 information on a tool to manipulate keybox files).
9724 When this option is omitted, @command{guix refresh} uses
9725 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9726 signing keys. OpenPGP signatures are checked against keys from this keyring;
9727 missing keys are downloaded to this keyring as well (see
9728 @option{--key-download} below.)
9730 You can export keys from your default GPG keyring into a keybox file using
9731 commands like this one:
9734 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9737 Likewise, you can fetch keys to a specific keybox file like this:
9740 gpg --no-default-keyring --keyring mykeyring.kbx \
9741 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9744 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9745 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9747 @item --key-download=@var{policy}
9748 Handle missing OpenPGP keys according to @var{policy}, which may be one
9753 Always download missing OpenPGP keys from the key server, and add them
9754 to the user's GnuPG keyring.
9757 Never try to download missing OpenPGP keys. Instead just bail out.
9760 When a package signed with an unknown OpenPGP key is encountered, ask
9761 the user whether to download it or not. This is the default behavior.
9764 @item --key-server=@var{host}
9765 Use @var{host} as the OpenPGP key server when importing a public key.
9767 @item --load-path=@var{directory}
9768 Add @var{directory} to the front of the package module search path
9769 (@pxref{Package Modules}).
9771 This allows users to define their own packages and make them visible to
9772 the command-line tools.
9776 The @code{github} updater uses the
9777 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9778 releases. When used repeatedly e.g.@: when refreshing all packages,
9779 GitHub will eventually refuse to answer any further API requests. By
9780 default 60 API requests per hour are allowed, and a full refresh on all
9781 GitHub packages in Guix requires more than this. Authentication with
9782 GitHub through the use of an API token alleviates these limits. To use
9783 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
9784 token procured from @uref{https://github.com/settings/tokens} or
9788 @node Invoking guix lint
9789 @section Invoking @command{guix lint}
9791 @cindex @command{guix lint}
9792 @cindex package, checking for errors
9793 The @command{guix lint} command is meant to help package developers avoid
9794 common errors and use a consistent style. It runs a number of checks on
9795 a given set of packages in order to find common mistakes in their
9796 definitions. Available @dfn{checkers} include (see
9797 @option{--list-checkers} for a complete list):
9802 Validate certain typographical and stylistic rules about package
9803 descriptions and synopses.
9805 @item inputs-should-be-native
9806 Identify inputs that should most likely be native inputs.
9812 @itemx source-file-name
9813 Probe @code{home-page} and @code{source} URLs and report those that are
9814 invalid. Suggest a @code{mirror://} URL when applicable. If the
9815 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9816 URL. Check that the source file name is meaningful, e.g.@: is not just a
9817 version number or ``git-checkout'', without a declared @code{file-name}
9818 (@pxref{origin Reference}).
9820 @item source-unstable-tarball
9821 Parse the @code{source} URL to determine if a tarball from GitHub is
9822 autogenerated or if it is a release tarball. Unfortunately GitHub's
9823 autogenerated tarballs are sometimes regenerated.
9826 @cindex Software Heritage, source code archive
9827 @cindex archival of source code, Software Heritage
9828 Checks whether the package's source code is archived at
9829 @uref{https://www.softwareheritage.org, Software Heritage}.
9831 When the source code that is not archived comes from a version-control system
9832 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9833 ``save'' request so that it eventually archives it. This ensures that the
9834 source will remain available in the long term, and that Guix can fall back to
9835 Software Heritage should the source code disappear from its original host.
9836 The status of recent ``save'' requests can be
9837 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9839 When source code is a tarball obtained with @code{url-fetch}, simply print a
9840 message when it is not archived. As of this writing, Software Heritage does
9841 not allow requests to save arbitrary tarballs; we are working on ways to
9842 ensure that non-VCS source code is also archived.
9845 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9846 request rate per IP address}. When the limit is reached, @command{guix lint}
9847 prints a message and the @code{archival} checker stops doing anything until
9848 that limit has been reset.
9851 @cindex security vulnerabilities
9852 @cindex CVE, Common Vulnerabilities and Exposures
9853 Report known vulnerabilities found in the Common Vulnerabilities and
9854 Exposures (CVE) databases of the current and past year
9855 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9858 To view information about a particular vulnerability, visit pages such as:
9862 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9864 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9868 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9869 @code{CVE-2015-7554}.
9871 Package developers can specify in package recipes the
9872 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9873 name and version of the package when they differ from the name or version
9874 that Guix uses, as in this example:
9880 ;; CPE calls this package "grub2".
9881 (properties '((cpe-name . "grub2")
9882 (cpe-version . "2.3"))))
9885 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9886 Some entries in the CVE database do not specify which version of a
9887 package they apply to, and would thus ``stick around'' forever. Package
9888 developers who found CVE alerts and verified they can be ignored can
9889 declare them as in this example:
9895 ;; These CVEs no longer apply and can be safely ignored.
9896 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9899 "CVE-2011-5244")))))
9903 Warn about obvious source code formatting issues: trailing white space,
9904 use of tabulations, etc.
9907 The general syntax is:
9910 guix lint @var{options} @var{package}@dots{}
9913 If no package is given on the command line, then all packages are checked.
9914 The @var{options} may be zero or more of the following:
9917 @item --list-checkers
9919 List and describe all the available checkers that will be run on packages
9924 Only enable the checkers specified in a comma-separated list using the
9925 names returned by @option{--list-checkers}.
9927 @item --load-path=@var{directory}
9928 @itemx -L @var{directory}
9929 Add @var{directory} to the front of the package module search path
9930 (@pxref{Package Modules}).
9932 This allows users to define their own packages and make them visible to
9933 the command-line tools.
9937 @node Invoking guix size
9938 @section Invoking @command{guix size}
9941 @cindex package size
9943 @cindex @command{guix size}
9944 The @command{guix size} command helps package developers profile the
9945 disk usage of packages. It is easy to overlook the impact of an
9946 additional dependency added to a package, or the impact of using a
9947 single output for a package that could easily be split (@pxref{Packages
9948 with Multiple Outputs}). Such are the typical issues that
9949 @command{guix size} can highlight.
9951 The command can be passed one or more package specifications
9952 such as @code{gcc@@4.8}
9953 or @code{guile:debug}, or a file name in the store. Consider this
9957 $ guix size coreutils
9958 store item total self
9959 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9960 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9961 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9962 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9963 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9964 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9965 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9966 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9971 The store items listed here constitute the @dfn{transitive closure} of
9972 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9973 would be returned by:
9976 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9979 Here the output shows three columns next to store items. The first column,
9980 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9981 the store item---that is, its own size plus the size of all its
9982 dependencies. The next column, labeled ``self'', shows the size of the
9983 item itself. The last column shows the ratio of the size of the item
9984 itself to the space occupied by all the items listed here.
9986 In this example, we see that the closure of Coreutils weighs in at
9987 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9988 libraries. (That libc and GCC's libraries represent a large fraction of
9989 the closure is not a problem @i{per se} because they are always available
9990 on the system anyway.)
9992 When the package(s) passed to @command{guix size} are available in the
9993 store@footnote{More precisely, @command{guix size} looks for the
9994 @emph{ungrafted} variant of the given package(s), as returned by
9995 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9996 for information on grafts.}, @command{guix size} queries the daemon to determine its
9997 dependencies, and measures its size in the store, similar to @command{du
9998 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10001 When the given packages are @emph{not} in the store, @command{guix size}
10002 reports information based on the available substitutes
10003 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10004 store items that are not even on disk, only available remotely.
10006 You can also specify several package names:
10009 $ guix size coreutils grep sed bash
10010 store item total self
10011 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10012 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10013 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10014 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10020 In this example we see that the combination of the four packages takes
10021 102.3@tie{}MiB in total, which is much less than the sum of each closure
10022 since they have a lot of dependencies in common.
10024 When looking at the profile returned by @command{guix size}, you may
10025 find yourself wondering why a given package shows up in the profile at
10026 all. To understand it, you can use @command{guix graph --path -t
10027 references} to display the shortest path between the two packages
10028 (@pxref{Invoking guix graph}).
10030 The available options are:
10034 @item --substitute-urls=@var{urls}
10035 Use substitute information from @var{urls}.
10036 @xref{client-substitute-urls, the same option for @code{guix build}}.
10038 @item --sort=@var{key}
10039 Sort lines according to @var{key}, one of the following options:
10043 the size of each item (the default);
10045 the total size of the item's closure.
10048 @item --map-file=@var{file}
10049 Write a graphical map of disk usage in PNG format to @var{file}.
10051 For the example above, the map looks like this:
10053 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10054 produced by @command{guix size}}
10056 This option requires that
10057 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10058 installed and visible in Guile's module search path. When that is not
10059 the case, @command{guix size} fails as it tries to load it.
10061 @item --system=@var{system}
10062 @itemx -s @var{system}
10063 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10065 @item --load-path=@var{directory}
10066 @itemx -L @var{directory}
10067 Add @var{directory} to the front of the package module search path
10068 (@pxref{Package Modules}).
10070 This allows users to define their own packages and make them visible to
10071 the command-line tools.
10074 @node Invoking guix graph
10075 @section Invoking @command{guix graph}
10078 @cindex @command{guix graph}
10079 @cindex package dependencies
10080 Packages and their dependencies form a @dfn{graph}, specifically a
10081 directed acyclic graph (DAG). It can quickly become difficult to have a
10082 mental model of the package DAG, so the @command{guix graph} command
10083 provides a visual representation of the DAG. By default,
10084 @command{guix graph} emits a DAG representation in the input format of
10085 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10086 directly to the @command{dot} command of Graphviz. It can also emit an
10087 HTML page with embedded JavaScript code to display a ``chord diagram''
10088 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10089 emit Cypher queries to construct a graph in a graph database supporting
10090 the @uref{https://www.opencypher.org/, openCypher} query language. With
10091 @option{--path}, it simply displays the shortest path between two
10092 packages. The general syntax is:
10095 guix graph @var{options} @var{package}@dots{}
10098 For example, the following command generates a PDF file representing the
10099 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10103 guix graph coreutils | dot -Tpdf > dag.pdf
10106 The output looks like this:
10108 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10110 Nice little graph, no?
10112 You may find it more pleasant to navigate the graph interactively with
10113 @command{xdot} (from the @code{xdot} package):
10116 guix graph coreutils | xdot -
10119 But there is more than one graph! The one above is concise: it is the
10120 graph of package objects, omitting implicit inputs such as GCC, libc,
10121 grep, etc. It is often useful to have such a concise graph, but
10122 sometimes one may want to see more details. @command{guix graph} supports
10123 several types of graphs, allowing you to choose the level of detail:
10127 This is the default type used in the example above. It shows the DAG of
10128 package objects, excluding implicit dependencies. It is concise, but
10129 filters out many details.
10131 @item reverse-package
10132 This shows the @emph{reverse} DAG of packages. For example:
10135 guix graph --type=reverse-package ocaml
10138 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10139 you are also interested in cases where OCaml is an implicit dependency, see
10140 @code{reverse-bag} below.)
10142 Note that for core packages this can yield huge graphs. If all you want
10143 is to know the number of packages that depend on a given package, use
10144 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10145 @option{--list-dependent}}).
10148 This is the package DAG, @emph{including} implicit inputs.
10150 For instance, the following command:
10153 guix graph --type=bag-emerged coreutils
10156 ...@: yields this bigger graph:
10158 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10160 At the bottom of the graph, we see all the implicit inputs of
10161 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10163 Now, note that the dependencies of these implicit inputs---that is, the
10164 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10165 here, for conciseness.
10168 Similar to @code{bag-emerged}, but this time including all the bootstrap
10171 @item bag-with-origins
10172 Similar to @code{bag}, but also showing origins and their dependencies.
10175 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10176 it also takes implicit dependencies into account. For example:
10179 guix graph -t reverse-bag dune
10183 ...@: yields the graph of all packages that depend on Dune, directly or
10184 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10185 @i{via} @code{dune-build-system}, this shows a large number of packages,
10186 whereas @code{reverse-package} would show very few if any.
10189 This is the most detailed representation: It shows the DAG of
10190 derivations (@pxref{Derivations}) and plain store items. Compared to
10191 the above representation, many additional nodes are visible, including
10192 build scripts, patches, Guile modules, etc.
10194 For this type of graph, it is also possible to pass a @file{.drv} file
10195 name instead of a package name, as in:
10198 guix graph -t derivation `guix system build -d my-config.scm`
10202 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10203 For example, the following command shows the graph for the package
10204 module that defines the @code{guile} package:
10207 guix graph -t module guile | xdot -
10211 All the types above correspond to @emph{build-time dependencies}. The
10212 following graph type represents the @emph{run-time dependencies}:
10216 This is the graph of @dfn{references} of a package output, as returned
10217 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10219 If the given package output is not available in the store, @command{guix
10220 graph} attempts to obtain dependency information from substitutes.
10222 Here you can also pass a store file name instead of a package name. For
10223 example, the command below produces the reference graph of your profile
10224 (which can be big!):
10227 guix graph -t references `readlink -f ~/.guix-profile`
10231 This is the graph of the @dfn{referrers} of a store item, as returned by
10232 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10234 This relies exclusively on local information from your store. For
10235 instance, let us suppose that the current Inkscape is available in 10
10236 profiles on your machine; @command{guix graph -t referrers inkscape}
10237 will show a graph rooted at Inkscape and with those 10 profiles linked
10240 It can help determine what is preventing a store item from being garbage
10245 @cindex shortest path, between packages
10246 Often, the graph of the package you are interested in does not fit on
10247 your screen, and anyway all you want to know is @emph{why} that package
10248 actually depends on some seemingly unrelated package. The
10249 @option{--path} option instructs @command{guix graph} to display the
10250 shortest path between two packages (or derivations, or store items,
10254 $ guix graph --path emacs libunistring
10257 libunistring@@0.9.10
10258 $ guix graph --path -t derivation emacs libunistring
10259 /gnu/store/@dots{}-emacs-26.3.drv
10260 /gnu/store/@dots{}-mailutils-3.9.drv
10261 /gnu/store/@dots{}-libunistring-0.9.10.drv
10262 $ guix graph --path -t references emacs libunistring
10263 /gnu/store/@dots{}-emacs-26.3
10264 /gnu/store/@dots{}-libidn2-2.2.0
10265 /gnu/store/@dots{}-libunistring-0.9.10
10268 The available options are the following:
10271 @item --type=@var{type}
10272 @itemx -t @var{type}
10273 Produce a graph output of @var{type}, where @var{type} must be one of
10274 the values listed above.
10277 List the supported graph types.
10279 @item --backend=@var{backend}
10280 @itemx -b @var{backend}
10281 Produce a graph using the selected @var{backend}.
10283 @item --list-backends
10284 List the supported graph backends.
10286 Currently, the available backends are Graphviz and d3.js.
10289 Display the shortest path between two nodes of the type specified by
10290 @option{--type}. The example below shows the shortest path between
10291 @code{libreoffice} and @code{llvm} according to the references of
10292 @code{libreoffice}:
10295 $ guix graph --path -t references libreoffice llvm
10296 /gnu/store/@dots{}-libreoffice-6.4.2.2
10297 /gnu/store/@dots{}-libepoxy-1.5.4
10298 /gnu/store/@dots{}-mesa-19.3.4
10299 /gnu/store/@dots{}-llvm-9.0.1
10302 @item --expression=@var{expr}
10303 @itemx -e @var{expr}
10304 Consider the package @var{expr} evaluates to.
10306 This is useful to precisely refer to a package, as in this example:
10309 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10312 @item --system=@var{system}
10313 @itemx -s @var{system}
10314 Display the graph for @var{system}---e.g., @code{i686-linux}.
10316 The package dependency graph is largely architecture-independent, but there
10317 are some architecture-dependent bits that this option allows you to visualize.
10319 @item --load-path=@var{directory}
10320 @itemx -L @var{directory}
10321 Add @var{directory} to the front of the package module search path
10322 (@pxref{Package Modules}).
10324 This allows users to define their own packages and make them visible to
10325 the command-line tools.
10328 On top of that, @command{guix graph} supports all the usual package
10329 transformation options (@pxref{Package Transformation Options}). This
10330 makes it easy to view the effect of a graph-rewriting transformation
10331 such as @option{--with-input}. For example, the command below outputs
10332 the graph of @code{git} once @code{openssl} has been replaced by
10333 @code{libressl} everywhere in the graph:
10336 guix graph git --with-input=openssl=libressl
10339 So many possibilities, so much fun!
10341 @node Invoking guix publish
10342 @section Invoking @command{guix publish}
10344 @cindex @command{guix publish}
10345 The purpose of @command{guix publish} is to enable users to easily share
10346 their store with others, who can then use it as a substitute server
10347 (@pxref{Substitutes}).
10349 When @command{guix publish} runs, it spawns an HTTP server which allows
10350 anyone with network access to obtain substitutes from it. This means
10351 that any machine running Guix can also act as if it were a build farm,
10352 since the HTTP interface is compatible with Cuirass, the software behind
10353 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10355 For security, each substitute is signed, allowing recipients to check
10356 their authenticity and integrity (@pxref{Substitutes}). Because
10357 @command{guix publish} uses the signing key of the system, which is only
10358 readable by the system administrator, it must be started as root; the
10359 @option{--user} option makes it drop root privileges early on.
10361 The signing key pair must be generated before @command{guix publish} is
10362 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10365 The general syntax is:
10368 guix publish @var{options}@dots{}
10371 Running @command{guix publish} without any additional arguments will
10372 spawn an HTTP server on port 8080:
10378 Once a publishing server has been authorized (@pxref{Invoking guix
10379 archive}), the daemon may download substitutes from it:
10382 guix-daemon --substitute-urls=http://example.org:8080
10385 By default, @command{guix publish} compresses archives on the fly as it
10386 serves them. This ``on-the-fly'' mode is convenient in that it requires
10387 no setup and is immediately available. However, when serving lots of
10388 clients, we recommend using the @option{--cache} option, which enables
10389 caching of the archives before they are sent to clients---see below for
10390 details. The @command{guix weather} command provides a handy way to
10391 check what a server provides (@pxref{Invoking guix weather}).
10393 As a bonus, @command{guix publish} also serves as a content-addressed
10394 mirror for source files referenced in @code{origin} records
10395 (@pxref{origin Reference}). For instance, assuming @command{guix
10396 publish} is running on @code{example.org}, the following URL returns the
10397 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10398 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10401 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10404 Obviously, these URLs only work for files that are in the store; in
10405 other cases, they return 404 (``Not Found'').
10407 @cindex build logs, publication
10408 Build logs are available from @code{/log} URLs like:
10411 http://example.org/log/gwspk@dots{}-guile-2.2.3
10415 When @command{guix-daemon} is configured to save compressed build logs,
10416 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10417 URLs return the compressed log as-is, with an appropriate
10418 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10419 running @command{guix-daemon} with @option{--log-compression=gzip} since
10420 Web browsers can automatically decompress it, which is not the case with
10423 The following options are available:
10426 @item --port=@var{port}
10427 @itemx -p @var{port}
10428 Listen for HTTP requests on @var{port}.
10430 @item --listen=@var{host}
10431 Listen on the network interface for @var{host}. The default is to
10432 accept connections from any interface.
10434 @item --user=@var{user}
10435 @itemx -u @var{user}
10436 Change privileges to @var{user} as soon as possible---i.e., once the
10437 server socket is open and the signing key has been read.
10439 @item --compression[=@var{method}[:@var{level}]]
10440 @itemx -C [@var{method}[:@var{level}]]
10441 Compress data using the given @var{method} and @var{level}. @var{method} is
10442 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10445 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10446 to different compression levels: 1 is the fastest, and 9 is the best
10447 (CPU-intensive). The default is 3.
10449 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10450 increase in CPU usage; see
10451 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10454 Unless @option{--cache} is used, compression occurs on the fly and
10455 the compressed streams are not
10456 cached. Thus, to reduce load on the machine that runs @command{guix
10457 publish}, it may be a good idea to choose a low compression level, to
10458 run @command{guix publish} behind a caching proxy, or to use
10459 @option{--cache}. Using @option{--cache} has the advantage that it
10460 allows @command{guix publish} to add @code{Content-Length} HTTP header
10463 This option can be repeated, in which case every substitute gets compressed
10464 using all the selected methods, and all of them are advertised. This is
10465 useful when users may not support all the compression methods: they can select
10466 the one they support.
10468 @item --cache=@var{directory}
10469 @itemx -c @var{directory}
10470 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10471 and only serve archives that are in cache.
10473 When this option is omitted, archives and meta-data are created
10474 on-the-fly. This can reduce the available bandwidth, especially when
10475 compression is enabled, since this may become CPU-bound. Another
10476 drawback of the default mode is that the length of archives is not known
10477 in advance, so @command{guix publish} does not add a
10478 @code{Content-Length} HTTP header to its responses, which in turn
10479 prevents clients from knowing the amount of data being downloaded.
10481 Conversely, when @option{--cache} is used, the first request for a store
10482 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10483 background process to @dfn{bake} the archive---computing its
10484 @code{.narinfo} and compressing the archive, if needed. Once the
10485 archive is cached in @var{directory}, subsequent requests succeed and
10486 are served directly from the cache, which guarantees that clients get
10487 the best possible bandwidth.
10489 The ``baking'' process is performed by worker threads. By default, one
10490 thread per CPU core is created, but this can be customized. See
10491 @option{--workers} below.
10493 When @option{--ttl} is used, cached entries are automatically deleted
10494 when they have expired.
10496 @item --workers=@var{N}
10497 When @option{--cache} is used, request the allocation of @var{N} worker
10498 threads to ``bake'' archives.
10500 @item --ttl=@var{ttl}
10501 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10502 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10503 days, @code{1m} means 1 month, and so on.
10505 This allows the user's Guix to keep substitute information in cache for
10506 @var{ttl}. However, note that @code{guix publish} does not itself
10507 guarantee that the store items it provides will indeed remain available
10508 for as long as @var{ttl}.
10510 Additionally, when @option{--cache} is used, cached entries that have
10511 not been accessed for @var{ttl} and that no longer have a corresponding
10512 item in the store, may be deleted.
10514 @item --nar-path=@var{path}
10515 Use @var{path} as the prefix for the URLs of ``nar'' files
10516 (@pxref{Invoking guix archive, normalized archives}).
10518 By default, nars are served at a URL such as
10519 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10520 change the @code{/nar} part to @var{path}.
10522 @item --public-key=@var{file}
10523 @itemx --private-key=@var{file}
10524 Use the specific @var{file}s as the public/private key pair used to sign
10525 the store items being published.
10527 The files must correspond to the same key pair (the private key is used
10528 for signing and the public key is merely advertised in the signature
10529 metadata). They must contain keys in the canonical s-expression format
10530 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10531 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10532 @file{/etc/guix/signing-key.sec} are used.
10534 @item --repl[=@var{port}]
10535 @itemx -r [@var{port}]
10536 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10537 Reference Manual}) on @var{port} (37146 by default). This is used
10538 primarily for debugging a running @command{guix publish} server.
10541 Enabling @command{guix publish} on Guix System is a one-liner: just
10542 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10543 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10544 @code{guix-publish-service-type}}).
10546 If you are instead running Guix on a ``foreign distro'', follow these
10551 If your host distro uses the systemd init system:
10554 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10555 /etc/systemd/system/
10556 # systemctl start guix-publish && systemctl enable guix-publish
10560 If your host distro uses the Upstart init system:
10563 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10564 # start guix-publish
10568 Otherwise, proceed similarly with your distro's init system.
10571 @node Invoking guix challenge
10572 @section Invoking @command{guix challenge}
10574 @cindex reproducible builds
10575 @cindex verifiable builds
10576 @cindex @command{guix challenge}
10578 Do the binaries provided by this server really correspond to the source
10579 code it claims to build? Is a package build process deterministic?
10580 These are the questions the @command{guix challenge} command attempts to
10583 The former is obviously an important question: Before using a substitute
10584 server (@pxref{Substitutes}), one had better @emph{verify} that it
10585 provides the right binaries, and thus @emph{challenge} it. The latter
10586 is what enables the former: If package builds are deterministic, then
10587 independent builds of the package should yield the exact same result,
10588 bit for bit; if a server provides a binary different from the one
10589 obtained locally, it may be either corrupt or malicious.
10591 We know that the hash that shows up in @file{/gnu/store} file names is
10592 the hash of all the inputs of the process that built the file or
10593 directory---compilers, libraries, build scripts,
10594 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10595 one store file name should map to exactly one build output.
10596 @command{guix challenge} checks whether there is, indeed, a single
10597 mapping by comparing the build outputs of several independent builds of
10598 any given store item.
10600 The command output looks like this:
10603 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10604 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10605 updating list of substitutes from 'https://guix.example.org'... 100.0%
10606 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10607 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10608 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10609 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10611 /lib/libcrypto.so.1.1
10614 /gnu/store/@dots{}-git-2.5.0 contents differ:
10615 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10616 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10617 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10619 /libexec/git-core/git-fsck
10621 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10622 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10623 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10624 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10626 /share/man/man1/pius.1.gz
10630 6,406 store items were analyzed:
10631 - 4,749 (74.1%) were identical
10632 - 525 (8.2%) differed
10633 - 1,132 (17.7%) were inconclusive
10637 In this example, @command{guix challenge} first scans the store to
10638 determine the set of locally-built derivations---as opposed to store
10639 items that were downloaded from a substitute server---and then queries
10640 all the substitute servers. It then reports those store items for which
10641 the servers obtained a result different from the local build.
10643 @cindex non-determinism, in package builds
10644 As an example, @code{guix.example.org} always gets a different answer.
10645 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10646 case of Git. This might indicate that the build process of Git is
10647 non-deterministic, meaning that its output varies as a function of
10648 various things that Guix does not fully control, in spite of building
10649 packages in isolated environments (@pxref{Features}). Most common
10650 sources of non-determinism include the addition of timestamps in build
10651 results, the inclusion of random numbers, and directory listings sorted
10652 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10655 To find out what is wrong with this Git binary, the easiest approach is
10659 guix challenge git \
10660 --diff=diffoscope \
10661 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10664 This automatically invokes @command{diffoscope}, which displays detailed
10665 information about files that differ.
10667 Alternately, we can do something along these lines (@pxref{Invoking guix
10671 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
10672 | lzip -d | guix archive -x /tmp/git
10673 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10676 This command shows the difference between the files resulting from the
10677 local build, and the files resulting from the build on
10678 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10679 diffutils, Comparing and Merging Files}). The @command{diff} command
10680 works great for text files. When binary files differ, a better option
10681 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10682 visualize differences for all kinds of files.
10684 Once you have done that work, you can tell whether the differences are due
10685 to a non-deterministic build process or to a malicious server. We try
10686 hard to remove sources of non-determinism in packages to make it easier
10687 to verify substitutes, but of course, this is a process that
10688 involves not just Guix, but a large part of the free software community.
10689 In the meantime, @command{guix challenge} is one tool to help address
10692 If you are writing packages for Guix, you are encouraged to check
10693 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10694 same build result as you did with:
10697 $ guix challenge @var{package}
10701 where @var{package} is a package specification such as
10702 @code{guile@@2.0} or @code{glibc:debug}.
10704 The general syntax is:
10707 guix challenge @var{options} [@var{packages}@dots{}]
10710 When a difference is found between the hash of a locally-built item and
10711 that of a server-provided substitute, or among substitutes provided by
10712 different servers, the command displays it as in the example above and
10713 its exit code is 2 (other non-zero exit codes denote other kinds of
10716 The one option that matters is:
10720 @item --substitute-urls=@var{urls}
10721 Consider @var{urls} the whitespace-separated list of substitute source
10722 URLs to compare to.
10724 @item --diff=@var{mode}
10725 Upon mismatches, show differences according to @var{mode}, one of:
10728 @item @code{simple} (the default)
10729 Show the list of files that differ.
10731 @item @code{diffoscope}
10732 @itemx @var{command}
10733 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10734 two directories whose contents do not match.
10736 When @var{command} is an absolute file name, run @var{command} instead
10740 Do not show further details about the differences.
10743 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
10744 downloads the store items from the given substitute servers so that it
10749 Show details about matches (identical contents) in addition to
10750 information about mismatches.
10754 @node Invoking guix copy
10755 @section Invoking @command{guix copy}
10757 @cindex copy, of store items, over SSH
10758 @cindex SSH, copy of store items
10759 @cindex sharing store items across machines
10760 @cindex transferring store items across machines
10761 The @command{guix copy} command copies items from the store of one
10762 machine to that of another machine over a secure shell (SSH)
10763 connection@footnote{This command is available only when Guile-SSH was
10764 found. @xref{Requirements}, for details.}. For example, the following
10765 command copies the @code{coreutils} package, the user's profile, and all
10766 their dependencies over to @var{host}, logged in as @var{user}:
10769 guix copy --to=@var{user}@@@var{host} \
10770 coreutils `readlink -f ~/.guix-profile`
10773 If some of the items to be copied are already present on @var{host},
10774 they are not actually sent.
10776 The command below retrieves @code{libreoffice} and @code{gimp} from
10777 @var{host}, assuming they are available there:
10780 guix copy --from=@var{host} libreoffice gimp
10783 The SSH connection is established using the Guile-SSH client, which is
10784 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10785 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10787 The key used to sign items that are sent must be accepted by the remote
10788 machine. Likewise, the key used by the remote machine to sign items you
10789 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10790 own daemon. @xref{Invoking guix archive}, for more information about
10791 store item authentication.
10793 The general syntax is:
10796 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10799 You must always specify one of the following options:
10802 @item --to=@var{spec}
10803 @itemx --from=@var{spec}
10804 Specify the host to send to or receive from. @var{spec} must be an SSH
10805 spec such as @code{example.org}, @code{charlie@@example.org}, or
10806 @code{charlie@@example.org:2222}.
10809 The @var{items} can be either package names, such as @code{gimp}, or
10810 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10812 When specifying the name of a package to send, it is first built if
10813 needed, unless @option{--dry-run} was specified. Common build options
10814 are supported (@pxref{Common Build Options}).
10817 @node Invoking guix container
10818 @section Invoking @command{guix container}
10820 @cindex @command{guix container}
10822 As of version @value{VERSION}, this tool is experimental. The interface
10823 is subject to radical change in the future.
10826 The purpose of @command{guix container} is to manipulate processes
10827 running within an isolated environment, commonly known as a
10828 ``container'', typically created by the @command{guix environment}
10829 (@pxref{Invoking guix environment}) and @command{guix system container}
10830 (@pxref{Invoking guix system}) commands.
10832 The general syntax is:
10835 guix container @var{action} @var{options}@dots{}
10838 @var{action} specifies the operation to perform with a container, and
10839 @var{options} specifies the context-specific arguments for the action.
10841 The following actions are available:
10845 Execute a command within the context of a running container.
10850 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10853 @var{pid} specifies the process ID of the running container.
10854 @var{program} specifies an executable file name within the root file
10855 system of the container. @var{arguments} are the additional options that
10856 will be passed to @var{program}.
10858 The following command launches an interactive login shell inside a
10859 Guix system container, started by @command{guix system container}, and whose
10860 process ID is 9001:
10863 guix container exec 9001 /run/current-system/profile/bin/bash --login
10866 Note that the @var{pid} cannot be the parent process of a container. It
10867 must be PID 1 of the container or one of its child processes.
10871 @node Invoking guix weather
10872 @section Invoking @command{guix weather}
10874 Occasionally you're grumpy because substitutes are lacking and you end
10875 up building packages by yourself (@pxref{Substitutes}). The
10876 @command{guix weather} command reports on substitute availability on the
10877 specified servers so you can have an idea of whether you'll be grumpy
10878 today. It can sometimes be useful info as a user, but it is primarily
10879 useful to people running @command{guix publish} (@pxref{Invoking guix
10882 @cindex statistics, for substitutes
10883 @cindex availability of substitutes
10884 @cindex substitute availability
10885 @cindex weather, substitute availability
10886 Here's a sample run:
10889 $ guix weather --substitute-urls=https://guix.example.org
10890 computing 5,872 package derivations for x86_64-linux...
10891 looking for 6,128 store items on https://guix.example.org..
10892 updating list of substitutes from 'https://guix.example.org'... 100.0%
10893 https://guix.example.org
10894 43.4% substitutes available (2,658 out of 6,128)
10895 7,032.5 MiB of nars (compressed)
10896 19,824.2 MiB on disk (uncompressed)
10897 0.030 seconds per request (182.9 seconds in total)
10898 33.5 requests per second
10900 9.8% (342 out of 3,470) of the missing items are queued
10902 x86_64-linux: 518 (59.7%)
10903 i686-linux: 221 (25.5%)
10904 aarch64-linux: 128 (14.8%)
10905 build rate: 23.41 builds per hour
10906 x86_64-linux: 11.16 builds per hour
10907 i686-linux: 6.03 builds per hour
10908 aarch64-linux: 6.41 builds per hour
10911 @cindex continuous integration, statistics
10912 As you can see, it reports the fraction of all the packages for which
10913 substitutes are available on the server---regardless of whether
10914 substitutes are enabled, and regardless of whether this server's signing
10915 key is authorized. It also reports the size of the compressed archives
10916 (``nars'') provided by the server, the size the corresponding store
10917 items occupy in the store (assuming deduplication is turned off), and
10918 the server's throughput. The second part gives continuous integration
10919 (CI) statistics, if the server supports it. In addition, using the
10920 @option{--coverage} option, @command{guix weather} can list ``important''
10921 package substitutes missing on the server (see below).
10923 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10924 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10925 challenge}, it ignores signatures on those substitutes, which is
10926 innocuous since the command only gathers statistics and cannot install
10929 The general syntax is:
10932 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10935 When @var{packages} is omitted, @command{guix weather} checks the availability
10936 of substitutes for @emph{all} the packages, or for those specified with
10937 @option{--manifest}; otherwise it only considers the specified packages. It
10938 is also possible to query specific system types with @option{--system}.
10939 @command{guix weather} exits with a non-zero code when the fraction of
10940 available substitutes is below 100%.
10942 The available options are listed below.
10945 @item --substitute-urls=@var{urls}
10946 @var{urls} is the space-separated list of substitute server URLs to
10947 query. When this option is omitted, the default set of substitute
10948 servers is queried.
10950 @item --system=@var{system}
10951 @itemx -s @var{system}
10952 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10953 option can be repeated, in which case @command{guix weather} will query
10954 substitutes for several system types.
10956 @item --manifest=@var{file}
10957 Instead of querying substitutes for all the packages, only ask for those
10958 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10959 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10962 This option can be repeated several times, in which case the manifests
10965 @item --coverage[=@var{count}]
10966 @itemx -c [@var{count}]
10967 Report on substitute coverage for packages: list packages with at least
10968 @var{count} dependents (zero by default) for which substitutes are
10969 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10970 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10971 @var{b} usually lacks substitutes as well. The result looks like this:
10974 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10975 computing 8,983 package derivations for x86_64-linux...
10976 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10977 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10978 @value{SUBSTITUTE-URL}
10979 64.7% substitutes available (6,047 out of 9,343)
10981 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10982 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10983 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10984 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10988 What this example shows is that @code{kcoreaddons} and presumably the 58
10989 packages that depend on it have no substitutes at @code{ci.guix.info};
10990 likewise for @code{qgpgme} and the 46 packages that depend on it.
10992 If you are a Guix developer, or if you are taking care of this build farm,
10993 you'll probably want to have a closer look at these packages: they may simply
10996 @item --display-missing
10997 Display the list of store items for which substitutes are missing.
11000 @node Invoking guix processes
11001 @section Invoking @command{guix processes}
11003 The @command{guix processes} command can be useful to developers and system
11004 administrators, especially on multi-user machines and on build farms: it lists
11005 the current sessions (connections to the daemon), as well as information about
11006 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11007 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11008 listed.}. Here's an example of the information it returns:
11011 $ sudo guix processes
11014 ClientCommand: guix environment --ad-hoc python
11018 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11022 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11023 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11024 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11025 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11026 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11027 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11028 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11031 In this example we see that @command{guix-daemon} has three clients:
11032 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11033 integration tool; their process identifier (PID) is given by the
11034 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11035 @command{guix-daemon} sub-process of this particular session.
11037 The @code{LockHeld} fields show which store items are currently locked by this
11038 session, which corresponds to store items being built or substituted (the
11039 @code{LockHeld} field is not displayed when @command{guix processes} is not
11040 running as root.) Last, by looking at the @code{ChildProcess} field, we
11041 understand that these three builds are being offloaded (@pxref{Daemon Offload
11044 The output is in Recutils format so we can use the handy @command{recsel}
11045 command to select sessions of interest (@pxref{Selection Expressions,,,
11046 recutils, GNU recutils manual}). As an example, the command shows the command
11047 line and PID of the client that triggered the build of a Perl package:
11050 $ sudo guix processes | \
11051 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11053 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11056 @node System Configuration
11057 @chapter System Configuration
11059 @cindex system configuration
11060 Guix System supports a consistent whole-system configuration
11061 mechanism. By that we mean that all aspects of the global system
11062 configuration---such as the available system services, timezone and
11063 locale settings, user accounts---are declared in a single place. Such
11064 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11066 One of the advantages of putting all the system configuration under the
11067 control of Guix is that it supports transactional system upgrades, and
11068 makes it possible to roll back to a previous system instantiation,
11069 should something go wrong with the new one (@pxref{Features}). Another
11070 advantage is that it makes it easy to replicate the exact same configuration
11071 across different machines, or at different points in time, without
11072 having to resort to additional administration tools layered on top of
11073 the own tools of the system.
11074 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11076 This section describes this mechanism. First we focus on the system
11077 administrator's viewpoint---explaining how the system is configured and
11078 instantiated. Then we show how this mechanism can be extended, for
11079 instance to support new system services.
11082 * Using the Configuration System:: Customizing your GNU system.
11083 * operating-system Reference:: Detail of operating-system declarations.
11084 * File Systems:: Configuring file system mounts.
11085 * Mapped Devices:: Block device extra processing.
11086 * User Accounts:: Specifying user accounts.
11087 * Keyboard Layout:: How the system interprets key strokes.
11088 * Locales:: Language and cultural convention settings.
11089 * Services:: Specifying system services.
11090 * Setuid Programs:: Programs running with root privileges.
11091 * X.509 Certificates:: Authenticating HTTPS servers.
11092 * Name Service Switch:: Configuring libc's name service switch.
11093 * Initial RAM Disk:: Linux-Libre bootstrapping.
11094 * Bootloader Configuration:: Configuring the boot loader.
11095 * Invoking guix system:: Instantiating a system configuration.
11096 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11097 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11098 * Defining Services:: Adding new service definitions.
11101 @node Using the Configuration System
11102 @section Using the Configuration System
11104 The operating system is configured by providing an
11105 @code{operating-system} declaration in a file that can then be passed to
11106 the @command{guix system} command (@pxref{Invoking guix system}). A
11107 simple setup, with the default system services, the default Linux-Libre
11108 kernel, initial RAM disk, and boot loader looks like this:
11110 @findex operating-system
11112 @include os-config-bare-bones.texi
11115 This example should be self-describing. Some of the fields defined
11116 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11117 Others, such as @code{packages} and @code{services}, can be omitted, in
11118 which case they get a default value.
11120 Below we discuss the effect of some of the most important fields
11121 (@pxref{operating-system Reference}, for details about all the available
11122 fields), and how to @dfn{instantiate} the operating system using
11123 @command{guix system}.
11125 @unnumberedsubsec Bootloader
11127 @cindex legacy boot, on Intel machines
11128 @cindex BIOS boot, on Intel machines
11131 The @code{bootloader} field describes the method that will be used to boot
11132 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11133 mode, as in the example above. However, more recent machines rely instead on
11134 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11135 the @code{bootloader} field should contain something along these lines:
11138 (bootloader-configuration
11139 (bootloader grub-efi-bootloader)
11140 (target "/boot/efi"))
11143 @xref{Bootloader Configuration}, for more information on the available
11144 configuration options.
11146 @unnumberedsubsec Globally-Visible Packages
11148 @vindex %base-packages
11149 The @code{packages} field lists packages that will be globally visible
11150 on the system, for all user accounts---i.e., in every user's @env{PATH}
11151 environment variable---in addition to the per-user profiles
11152 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11153 provides all the tools one would expect for basic user and administrator
11154 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11155 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11156 etc. The example above adds GNU@tie{}Screen to those,
11157 taken from the @code{(gnu packages screen)}
11158 module (@pxref{Package Modules}). The
11159 @code{(list package output)} syntax can be used to add a specific output
11163 (use-modules (gnu packages))
11164 (use-modules (gnu packages dns))
11168 (packages (cons (list bind "utils")
11172 @findex specification->package
11173 Referring to packages by variable name, like @code{bind} above, has
11174 the advantage of being unambiguous; it also allows typos and such to be
11175 diagnosed right away as ``unbound variables''. The downside is that one
11176 needs to know which module defines which package, and to augment the
11177 @code{use-package-modules} line accordingly. To avoid that, one can use
11178 the @code{specification->package} procedure of the @code{(gnu packages)}
11179 module, which returns the best package for a given name or name and
11183 (use-modules (gnu packages))
11187 (packages (append (map specification->package
11188 '("tcpdump" "htop" "gnupg@@2.0"))
11192 @unnumberedsubsec System Services
11195 @vindex %base-services
11196 The @code{services} field lists @dfn{system services} to be made
11197 available when the system starts (@pxref{Services}).
11198 The @code{operating-system} declaration above specifies that, in
11199 addition to the basic services, we want the OpenSSH secure shell
11200 daemon listening on port 2222 (@pxref{Networking Services,
11201 @code{openssh-service-type}}). Under the hood,
11202 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11203 right command-line options, possibly with supporting configuration files
11204 generated as needed (@pxref{Defining Services}).
11206 @cindex customization, of services
11207 @findex modify-services
11208 Occasionally, instead of using the base services as is, you will want to
11209 customize them. To do this, use @code{modify-services} (@pxref{Service
11210 Reference, @code{modify-services}}) to modify the list.
11212 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11213 (the console log-in) in the @code{%base-services} list (@pxref{Base
11214 Services, @code{%base-services}}). To do that, you can write the
11215 following in your operating system declaration:
11218 (define %my-services
11219 ;; My very own list of services.
11220 (modify-services %base-services
11221 (guix-service-type config =>
11222 (guix-configuration
11224 (use-substitutes? #f)
11225 (extra-options '("--gc-keep-derivations"))))
11226 (mingetty-service-type config =>
11227 (mingetty-configuration
11228 (inherit config)))))
11232 (services %my-services))
11235 This changes the configuration---i.e., the service parameters---of the
11236 @code{guix-service-type} instance, and that of all the
11237 @code{mingetty-service-type} instances in the @code{%base-services} list.
11238 Observe how this is accomplished: first, we arrange for the original
11239 configuration to be bound to the identifier @code{config} in the
11240 @var{body}, and then we write the @var{body} so that it evaluates to the
11241 desired configuration. In particular, notice how we use @code{inherit}
11242 to create a new configuration which has the same values as the old
11243 configuration, but with a few modifications.
11245 @cindex encrypted disk
11246 The configuration for a typical ``desktop'' usage, with an encrypted
11247 root partition, the X11 display
11248 server, GNOME and Xfce (users can choose which of these desktop
11249 environments to use at the log-in screen by pressing @kbd{F1}), network
11250 management, power management, and more, would look like this:
11253 @include os-config-desktop.texi
11256 A graphical system with a choice of lightweight window managers
11257 instead of full-blown desktop environments would look like this:
11260 @include os-config-lightweight-desktop.texi
11263 This example refers to the @file{/boot/efi} file system by its UUID,
11264 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11265 as returned by the @command{blkid} command.
11267 @xref{Desktop Services}, for the exact list of services provided by
11268 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11269 information about the @code{nss-certs} package that is used here.
11271 Again, @code{%desktop-services} is just a list of service objects. If
11272 you want to remove services from there, you can do so using the
11273 procedures for list filtering (@pxref{SRFI-1 Filtering and
11274 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11275 following expression returns a list that contains all the services in
11276 @code{%desktop-services} minus the Avahi service:
11279 (remove (lambda (service)
11280 (eq? (service-kind service) avahi-service-type))
11284 @unnumberedsubsec Instantiating the System
11286 Assuming the @code{operating-system} declaration
11287 is stored in the @file{my-system-config.scm}
11288 file, the @command{guix system reconfigure my-system-config.scm} command
11289 instantiates that configuration, and makes it the default GRUB boot
11290 entry (@pxref{Invoking guix system}).
11292 The normal way to change the system configuration is by updating this
11293 file and re-running @command{guix system reconfigure}. One should never
11294 have to touch files in @file{/etc} or to run commands that modify the
11295 system state such as @command{useradd} or @command{grub-install}. In
11296 fact, you must avoid that since that would not only void your warranty
11297 but also prevent you from rolling back to previous versions of your
11298 system, should you ever need to.
11300 @cindex roll-back, of the operating system
11301 Speaking of roll-back, each time you run @command{guix system
11302 reconfigure}, a new @dfn{generation} of the system is created---without
11303 modifying or deleting previous generations. Old system generations get
11304 an entry in the bootloader boot menu, allowing you to boot them in case
11305 something went wrong with the latest generation. Reassuring, no? The
11306 @command{guix system list-generations} command lists the system
11307 generations available on disk. It is also possible to roll back the
11308 system via the commands @command{guix system roll-back} and
11309 @command{guix system switch-generation}.
11311 Although the @command{guix system reconfigure} command will not modify
11312 previous generations, you must take care when the current generation is not
11313 the latest (e.g., after invoking @command{guix system roll-back}), since
11314 the operation might overwrite a later generation (@pxref{Invoking guix
11317 @unnumberedsubsec The Programming Interface
11319 At the Scheme level, the bulk of an @code{operating-system} declaration
11320 is instantiated with the following monadic procedure (@pxref{The Store
11323 @deffn {Monadic Procedure} operating-system-derivation os
11324 Return a derivation that builds @var{os}, an @code{operating-system}
11325 object (@pxref{Derivations}).
11327 The output of the derivation is a single directory that refers to all
11328 the packages, configuration files, and other supporting files needed to
11329 instantiate @var{os}.
11332 This procedure is provided by the @code{(gnu system)} module. Along
11333 with @code{(gnu services)} (@pxref{Services}), this module contains the
11334 guts of Guix System. Make sure to visit it!
11337 @node operating-system Reference
11338 @section @code{operating-system} Reference
11340 This section summarizes all the options available in
11341 @code{operating-system} declarations (@pxref{Using the Configuration
11344 @deftp {Data Type} operating-system
11345 This is the data type representing an operating system configuration.
11346 By that, we mean all the global system configuration, not per-user
11347 configuration (@pxref{Using the Configuration System}).
11350 @item @code{kernel} (default: @code{linux-libre})
11351 The package object of the operating system kernel to use@footnote{Currently
11352 only the Linux-libre kernel is supported. In the future, it will be
11353 possible to use the GNU@tie{}Hurd.}.
11355 @item @code{kernel-loadable-modules} (default: '())
11356 A list of objects (usually packages) to collect loadable kernel modules
11357 from--e.g. @code{(list ddcci-driver-linux)}.
11359 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
11360 List of strings or gexps representing additional arguments to pass on
11361 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11363 @item @code{bootloader}
11364 The system bootloader configuration object. @xref{Bootloader Configuration}.
11367 This is the label (a string) as it appears in the bootloader's menu entry.
11368 The default label includes the kernel name and version.
11370 @item @code{keyboard-layout} (default: @code{#f})
11371 This field specifies the keyboard layout to use in the console. It can be
11372 either @code{#f}, in which case the default keyboard layout is used (usually
11373 US English), or a @code{<keyboard-layout>} record.
11375 This keyboard layout is in effect as soon as the kernel has booted. For
11376 instance, it is the keyboard layout in effect when you type a passphrase if
11377 your root file system is on a @code{luks-device-mapping} mapped device
11378 (@pxref{Mapped Devices}).
11381 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11382 that used by the graphical display server. @xref{Bootloader Configuration},
11383 for information on how to specify the bootloader's keyboard layout. @xref{X
11384 Window}, for information on how to specify the keyboard layout used by the X
11388 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11390 @cindex initial RAM disk
11391 The list of Linux kernel modules that need to be available in the
11392 initial RAM disk. @xref{Initial RAM Disk}.
11394 @item @code{initrd} (default: @code{base-initrd})
11395 A procedure that returns an initial RAM disk for the Linux
11396 kernel. This field is provided to support low-level customization and
11397 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11399 @item @code{firmware} (default: @code{%base-firmware})
11401 List of firmware packages loadable by the operating system kernel.
11403 The default includes firmware needed for Atheros- and Broadcom-based
11404 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11405 respectively). @xref{Hardware Considerations}, for more info on
11406 supported hardware.
11408 @item @code{host-name}
11411 @item @code{hosts-file}
11413 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11414 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11415 Reference Manual}). The default is a file with entries for
11416 @code{localhost} and @var{host-name}.
11418 @item @code{mapped-devices} (default: @code{'()})
11419 A list of mapped devices. @xref{Mapped Devices}.
11421 @item @code{file-systems}
11422 A list of file systems. @xref{File Systems}.
11424 @item @code{swap-devices} (default: @code{'()})
11425 @cindex swap devices
11426 A list of strings identifying devices or files to be used for ``swap
11427 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11428 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11429 It is possible to specify a swap file in a file system on a mapped
11430 device, provided that the necessary device mapping and file system are
11431 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11433 @item @code{users} (default: @code{%base-user-accounts})
11434 @itemx @code{groups} (default: @code{%base-groups})
11435 List of user accounts and groups. @xref{User Accounts}.
11437 If the @code{users} list lacks a user account with UID@tie{}0, a
11438 ``root'' account with UID@tie{}0 is automatically added.
11440 @item @code{skeletons} (default: @code{(default-skeletons)})
11441 A list target file name/file-like object tuples (@pxref{G-Expressions,
11442 file-like objects}). These are the skeleton files that will be added to
11443 the home directory of newly-created user accounts.
11445 For instance, a valid value may look like this:
11448 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11449 (".guile" ,(plain-file "guile"
11450 "(use-modules (ice-9 readline))
11451 (activate-readline)")))
11454 @item @code{issue} (default: @code{%default-issue})
11455 A string denoting the contents of the @file{/etc/issue} file, which is
11456 displayed when users log in on a text console.
11458 @item @code{packages} (default: @code{%base-packages})
11459 The set of packages installed in the global profile, which is accessible
11460 at @file{/run/current-system/profile}.
11462 The default set includes core utilities and it is good practice to
11463 install non-core utilities in user profiles (@pxref{Invoking guix
11466 @item @code{timezone}
11467 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11469 You can run the @command{tzselect} command to find out which timezone
11470 string corresponds to your region. Choosing an invalid timezone name
11471 causes @command{guix system} to fail.
11473 @item @code{locale} (default: @code{"en_US.utf8"})
11474 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11475 Library Reference Manual}). @xref{Locales}, for more information.
11477 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11478 The list of locale definitions to be compiled and that may be used at
11479 run time. @xref{Locales}.
11481 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11482 The list of GNU@tie{}libc packages whose locale data and tools are used
11483 to build the locale definitions. @xref{Locales}, for compatibility
11484 considerations that justify this option.
11486 @item @code{name-service-switch} (default: @code{%default-nss})
11487 Configuration of the libc name service switch (NSS)---a
11488 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11491 @item @code{services} (default: @code{%base-services})
11492 A list of service objects denoting system services. @xref{Services}.
11494 @cindex essential services
11495 @item @code{essential-services} (default: ...)
11496 The list of ``essential services''---i.e., things like instances of
11497 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11498 Reference}), which are derived from the operating system definition itself.
11499 As a user you should @emph{never} need to touch this field.
11501 @item @code{pam-services} (default: @code{(base-pam-services)})
11503 @cindex pluggable authentication modules
11504 Linux @dfn{pluggable authentication module} (PAM) services.
11505 @c FIXME: Add xref to PAM services section.
11507 @item @code{setuid-programs} (default: @code{%setuid-programs})
11508 List of string-valued G-expressions denoting setuid programs.
11509 @xref{Setuid Programs}.
11511 @item @code{sudoers-file} (default: @code{%sudoers-specification})
11512 @cindex sudoers file
11513 The contents of the @file{/etc/sudoers} file as a file-like object
11514 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11516 This file specifies which users can use the @command{sudo} command, what
11517 they are allowed to do, and what privileges they may gain. The default
11518 is that only @code{root} and members of the @code{wheel} group may use
11523 @deffn {Scheme Syntax} this-operating-system
11524 When used in the @emph{lexical scope} of an operating system field definition,
11525 this identifier resolves to the operating system being defined.
11527 The example below shows how to refer to the operating system being defined in
11528 the definition of the @code{label} field:
11531 (use-modules (gnu) (guix))
11535 (label (package-full-name
11536 (operating-system-kernel this-operating-system))))
11539 It is an error to refer to @code{this-operating-system} outside an operating
11546 @section File Systems
11548 The list of file systems to be mounted is specified in the
11549 @code{file-systems} field of the operating system declaration
11550 (@pxref{Using the Configuration System}). Each file system is declared
11551 using the @code{file-system} form, like this:
11555 (mount-point "/home")
11556 (device "/dev/sda3")
11560 As usual, some of the fields are mandatory---those shown in the example
11561 above---while others can be omitted. These are described below.
11563 @deftp {Data Type} file-system
11564 Objects of this type represent file systems to be mounted. They
11565 contain the following members:
11569 This is a string specifying the type of the file system---e.g.,
11572 @item @code{mount-point}
11573 This designates the place where the file system is to be mounted.
11575 @item @code{device}
11576 This names the ``source'' of the file system. It can be one of three
11577 things: a file system label, a file system UUID, or the name of a
11578 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11579 systems without having to hard-code their actual device
11580 name@footnote{Note that, while it is tempting to use
11581 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11582 result, this is not recommended: These special device nodes are created
11583 by the udev daemon and may be unavailable at the time the device is
11586 @findex file-system-label
11587 File system labels are created using the @code{file-system-label}
11588 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11589 plain strings. Here's an example of a file system referred to by its
11590 label, as shown by the @command{e2label} command:
11594 (mount-point "/home")
11596 (device (file-system-label "my-home")))
11600 UUIDs are converted from their string representation (as shown by the
11601 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11602 @code{uuid} form expects 16-byte UUIDs as defined in
11603 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11604 form of UUID used by the ext2 family of file systems and others, but it
11605 is different from ``UUIDs'' found in FAT file systems, for instance.},
11610 (mount-point "/home")
11612 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11615 When the source of a file system is a mapped device (@pxref{Mapped
11616 Devices}), its @code{device} field @emph{must} refer to the mapped
11617 device name---e.g., @file{"/dev/mapper/root-partition"}.
11618 This is required so that
11619 the system knows that mounting the file system depends on having the
11620 corresponding device mapping established.
11622 @item @code{flags} (default: @code{'()})
11623 This is a list of symbols denoting mount flags. Recognized flags
11624 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11625 access to special files), @code{no-suid} (ignore setuid and setgid
11626 bits), @code{no-atime} (do not update file access times),
11627 @code{strict-atime} (update file access time), @code{lazy-time} (only
11628 update time on the in-memory version of the file inode), and
11629 @code{no-exec} (disallow program execution).
11630 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11631 Manual}, for more information on these flags.
11633 @item @code{options} (default: @code{#f})
11634 This is either @code{#f}, or a string denoting mount options passed to the
11635 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11636 Reference Manual}, for details and run @command{man 8 mount} for options for
11637 various file systems.
11639 @item @code{mount?} (default: @code{#t})
11640 This value indicates whether to automatically mount the file system when
11641 the system is brought up. When set to @code{#f}, the file system gets
11642 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11643 is not automatically mounted.
11645 @item @code{needed-for-boot?} (default: @code{#f})
11646 This Boolean value indicates whether the file system is needed when
11647 booting. If that is true, then the file system is mounted when the
11648 initial RAM disk (initrd) is loaded. This is always the case, for
11649 instance, for the root file system.
11651 @item @code{check?} (default: @code{#t})
11652 This Boolean indicates whether the file system needs to be checked for
11653 errors before being mounted.
11655 @item @code{create-mount-point?} (default: @code{#f})
11656 When true, the mount point is created if it does not exist yet.
11658 @item @code{dependencies} (default: @code{'()})
11659 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11660 representing file systems that must be mounted or mapped devices that
11661 must be opened before (and unmounted or closed after) this one.
11663 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11664 a dependency of @file{/sys/fs/cgroup/cpu} and
11665 @file{/sys/fs/cgroup/memory}.
11667 Another example is a file system that depends on a mapped device, for
11668 example for an encrypted partition (@pxref{Mapped Devices}).
11672 The @code{(gnu system file-systems)} exports the following useful
11675 @defvr {Scheme Variable} %base-file-systems
11676 These are essential file systems that are required on normal systems,
11677 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
11678 below.) Operating system declarations should always contain at least
11682 @defvr {Scheme Variable} %pseudo-terminal-file-system
11683 This is the file system to be mounted as @file{/dev/pts}. It supports
11684 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11685 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11686 Manual}). Pseudo-terminals are used by terminal emulators such as
11690 @defvr {Scheme Variable} %shared-memory-file-system
11691 This file system is mounted as @file{/dev/shm} and is used to support
11692 memory sharing across processes (@pxref{Memory-mapped I/O,
11693 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11696 @defvr {Scheme Variable} %immutable-store
11697 This file system performs a read-only ``bind mount'' of
11698 @file{/gnu/store}, making it read-only for all the users including
11699 @code{root}. This prevents against accidental modification by software
11700 running as @code{root} or by system administrators.
11702 The daemon itself is still able to write to the store: it remounts it
11703 read-write in its own ``name space.''
11706 @defvr {Scheme Variable} %binary-format-file-system
11707 The @code{binfmt_misc} file system, which allows handling of arbitrary
11708 executable file types to be delegated to user space. This requires the
11709 @code{binfmt.ko} kernel module to be loaded.
11712 @defvr {Scheme Variable} %fuse-control-file-system
11713 The @code{fusectl} file system, which allows unprivileged users to mount
11714 and unmount user-space FUSE file systems. This requires the
11715 @code{fuse.ko} kernel module to be loaded.
11718 @node Mapped Devices
11719 @section Mapped Devices
11721 @cindex device mapping
11722 @cindex mapped devices
11723 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11724 such as a hard disk partition, can be @dfn{mapped} into another device,
11725 usually in @code{/dev/mapper/},
11726 with additional processing over the data that flows through
11727 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11728 concept of a ``mapped device'' and that of a file system: both boil down
11729 to @emph{translating} input/output operations made on a file to
11730 operations on its backing store. Thus, the Hurd implements mapped
11731 devices, like file systems, using the generic @dfn{translator} mechanism
11732 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11733 typical example is encryption device mapping: all writes to the mapped
11734 device are encrypted, and all reads are deciphered, transparently.
11735 Guix extends this notion by considering any device or set of devices that
11736 are @dfn{transformed} in some way to create a new device; for instance,
11737 RAID devices are obtained by @dfn{assembling} several other devices, such
11738 as hard disks or partitions, into a new one that behaves as one partition.
11739 Other examples, not yet implemented, are LVM logical volumes.
11741 Mapped devices are declared using the @code{mapped-device} form,
11742 defined as follows; for examples, see below.
11744 @deftp {Data Type} mapped-device
11745 Objects of this type represent device mappings that will be made when
11746 the system boots up.
11750 This is either a string specifying the name of the block device to be mapped,
11751 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11752 need to be assembled for creating a new one.
11755 This string specifies the name of the resulting mapped device. For
11756 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11757 specifying @code{"my-partition"} leads to the creation of
11758 the @code{"/dev/mapper/my-partition"} device.
11759 For RAID devices of type @code{raid-device-mapping}, the full device name
11760 such as @code{"/dev/md0"} needs to be given.
11763 This must be a @code{mapped-device-kind} object, which specifies how
11764 @var{source} is mapped to @var{target}.
11768 @defvr {Scheme Variable} luks-device-mapping
11769 This defines LUKS block device encryption using the @command{cryptsetup}
11770 command from the package with the same name. It relies on the
11771 @code{dm-crypt} Linux kernel module.
11774 @defvr {Scheme Variable} raid-device-mapping
11775 This defines a RAID device, which is assembled using the @code{mdadm}
11776 command from the package with the same name. It requires a Linux kernel
11777 module for the appropriate RAID level to be loaded, such as @code{raid456}
11778 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11781 @cindex disk encryption
11783 The following example specifies a mapping from @file{/dev/sda3} to
11784 @file{/dev/mapper/home} using LUKS---the
11785 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11786 standard mechanism for disk encryption.
11787 The @file{/dev/mapper/home}
11788 device can then be used as the @code{device} of a @code{file-system}
11789 declaration (@pxref{File Systems}).
11793 (source "/dev/sda3")
11795 (type luks-device-mapping))
11798 Alternatively, to become independent of device numbering, one may obtain
11799 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11803 cryptsetup luksUUID /dev/sda3
11806 and use it as follows:
11810 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11812 (type luks-device-mapping))
11815 @cindex swap encryption
11816 It is also desirable to encrypt swap space, since swap space may contain
11817 sensitive data. One way to accomplish that is to use a swap file in a
11818 file system on a device mapped via LUKS encryption. In this way, the
11819 swap file is encrypted because the entire device is encrypted.
11820 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11822 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11823 may be declared as follows:
11827 (source (list "/dev/sda1" "/dev/sdb1"))
11828 (target "/dev/md0")
11829 (type raid-device-mapping))
11832 The @file{/dev/md0} device can then be used as the @code{device} of a
11833 @code{file-system} declaration (@pxref{File Systems}).
11834 Note that the RAID level need not be given; it is chosen during the
11835 initial creation and formatting of the RAID device and is determined
11836 automatically later.
11839 @node User Accounts
11840 @section User Accounts
11844 @cindex user accounts
11845 User accounts and groups are entirely managed through the
11846 @code{operating-system} declaration. They are specified with the
11847 @code{user-account} and @code{user-group} forms:
11853 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11854 "audio" ;sound card
11855 "video" ;video devices such as webcams
11856 "cdrom")) ;the good ol' CD-ROM
11857 (comment "Bob's sister")
11858 (home-directory "/home/alice"))
11861 When booting or upon completion of @command{guix system reconfigure},
11862 the system ensures that only the user accounts and groups specified in
11863 the @code{operating-system} declaration exist, and with the specified
11864 properties. Thus, account or group creations or modifications made by
11865 directly invoking commands such as @command{useradd} are lost upon
11866 reconfiguration or reboot. This ensures that the system remains exactly
11869 @deftp {Data Type} user-account
11870 Objects of this type represent user accounts. The following members may
11875 The name of the user account.
11879 This is the name (a string) or identifier (a number) of the user group
11880 this account belongs to.
11882 @item @code{supplementary-groups} (default: @code{'()})
11883 Optionally, this can be defined as a list of group names that this
11884 account belongs to.
11886 @item @code{uid} (default: @code{#f})
11887 This is the user ID for this account (a number), or @code{#f}. In the
11888 latter case, a number is automatically chosen by the system when the
11889 account is created.
11891 @item @code{comment} (default: @code{""})
11892 A comment about the account, such as the account owner's full name.
11894 @item @code{home-directory}
11895 This is the name of the home directory for the account.
11897 @item @code{create-home-directory?} (default: @code{#t})
11898 Indicates whether the home directory of this account should be created
11899 if it does not exist yet.
11901 @item @code{shell} (default: Bash)
11902 This is a G-expression denoting the file name of a program to be used as
11903 the shell (@pxref{G-Expressions}).
11905 @item @code{system?} (default: @code{#f})
11906 This Boolean value indicates whether the account is a ``system''
11907 account. System accounts are sometimes treated specially; for instance,
11908 graphical login managers do not list them.
11910 @anchor{user-account-password}
11911 @cindex password, for user accounts
11912 @item @code{password} (default: @code{#f})
11913 You would normally leave this field to @code{#f}, initialize user
11914 passwords as @code{root} with the @command{passwd} command, and then let
11915 users change it with @command{passwd}. Passwords set with
11916 @command{passwd} are of course preserved across reboot and
11919 If you @emph{do} want to set an initial password for an account, then
11920 this field must contain the encrypted password, as a string. You can use the
11921 @code{crypt} procedure for this purpose:
11928 ;; Specify a SHA-512-hashed initial password.
11929 (password (crypt "InitialPassword!" "$6$abc")))
11933 The hash of this initial password will be available in a file in
11934 @file{/gnu/store}, readable by all the users, so this method must be used with
11938 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11939 more information on password encryption, and @ref{Encryption,,, guile, GNU
11940 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11946 User group declarations are even simpler:
11949 (user-group (name "students"))
11952 @deftp {Data Type} user-group
11953 This type is for, well, user groups. There are just a few fields:
11957 The name of the group.
11959 @item @code{id} (default: @code{#f})
11960 The group identifier (a number). If @code{#f}, a new number is
11961 automatically allocated when the group is created.
11963 @item @code{system?} (default: @code{#f})
11964 This Boolean value indicates whether the group is a ``system'' group.
11965 System groups have low numerical IDs.
11967 @item @code{password} (default: @code{#f})
11968 What, user groups can have a password? Well, apparently yes. Unless
11969 @code{#f}, this field specifies the password of the group.
11974 For convenience, a variable lists all the basic user groups one may
11977 @defvr {Scheme Variable} %base-groups
11978 This is the list of basic user groups that users and/or packages expect
11979 to be present on the system. This includes groups such as ``root'',
11980 ``wheel'', and ``users'', as well as groups used to control access to
11981 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11984 @defvr {Scheme Variable} %base-user-accounts
11985 This is the list of basic system accounts that programs may expect to
11986 find on a GNU/Linux system, such as the ``nobody'' account.
11988 Note that the ``root'' account is not included here. It is a
11989 special-case and is automatically added whether or not it is specified.
11992 @node Keyboard Layout
11993 @section Keyboard Layout
11995 @cindex keyboard layout
11997 To specify what each key of your keyboard does, you need to tell the operating
11998 system what @dfn{keyboard layout} you want to use. The default, when nothing
11999 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12000 However, German speakers will usually prefer the German QWERTZ layout, French
12001 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12002 or bépo, and they might even want to further customize the effect of some of
12003 the keys. This section explains how to get that done.
12005 @cindex keyboard layout, definition
12006 There are three components that will want to know about your keyboard layout:
12010 The @emph{bootloader} may want to know what keyboard layout you want to use
12011 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12012 you want, for instance, to make sure that you can type the passphrase of your
12013 encrypted root partition using the right layout.
12016 The @emph{operating system kernel}, Linux, will need that so that the console
12017 is properly configured (@pxref{operating-system Reference,
12018 @code{keyboard-layout}}).
12021 The @emph{graphical display server}, usually Xorg, also has its own idea of
12022 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12025 Guix allows you to configure all three separately but, fortunately, it allows
12026 you to share the same keyboard layout for all three components.
12028 @cindex XKB, keyboard layouts
12029 Keyboard layouts are represented by records created by the
12030 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12031 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12032 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12033 optional variant name, an optional keyboard model name, and a possibly empty
12034 list of additional options. In most cases the layout name is all you care
12035 about. Here are a few example:
12038 ;; The German QWERTZ layout. Here we assume a standard
12039 ;; "pc105" keyboard model.
12040 (keyboard-layout "de")
12042 ;; The bépo variant of the French layout.
12043 (keyboard-layout "fr" "bepo")
12045 ;; The Catalan layout.
12046 (keyboard-layout "es" "cat")
12048 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12049 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12051 ;; The Latin American Spanish layout. In addition, the
12052 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12053 ;; and the "Menu" key is used as a "Compose" key to enter
12054 ;; accented letters.
12055 (keyboard-layout "latam"
12056 #:options '("ctrl:nocaps" "compose:menu"))
12058 ;; The Russian layout for a ThinkPad keyboard.
12059 (keyboard-layout "ru" #:model "thinkpad")
12061 ;; The "US international" layout, which is the US layout plus
12062 ;; dead keys to enter accented characters. This is for an
12063 ;; Apple MacBook keyboard.
12064 (keyboard-layout "us" "intl" #:model "macbook78")
12067 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12068 for a complete list of supported layouts, variants, and models.
12070 @cindex keyboard layout, configuration
12071 Let's say you want your system to use the Turkish keyboard layout throughout
12072 your system---bootloader, console, and Xorg. Here's what your system
12073 configuration would look like:
12075 @findex set-xorg-configuration
12077 ;; Using the Turkish layout for the bootloader, the console,
12082 (keyboard-layout (keyboard-layout "tr")) ;for the console
12083 (bootloader (bootloader-configuration
12084 (bootloader grub-efi-bootloader)
12085 (target "/boot/efi")
12086 (keyboard-layout keyboard-layout))) ;for GRUB
12087 (services (cons (set-xorg-configuration
12088 (xorg-configuration ;for Xorg
12089 (keyboard-layout keyboard-layout)))
12090 %desktop-services)))
12093 In the example above, for GRUB and for Xorg, we just refer to the
12094 @code{keyboard-layout} field defined above, but we could just as well refer to
12095 a different layout. The @code{set-xorg-configuration} procedure communicates
12096 the desired Xorg configuration to the graphical log-in manager, by default
12099 We've discussed how to specify the @emph{default} keyboard layout of your
12100 system when it starts, but you can also adjust it at run time:
12104 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12105 where you can select one or more keyboard layouts.
12108 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12109 allows you to change the current layout. For example, this is how you would
12110 change the layout to US Dvorak:
12113 setxkbmap us dvorak
12117 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
12118 console. However, note that @code{loadkeys} does @emph{not} use the XKB
12119 keyboard layout categorization described above. The command below loads the
12120 French bépo layout:
12131 A @dfn{locale} defines cultural conventions for a particular language
12132 and region of the world (@pxref{Locales,,, libc, The GNU C Library
12133 Reference Manual}). Each locale has a name that typically has the form
12134 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12135 @code{fr_LU.utf8} designates the locale for the French language, with
12136 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12138 @cindex locale definition
12139 Usually, you will want to specify the default locale for the machine
12140 using the @code{locale} field of the @code{operating-system} declaration
12141 (@pxref{operating-system Reference, @code{locale}}).
12143 The selected locale is automatically added to the @dfn{locale
12144 definitions} known to the system if needed, with its codeset inferred
12145 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12146 @code{UTF-8} codeset. Additional locale definitions can be specified in
12147 the @code{locale-definitions} slot of @code{operating-system}---this is
12148 useful, for instance, if the codeset could not be inferred from the
12149 locale name. The default set of locale definitions includes some widely
12150 used locales, but not all the available locales, in order to save space.
12152 For instance, to add the North Frisian locale for Germany, the value of
12156 (cons (locale-definition
12157 (name "fy_DE.utf8") (source "fy_DE"))
12158 %default-locale-definitions)
12161 Likewise, to save space, one might want @code{locale-definitions} to
12162 list only the locales that are actually used, as in:
12165 (list (locale-definition
12166 (name "ja_JP.eucjp") (source "ja_JP")
12167 (charset "EUC-JP")))
12171 The compiled locale definitions are available at
12172 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12173 version, which is the default location where the GNU@tie{}libc provided
12174 by Guix looks for locale data. This can be overridden using the
12175 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
12176 @env{LOCPATH} and locale packages}).
12178 The @code{locale-definition} form is provided by the @code{(gnu system
12179 locale)} module. Details are given below.
12181 @deftp {Data Type} locale-definition
12182 This is the data type of a locale definition.
12187 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12188 Reference Manual}, for more information on locale names.
12190 @item @code{source}
12191 The name of the source for that locale. This is typically the
12192 @code{@var{language}_@var{territory}} part of the locale name.
12194 @item @code{charset} (default: @code{"UTF-8"})
12195 The ``character set'' or ``code set'' for that locale,
12196 @uref{https://www.iana.org/assignments/character-sets, as defined by
12202 @defvr {Scheme Variable} %default-locale-definitions
12203 A list of commonly used UTF-8 locales, used as the default
12204 value of the @code{locale-definitions} field of @code{operating-system}
12207 @cindex locale name
12208 @cindex normalized codeset in locale names
12209 These locale definitions use the @dfn{normalized codeset} for the part
12210 that follows the dot in the name (@pxref{Using gettextized software,
12211 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12212 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12213 @code{uk_UA.UTF-8}.
12216 @subsection Locale Data Compatibility Considerations
12218 @cindex incompatibility, of locale data
12219 @code{operating-system} declarations provide a @code{locale-libcs} field
12220 to specify the GNU@tie{}libc packages that are used to compile locale
12221 declarations (@pxref{operating-system Reference}). ``Why would I
12222 care?'', you may ask. Well, it turns out that the binary format of
12223 locale data is occasionally incompatible from one libc version to
12226 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12227 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12228 For instance, a program linked against libc version 2.21 is unable to
12229 read locale data produced with libc 2.22; worse, that program
12230 @emph{aborts} instead of simply ignoring the incompatible locale
12231 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12232 the incompatible locale data, which is already an improvement.}.
12233 Similarly, a program linked against libc 2.22 can read most, but not
12234 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
12235 data is incompatible); thus calls to @code{setlocale} may fail, but
12236 programs will not abort.
12238 The ``problem'' with Guix is that users have a lot of freedom: They can
12239 choose whether and when to upgrade software in their profiles, and might
12240 be using a libc version different from the one the system administrator
12241 used to build the system-wide locale data.
12243 Fortunately, unprivileged users can also install their own locale data
12244 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12245 @env{GUIX_LOCPATH} and locale packages}).
12247 Still, it is best if the system-wide locale data at
12248 @file{/run/current-system/locale} is built for all the libc versions
12249 actually in use on the system, so that all the programs can access
12250 it---this is especially crucial on a multi-user system. To do that, the
12251 administrator can specify several libc packages in the
12252 @code{locale-libcs} field of @code{operating-system}:
12255 (use-package-modules base)
12259 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12262 This example would lead to a system containing locale definitions for
12263 both libc 2.21 and the current version of libc in
12264 @file{/run/current-system/locale}.
12270 @cindex system services
12271 An important part of preparing an @code{operating-system} declaration is
12272 listing @dfn{system services} and their configuration (@pxref{Using the
12273 Configuration System}). System services are typically daemons launched
12274 when the system boots, or other actions needed at that time---e.g.,
12275 configuring network access.
12277 Guix has a broad definition of ``service'' (@pxref{Service
12278 Composition}), but many services are managed by the GNU@tie{}Shepherd
12279 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12280 command allows you to list the available services, show their status,
12281 start and stop them, or do other specific operations (@pxref{Jump
12282 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12288 The above command, run as @code{root}, lists the currently defined
12289 services. The @command{herd doc} command shows a synopsis of the given
12290 service and its associated actions:
12294 Run libc's name service cache daemon (nscd).
12296 # herd doc nscd action invalidate
12297 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12300 The @command{start}, @command{stop}, and @command{restart} sub-commands
12301 have the effect you would expect. For instance, the commands below stop
12302 the nscd service and restart the Xorg display server:
12306 Service nscd has been stopped.
12307 # herd restart xorg-server
12308 Service xorg-server has been stopped.
12309 Service xorg-server has been started.
12312 The following sections document the available services, starting with
12313 the core services, that may be used in an @code{operating-system}
12317 * Base Services:: Essential system services.
12318 * Scheduled Job Execution:: The mcron service.
12319 * Log Rotation:: The rottlog service.
12320 * Networking Services:: Network setup, SSH daemon, etc.
12321 * X Window:: Graphical display.
12322 * Printing Services:: Local and remote printer support.
12323 * Desktop Services:: D-Bus and desktop services.
12324 * Sound Services:: ALSA and Pulseaudio services.
12325 * Database Services:: SQL databases, key-value stores, etc.
12326 * Mail Services:: IMAP, POP3, SMTP, and all that.
12327 * Messaging Services:: Messaging services.
12328 * Telephony Services:: Telephony services.
12329 * Monitoring Services:: Monitoring services.
12330 * Kerberos Services:: Kerberos services.
12331 * LDAP Services:: LDAP services.
12332 * Web Services:: Web servers.
12333 * Certificate Services:: TLS certificates via Let's Encrypt.
12334 * DNS Services:: DNS daemons.
12335 * VPN Services:: VPN daemons.
12336 * Network File System:: NFS related services.
12337 * Continuous Integration:: The Cuirass service.
12338 * Power Management Services:: Extending battery life.
12339 * Audio Services:: The MPD.
12340 * Virtualization Services:: Virtualization services.
12341 * Version Control Services:: Providing remote access to Git repositories.
12342 * Game Services:: Game servers.
12343 * PAM Mount Service:: Service to mount volumes when logging in.
12344 * Guix Services:: Services relating specifically to Guix.
12345 * Linux Services:: Services tied to the Linux kernel.
12346 * Miscellaneous Services:: Other services.
12349 @node Base Services
12350 @subsection Base Services
12352 The @code{(gnu services base)} module provides definitions for the basic
12353 services that one expects from the system. The services exported by
12354 this module are listed below.
12356 @defvr {Scheme Variable} %base-services
12357 This variable contains a list of basic services (@pxref{Service Types
12358 and Services}, for more information on service objects) one would
12359 expect from the system: a login service (mingetty) on each tty, syslogd,
12360 the libc name service cache daemon (nscd), the udev device manager, and
12363 This is the default value of the @code{services} field of
12364 @code{operating-system} declarations. Usually, when customizing a
12365 system, you will want to append services to @code{%base-services}, like
12369 (append (list (service avahi-service-type)
12370 (service openssh-service-type))
12375 @defvr {Scheme Variable} special-files-service-type
12376 This is the service that sets up ``special files'' such as
12377 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12379 The value associated with @code{special-files-service-type} services
12380 must be a list of tuples where the first element is the ``special file''
12381 and the second element is its target. By default it is:
12383 @cindex @file{/bin/sh}
12384 @cindex @file{sh}, in @file{/bin}
12386 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12389 @cindex @file{/usr/bin/env}
12390 @cindex @file{env}, in @file{/usr/bin}
12391 If you want to add, say, @code{/usr/bin/env} to your system, you can
12395 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12396 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12399 Since this is part of @code{%base-services}, you can use
12400 @code{modify-services} to customize the set of special files
12401 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12402 to add a special file is @i{via} the @code{extra-special-file} procedure
12406 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12407 Use @var{target} as the ``special file'' @var{file}.
12409 For example, adding the following lines to the @code{services} field of
12410 your operating system declaration leads to a @file{/usr/bin/env}
12414 (extra-special-file "/usr/bin/env"
12415 (file-append coreutils "/bin/env"))
12419 @deffn {Scheme Procedure} host-name-service @var{name}
12420 Return a service that sets the host name to @var{name}.
12423 @defvr {Scheme Variable} console-font-service-type
12424 Install the given fonts on the specified ttys (fonts are per
12425 virtual console on the kernel Linux). The value of this service is a list of
12426 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
12427 package or any valid argument to @command{setfont}, as in this example:
12430 `(("tty1" . "LatGrkCyr-8x16")
12431 ("tty2" . ,(file-append
12433 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
12434 ("tty3" . ,(file-append
12436 "/share/consolefonts/ter-132n"))) ; for HDPI
12440 @deffn {Scheme Procedure} login-service @var{config}
12441 Return a service to run login according to @var{config}, a
12442 @code{<login-configuration>} object, which specifies the message of the day,
12443 among other things.
12446 @deftp {Data Type} login-configuration
12447 This is the data type representing the configuration of login.
12452 @cindex message of the day
12453 A file-like object containing the ``message of the day''.
12455 @item @code{allow-empty-passwords?} (default: @code{#t})
12456 Allow empty passwords by default so that first-time users can log in when
12457 the 'root' account has just been created.
12462 @deffn {Scheme Procedure} mingetty-service @var{config}
12463 Return a service to run mingetty according to @var{config}, a
12464 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12468 @deftp {Data Type} mingetty-configuration
12469 This is the data type representing the configuration of Mingetty, which
12470 provides the default implementation of virtual console log-in.
12475 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12477 @item @code{auto-login} (default: @code{#f})
12478 When true, this field must be a string denoting the user name under
12479 which the system automatically logs in. When it is @code{#f}, a
12480 user name and password must be entered to log in.
12482 @item @code{login-program} (default: @code{#f})
12483 This must be either @code{#f}, in which case the default log-in program
12484 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12485 the name of the log-in program.
12487 @item @code{login-pause?} (default: @code{#f})
12488 When set to @code{#t} in conjunction with @var{auto-login}, the user
12489 will have to press a key before the log-in shell is launched.
12491 @item @code{mingetty} (default: @var{mingetty})
12492 The Mingetty package to use.
12497 @deffn {Scheme Procedure} agetty-service @var{config}
12498 Return a service to run agetty according to @var{config}, an
12499 @code{<agetty-configuration>} object, which specifies the tty to run,
12500 among other things.
12503 @deftp {Data Type} agetty-configuration
12504 This is the data type representing the configuration of agetty, which
12505 implements virtual and serial console log-in. See the @code{agetty(8)}
12506 man page for more information.
12511 The name of the console this agetty runs on, as a string---e.g.,
12512 @code{"ttyS0"}. This argument is optional, it will default to
12513 a reasonable default serial port used by the kernel Linux.
12515 For this, if there is a value for an option @code{agetty.tty} in the kernel
12516 command line, agetty will extract the device name of the serial port
12517 from it and use that.
12519 If not and if there is a value for an option @code{console} with a tty in
12520 the Linux command line, agetty will extract the device name of the
12521 serial port from it and use that.
12523 In both cases, agetty will leave the other serial device settings
12524 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12527 @item @code{baud-rate} (default: @code{#f})
12528 A string containing a comma-separated list of one or more baud rates, in
12531 @item @code{term} (default: @code{#f})
12532 A string containing the value used for the @env{TERM} environment
12535 @item @code{eight-bits?} (default: @code{#f})
12536 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12539 @item @code{auto-login} (default: @code{#f})
12540 When passed a login name, as a string, the specified user will be logged
12541 in automatically without prompting for their login name or password.
12543 @item @code{no-reset?} (default: @code{#f})
12544 When @code{#t}, don't reset terminal cflags (control modes).
12546 @item @code{host} (default: @code{#f})
12547 This accepts a string containing the ``login_host'', which will be written
12548 into the @file{/var/run/utmpx} file.
12550 @item @code{remote?} (default: @code{#f})
12551 When set to @code{#t} in conjunction with @var{host}, this will add an
12552 @code{-r} fakehost option to the command line of the login program
12553 specified in @var{login-program}.
12555 @item @code{flow-control?} (default: @code{#f})
12556 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12558 @item @code{no-issue?} (default: @code{#f})
12559 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12560 not be displayed before presenting the login prompt.
12562 @item @code{init-string} (default: @code{#f})
12563 This accepts a string that will be sent to the tty or modem before
12564 sending anything else. It can be used to initialize a modem.
12566 @item @code{no-clear?} (default: @code{#f})
12567 When set to @code{#t}, agetty will not clear the screen before showing
12570 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12571 This must be either a gexp denoting the name of a log-in program, or
12572 unset, in which case the default value is the @command{login} from the
12575 @item @code{local-line} (default: @code{#f})
12576 Control the CLOCAL line flag. This accepts one of three symbols as
12577 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12578 the default value chosen by agetty is @code{'auto}.
12580 @item @code{extract-baud?} (default: @code{#f})
12581 When set to @code{#t}, instruct agetty to try to extract the baud rate
12582 from the status messages produced by certain types of modems.
12584 @item @code{skip-login?} (default: @code{#f})
12585 When set to @code{#t}, do not prompt the user for a login name. This
12586 can be used with @var{login-program} field to use non-standard login
12589 @item @code{no-newline?} (default: @code{#f})
12590 When set to @code{#t}, do not print a newline before printing the
12591 @file{/etc/issue} file.
12593 @c Is this dangerous only when used with login-program, or always?
12594 @item @code{login-options} (default: @code{#f})
12595 This option accepts a string containing options that are passed to the
12596 login program. When used with the @var{login-program}, be aware that a
12597 malicious user could try to enter a login name containing embedded
12598 options that could be parsed by the login program.
12600 @item @code{login-pause} (default: @code{#f})
12601 When set to @code{#t}, wait for any key before showing the login prompt.
12602 This can be used in conjunction with @var{auto-login} to save memory by
12603 lazily spawning shells.
12605 @item @code{chroot} (default: @code{#f})
12606 Change root to the specified directory. This option accepts a directory
12609 @item @code{hangup?} (default: @code{#f})
12610 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12611 specified terminal.
12613 @item @code{keep-baud?} (default: @code{#f})
12614 When set to @code{#t}, try to keep the existing baud rate. The baud
12615 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12618 @item @code{timeout} (default: @code{#f})
12619 When set to an integer value, terminate if no user name could be read
12620 within @var{timeout} seconds.
12622 @item @code{detect-case?} (default: @code{#f})
12623 When set to @code{#t}, turn on support for detecting an uppercase-only
12624 terminal. This setting will detect a login name containing only
12625 uppercase letters as indicating an uppercase-only terminal and turn on
12626 some upper-to-lower case conversions. Note that this will not support
12627 Unicode characters.
12629 @item @code{wait-cr?} (default: @code{#f})
12630 When set to @code{#t}, wait for the user or modem to send a
12631 carriage-return or linefeed character before displaying
12632 @file{/etc/issue} or login prompt. This is typically used with the
12633 @var{init-string} option.
12635 @item @code{no-hints?} (default: @code{#f})
12636 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12639 @item @code{no-hostname?} (default: @code{#f})
12640 By default, the hostname is printed. When this option is set to
12641 @code{#t}, no hostname will be shown at all.
12643 @item @code{long-hostname?} (default: @code{#f})
12644 By default, the hostname is only printed until the first dot. When this
12645 option is set to @code{#t}, the fully qualified hostname by
12646 @code{gethostname} or @code{getaddrinfo} is shown.
12648 @item @code{erase-characters} (default: @code{#f})
12649 This option accepts a string of additional characters that should be
12650 interpreted as backspace when the user types their login name.
12652 @item @code{kill-characters} (default: @code{#f})
12653 This option accepts a string that should be interpreted to mean ``ignore
12654 all previous characters'' (also called a ``kill'' character) when the user
12655 types their login name.
12657 @item @code{chdir} (default: @code{#f})
12658 This option accepts, as a string, a directory path that will be changed
12661 @item @code{delay} (default: @code{#f})
12662 This options accepts, as an integer, the number of seconds to sleep
12663 before opening the tty and displaying the login prompt.
12665 @item @code{nice} (default: @code{#f})
12666 This option accepts, as an integer, the nice value with which to run the
12667 @command{login} program.
12669 @item @code{extra-options} (default: @code{'()})
12670 This option provides an ``escape hatch'' for the user to provide arbitrary
12671 command-line arguments to @command{agetty} as a list of strings.
12676 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12677 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12678 according to @var{config}, a @code{<kmscon-configuration>} object, which
12679 specifies the tty to run, among other things.
12682 @deftp {Data Type} kmscon-configuration
12683 This is the data type representing the configuration of Kmscon, which
12684 implements virtual console log-in.
12688 @item @code{virtual-terminal}
12689 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12691 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12692 A gexp denoting the name of the log-in program. The default log-in program is
12693 @command{login} from the Shadow tool suite.
12695 @item @code{login-arguments} (default: @code{'("-p")})
12696 A list of arguments to pass to @command{login}.
12698 @item @code{auto-login} (default: @code{#f})
12699 When passed a login name, as a string, the specified user will be logged
12700 in automatically without prompting for their login name or password.
12702 @item @code{hardware-acceleration?} (default: #f)
12703 Whether to use hardware acceleration.
12705 @item @code{kmscon} (default: @var{kmscon})
12706 The Kmscon package to use.
12711 @cindex name service cache daemon
12713 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12714 [#:name-services '()]
12715 Return a service that runs the libc name service cache daemon (nscd) with the
12716 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12717 Service Switch}, for an example.
12719 For convenience, the Shepherd service for nscd provides the following actions:
12723 @cindex cache invalidation, nscd
12724 @cindex nscd, cache invalidation
12725 This invalidate the given cache. For instance, running:
12728 herd invalidate nscd hosts
12732 invalidates the host name lookup cache of nscd.
12735 Running @command{herd statistics nscd} displays information about nscd usage
12741 @defvr {Scheme Variable} %nscd-default-configuration
12742 This is the default @code{<nscd-configuration>} value (see below) used
12743 by @code{nscd-service}. It uses the caches defined by
12744 @code{%nscd-default-caches}; see below.
12747 @deftp {Data Type} nscd-configuration
12748 This is the data type representing the name service cache daemon (nscd)
12753 @item @code{name-services} (default: @code{'()})
12754 List of packages denoting @dfn{name services} that must be visible to
12755 the nscd---e.g., @code{(list @var{nss-mdns})}.
12757 @item @code{glibc} (default: @var{glibc})
12758 Package object denoting the GNU C Library providing the @command{nscd}
12761 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12762 Name of the nscd log file. This is where debugging output goes when
12763 @code{debug-level} is strictly positive.
12765 @item @code{debug-level} (default: @code{0})
12766 Integer denoting the debugging levels. Higher numbers mean that more
12767 debugging output is logged.
12769 @item @code{caches} (default: @code{%nscd-default-caches})
12770 List of @code{<nscd-cache>} objects denoting things to be cached; see
12776 @deftp {Data Type} nscd-cache
12777 Data type representing a cache database of nscd and its parameters.
12781 @item @code{database}
12782 This is a symbol representing the name of the database to be cached.
12783 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12784 @code{services}, which designate the corresponding NSS database
12785 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12787 @item @code{positive-time-to-live}
12788 @itemx @code{negative-time-to-live} (default: @code{20})
12789 A number representing the number of seconds during which a positive or
12790 negative lookup result remains in cache.
12792 @item @code{check-files?} (default: @code{#t})
12793 Whether to check for updates of the files corresponding to
12796 For instance, when @var{database} is @code{hosts}, setting this flag
12797 instructs nscd to check for updates in @file{/etc/hosts} and to take
12800 @item @code{persistent?} (default: @code{#t})
12801 Whether the cache should be stored persistently on disk.
12803 @item @code{shared?} (default: @code{#t})
12804 Whether the cache should be shared among users.
12806 @item @code{max-database-size} (default: 32@tie{}MiB)
12807 Maximum size in bytes of the database cache.
12809 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12810 @c settings, so leave them out.
12815 @defvr {Scheme Variable} %nscd-default-caches
12816 List of @code{<nscd-cache>} objects used by default by
12817 @code{nscd-configuration} (see above).
12819 It enables persistent and aggressive caching of service and host name
12820 lookups. The latter provides better host name lookup performance,
12821 resilience in the face of unreliable name servers, and also better
12822 privacy---often the result of host name lookups is in local cache, so
12823 external name servers do not even need to be queried.
12826 @anchor{syslog-configuration-type}
12829 @deftp {Data Type} syslog-configuration
12830 This data type represents the configuration of the syslog daemon.
12833 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12834 The syslog daemon to use.
12836 @item @code{config-file} (default: @code{%default-syslog.conf})
12837 The syslog configuration file to use.
12842 @anchor{syslog-service}
12844 @deffn {Scheme Procedure} syslog-service @var{config}
12845 Return a service that runs a syslog daemon according to @var{config}.
12847 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12848 information on the configuration file syntax.
12851 @defvr {Scheme Variable} guix-service-type
12852 This is the type of the service that runs the build daemon,
12853 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12854 @code{guix-configuration} record as described below.
12857 @anchor{guix-configuration-type}
12858 @deftp {Data Type} guix-configuration
12859 This data type represents the configuration of the Guix build daemon.
12860 @xref{Invoking guix-daemon}, for more information.
12863 @item @code{guix} (default: @var{guix})
12864 The Guix package to use.
12866 @item @code{build-group} (default: @code{"guixbuild"})
12867 Name of the group for build user accounts.
12869 @item @code{build-accounts} (default: @code{10})
12870 Number of build user accounts to create.
12872 @item @code{authorize-key?} (default: @code{#t})
12873 @cindex substitutes, authorization thereof
12874 Whether to authorize the substitute keys listed in
12875 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12876 (@pxref{Substitutes}).
12878 @vindex %default-authorized-guix-keys
12879 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12880 The list of authorized key files for archive imports, as a list of
12881 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12882 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12884 @item @code{use-substitutes?} (default: @code{#t})
12885 Whether to use substitutes.
12887 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12888 The list of URLs where to look for substitutes by default.
12890 @item @code{max-silent-time} (default: @code{0})
12891 @itemx @code{timeout} (default: @code{0})
12892 The number of seconds of silence and the number of seconds of activity,
12893 respectively, after which a build process times out. A value of zero
12894 disables the timeout.
12896 @item @code{log-compression} (default: @code{'bzip2})
12897 The type of compression used for build logs---one of @code{gzip},
12898 @code{bzip2}, or @code{none}.
12900 @item @code{extra-options} (default: @code{'()})
12901 List of extra command-line options for @command{guix-daemon}.
12903 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12904 File where @command{guix-daemon}'s standard output and standard error
12907 @cindex HTTP proxy, for @code{guix-daemon}
12908 @cindex proxy, for @code{guix-daemon} HTTP access
12909 @item @code{http-proxy} (default: @code{#f})
12910 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
12911 derivations and substitutes.
12913 It is also possible to change the daemon's proxy at run time through the
12914 @code{set-http-proxy} action, which restarts it:
12917 herd set-http-proxy guix-daemon http://localhost:8118
12920 To clear the proxy settings, run:
12923 herd set-http-proxy guix-daemon
12926 @item @code{tmpdir} (default: @code{#f})
12927 A directory path where the @command{guix-daemon} will perform builds.
12932 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12933 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12934 udev rules can be provided as a list of files through the @var{rules}
12935 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
12936 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
12937 creation of such rule files.
12939 The @command{herd rules udev} command, as root, returns the name of the
12940 directory containing all the active udev rules.
12943 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12944 Return a udev-rule file named @var{file-name} containing the rules
12945 defined by the @var{contents} literal.
12947 In the following example, a rule for a USB device is defined to be
12948 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12949 upon detecting a USB device with a given product identifier.
12952 (define %example-udev-rule
12954 "90-usb-thing.rules"
12955 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12956 "ATTR@{product@}==\"Example\", "
12957 "RUN+=\"/path/to/script\"")))
12961 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
12962 [#:groups @var{groups}]
12963 Return a service that extends @code{udev-service-type } with @var{rules}
12964 and @code{account-service-type} with @var{groups} as system groups.
12965 This works by creating a singleton service type
12966 @code{@var{name}-udev-rules}, of which the returned service is an
12969 Here we show how it can be used to extend @code{udev-service-type} with the
12970 previously defined rule @code{%example-udev-rule}.
12976 (cons (udev-rules-service 'usb-thing %example-udev-rule)
12977 %desktop-services)))
12981 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12982 Return a udev file named @var{file-name} containing the rules defined
12983 within @var{file}, a file-like object.
12985 The following example showcases how we can use an existing rule file.
12988 (use-modules (guix download) ;for url-fetch
12989 (guix packages) ;for origin
12992 (define %android-udev-rules
12994 "51-android-udev.rules"
12995 (let ((version "20170910"))
12998 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12999 "android-udev-rules/" version "/51-android.rules"))
13001 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13005 Additionally, Guix package definitions can be included in @var{rules} in
13006 order to extend the udev rules with the definitions found under their
13007 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13008 @var{file->udev-rule} example, we could have used the
13009 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13010 packages android)} module.
13012 The following example shows how to use the @var{android-udev-rules}
13013 package so that the Android tool @command{adb} can detect devices
13014 without root privileges. It also details how to create the
13015 @code{adbusers} group, which is required for the proper functioning of
13016 the rules defined within the @code{android-udev-rules} package. To
13017 create such a group, we must define it both as part of the
13018 @code{supplementary-groups} of our @code{user-account} declaration, as
13019 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13022 (use-modules (gnu packages android) ;for android-udev-rules
13023 (gnu system shadow) ;for user-group
13028 (users (cons (user-account
13030 (supplementary-groups
13031 '("adbusers" ;for adb
13032 "wheel" "netdev" "audio" "video")))))
13035 (cons (udev-rules-service 'android android-udev-rules
13036 #:groups '("adbusers"))
13037 %desktop-services)))
13040 @defvr {Scheme Variable} urandom-seed-service-type
13041 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13042 when rebooting. It also tries to seed @file{/dev/urandom} from
13043 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13047 @defvr {Scheme Variable} %random-seed-file
13048 This is the name of the file where some random bytes are saved by
13049 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13050 It defaults to @file{/var/lib/random-seed}.
13055 @defvr {Scheme Variable} gpm-service-type
13056 This is the type of the service that runs GPM, the @dfn{general-purpose
13057 mouse daemon}, which provides mouse support to the Linux console. GPM
13058 allows users to use the mouse in the console, notably to select, copy,
13061 The value for services of this type must be a @code{gpm-configuration}
13062 (see below). This service is not part of @code{%base-services}.
13065 @deftp {Data Type} gpm-configuration
13066 Data type representing the configuration of GPM.
13069 @item @code{options} (default: @code{%default-gpm-options})
13070 Command-line options passed to @command{gpm}. The default set of
13071 options instruct @command{gpm} to listen to mouse events on
13072 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13075 @item @code{gpm} (default: @code{gpm})
13076 The GPM package to use.
13081 @anchor{guix-publish-service-type}
13082 @deffn {Scheme Variable} guix-publish-service-type
13083 This is the service type for @command{guix publish} (@pxref{Invoking
13084 guix publish}). Its value must be a @code{guix-publish-configuration}
13085 object, as described below.
13087 This assumes that @file{/etc/guix} already contains a signing key pair as
13088 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13089 archive}). If that is not the case, the service will fail to start.
13092 @deftp {Data Type} guix-publish-configuration
13093 Data type representing the configuration of the @code{guix publish}
13097 @item @code{guix} (default: @code{guix})
13098 The Guix package to use.
13100 @item @code{port} (default: @code{80})
13101 The TCP port to listen for connections.
13103 @item @code{host} (default: @code{"localhost"})
13104 The host (and thus, network interface) to listen to. Use
13105 @code{"0.0.0.0"} to listen on all the network interfaces.
13107 @item @code{compression} (default: @code{'(("gzip" 3))})
13108 This is a list of compression method/level tuple used when compressing
13109 substitutes. For example, to compress all substitutes with @emph{both} lzip
13110 at level 7 and gzip at level 9, write:
13113 '(("lzip" 7) ("gzip" 9))
13116 Level 9 achieves the best compression ratio at the expense of increased CPU
13117 usage, whereas level 1 achieves fast compression.
13119 An empty list disables compression altogether.
13121 @item @code{nar-path} (default: @code{"nar"})
13122 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
13123 publish, @option{--nar-path}}, for details.
13125 @item @code{cache} (default: @code{#f})
13126 When it is @code{#f}, disable caching and instead generate archives on
13127 demand. Otherwise, this should be the name of a directory---e.g.,
13128 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
13129 archives and meta-data ready to be sent. @xref{Invoking guix publish,
13130 @option{--cache}}, for more information on the tradeoffs involved.
13132 @item @code{workers} (default: @code{#f})
13133 When it is an integer, this is the number of worker threads used for
13134 caching; when @code{#f}, the number of processors is used.
13135 @xref{Invoking guix publish, @option{--workers}}, for more information.
13137 @item @code{ttl} (default: @code{#f})
13138 When it is an integer, this denotes the @dfn{time-to-live} in seconds
13139 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
13140 for more information.
13144 @anchor{rngd-service}
13145 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
13146 [#:device "/dev/hwrng"]
13147 Return a service that runs the @command{rngd} program from @var{rng-tools}
13148 to add @var{device} to the kernel's entropy pool. The service will fail if
13149 @var{device} does not exist.
13152 @anchor{pam-limits-service}
13153 @cindex session limits
13158 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
13160 Return a service that installs a configuration file for the
13161 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
13162 @code{pam_limits} module}. The procedure optionally takes a list of
13163 @code{pam-limits-entry} values, which can be used to specify
13164 @code{ulimit} limits and nice priority limits to user sessions.
13166 The following limits definition sets two hard and soft limits for all
13167 login sessions of users in the @code{realtime} group:
13170 (pam-limits-service
13172 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13173 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13176 The first entry increases the maximum realtime priority for
13177 non-privileged processes; the second entry lifts any restriction of the
13178 maximum address space that can be locked in memory. These settings are
13179 commonly used for real-time audio systems.
13182 @node Scheduled Job Execution
13183 @subsection Scheduled Job Execution
13187 @cindex scheduling jobs
13188 The @code{(gnu services mcron)} module provides an interface to
13189 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13190 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13191 Unix @command{cron} daemon; the main difference is that it is
13192 implemented in Guile Scheme, which provides a lot of flexibility when
13193 specifying the scheduling of jobs and their actions.
13195 The example below defines an operating system that runs the
13196 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13197 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13198 well as the @command{mkid} command on behalf of an unprivileged user
13199 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13200 gexps to introduce job definitions that are passed to mcron
13201 (@pxref{G-Expressions}).
13204 (use-modules (guix) (gnu) (gnu services mcron))
13205 (use-package-modules base idutils)
13207 (define updatedb-job
13208 ;; Run 'updatedb' at 3AM every day. Here we write the
13209 ;; job's action as a Scheme procedure.
13210 #~(job '(next-hour '(3))
13212 (execl (string-append #$findutils "/bin/updatedb")
13214 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13216 (define garbage-collector-job
13217 ;; Collect garbage 5 minutes after midnight every day.
13218 ;; The job's action is a shell command.
13219 #~(job "5 0 * * *" ;Vixie cron syntax
13222 (define idutils-job
13223 ;; Update the index database as user "charlie" at 12:15PM
13224 ;; and 19:15PM. This runs from the user's home directory.
13225 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13226 (string-append #$idutils "/bin/mkid src")
13231 (services (cons (service mcron-service-type
13232 (mcron-configuration
13233 (jobs (list garbage-collector-job
13239 For more complex jobs defined in Scheme where you need control over the top
13240 level, for instance to introduce a @code{use-modules} form, you can move your
13241 code to a separate program using the @code{program-file} procedure of the
13242 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13246 (define %battery-alert-job
13247 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13249 '(next-minute (range 0 60 1))
13251 "battery-alert.scm"
13252 (with-imported-modules (source-module-closure
13253 '((guix build utils)))
13255 (define %min-level 20)
13256 (use-modules (guix build utils)
13259 (ice-9 textual-ports)
13261 (setenv "LC_ALL" "C") ;ensure English output
13262 (and-let* ((input-pipe (open-pipe*
13264 #$(file-append acpi "/bin/acpi")))
13265 (output (get-string-all input-pipe))
13266 (m (string-match "Discharging, ([0-9]+)%" output))
13267 (level (string->number (match:substring m 1)))
13268 ((< level %min-level)))
13269 (format #t "warning: Battery level is low (~a%)~%" level)
13270 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13273 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13274 for more information on mcron job specifications. Below is the
13275 reference of the mcron service.
13277 On a running system, you can use the @code{schedule} action of the service to
13278 visualize the mcron jobs that will be executed next:
13281 # herd schedule mcron
13285 The example above lists the next five tasks that will be executed, but you can
13286 also specify the number of tasks to display:
13289 # herd schedule mcron 10
13292 @defvr {Scheme Variable} mcron-service-type
13293 This is the type of the @code{mcron} service, whose value is an
13294 @code{mcron-configuration} object.
13296 This service type can be the target of a service extension that provides
13297 it additional job specifications (@pxref{Service Composition}). In
13298 other words, it is possible to define services that provide additional
13302 @deftp {Data Type} mcron-configuration
13303 Data type representing the configuration of mcron.
13306 @item @code{mcron} (default: @var{mcron})
13307 The mcron package to use.
13310 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13311 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13312 specifications,, mcron, GNU@tie{}mcron}).
13318 @subsection Log Rotation
13321 @cindex log rotation
13323 Log files such as those found in @file{/var/log} tend to grow endlessly,
13324 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13325 their contents in separate files, possibly compressed. The @code{(gnu
13326 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13327 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13329 This service is part of @code{%base-services}, and thus enabled by
13330 default, with the default settings, for commonly encountered log files.
13331 The example below shows how to extend it with an additional
13332 @dfn{rotation}, should you need to do that (usually, services that
13333 produce log files already take care of that):
13336 (use-modules (guix) (gnu))
13337 (use-service-modules admin)
13339 (define my-log-files
13340 ;; Log files that I want to rotate.
13341 '("/var/log/something.log" "/var/log/another.log"))
13345 (services (cons (simple-service 'rotate-my-stuff
13346 rottlog-service-type
13347 (list (log-rotation
13349 (files my-log-files))))
13353 @defvr {Scheme Variable} rottlog-service-type
13354 This is the type of the Rottlog service, whose value is a
13355 @code{rottlog-configuration} object.
13357 Other services can extend this one with new @code{log-rotation} objects
13358 (see below), thereby augmenting the set of files to be rotated.
13360 This service type can define mcron jobs (@pxref{Scheduled Job
13361 Execution}) to run the rottlog service.
13364 @deftp {Data Type} rottlog-configuration
13365 Data type representing the configuration of rottlog.
13368 @item @code{rottlog} (default: @code{rottlog})
13369 The Rottlog package to use.
13371 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13372 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13373 rottlog, GNU Rot[t]log Manual}).
13375 @item @code{rotations} (default: @code{%default-rotations})
13376 A list of @code{log-rotation} objects as defined below.
13379 This is a list of gexps where each gexp corresponds to an mcron job
13380 specification (@pxref{Scheduled Job Execution}).
13384 @deftp {Data Type} log-rotation
13385 Data type representing the rotation of a group of log files.
13387 Taking an example from the Rottlog manual (@pxref{Period Related File
13388 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13394 (files '("/var/log/apache/*"))
13395 (options '("storedir apache-archives"
13401 The list of fields is as follows:
13404 @item @code{frequency} (default: @code{'weekly})
13405 The log rotation frequency, a symbol.
13408 The list of files or file glob patterns to rotate.
13410 @item @code{options} (default: @code{'()})
13411 The list of rottlog options for this rotation (@pxref{Configuration
13412 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13414 @item @code{post-rotate} (default: @code{#f})
13415 Either @code{#f} or a gexp to execute once the rotation has completed.
13419 @defvr {Scheme Variable} %default-rotations
13420 Specifies weekly rotation of @code{%rotated-files} and of
13421 @file{/var/log/guix-daemon.log}.
13424 @defvr {Scheme Variable} %rotated-files
13425 The list of syslog-controlled files to be rotated. By default it is:
13426 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13427 "/var/log/maillog")}.
13430 @node Networking Services
13431 @subsection Networking Services
13433 The @code{(gnu services networking)} module provides services to configure
13434 the network interface.
13436 @cindex DHCP, networking service
13437 @defvr {Scheme Variable} dhcp-client-service-type
13438 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13439 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13440 is the DHCP client package to use, @code{isc-dhcp} by default.
13443 @deffn {Scheme Procedure} dhcpd-service-type
13444 This type defines a service that runs a DHCP daemon. To create a
13445 service of this type, you must supply a @code{<dhcpd-configuration>}.
13449 (service dhcpd-service-type
13450 (dhcpd-configuration
13451 (config-file (local-file "my-dhcpd.conf"))
13452 (interfaces '("enp0s25"))))
13456 @deftp {Data Type} dhcpd-configuration
13458 @item @code{package} (default: @code{isc-dhcp})
13459 The package that provides the DHCP daemon. This package is expected to
13460 provide the daemon at @file{sbin/dhcpd} relative to its output
13461 directory. The default package is the
13462 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13463 @item @code{config-file} (default: @code{#f})
13464 The configuration file to use. This is required. It will be passed to
13465 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13466 object (@pxref{G-Expressions, file-like objects}). See @code{man
13467 dhcpd.conf} for details on the configuration file syntax.
13468 @item @code{version} (default: @code{"4"})
13469 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13470 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13471 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13473 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13474 The run directory to use. At service activation time, this directory
13475 will be created if it does not exist.
13476 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13477 The PID file to use. This corresponds to the @code{-pf} option of
13478 @code{dhcpd}. See @code{man dhcpd} for details.
13479 @item @code{interfaces} (default: @code{'()})
13480 The names of the network interfaces on which dhcpd should listen for
13481 broadcasts. If this list is not empty, then its elements (which must be
13482 strings) will be appended to the @code{dhcpd} invocation when starting
13483 the daemon. It may not be necessary to explicitly specify any
13484 interfaces here; see @code{man dhcpd} for details.
13488 @defvr {Scheme Variable} static-networking-service-type
13489 This is the type for statically-configured network interfaces.
13490 @c TODO Document <static-networking> data structures.
13493 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13494 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13495 [#:requirement @code{'(udev)}]
13496 Return a service that starts @var{interface} with address @var{ip}. If
13497 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13498 it must be a string specifying the default network gateway. @var{requirement}
13499 can be used to declare a dependency on another service before configuring the
13502 This procedure can be called several times, one for each network
13503 interface of interest. Behind the scenes what it does is extend
13504 @code{static-networking-service-type} with additional network interfaces
13510 (static-networking-service "eno1" "192.168.1.82"
13511 #:gateway "192.168.1.2"
13512 #:name-servers '("192.168.1.2"))
13519 @cindex network management
13520 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13521 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13522 management daemon that aims to simplify wired and wireless networking.
13524 This service adds the @var{wicd} package to the global profile, providing
13525 several commands to interact with the daemon and configure networking:
13526 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13527 and @command{wicd-curses} user interfaces.
13530 @cindex ModemManager
13532 @defvr {Scheme Variable} modem-manager-service-type
13533 This is the service type for the
13534 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13535 service. The value for this service type is a
13536 @code{modem-manager-configuration} record.
13538 This service is part of @code{%desktop-services} (@pxref{Desktop
13542 @deftp {Data Type} modem-manager-configuration
13543 Data type representing the configuration of ModemManager.
13546 @item @code{modem-manager} (default: @code{modem-manager})
13547 The ModemManager package to use.
13552 @cindex USB_ModeSwitch
13553 @cindex Modeswitching
13555 @defvr {Scheme Variable} usb-modeswitch-service-type
13556 This is the service type for the
13557 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13558 value for this service type is a @code{usb-modeswitch-configuration} record.
13560 When plugged in, some USB modems (and other USB devices) initially present
13561 themselves as a read-only storage medium and not as a modem. They need to be
13562 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13563 installs udev rules to automatically modeswitch these devices when they are
13566 This service is part of @code{%desktop-services} (@pxref{Desktop
13570 @deftp {Data Type} usb-modeswitch-configuration
13571 Data type representing the configuration of USB_ModeSwitch.
13574 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13575 The USB_ModeSwitch package providing the binaries for modeswitching.
13577 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13578 The package providing the device data and udev rules file used by
13581 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13582 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13583 config file shipped with USB_ModeSwitch is used which disables logging to
13584 @file{/var/log} among other default settings. If set to @code{#f}, no config
13590 @cindex NetworkManager
13592 @defvr {Scheme Variable} network-manager-service-type
13593 This is the service type for the
13594 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13595 service. The value for this service type is a
13596 @code{network-manager-configuration} record.
13598 This service is part of @code{%desktop-services} (@pxref{Desktop
13602 @deftp {Data Type} network-manager-configuration
13603 Data type representing the configuration of NetworkManager.
13606 @item @code{network-manager} (default: @code{network-manager})
13607 The NetworkManager package to use.
13609 @item @code{dns} (default: @code{"default"})
13610 Processing mode for DNS, which affects how NetworkManager uses the
13611 @code{resolv.conf} configuration file.
13615 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13616 provided by currently active connections.
13619 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13620 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13621 then update @code{resolv.conf} to point to the local nameserver.
13623 With this setting, you can share your network connection. For example when
13624 you want to share your network connection to another laptop @i{via} an
13625 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13626 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13627 and reestablish the connection (or reboot).
13629 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13630 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13631 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13632 browser on your host system, or connect to the VM @i{via} SSH
13633 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13634 host-to-guest connection, run this command once:
13637 nmcli connection add type tun \
13638 connection.interface-name tap0 \
13639 tun.mode tap tun.owner $(id -u) \
13640 ipv4.method shared \
13641 ipv4.addresses 172.28.112.1/24
13644 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13645 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13646 @command{qemu-system-...}.
13649 NetworkManager will not modify @code{resolv.conf}.
13652 @item @code{vpn-plugins} (default: @code{'()})
13653 This is the list of available plugins for virtual private networks
13654 (VPNs). An example of this is the @code{network-manager-openvpn}
13655 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13661 @deffn {Scheme Variable} connman-service-type
13662 This is the service type to run @url{https://01.org/connman,Connman},
13663 a network connection manager.
13665 Its value must be an
13666 @code{connman-configuration} record as in this example:
13669 (service connman-service-type
13670 (connman-configuration
13671 (disable-vpn? #t)))
13674 See below for details about @code{connman-configuration}.
13677 @deftp {Data Type} connman-configuration
13678 Data Type representing the configuration of connman.
13681 @item @code{connman} (default: @var{connman})
13682 The connman package to use.
13684 @item @code{disable-vpn?} (default: @code{#f})
13685 When true, disable connman's vpn plugin.
13689 @cindex WPA Supplicant
13690 @defvr {Scheme Variable} wpa-supplicant-service-type
13691 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13692 supplicant}, an authentication daemon required to authenticate against
13693 encrypted WiFi or ethernet networks.
13696 @deftp {Data Type} wpa-supplicant-configuration
13697 Data type representing the configuration of WPA Supplicant.
13699 It takes the following parameters:
13702 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13703 The WPA Supplicant package to use.
13705 @item @code{dbus?} (default: @code{#t})
13706 Whether to listen for requests on D-Bus.
13708 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13709 Where to store the PID file.
13711 @item @code{interface} (default: @code{#f})
13712 If this is set, it must specify the name of a network interface that
13713 WPA supplicant will control.
13715 @item @code{config-file} (default: @code{#f})
13716 Optional configuration file to use.
13718 @item @code{extra-options} (default: @code{'()})
13719 List of additional command-line arguments to pass to the daemon.
13723 @cindex hostapd service, for Wi-Fi access points
13724 @cindex Wi-Fi access points, hostapd service
13725 @defvr {Scheme Variable} hostapd-service-type
13726 This is the service type to run the @uref{https://w1.fi/hostapd/,
13727 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
13728 authentication servers. Its associated value must be a
13729 @code{hostapd-configuration} as shown below:
13732 ;; Use wlan1 to run the access point for "My Network".
13733 (service hostapd-service-type
13734 (hostapd-configuration
13735 (interface "wlan1")
13736 (ssid "My Network")
13741 @deftp {Data Type} hostapd-configuration
13742 This data type represents the configuration of the hostapd service, with
13743 the following fields:
13746 @item @code{package} (default: @code{hostapd})
13747 The hostapd package to use.
13749 @item @code{interface} (default: @code{"wlan0"})
13750 The network interface to run the WiFi access point.
13753 The SSID (@dfn{service set identifier}), a string that identifies this
13756 @item @code{broadcast-ssid?} (default: @code{#t})
13757 Whether to broadcast this SSID.
13759 @item @code{channel} (default: @code{1})
13760 The WiFi channel to use.
13762 @item @code{driver} (default: @code{"nl80211"})
13763 The driver interface type. @code{"nl80211"} is used with all Linux
13764 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
13765 RADIUS server that does # not control any wireless/wired driver.
13767 @item @code{extra-settings} (default: @code{""})
13768 Extra settings to append as-is to the hostapd configuration file. See
13769 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
13770 configuration file reference.
13774 @defvr {Scheme Variable} simulated-wifi-service-type
13775 This is the type of a service to simulate WiFi networking, which can be
13776 useful in virtual machines for testing purposes. The service loads the
13778 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
13779 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
13780 network that can be seen on @code{wlan0}, by default.
13782 The service's value is a @code{hostapd-configuration} record.
13786 @defvr {Scheme Variable} iptables-service-type
13787 This is the service type to set up an iptables configuration. iptables is a
13788 packet filtering framework supported by the Linux kernel. This service
13789 supports configuring iptables for both IPv4 and IPv6. A simple example
13790 configuration rejecting all incoming connections except those to the ssh port
13794 (service iptables-service-type
13795 (iptables-configuration
13796 (ipv4-rules (plain-file "iptables.rules" "*filter
13800 -A INPUT -p tcp --dport 22 -j ACCEPT
13801 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13804 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13808 -A INPUT -p tcp --dport 22 -j ACCEPT
13809 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13815 @deftp {Data Type} iptables-configuration
13816 The data type representing the configuration of iptables.
13819 @item @code{iptables} (default: @code{iptables})
13820 The iptables package that provides @code{iptables-restore} and
13821 @code{ip6tables-restore}.
13822 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13823 The iptables rules to use. It will be passed to @code{iptables-restore}.
13824 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13826 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13827 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13828 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13834 @defvr {Scheme Variable} nftables-service-type
13835 This is the service type to set up a nftables configuration. nftables is a
13836 netfilter project that aims to replace the existing iptables, ip6tables,
13837 arptables and ebtables framework. It provides a new packet filtering
13838 framework, a new user-space utility @command{nft}, and a compatibility layer
13839 for iptables. This service comes with a default ruleset
13840 @code{%default-nftables-ruleset} that rejecting all incomming connections
13841 except those to the ssh port 22. To use it, simply write:
13844 (service nftables-service-type)
13848 @deftp {Data Type} nftables-configuration
13849 The data type representing the configuration of nftables.
13852 @item @code{package} (default: @code{nftables})
13853 The nftables package that provides @command{nft}.
13854 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13855 The nftables ruleset to use. This may be any ``file-like'' object
13856 (@pxref{G-Expressions, file-like objects}).
13860 @cindex NTP (Network Time Protocol), service
13861 @cindex ntpd, service for the Network Time Protocol daemon
13862 @cindex real time clock
13863 @defvr {Scheme Variable} ntp-service-type
13864 This is the type of the service running the @uref{https://www.ntp.org,
13865 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13866 system clock synchronized with that of the specified NTP servers.
13868 The value of this service is an @code{ntpd-configuration} object, as described
13872 @deftp {Data Type} ntp-configuration
13873 This is the data type for the NTP service configuration.
13876 @item @code{servers} (default: @code{%ntp-servers})
13877 This is the list of servers (@code{<ntp-server>} records) with which
13878 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13881 @item @code{allow-large-adjustment?} (default: @code{#t})
13882 This determines whether @command{ntpd} is allowed to make an initial
13883 adjustment of more than 1,000 seconds.
13885 @item @code{ntp} (default: @code{ntp})
13886 The NTP package to use.
13890 @defvr {Scheme Variable} %ntp-servers
13891 List of host names used as the default NTP servers. These are servers of the
13892 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13895 @deftp {Data Type} ntp-server
13896 The data type representing the configuration of a NTP server.
13899 @item @code{type} (default: @code{'server})
13900 The type of the NTP server, given as a symbol. One of @code{'pool},
13901 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13903 @item @code{address}
13904 The address of the server, as a string.
13906 @item @code{options}
13907 NTPD options to use with that specific server, given as a list of option names
13908 and/or of option names and values tuples. The following example define a server
13909 to use with the options @option{iburst} and @option{prefer}, as well as
13910 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13915 (address "some.ntp.server.org")
13916 (options `(iburst (version 3) (maxpoll 16) prefer))))
13922 @deffn {Scheme Procedure} openntpd-service-type
13923 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13924 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13925 clock synchronized with that of the given servers.
13929 openntpd-service-type
13930 (openntpd-configuration
13931 (listen-on '("127.0.0.1" "::1"))
13932 (sensor '("udcf0 correction 70000"))
13933 (constraint-from '("www.gnu.org"))
13934 (constraints-from '("https://www.google.com/"))
13935 (allow-large-adjustment? #t)))
13940 @defvr {Scheme Variable} %openntpd-servers
13941 This variable is a list of the server addresses defined in
13942 @code{%ntp-servers}.
13945 @deftp {Data Type} openntpd-configuration
13947 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13948 The openntpd executable to use.
13949 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13950 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13951 @item @code{query-from} (default: @code{'()})
13952 A list of local IP address the ntpd daemon should use for outgoing queries.
13953 @item @code{sensor} (default: @code{'()})
13954 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13955 will listen to each sensor that actually exists and ignore non-existent ones.
13956 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13958 @item @code{server} (default: @code{'()})
13959 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13960 @item @code{servers} (default: @code{%openntp-servers})
13961 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13962 @item @code{constraint-from} (default: @code{'()})
13963 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13964 This time information is not used for precision but acts as an authenticated
13965 constraint, thereby reducing the impact of unauthenticated NTP
13966 man-in-the-middle attacks.
13967 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13969 @item @code{constraints-from} (default: @code{'()})
13970 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13971 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13972 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13973 @item @code{allow-large-adjustment?} (default: @code{#f})
13974 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13980 @deffn {Scheme variable} inetd-service-type
13981 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13982 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13983 connections on internet sockets, and lazily starts the specified server
13984 program when a connection is made on one of these sockets.
13986 The value of this service is an @code{inetd-configuration} object. The
13987 following example configures the @command{inetd} daemon to provide the
13988 built-in @command{echo} service, as well as an smtp service which
13989 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13990 gateway @code{hostname}:
13995 (inetd-configuration
13999 (socket-type 'stream)
14006 (socket-type 'stream)
14010 (program (file-append openssh "/bin/ssh"))
14012 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14013 "-W" "smtp-server:25" "user@@hostname")))))))
14016 See below for more details about @code{inetd-configuration}.
14019 @deftp {Data Type} inetd-configuration
14020 Data type representing the configuration of @command{inetd}.
14023 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14024 The @command{inetd} executable to use.
14026 @item @code{entries} (default: @code{'()})
14027 A list of @command{inetd} service entries. Each entry should be created
14028 by the @code{inetd-entry} constructor.
14032 @deftp {Data Type} inetd-entry
14033 Data type representing an entry in the @command{inetd} configuration.
14034 Each entry corresponds to a socket where @command{inetd} will listen for
14038 @item @code{node} (default: @code{#f})
14039 Optional string, a comma-separated list of local addresses
14040 @command{inetd} should use when listening for this service.
14041 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14042 description of all options.
14044 A string, the name must correspond to an entry in @code{/etc/services}.
14045 @item @code{socket-type}
14046 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14048 @item @code{protocol}
14049 A string, must correspond to an entry in @code{/etc/protocols}.
14050 @item @code{wait?} (default: @code{#t})
14051 Whether @command{inetd} should wait for the server to exit before
14052 listening to new service requests.
14054 A string containing the user (and, optionally, group) name of the user
14055 as whom the server should run. The group name can be specified in a
14056 suffix, separated by a colon or period, i.e.@: @code{"user"},
14057 @code{"user:group"} or @code{"user.group"}.
14058 @item @code{program} (default: @code{"internal"})
14059 The server program which will serve the requests, or @code{"internal"}
14060 if @command{inetd} should use a built-in service.
14061 @item @code{arguments} (default: @code{'()})
14062 A list strings or file-like objects, which are the server program's
14063 arguments, starting with the zeroth argument, i.e.@: the name of the
14064 program itself. For @command{inetd}'s internal services, this entry
14065 must be @code{'()} or @code{'("internal")}.
14068 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14069 detailed discussion of each configuration field.
14073 @defvr {Scheme Variable} tor-service-type
14074 This is the type for a service that runs the @uref{https://torproject.org,
14075 Tor} anonymous networking daemon. The service is configured using a
14076 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14077 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14081 @deftp {Data Type} tor-configuration
14083 @item @code{tor} (default: @code{tor})
14084 The package that provides the Tor daemon. This package is expected to provide
14085 the daemon at @file{bin/tor} relative to its output directory. The default
14086 package is the @uref{https://www.torproject.org, Tor Project's}
14089 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14090 The configuration file to use. It will be appended to a default configuration
14091 file, and the final configuration file will be passed to @code{tor} via its
14092 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14093 file-like objects}). See @code{man tor} for details on the configuration file
14096 @item @code{hidden-services} (default: @code{'()})
14097 The list of @code{<hidden-service>} records to use. For any hidden service
14098 you include in this list, appropriate configuration to enable the hidden
14099 service will be automatically added to the default configuration file. You
14100 may conveniently create @code{<hidden-service>} records using the
14101 @code{tor-hidden-service} procedure described below.
14103 @item @code{socks-socket-type} (default: @code{'tcp})
14104 The default socket type that Tor should use for its SOCKS socket. This must
14105 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14106 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14107 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
14108 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
14111 If you want to customize the SOCKS socket in more detail, leave
14112 @code{socks-socket-type} at its default value of @code{'tcp} and use
14113 @code{config-file} to override the default by providing your own
14114 @code{SocksPort} option.
14118 @cindex hidden service
14119 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
14120 Define a new Tor @dfn{hidden service} called @var{name} and implementing
14121 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
14124 '((22 "127.0.0.1:22")
14125 (80 "127.0.0.1:8080"))
14128 In this example, port 22 of the hidden service is mapped to local port 22, and
14129 port 80 is mapped to local port 8080.
14131 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
14132 the @file{hostname} file contains the @code{.onion} host name for the hidden
14135 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
14136 project's documentation} for more information.
14139 The @code{(gnu services rsync)} module provides the following services:
14141 You might want an rsync daemon if you have files that you want available
14142 so anyone (or just yourself) can download existing files or upload new
14145 @deffn {Scheme Variable} rsync-service-type
14146 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
14147 The value for this service type is a
14148 @command{rsync-configuration} record as in this example:
14151 (service rsync-service-type)
14154 See below for details about @code{rsync-configuration}.
14157 @deftp {Data Type} rsync-configuration
14158 Data type representing the configuration for @code{rsync-service}.
14161 @item @code{package} (default: @var{rsync})
14162 @code{rsync} package to use.
14164 @item @code{port-number} (default: @code{873})
14165 TCP port on which @command{rsync} listens for incoming connections. If port
14166 is less than @code{1024} @command{rsync} needs to be started as the
14167 @code{root} user and group.
14169 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
14170 Name of the file where @command{rsync} writes its PID.
14172 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
14173 Name of the file where @command{rsync} writes its lock file.
14175 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
14176 Name of the file where @command{rsync} writes its log file.
14178 @item @code{use-chroot?} (default: @var{#t})
14179 Whether to use chroot for @command{rsync} shared directory.
14181 @item @code{share-path} (default: @file{/srv/rsync})
14182 Location of the @command{rsync} shared directory.
14184 @item @code{share-comment} (default: @code{"Rsync share"})
14185 Comment of the @command{rsync} shared directory.
14187 @item @code{read-only?} (default: @var{#f})
14188 Read-write permissions to shared directory.
14190 @item @code{timeout} (default: @code{300})
14191 I/O timeout in seconds.
14193 @item @code{user} (default: @var{"root"})
14194 Owner of the @code{rsync} process.
14196 @item @code{group} (default: @var{"root"})
14197 Group of the @code{rsync} process.
14199 @item @code{uid} (default: @var{"rsyncd"})
14200 User name or user ID that file transfers to and from that module should take
14201 place as when the daemon was run as @code{root}.
14203 @item @code{gid} (default: @var{"rsyncd"})
14204 Group name or group ID that will be used when accessing the module.
14209 Furthermore, @code{(gnu services ssh)} provides the following services.
14213 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
14214 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
14215 [#:allow-empty-passwords? #f] [#:root-login? #f] @
14216 [#:syslog-output? #t] [#:x11-forwarding? #t] @
14217 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
14218 [#:public-key-authentication? #t] [#:initialize? #t]
14219 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
14220 @var{host-key} must designate a file containing the host key, and readable
14223 When @var{daemonic?} is true, @command{lshd} will detach from the
14224 controlling terminal and log its output to syslogd, unless one sets
14225 @var{syslog-output?} to false. Obviously, it also makes lsh-service
14226 depend on existence of syslogd service. When @var{pid-file?} is true,
14227 @command{lshd} writes its PID to the file called @var{pid-file}.
14229 When @var{initialize?} is true, automatically create the seed and host key
14230 upon service activation if they do not exist yet. This may take long and
14231 require interaction.
14233 When @var{initialize?} is false, it is up to the user to initialize the
14234 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
14235 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
14236 basics,,, lsh, LSH Manual}).
14238 When @var{interfaces} is empty, lshd listens for connections on all the
14239 network interfaces; otherwise, @var{interfaces} must be a list of host names
14242 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14243 passwords, and @var{root-login?} specifies whether to accept log-ins as
14246 The other options should be self-descriptive.
14251 @deffn {Scheme Variable} openssh-service-type
14252 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14253 shell daemon, @command{sshd}. Its value must be an
14254 @code{openssh-configuration} record as in this example:
14257 (service openssh-service-type
14258 (openssh-configuration
14259 (x11-forwarding? #t)
14260 (permit-root-login 'without-password)
14262 `(("alice" ,(local-file "alice.pub"))
14263 ("bob" ,(local-file "bob.pub"))))))
14266 See below for details about @code{openssh-configuration}.
14268 This service can be extended with extra authorized keys, as in this
14272 (service-extension openssh-service-type
14273 (const `(("charlie"
14274 ,(local-file "charlie.pub")))))
14278 @deftp {Data Type} openssh-configuration
14279 This is the configuration record for OpenSSH's @command{sshd}.
14282 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14283 Name of the file where @command{sshd} writes its PID.
14285 @item @code{port-number} (default: @code{22})
14286 TCP port on which @command{sshd} listens for incoming connections.
14288 @item @code{permit-root-login} (default: @code{#f})
14289 This field determines whether and when to allow logins as root. If
14290 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14291 If it's the symbol @code{'without-password}, then root logins are
14292 permitted but not with password-based authentication.
14294 @item @code{allow-empty-passwords?} (default: @code{#f})
14295 When true, users with empty passwords may log in. When false, they may
14298 @item @code{password-authentication?} (default: @code{#t})
14299 When true, users may log in with their password. When false, they have
14300 other authentication methods.
14302 @item @code{public-key-authentication?} (default: @code{#t})
14303 When true, users may log in using public key authentication. When
14304 false, users have to use other authentication method.
14306 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14307 This is used only by protocol version 2.
14309 @item @code{x11-forwarding?} (default: @code{#f})
14310 When true, forwarding of X11 graphical client connections is
14311 enabled---in other words, @command{ssh} options @option{-X} and
14312 @option{-Y} will work.
14314 @item @code{allow-agent-forwarding?} (default: @code{#t})
14315 Whether to allow agent forwarding.
14317 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14318 Whether to allow TCP forwarding.
14320 @item @code{gateway-ports?} (default: @code{#f})
14321 Whether to allow gateway ports.
14323 @item @code{challenge-response-authentication?} (default: @code{#f})
14324 Specifies whether challenge response authentication is allowed (e.g.@: via
14327 @item @code{use-pam?} (default: @code{#t})
14328 Enables the Pluggable Authentication Module interface. If set to
14329 @code{#t}, this will enable PAM authentication using
14330 @code{challenge-response-authentication?} and
14331 @code{password-authentication?}, in addition to PAM account and session
14332 module processing for all authentication types.
14334 Because PAM challenge response authentication usually serves an
14335 equivalent role to password authentication, you should disable either
14336 @code{challenge-response-authentication?} or
14337 @code{password-authentication?}.
14339 @item @code{print-last-log?} (default: @code{#t})
14340 Specifies whether @command{sshd} should print the date and time of the
14341 last user login when a user logs in interactively.
14343 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14344 Configures external subsystems (e.g.@: file transfer daemon).
14346 This is a list of two-element lists, each of which containing the
14347 subsystem name and a command (with optional arguments) to execute upon
14350 The command @command{internal-sftp} implements an in-process SFTP
14351 server. Alternately, one can specify the @command{sftp-server} command:
14353 (service openssh-service-type
14354 (openssh-configuration
14356 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14359 @item @code{accepted-environment} (default: @code{'()})
14360 List of strings describing which environment variables may be exported.
14362 Each string gets on its own line. See the @code{AcceptEnv} option in
14363 @code{man sshd_config}.
14365 This example allows ssh-clients to export the @env{COLORTERM} variable.
14366 It is set by terminal emulators, which support colors. You can use it in
14367 your shell's resource file to enable colors for the prompt and commands
14368 if this variable is set.
14371 (service openssh-service-type
14372 (openssh-configuration
14373 (accepted-environment '("COLORTERM"))))
14376 @item @code{authorized-keys} (default: @code{'()})
14377 @cindex authorized keys, SSH
14378 @cindex SSH authorized keys
14379 This is the list of authorized keys. Each element of the list is a user
14380 name followed by one or more file-like objects that represent SSH public
14384 (openssh-configuration
14386 `(("rekado" ,(local-file "rekado.pub"))
14387 ("chris" ,(local-file "chris.pub"))
14388 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
14392 registers the specified public keys for user accounts @code{rekado},
14393 @code{chris}, and @code{root}.
14395 Additional authorized keys can be specified @i{via}
14396 @code{service-extension}.
14398 Note that this does @emph{not} interfere with the use of
14399 @file{~/.ssh/authorized_keys}.
14401 @item @code{log-level} (default: @code{'info})
14402 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14403 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14404 page for @file{sshd_config} for the full list of level names.
14406 @item @code{extra-content} (default: @code{""})
14407 This field can be used to append arbitrary text to the configuration file. It
14408 is especially useful for elaborate configurations that cannot be expressed
14409 otherwise. This configuration, for example, would generally disable root
14410 logins, but permit them from one specific IP address:
14413 (openssh-configuration
14415 Match Address 192.168.0.1
14416 PermitRootLogin yes"))
14422 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14423 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14424 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14427 For example, to specify a Dropbear service listening on port 1234, add
14428 this call to the operating system's @code{services} field:
14431 (dropbear-service (dropbear-configuration
14432 (port-number 1234)))
14436 @deftp {Data Type} dropbear-configuration
14437 This data type represents the configuration of a Dropbear SSH daemon.
14440 @item @code{dropbear} (default: @var{dropbear})
14441 The Dropbear package to use.
14443 @item @code{port-number} (default: 22)
14444 The TCP port where the daemon waits for incoming connections.
14446 @item @code{syslog-output?} (default: @code{#t})
14447 Whether to enable syslog output.
14449 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14450 File name of the daemon's PID file.
14452 @item @code{root-login?} (default: @code{#f})
14453 Whether to allow @code{root} logins.
14455 @item @code{allow-empty-passwords?} (default: @code{#f})
14456 Whether to allow empty passwords.
14458 @item @code{password-authentication?} (default: @code{#t})
14459 Whether to enable password-based authentication.
14464 @deffn {Scheme Variable} autossh-service-type
14465 This is the type for the @uref{https://www.harding.motd.ca/autossh,
14466 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
14467 restarting it as necessary should it die or stop passing traffic.
14468 AutoSSH can be run manually from the command-line by passing arguments
14469 to the binary @command{autossh} from the package @code{autossh}, but it
14470 can also be run as a Guix service. This latter use case is documented
14473 AutoSSH can be used to forward local traffic to a remote machine using
14474 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
14477 For example, to specify a service running autossh as the user
14478 @code{pino} and forwarding all local connections to port @code{8081} to
14479 @code{remote:8081} using an SSH tunnel, add this call to the operating
14480 system's @code{services} field:
14483 (service autossh-service-type
14484 (autossh-configuration
14486 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
14490 @deftp {Data Type} autossh-configuration
14491 This data type represents the configuration of an AutoSSH service.
14495 @item @code{user} (default @code{"autossh"})
14496 The user as which the AutoSSH service is to be run.
14497 This assumes that the specified user exists.
14499 @item @code{poll} (default @code{600})
14500 Specifies the connection poll time in seconds.
14502 @item @code{first-poll} (default @code{#f})
14503 Specifies how many seconds AutoSSH waits before the first connection
14504 test. After this first test, polling is resumed at the pace defined in
14505 @code{poll}. When set to @code{#f}, the first poll is not treated
14506 specially and will also use the connection poll specified in
14509 @item @code{gate-time} (default @code{30})
14510 Specifies how many seconds an SSH connection must be active before it is
14511 considered successful.
14513 @item @code{log-level} (default @code{1})
14514 The log level, corresponding to the levels used by syslog---so @code{0}
14515 is the most silent while @code{7} is the chattiest.
14517 @item @code{max-start} (default @code{#f})
14518 The maximum number of times SSH may be (re)started before AutoSSH exits.
14519 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
14521 @item @code{message} (default @code{""})
14522 The message to append to the echo message sent when testing connections.
14524 @item @code{port} (default @code{"0"})
14525 The ports used for monitoring the connection. When set to @code{"0"},
14526 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
14527 a positive integer, ports @var{n} and @var{n}+1 are used for
14528 monitoring the connection, such that port @var{n} is the base
14529 monitoring port and @code{n+1} is the echo port. When set to
14530 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
14531 integers, the ports @var{n} and @var{n}+1 are used for monitoring the
14532 connection, such that port @var{n} is the base monitoring port and
14533 @var{m} is the echo port.
14535 @item @code{ssh-options} (default @code{'()})
14536 The list of command-line arguments to pass to @command{ssh} when it is
14537 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
14538 may cause undefined behaviour.
14543 @defvr {Scheme Variable} %facebook-host-aliases
14544 This variable contains a string for use in @file{/etc/hosts}
14545 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14546 line contains a entry that maps a known server name of the Facebook
14547 on-line service---e.g., @code{www.facebook.com}---to the local
14548 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14550 This variable is typically used in the @code{hosts-file} field of an
14551 @code{operating-system} declaration (@pxref{operating-system Reference,
14552 @file{/etc/hosts}}):
14555 (use-modules (gnu) (guix))
14558 (host-name "mymachine")
14561 ;; Create a /etc/hosts file with aliases for "localhost"
14562 ;; and "mymachine", as well as for Facebook servers.
14563 (plain-file "hosts"
14564 (string-append (local-host-aliases host-name)
14565 %facebook-host-aliases))))
14568 This mechanism can prevent programs running locally, such as Web
14569 browsers, from accessing Facebook.
14572 The @code{(gnu services avahi)} provides the following definition.
14574 @defvr {Scheme Variable} avahi-service-type
14575 This is the service that runs @command{avahi-daemon}, a system-wide
14576 mDNS/DNS-SD responder that allows for service discovery and
14577 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14578 Its value must be a @code{zero-configuration} record---see below.
14580 This service extends the name service cache daemon (nscd) so that it can
14581 resolve @code{.local} host names using
14582 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14583 Service Switch}, for information on host name resolution.
14585 Additionally, add the @var{avahi} package to the system profile so that
14586 commands such as @command{avahi-browse} are directly usable.
14589 @deftp {Data Type} avahi-configuration
14590 Data type representation the configuration for Avahi.
14594 @item @code{host-name} (default: @code{#f})
14595 If different from @code{#f}, use that as the host name to
14596 publish for this machine; otherwise, use the machine's actual host name.
14598 @item @code{publish?} (default: @code{#t})
14599 When true, allow host names and services to be published (broadcast) over the
14602 @item @code{publish-workstation?} (default: @code{#t})
14603 When true, @command{avahi-daemon} publishes the machine's host name and IP
14604 address via mDNS on the local network. To view the host names published on
14605 your local network, you can run:
14608 avahi-browse _workstation._tcp
14611 @item @code{wide-area?} (default: @code{#f})
14612 When true, DNS-SD over unicast DNS is enabled.
14614 @item @code{ipv4?} (default: @code{#t})
14615 @itemx @code{ipv6?} (default: @code{#t})
14616 These fields determine whether to use IPv4/IPv6 sockets.
14618 @item @code{domains-to-browse} (default: @code{'()})
14619 This is a list of domains to browse.
14623 @deffn {Scheme Variable} openvswitch-service-type
14624 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14625 service, whose value should be an @code{openvswitch-configuration}
14629 @deftp {Data Type} openvswitch-configuration
14630 Data type representing the configuration of Open vSwitch, a multilayer
14631 virtual switch which is designed to enable massive network automation
14632 through programmatic extension.
14635 @item @code{package} (default: @var{openvswitch})
14636 Package object of the Open vSwitch.
14641 @defvr {Scheme Variable} pagekite-service-type
14642 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14643 a tunneling solution for making localhost servers publicly visible, even from
14644 behind restrictive firewalls or NAT without forwarded ports. The value for
14645 this service type is a @code{pagekite-configuration} record.
14647 Here's an example exposing the local HTTP and SSH daemons:
14650 (service pagekite-service-type
14651 (pagekite-configuration
14652 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14653 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14654 (extra-file "/etc/pagekite.rc")))
14658 @deftp {Data Type} pagekite-configuration
14659 Data type representing the configuration of PageKite.
14662 @item @code{package} (default: @var{pagekite})
14663 Package object of PageKite.
14665 @item @code{kitename} (default: @code{#f})
14666 PageKite name for authenticating to the frontend server.
14668 @item @code{kitesecret} (default: @code{#f})
14669 Shared secret for authenticating to the frontend server. You should probably
14670 put this inside @code{extra-file} instead.
14672 @item @code{frontend} (default: @code{#f})
14673 Connect to the named PageKite frontend server instead of the
14674 @uref{https://pagekite.net,,pagekite.net} service.
14676 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14677 List of service kites to use. Exposes HTTP on port 80 by default. The format
14678 is @code{proto:kitename:host:port:secret}.
14680 @item @code{extra-file} (default: @code{#f})
14681 Extra configuration file to read, which you are expected to create manually.
14682 Use this to add additional options and manage shared secrets out-of-band.
14688 @subsection X Window
14691 @cindex X Window System
14692 @cindex login manager
14693 Support for the X Window graphical display system---specifically
14694 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14695 there is no @code{xorg-service} procedure. Instead, the X server is
14696 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14699 @cindex GNOME, login manager
14700 GDM of course allows users to log in into window managers and desktop
14701 environments other than GNOME; for those using GNOME, GDM is required for
14702 features such as automatic screen locking.
14704 @cindex window manager
14705 To use X11, you must install at least one @dfn{window manager}---for
14706 example the @code{windowmaker} or @code{openbox} packages---preferably
14707 by adding it to the @code{packages} field of your operating system
14708 definition (@pxref{operating-system Reference, system-wide packages}).
14710 @defvr {Scheme Variable} gdm-service-type
14711 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14712 Desktop Manager} (GDM), a program that manages graphical display servers and
14713 handles graphical user logins. Its value must be a @code{gdm-configuration}
14716 @cindex session types (X11)
14717 @cindex X11 session types
14718 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14719 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14720 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14721 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14722 set of packages automatically makes them available at the log-in screen.
14724 In addition, @file{~/.xsession} files are honored. When available,
14725 @file{~/.xsession} must be an executable that starts a window manager
14726 and/or other X clients.
14729 @deftp {Data Type} gdm-configuration
14731 @item @code{auto-login?} (default: @code{#f})
14732 @itemx @code{default-user} (default: @code{#f})
14733 When @code{auto-login?} is false, GDM presents a log-in screen.
14735 When @code{auto-login?} is true, GDM logs in directly as
14736 @code{default-user}.
14738 @item @code{debug?} (default: @code{#f})
14739 When true, GDM writes debug messages to its log.
14741 @item @code{gnome-shell-assets} (default: ...)
14742 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14744 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14745 Configuration of the Xorg graphical server.
14747 @item @code{xsession} (default: @code{(xinitrc)})
14748 Script to run before starting a X session.
14750 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14751 File name of the @code{dbus-daemon} executable.
14753 @item @code{gdm} (default: @code{gdm})
14754 The GDM package to use.
14758 @defvr {Scheme Variable} slim-service-type
14759 This is the type for the SLiM graphical login manager for X11.
14761 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14762 allows users to choose a session from the log-in screen using @kbd{F1}. It
14763 also honors @file{~/.xsession} files.
14765 Unlike GDM, SLiM does not spawn the user session on a different VT after
14766 logging in, which means that you can only start one graphical session. If you
14767 want to be able to run multiple graphical sessions at the same time you have
14768 to add multiple SLiM services to your system services. The following example
14769 shows how to replace the default GDM service with two SLiM services on tty7
14773 (use-modules (gnu services)
14774 (gnu services desktop)
14775 (gnu services xorg)
14776 (srfi srfi-1)) ;for 'remove'
14780 (services (cons* (service slim-service-type (slim-configuration
14783 (service slim-service-type (slim-configuration
14786 (remove (lambda (service)
14787 (eq? (service-kind service) gdm-service-type))
14788 %desktop-services))))
14793 @deftp {Data Type} slim-configuration
14794 Data type representing the configuration of @code{slim-service-type}.
14797 @item @code{allow-empty-passwords?} (default: @code{#t})
14798 Whether to allow logins with empty passwords.
14800 @item @code{auto-login?} (default: @code{#f})
14801 @itemx @code{default-user} (default: @code{""})
14802 When @code{auto-login?} is false, SLiM presents a log-in screen.
14804 When @code{auto-login?} is true, SLiM logs in directly as
14805 @code{default-user}.
14807 @item @code{theme} (default: @code{%default-slim-theme})
14808 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14809 The graphical theme to use and its name.
14811 @item @code{auto-login-session} (default: @code{#f})
14812 If true, this must be the name of the executable to start as the default
14813 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14815 If false, a session described by one of the available @file{.desktop}
14816 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14820 You must install at least one window manager in the system profile or in
14821 your user profile. Failing to do that, if @code{auto-login-session} is
14822 false, you will be unable to log in.
14825 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14826 Configuration of the Xorg graphical server.
14828 @item @code{display} (default @code{":0"})
14829 The display on which to start the Xorg graphical server.
14831 @item @code{vt} (default @code{"vt7"})
14832 The VT on which to start the Xorg graphical server.
14834 @item @code{xauth} (default: @code{xauth})
14835 The XAuth package to use.
14837 @item @code{shepherd} (default: @code{shepherd})
14838 The Shepherd package used when invoking @command{halt} and
14841 @item @code{sessreg} (default: @code{sessreg})
14842 The sessreg package used in order to register the session.
14844 @item @code{slim} (default: @code{slim})
14845 The SLiM package to use.
14849 @defvr {Scheme Variable} %default-theme
14850 @defvrx {Scheme Variable} %default-theme-name
14851 The default SLiM theme and its name.
14855 @deftp {Data Type} sddm-configuration
14856 This is the data type representing the SDDM service configuration.
14859 @item @code{display-server} (default: "x11")
14860 Select display server to use for the greeter. Valid values are
14861 @samp{"x11"} or @samp{"wayland"}.
14863 @item @code{numlock} (default: "on")
14864 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
14866 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14867 Command to run when halting.
14869 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14870 Command to run when rebooting.
14872 @item @code{theme} (default "maldives")
14873 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
14874 @samp{"maldives"} or @samp{"maya"}.
14876 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14877 Directory to look for themes.
14879 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14880 Directory to look for faces.
14882 @item @code{default-path} (default "/run/current-system/profile/bin")
14883 Default PATH to use.
14885 @item @code{minimum-uid} (default: 1000)
14886 Minimum UID displayed in SDDM and allowed for log-in.
14888 @item @code{maximum-uid} (default: 2000)
14889 Maximum UID to display in SDDM.
14891 @item @code{remember-last-user?} (default #t)
14892 Remember last user.
14894 @item @code{remember-last-session?} (default #t)
14895 Remember last session.
14897 @item @code{hide-users} (default "")
14898 Usernames to hide from SDDM greeter.
14900 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14901 Users with shells listed will be hidden from the SDDM greeter.
14903 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14904 Script to run before starting a wayland session.
14906 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14907 Directory to look for desktop files starting wayland sessions.
14909 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14910 Configuration of the Xorg graphical server.
14912 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14915 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14918 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14919 Script to run after starting xorg-server.
14921 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14922 Script to run before stopping xorg-server.
14924 @item @code{xsession-command} (default: @code{xinitrc})
14925 Script to run before starting a X session.
14927 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14928 Directory to look for desktop files starting X sessions.
14930 @item @code{minimum-vt} (default: 7)
14933 @item @code{auto-login-user} (default "")
14934 User to use for auto-login.
14936 @item @code{auto-login-session} (default "")
14937 Desktop file to use for auto-login.
14939 @item @code{relogin?} (default #f)
14940 Relogin after logout.
14945 @cindex login manager
14947 @defvr {Scheme Variable} sddm-service-type
14948 This is the type of the service to run the
14949 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
14950 must be a @code{sddm-configuration} record (see below).
14952 Here's an example use:
14955 (service sddm-service-type
14956 (sddm-configuration
14957 (auto-login-user "alice")
14958 (auto-login-session "xfce.desktop")))
14962 @deftp {Data Type} sddm-configuration
14963 This data type represents the configuration of the SDDM login manager.
14964 The available fields are:
14967 @item @code{sddm} (default: @code{sddm})
14968 The SDDM package to use.
14970 @item @code{display-server} (default: @code{"x11"})
14971 This must be either @code{"x11"} or @code{"wayland"}.
14973 @c FIXME: Add more fields.
14975 @item @code{auto-login-user} (default: @code{""})
14976 If non-empty, this is the user account under which to log in
14979 @item @code{auto-login-session} (default: @code{""})
14980 If non-empty, this is the @file{.desktop} file name to use as the
14981 auto-login session.
14985 @cindex Xorg, configuration
14986 @deftp {Data Type} xorg-configuration
14987 This data type represents the configuration of the Xorg graphical display
14988 server. Note that there is not Xorg service; instead, the X server is started
14989 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14990 of these display managers aggregates an @code{xorg-configuration} record.
14993 @item @code{modules} (default: @code{%default-xorg-modules})
14994 This is a list of @dfn{module packages} loaded by the Xorg
14995 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14997 @item @code{fonts} (default: @code{%default-xorg-fonts})
14998 This is a list of font directories to add to the server's @dfn{font path}.
15000 @item @code{drivers} (default: @code{'()})
15001 This must be either the empty list, in which case Xorg chooses a graphics
15002 driver automatically, or a list of driver names that will be tried in this
15003 order---e.g., @code{("modesetting" "vesa")}.
15005 @item @code{resolutions} (default: @code{'()})
15006 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
15007 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
15010 @cindex keyboard layout, for Xorg
15011 @cindex keymap, for Xorg
15012 @item @code{keyboard-layout} (default: @code{#f})
15013 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
15014 English (``qwerty'') for a 105-key PC keyboard.
15016 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
15017 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
15018 information on how to specify the keyboard layout.
15020 @item @code{extra-config} (default: @code{'()})
15021 This is a list of strings or objects appended to the configuration file. It
15022 is used to pass extra text to be added verbatim to the configuration file.
15024 @item @code{server} (default: @code{xorg-server})
15025 This is the package providing the Xorg server.
15027 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
15028 This is the list of command-line arguments to pass to the X server. The
15029 default is @code{-nolisten tcp}.
15033 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
15034 [@var{login-manager-service-type}]
15035 Tell the log-in manager (of type @var{login-manager-service-type}) to use
15036 @var{config}, an @code{<xorg-configuration>} record.
15038 Since the Xorg configuration is embedded in the log-in manager's
15039 configuration---e.g., @code{gdm-configuration}---this procedure provides a
15040 shorthand to set the Xorg configuration.
15043 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
15044 Return a @code{startx} script in which the modules, fonts, etc. specified
15045 in @var{config}, are available. The result should be used in place of
15048 Usually the X server is started by a login manager.
15052 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
15053 Add @var{package}, a package for a screen locker or screen saver whose
15054 command is @var{program}, to the set of setuid programs and add a PAM entry
15055 for it. For example:
15058 (screen-locker-service xlockmore "xlock")
15061 makes the good ol' XlockMore usable.
15065 @node Printing Services
15066 @subsection Printing Services
15068 @cindex printer support with CUPS
15069 The @code{(gnu services cups)} module provides a Guix service definition
15070 for the CUPS printing service. To add printer support to a Guix
15071 system, add a @code{cups-service} to the operating system definition:
15073 @deffn {Scheme Variable} cups-service-type
15074 The service type for the CUPS print server. Its value should be a valid
15075 CUPS configuration (see below). To use the default settings, simply
15078 (service cups-service-type)
15082 The CUPS configuration controls the basic things about your CUPS
15083 installation: what interfaces it listens on, what to do if a print job
15084 fails, how much logging to do, and so on. To actually add a printer,
15085 you have to visit the @url{http://localhost:631} URL, or use a tool such
15086 as GNOME's printer configuration services. By default, configuring a
15087 CUPS service will generate a self-signed certificate if needed, for
15088 secure connections to the print server.
15090 Suppose you want to enable the Web interface of CUPS and also add
15091 support for Epson printers @i{via} the @code{escpr} package and for HP
15092 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
15093 like this (you need to use the @code{(gnu packages cups)} module):
15096 (service cups-service-type
15097 (cups-configuration
15098 (web-interface? #t)
15100 (list cups-filters escpr hplip-minimal))))
15103 Note: If you wish to use the Qt5 based GUI which comes with the hplip
15104 package then it is suggested that you install the @code{hplip} package,
15105 either in your OS configuration file or as your user.
15107 The available configuration parameters follow. Each parameter
15108 definition is preceded by its type; for example, @samp{string-list foo}
15109 indicates that the @code{foo} parameter should be specified as a list of
15110 strings. There is also a way to specify the configuration as a string,
15111 if you have an old @code{cupsd.conf} file that you want to port over
15112 from some other system; see the end for more details.
15114 @c The following documentation was initially generated by
15115 @c (generate-documentation) in (gnu services cups). Manually maintained
15116 @c documentation is better, so we shouldn't hesitate to edit below as
15117 @c needed. However if the change you want to make to this documentation
15118 @c can be done in an automated way, it's probably easier to change
15119 @c (generate-documentation) than to make it below and have to deal with
15120 @c the churn as CUPS updates.
15123 Available @code{cups-configuration} fields are:
15125 @deftypevr {@code{cups-configuration} parameter} package cups
15129 @deftypevr {@code{cups-configuration} parameter} package-list extensions
15130 Drivers and other extensions to the CUPS package.
15133 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
15134 Configuration of where to write logs, what directories to use for print
15135 spools, and related privileged configuration parameters.
15137 Available @code{files-configuration} fields are:
15139 @deftypevr {@code{files-configuration} parameter} log-location access-log
15140 Defines the access log filename. Specifying a blank filename disables
15141 access log generation. The value @code{stderr} causes log entries to be
15142 sent to the standard error file when the scheduler is running in the
15143 foreground, or to the system log daemon when run in the background. The
15144 value @code{syslog} causes log entries to be sent to the system log
15145 daemon. The server name may be included in filenames using the string
15146 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
15148 Defaults to @samp{"/var/log/cups/access_log"}.
15151 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
15152 Where CUPS should cache data.
15154 Defaults to @samp{"/var/cache/cups"}.
15157 @deftypevr {@code{files-configuration} parameter} string config-file-perm
15158 Specifies the permissions for all configuration files that the scheduler
15161 Note that the permissions for the printers.conf file are currently
15162 masked to only allow access from the scheduler user (typically root).
15163 This is done because printer device URIs sometimes contain sensitive
15164 authentication information that should not be generally known on the
15165 system. There is no way to disable this security feature.
15167 Defaults to @samp{"0640"}.
15170 @deftypevr {@code{files-configuration} parameter} log-location error-log
15171 Defines the error log filename. Specifying a blank filename disables
15172 error log generation. The value @code{stderr} causes log entries to be
15173 sent to the standard error file when the scheduler is running in the
15174 foreground, or to the system log daemon when run in the background. The
15175 value @code{syslog} causes log entries to be sent to the system log
15176 daemon. The server name may be included in filenames using the string
15177 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
15179 Defaults to @samp{"/var/log/cups/error_log"}.
15182 @deftypevr {@code{files-configuration} parameter} string fatal-errors
15183 Specifies which errors are fatal, causing the scheduler to exit. The
15188 No errors are fatal.
15191 All of the errors below are fatal.
15194 Browsing initialization errors are fatal, for example failed connections
15195 to the DNS-SD daemon.
15198 Configuration file syntax errors are fatal.
15201 Listen or Port errors are fatal, except for IPv6 failures on the
15202 loopback or @code{any} addresses.
15205 Log file creation or write errors are fatal.
15208 Bad startup file permissions are fatal, for example shared TLS
15209 certificate and key files with world-read permissions.
15212 Defaults to @samp{"all -browse"}.
15215 @deftypevr {@code{files-configuration} parameter} boolean file-device?
15216 Specifies whether the file pseudo-device can be used for new printer
15217 queues. The URI @uref{file:///dev/null} is always allowed.
15219 Defaults to @samp{#f}.
15222 @deftypevr {@code{files-configuration} parameter} string group
15223 Specifies the group name or ID that will be used when executing external
15226 Defaults to @samp{"lp"}.
15229 @deftypevr {@code{files-configuration} parameter} string log-file-perm
15230 Specifies the permissions for all log files that the scheduler writes.
15232 Defaults to @samp{"0644"}.
15235 @deftypevr {@code{files-configuration} parameter} log-location page-log
15236 Defines the page log filename. Specifying a blank filename disables
15237 page log generation. The value @code{stderr} causes log entries to be
15238 sent to the standard error file when the scheduler is running in the
15239 foreground, or to the system log daemon when run in the background. The
15240 value @code{syslog} causes log entries to be sent to the system log
15241 daemon. The server name may be included in filenames using the string
15242 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
15244 Defaults to @samp{"/var/log/cups/page_log"}.
15247 @deftypevr {@code{files-configuration} parameter} string remote-root
15248 Specifies the username that is associated with unauthenticated accesses
15249 by clients claiming to be the root user. The default is @code{remroot}.
15251 Defaults to @samp{"remroot"}.
15254 @deftypevr {@code{files-configuration} parameter} file-name request-root
15255 Specifies the directory that contains print jobs and other HTTP request
15258 Defaults to @samp{"/var/spool/cups"}.
15261 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
15262 Specifies the level of security sandboxing that is applied to print
15263 filters, backends, and other child processes of the scheduler; either
15264 @code{relaxed} or @code{strict}. This directive is currently only
15265 used/supported on macOS.
15267 Defaults to @samp{strict}.
15270 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
15271 Specifies the location of TLS certificates and private keys. CUPS will
15272 look for public and private keys in this directory: @file{.crt} files
15273 for PEM-encoded certificates and corresponding @file{.key} files for
15274 PEM-encoded private keys.
15276 Defaults to @samp{"/etc/cups/ssl"}.
15279 @deftypevr {@code{files-configuration} parameter} file-name server-root
15280 Specifies the directory containing the server configuration files.
15282 Defaults to @samp{"/etc/cups"}.
15285 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
15286 Specifies whether the scheduler calls fsync(2) after writing
15287 configuration or state files.
15289 Defaults to @samp{#f}.
15292 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
15293 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
15296 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
15297 Specifies the directory where temporary files are stored.
15299 Defaults to @samp{"/var/spool/cups/tmp"}.
15302 @deftypevr {@code{files-configuration} parameter} string user
15303 Specifies the user name or ID that is used when running external
15306 Defaults to @samp{"lp"}.
15309 @deftypevr {@code{files-configuration} parameter} string set-env
15310 Set the specified environment variable to be passed to child processes.
15312 Defaults to @samp{"variable value"}.
15316 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
15317 Specifies the logging level for the AccessLog file. The @code{config}
15318 level logs when printers and classes are added, deleted, or modified and
15319 when configuration files are accessed or updated. The @code{actions}
15320 level logs when print jobs are submitted, held, released, modified, or
15321 canceled, and any of the conditions for @code{config}. The @code{all}
15322 level logs all requests.
15324 Defaults to @samp{actions}.
15327 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
15328 Specifies whether to purge job history data automatically when it is no
15329 longer required for quotas.
15331 Defaults to @samp{#f}.
15334 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
15335 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
15336 For example, @samp{"_cups" "_print"} will tell network clients that both
15337 CUPS sharing and IPP Everywhere are supported.
15339 Defaults to @samp{"_cups"}.
15342 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
15343 Specifies which protocols to use for local printer sharing.
15345 Defaults to @samp{dnssd}.
15348 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
15349 Specifies whether the CUPS web interface is advertised.
15351 Defaults to @samp{#f}.
15354 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
15355 Specifies whether shared printers are advertised.
15357 Defaults to @samp{#f}.
15360 @deftypevr {@code{cups-configuration} parameter} string classification
15361 Specifies the security classification of the server. Any valid banner
15362 name can be used, including @samp{"classified"}, @samp{"confidential"},
15363 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
15364 banner can be omitted to disable secure printing functions.
15366 Defaults to @samp{""}.
15369 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
15370 Specifies whether users may override the classification (cover page) of
15371 individual print jobs using the @code{job-sheets} option.
15373 Defaults to @samp{#f}.
15376 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
15377 Specifies the default type of authentication to use.
15379 Defaults to @samp{Basic}.
15382 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
15383 Specifies whether encryption will be used for authenticated requests.
15385 Defaults to @samp{Required}.
15388 @deftypevr {@code{cups-configuration} parameter} string default-language
15389 Specifies the default language to use for text and web content.
15391 Defaults to @samp{"en"}.
15394 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
15395 Specifies the default paper size for new print queues. @samp{"Auto"}
15396 uses a locale-specific default, while @samp{"None"} specifies there is
15397 no default paper size. Specific size names are typically
15398 @samp{"Letter"} or @samp{"A4"}.
15400 Defaults to @samp{"Auto"}.
15403 @deftypevr {@code{cups-configuration} parameter} string default-policy
15404 Specifies the default access policy to use.
15406 Defaults to @samp{"default"}.
15409 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
15410 Specifies whether local printers are shared by default.
15412 Defaults to @samp{#t}.
15415 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
15416 Specifies the delay for updating of configuration and state files, in
15417 seconds. A value of 0 causes the update to happen as soon as possible,
15418 typically within a few milliseconds.
15420 Defaults to @samp{30}.
15423 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
15424 Specifies what to do when an error occurs. Possible values are
15425 @code{abort-job}, which will discard the failed print job;
15426 @code{retry-job}, which will retry the job at a later time;
15427 @code{retry-current-job}, which retries the failed job immediately; and
15428 @code{stop-printer}, which stops the printer.
15430 Defaults to @samp{stop-printer}.
15433 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
15434 Specifies the maximum cost of filters that are run concurrently, which
15435 can be used to minimize disk, memory, and CPU resource problems. A
15436 limit of 0 disables filter limiting. An average print to a
15437 non-PostScript printer needs a filter limit of about 200. A PostScript
15438 printer needs about half that (100). Setting the limit below these
15439 thresholds will effectively limit the scheduler to printing a single job
15442 Defaults to @samp{0}.
15445 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
15446 Specifies the scheduling priority of filters that are run to print a
15447 job. The nice value ranges from 0, the highest priority, to 19, the
15450 Defaults to @samp{0}.
15453 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
15454 Specifies whether to do reverse lookups on connecting clients. The
15455 @code{double} setting causes @code{cupsd} to verify that the hostname
15456 resolved from the address matches one of the addresses returned for that
15457 hostname. Double lookups also prevent clients with unregistered
15458 addresses from connecting to your server. Only set this option to
15459 @code{#t} or @code{double} if absolutely required.
15461 Defaults to @samp{#f}.
15464 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
15465 Specifies the number of seconds to wait before killing the filters and
15466 backend associated with a canceled or held job.
15468 Defaults to @samp{30}.
15471 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
15472 Specifies the interval between retries of jobs in seconds. This is
15473 typically used for fax queues but can also be used with normal print
15474 queues whose error policy is @code{retry-job} or
15475 @code{retry-current-job}.
15477 Defaults to @samp{30}.
15480 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
15481 Specifies the number of retries that are done for jobs. This is
15482 typically used for fax queues but can also be used with normal print
15483 queues whose error policy is @code{retry-job} or
15484 @code{retry-current-job}.
15486 Defaults to @samp{5}.
15489 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15490 Specifies whether to support HTTP keep-alive connections.
15492 Defaults to @samp{#t}.
15495 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15496 Specifies how long an idle client connection remains open, in seconds.
15498 Defaults to @samp{30}.
15501 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15502 Specifies the maximum size of print files, IPP requests, and HTML form
15503 data. A limit of 0 disables the limit check.
15505 Defaults to @samp{0}.
15508 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15509 Listens on the specified interfaces for connections. Valid values are
15510 of the form @var{address}:@var{port}, where @var{address} is either an
15511 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15512 indicate all addresses. Values can also be file names of local UNIX
15513 domain sockets. The Listen directive is similar to the Port directive
15514 but allows you to restrict access to specific interfaces or networks.
15517 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15518 Specifies the number of pending connections that will be allowed. This
15519 normally only affects very busy servers that have reached the MaxClients
15520 limit, but can also be triggered by large numbers of simultaneous
15521 connections. When the limit is reached, the operating system will
15522 refuse additional connections until the scheduler can accept the pending
15525 Defaults to @samp{128}.
15528 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15529 Specifies a set of additional access controls.
15531 Available @code{location-access-controls} fields are:
15533 @deftypevr {@code{location-access-controls} parameter} file-name path
15534 Specifies the URI path to which the access control applies.
15537 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15538 Access controls for all access to this path, in the same format as the
15539 @code{access-controls} of @code{operation-access-control}.
15541 Defaults to @samp{()}.
15544 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15545 Access controls for method-specific access to this path.
15547 Defaults to @samp{()}.
15549 Available @code{method-access-controls} fields are:
15551 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15552 If @code{#t}, apply access controls to all methods except the listed
15553 methods. Otherwise apply to only the listed methods.
15555 Defaults to @samp{#f}.
15558 @deftypevr {@code{method-access-controls} parameter} method-list methods
15559 Methods to which this access control applies.
15561 Defaults to @samp{()}.
15564 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15565 Access control directives, as a list of strings. Each string should be
15566 one directive, such as @samp{"Order allow,deny"}.
15568 Defaults to @samp{()}.
15573 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15574 Specifies the number of debugging messages that are retained for logging
15575 if an error occurs in a print job. Debug messages are logged regardless
15576 of the LogLevel setting.
15578 Defaults to @samp{100}.
15581 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15582 Specifies the level of logging for the ErrorLog file. The value
15583 @code{none} stops all logging while @code{debug2} logs everything.
15585 Defaults to @samp{info}.
15588 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15589 Specifies the format of the date and time in the log files. The value
15590 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15592 Defaults to @samp{standard}.
15595 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15596 Specifies the maximum number of simultaneous clients that are allowed by
15599 Defaults to @samp{100}.
15602 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15603 Specifies the maximum number of simultaneous clients that are allowed
15604 from a single address.
15606 Defaults to @samp{100}.
15609 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15610 Specifies the maximum number of copies that a user can print of each
15613 Defaults to @samp{9999}.
15616 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15617 Specifies the maximum time a job may remain in the @code{indefinite}
15618 hold state before it is canceled. A value of 0 disables cancellation of
15621 Defaults to @samp{0}.
15624 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15625 Specifies the maximum number of simultaneous jobs that are allowed. Set
15626 to 0 to allow an unlimited number of jobs.
15628 Defaults to @samp{500}.
15631 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15632 Specifies the maximum number of simultaneous jobs that are allowed per
15633 printer. A value of 0 allows up to MaxJobs jobs per printer.
15635 Defaults to @samp{0}.
15638 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15639 Specifies the maximum number of simultaneous jobs that are allowed per
15640 user. A value of 0 allows up to MaxJobs jobs per user.
15642 Defaults to @samp{0}.
15645 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15646 Specifies the maximum time a job may take to print before it is
15647 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
15649 Defaults to @samp{10800}.
15652 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15653 Specifies the maximum size of the log files before they are rotated, in
15654 bytes. The value 0 disables log rotation.
15656 Defaults to @samp{1048576}.
15659 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15660 Specifies the maximum amount of time to allow between files in a
15661 multiple file print job, in seconds.
15663 Defaults to @samp{300}.
15666 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15667 Specifies the format of PageLog lines. Sequences beginning with percent
15668 (@samp{%}) characters are replaced with the corresponding information,
15669 while all other characters are copied literally. The following percent
15670 sequences are recognized:
15674 insert a single percent character
15677 insert the value of the specified IPP attribute
15680 insert the number of copies for the current page
15683 insert the current page number
15686 insert the current date and time in common log format
15692 insert the printer name
15695 insert the username
15698 A value of the empty string disables page logging. The string @code{%p
15699 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15700 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15703 Defaults to @samp{""}.
15706 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15707 Passes the specified environment variable(s) to child processes; a list
15710 Defaults to @samp{()}.
15713 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15714 Specifies named access control policies.
15716 Available @code{policy-configuration} fields are:
15718 @deftypevr {@code{policy-configuration} parameter} string name
15719 Name of the policy.
15722 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15723 Specifies an access list for a job's private values. @code{@@ACL} maps
15724 to the printer's requesting-user-name-allowed or
15725 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15726 owner. @code{@@SYSTEM} maps to the groups listed for the
15727 @code{system-group} field of the @code{files-config} configuration,
15728 which is reified into the @code{cups-files.conf(5)} file. Other
15729 possible elements of the access list include specific user names, and
15730 @code{@@@var{group}} to indicate members of a specific group. The
15731 access list may also be simply @code{all} or @code{default}.
15733 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15736 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15737 Specifies the list of job values to make private, or @code{all},
15738 @code{default}, or @code{none}.
15740 Defaults to @samp{"job-name job-originating-host-name
15741 job-originating-user-name phone"}.
15744 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15745 Specifies an access list for a subscription's private values.
15746 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15747 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15748 owner. @code{@@SYSTEM} maps to the groups listed for the
15749 @code{system-group} field of the @code{files-config} configuration,
15750 which is reified into the @code{cups-files.conf(5)} file. Other
15751 possible elements of the access list include specific user names, and
15752 @code{@@@var{group}} to indicate members of a specific group. The
15753 access list may also be simply @code{all} or @code{default}.
15755 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15758 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15759 Specifies the list of job values to make private, or @code{all},
15760 @code{default}, or @code{none}.
15762 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15763 notify-subscriber-user-name notify-user-data"}.
15766 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15767 Access control by IPP operation.
15769 Defaults to @samp{()}.
15773 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15774 Specifies whether job files (documents) are preserved after a job is
15775 printed. If a numeric value is specified, job files are preserved for
15776 the indicated number of seconds after printing. Otherwise a boolean
15777 value applies indefinitely.
15779 Defaults to @samp{86400}.
15782 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15783 Specifies whether the job history is preserved after a job is printed.
15784 If a numeric value is specified, the job history is preserved for the
15785 indicated number of seconds after printing. If @code{#t}, the job
15786 history is preserved until the MaxJobs limit is reached.
15788 Defaults to @samp{#t}.
15791 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15792 Specifies the amount of time to wait for job completion before
15793 restarting the scheduler.
15795 Defaults to @samp{30}.
15798 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15799 Specifies the maximum amount of memory to use when converting documents
15800 into bitmaps for a printer.
15802 Defaults to @samp{"128m"}.
15805 @deftypevr {@code{cups-configuration} parameter} string server-admin
15806 Specifies the email address of the server administrator.
15808 Defaults to @samp{"root@@localhost.localdomain"}.
15811 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15812 The ServerAlias directive is used for HTTP Host header validation when
15813 clients connect to the scheduler from external interfaces. Using the
15814 special name @code{*} can expose your system to known browser-based DNS
15815 rebinding attacks, even when accessing sites through a firewall. If the
15816 auto-discovery of alternate names does not work, we recommend listing
15817 each alternate name with a ServerAlias directive instead of using
15820 Defaults to @samp{*}.
15823 @deftypevr {@code{cups-configuration} parameter} string server-name
15824 Specifies the fully-qualified host name of the server.
15826 Defaults to @samp{"localhost"}.
15829 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15830 Specifies what information is included in the Server header of HTTP
15831 responses. @code{None} disables the Server header. @code{ProductOnly}
15832 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15833 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15834 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15835 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15836 2.0.0 (@var{uname}) IPP/2.0}.
15838 Defaults to @samp{Minimal}.
15841 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15842 Listens on the specified interfaces for encrypted connections. Valid
15843 values are of the form @var{address}:@var{port}, where @var{address} is
15844 either an IPv6 address enclosed in brackets, an IPv4 address, or
15845 @code{*} to indicate all addresses.
15847 Defaults to @samp{()}.
15850 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15851 Sets encryption options. By default, CUPS only supports encryption
15852 using TLS v1.0 or higher using known secure cipher suites. Security is
15853 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15854 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15855 suites, which are required for some older clients. The @code{AllowSSL3} option
15856 enables SSL v3.0, which is required for some older clients that do not support
15857 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15858 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15859 protocol version to TLS v1.1.
15861 Defaults to @samp{()}.
15864 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15865 Specifies whether the scheduler requires clients to strictly adhere to
15866 the IPP specifications.
15868 Defaults to @samp{#f}.
15871 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15872 Specifies the HTTP request timeout, in seconds.
15874 Defaults to @samp{300}.
15878 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15879 Specifies whether the web interface is enabled.
15881 Defaults to @samp{#f}.
15884 At this point you're probably thinking ``oh dear, Guix manual, I like
15885 you but you can stop already with the configuration options''. Indeed.
15886 However, one more point: it could be that you have an existing
15887 @code{cupsd.conf} that you want to use. In that case, you can pass an
15888 @code{opaque-cups-configuration} as the configuration of a
15889 @code{cups-service-type}.
15891 Available @code{opaque-cups-configuration} fields are:
15893 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15897 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15898 The contents of the @code{cupsd.conf}, as a string.
15901 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15902 The contents of the @code{cups-files.conf} file, as a string.
15905 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15906 strings of the same name, you could instantiate a CUPS service like
15910 (service cups-service-type
15911 (opaque-cups-configuration
15912 (cupsd.conf cupsd.conf)
15913 (cups-files.conf cups-files.conf)))
15917 @node Desktop Services
15918 @subsection Desktop Services
15920 The @code{(gnu services desktop)} module provides services that are
15921 usually useful in the context of a ``desktop'' setup---that is, on a
15922 machine running a graphical display server, possibly with graphical user
15923 interfaces, etc. It also defines services that provide specific desktop
15924 environments like GNOME, Xfce or MATE.
15926 To simplify things, the module defines a variable containing the set of
15927 services that users typically expect on a machine with a graphical
15928 environment and networking:
15930 @defvr {Scheme Variable} %desktop-services
15931 This is a list of services that builds upon @code{%base-services} and
15932 adds or adjusts services for a typical ``desktop'' setup.
15934 In particular, it adds a graphical login manager (@pxref{X Window,
15935 @code{gdm-service-type}}), screen lockers, a network management tool
15936 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15937 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15938 energy and color management services, the @code{elogind} login and seat
15939 manager, the Polkit privilege service, the GeoClue location service, the
15940 AccountsService daemon that allows authorized users change system passwords,
15941 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15942 name service switch service configured to be able to use @code{nss-mdns}
15943 (@pxref{Name Service Switch, mDNS}).
15946 The @code{%desktop-services} variable can be used as the @code{services}
15947 field of an @code{operating-system} declaration (@pxref{operating-system
15948 Reference, @code{services}}).
15950 Additionally, the @code{gnome-desktop-service-type},
15951 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15952 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15953 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15954 services like the backlight adjustment helpers and the power management
15955 utilities are added to the system, extending @code{polkit} and @code{dbus}
15956 appropriately, allowing GNOME to operate with elevated privileges on a
15957 limited number of special-purpose system interfaces. Additionally,
15958 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15959 metapackage to the system profile. Likewise, adding the Xfce service
15960 not only adds the @code{xfce} metapackage to the system profile, but it
15961 also gives the Thunar file manager the ability to open a ``root-mode''
15962 file management window, if the user authenticates using the
15963 administrator's password via the standard polkit graphical interface.
15964 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15965 appropriately, allowing MATE to operate with elevated privileges on a
15966 limited number of special-purpose system interfaces. Additionally,
15967 adding a service of type @code{mate-desktop-service-type} adds the MATE
15968 metapackage to the system profile. ``Adding Enlightenment'' means that
15969 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15970 are set as setuid, allowing Enlightenment's screen locker and other
15971 functionality to work as expected.
15973 The desktop environments in Guix use the Xorg display server by
15974 default. If you'd like to use the newer display server protocol
15975 called Wayland, you need to use the @code{sddm-service} instead of
15976 GDM as the graphical login manager. You should then
15977 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15978 also try starting GNOME on Wayland manually from a TTY with the
15979 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15980 gnome-session``. Currently only GNOME has support for Wayland.
15982 @defvr {Scheme Variable} gnome-desktop-service-type
15983 This is the type of the service that adds the @uref{https://www.gnome.org,
15984 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15985 object (see below.)
15987 This service adds the @code{gnome} package to the system profile, and extends
15988 polkit with the actions from @code{gnome-settings-daemon}.
15991 @deftp {Data Type} gnome-desktop-configuration
15992 Configuration record for the GNOME desktop environment.
15995 @item @code{gnome} (default: @code{gnome})
15996 The GNOME package to use.
16000 @defvr {Scheme Variable} xfce-desktop-service-type
16001 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
16002 desktop environment. Its value is an @code{xfce-desktop-configuration} object
16005 This service adds the @code{xfce} package to the system profile, and
16006 extends polkit with the ability for @code{thunar} to manipulate the file
16007 system as root from within a user session, after the user has authenticated
16008 with the administrator's password.
16011 @deftp {Data Type} xfce-desktop-configuration
16012 Configuration record for the Xfce desktop environment.
16015 @item @code{xfce} (default: @code{xfce})
16016 The Xfce package to use.
16020 @deffn {Scheme Variable} mate-desktop-service-type
16021 This is the type of the service that runs the @uref{https://mate-desktop.org/,
16022 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
16023 object (see below.)
16025 This service adds the @code{mate} package to the system
16026 profile, and extends polkit with the actions from
16027 @code{mate-settings-daemon}.
16030 @deftp {Data Type} mate-desktop-configuration
16031 Configuration record for the MATE desktop environment.
16034 @item @code{mate} (default: @code{mate})
16035 The MATE package to use.
16039 @deffn {Scheme Variable} enlightenment-desktop-service-type
16040 Return a service that adds the @code{enlightenment} package to the system
16041 profile, and extends dbus with actions from @code{efl}.
16044 @deftp {Data Type} enlightenment-desktop-service-configuration
16046 @item @code{enlightenment} (default: @code{enlightenment})
16047 The enlightenment package to use.
16051 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
16052 the default @code{%desktop-services} variable doesn't include any of
16053 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
16054 @code{%desktop-services} in the @code{services} field of your
16055 @code{operating-system}:
16058 (use-modules (gnu))
16059 (use-service-modules desktop)
16062 ;; cons* adds items to the list given as its last argument.
16063 (services (cons* (service gnome-desktop-service-type)
16064 (service xfce-desktop-service)
16065 %desktop-services))
16069 These desktop environments will then be available as options in the
16070 graphical login window.
16072 The actual service definitions included in @code{%desktop-services} and
16073 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
16074 are described below.
16076 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
16077 Return a service that runs the ``system bus'', using @var{dbus}, with
16078 support for @var{services}.
16080 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
16081 facility. Its system bus is used to allow system services to communicate
16082 and to be notified of system-wide events.
16084 @var{services} must be a list of packages that provide an
16085 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
16086 and policy files. For example, to allow avahi-daemon to use the system bus,
16087 @var{services} must be equal to @code{(list avahi)}.
16090 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
16091 Return a service that runs the @code{elogind} login and
16092 seat management daemon. @uref{https://github.com/elogind/elogind,
16093 Elogind} exposes a D-Bus interface that can be used to know which users
16094 are logged in, know what kind of sessions they have open, suspend the
16095 system, inhibit system suspend, reboot the system, and other tasks.
16097 Elogind handles most system-level power events for a computer, for
16098 example suspending the system when a lid is closed, or shutting it down
16099 when the power button is pressed.
16101 The @var{config} keyword argument specifies the configuration for
16102 elogind, and should be the result of an @code{(elogind-configuration
16103 (@var{parameter} @var{value})...)} invocation. Available parameters and
16104 their default values are:
16107 @item kill-user-processes?
16109 @item kill-only-users
16111 @item kill-exclude-users
16113 @item inhibit-delay-max-seconds
16115 @item handle-power-key
16117 @item handle-suspend-key
16119 @item handle-hibernate-key
16121 @item handle-lid-switch
16123 @item handle-lid-switch-docked
16125 @item power-key-ignore-inhibited?
16127 @item suspend-key-ignore-inhibited?
16129 @item hibernate-key-ignore-inhibited?
16131 @item lid-switch-ignore-inhibited?
16133 @item holdoff-timeout-seconds
16137 @item idle-action-seconds
16139 @item runtime-directory-size-percent
16141 @item runtime-directory-size
16145 @item suspend-state
16146 @code{("mem" "standby" "freeze")}
16149 @item hibernate-state
16151 @item hibernate-mode
16152 @code{("platform" "shutdown")}
16153 @item hybrid-sleep-state
16155 @item hybrid-sleep-mode
16156 @code{("suspend" "platform" "shutdown")}
16160 @deffn {Scheme Procedure} accountsservice-service @
16161 [#:accountsservice @var{accountsservice}]
16162 Return a service that runs AccountsService, a system service that can
16163 list available accounts, change their passwords, and so on.
16164 AccountsService integrates with PolicyKit to enable unprivileged users
16165 to acquire the capability to modify their system configuration.
16166 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
16167 accountsservice web site} for more information.
16169 The @var{accountsservice} keyword argument is the @code{accountsservice}
16170 package to expose as a service.
16173 @deffn {Scheme Procedure} polkit-service @
16174 [#:polkit @var{polkit}]
16175 Return a service that runs the
16176 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
16177 management service}, which allows system administrators to grant access to
16178 privileged operations in a structured way. By querying the Polkit service, a
16179 privileged system component can know when it should grant additional
16180 capabilities to ordinary users. For example, an ordinary user can be granted
16181 the capability to suspend the system if the user is logged in locally.
16184 @defvr {Scheme Variable} polkit-wheel-service
16185 Service that adds the @code{wheel} group as admins to the Polkit
16186 service. This makes it so that users in the @code{wheel} group are queried
16187 for their own passwords when performing administrative actions instead of
16188 @code{root}'s, similar to the behaviour used by @code{sudo}.
16191 @defvr {Scheme Variable} upower-service-type
16192 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
16193 system-wide monitor for power consumption and battery levels, with the given
16194 configuration settings.
16196 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
16197 notably used by GNOME.
16200 @deftp {Data Type} upower-configuration
16201 Data type representation the configuration for UPower.
16205 @item @code{upower} (default: @var{upower})
16206 Package to use for @code{upower}.
16208 @item @code{watts-up-pro?} (default: @code{#f})
16209 Enable the Watts Up Pro device.
16211 @item @code{poll-batteries?} (default: @code{#t})
16212 Enable polling the kernel for battery level changes.
16214 @item @code{ignore-lid?} (default: @code{#f})
16215 Ignore the lid state, this can be useful if it's incorrect on a device.
16217 @item @code{use-percentage-for-policy?} (default: @code{#f})
16218 Whether battery percentage based policy should be used. The default is to use
16219 the time left, change to @code{#t} to use the percentage.
16221 @item @code{percentage-low} (default: @code{10})
16222 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16223 at which the battery is considered low.
16225 @item @code{percentage-critical} (default: @code{3})
16226 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16227 at which the battery is considered critical.
16229 @item @code{percentage-action} (default: @code{2})
16230 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16231 at which action will be taken.
16233 @item @code{time-low} (default: @code{1200})
16234 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16235 seconds at which the battery is considered low.
16237 @item @code{time-critical} (default: @code{300})
16238 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16239 seconds at which the battery is considered critical.
16241 @item @code{time-action} (default: @code{120})
16242 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16243 seconds at which action will be taken.
16245 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
16246 The action taken when @code{percentage-action} or @code{time-action} is
16247 reached (depending on the configuration of @code{use-percentage-for-policy?}).
16249 Possible values are:
16259 @code{'hybrid-sleep}.
16265 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
16266 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
16267 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
16268 notifications and ways to mount/unmount disks. Programs that talk to UDisks
16269 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
16272 @deffn {Scheme Variable} colord-service-type
16273 This is the type of the service that runs @command{colord}, a system
16274 service with a D-Bus
16275 interface to manage the color profiles of input and output devices such as
16276 screens and scanners. It is notably used by the GNOME Color Manager graphical
16277 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
16278 site} for more information.
16281 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
16282 Return a configuration allowing an application to access GeoClue
16283 location data. @var{name} is the Desktop ID of the application, without
16284 the @code{.desktop} part. If @var{allowed?} is true, the application
16285 will have access to location information by default. The boolean
16286 @var{system?} value indicates whether an application is a system component
16287 or not. Finally @var{users} is a list of UIDs of all users for which
16288 this application is allowed location info access. An empty users list
16289 means that all users are allowed.
16292 @cindex scanner access
16293 @deffn {Scheme Procedure} sane-service-type
16294 This service provides access to scanners @i{via}
16295 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
16299 @defvr {Scheme Variable} %standard-geoclue-applications
16300 The standard list of well-known GeoClue application configurations,
16301 granting authority to the GNOME date-and-time utility to ask for the
16302 current location in order to set the time zone, and allowing the
16303 IceCat and Epiphany web browsers to request location information.
16304 IceCat and Epiphany both query the user before allowing a web page to
16305 know the user's location.
16308 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
16309 [#:whitelist '()] @
16310 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
16311 [#:submit-data? #f]
16312 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
16313 [#:submission-nick "geoclue"] @
16314 [#:applications %standard-geoclue-applications]
16315 Return a service that runs the GeoClue location service. This service
16316 provides a D-Bus interface to allow applications to request access to a
16317 user's physical location, and optionally to add information to online
16318 location databases. See
16319 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
16320 web site} for more information.
16323 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
16324 [@w{#:auto-enable? #f}]
16325 Return a service that runs the @command{bluetoothd} daemon, which
16326 manages all the Bluetooth devices and provides a number of D-Bus
16327 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
16328 powered automatically at boot, which can be useful when using a
16329 bluetooth keyboard or mouse.
16331 Users need to be in the @code{lp} group to access the D-Bus service.
16334 @defvr {Scheme Variable} gnome-keyring-service-type
16335 This is the type of the service that adds the
16336 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
16337 value is a @code{gnome-keyring-configuration} object (see below.)
16339 This service adds the @code{gnome-keyring} package to the system profile
16340 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
16341 a user's login keyring when they log in or setting its password with passwd.
16344 @deftp {Data Type} gnome-keyring-configuration
16345 Configuration record for the GNOME Keyring service.
16348 @item @code{keyring} (default: @code{gnome-keyring})
16349 The GNOME keyring package to use.
16351 @item @code{pam-services}
16352 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
16353 services to extend, where @var{service} is the name of an existing
16354 service to extend and @var{kind} is one of @code{login} or
16357 If @code{login} is given, it adds an optional
16358 @code{pam_gnome_keyring.so} to the auth block without arguments and to
16359 the session block with @code{auto_start}. If @code{passwd} is given, it
16360 adds an optional @code{pam_gnome_keyring.so} to the password block
16363 By default, this field contains ``gdm-password'' with the value @code{login}
16364 and ``passwd'' is with the value @code{passwd}.
16369 @node Sound Services
16370 @subsection Sound Services
16372 @cindex sound support
16374 @cindex PulseAudio, sound support
16376 The @code{(gnu services sound)} module provides a service to configure the
16377 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
16378 preferred ALSA output driver.
16380 @deffn {Scheme Variable} alsa-service-type
16381 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
16382 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
16383 configuration file. The value for this type is a @command{alsa-configuration}
16384 record as in this example:
16387 (service alsa-service-type)
16390 See below for details about @code{alsa-configuration}.
16393 @deftp {Data Type} alsa-configuration
16394 Data type representing the configuration for @code{alsa-service}.
16397 @item @code{alsa-plugins} (default: @var{alsa-plugins})
16398 @code{alsa-plugins} package to use.
16400 @item @code{pulseaudio?} (default: @var{#t})
16401 Whether ALSA applications should transparently be made to use the
16402 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
16404 Using PulseAudio allows you to run several sound-producing applications
16405 at the same time and to individual control them @i{via}
16406 @command{pavucontrol}, among other things.
16408 @item @code{extra-options} (default: @var{""})
16409 String to append to the @file{/etc/asound.conf} file.
16414 Individual users who want to override the system configuration of ALSA can do
16415 it with the @file{~/.asoundrc} file:
16418 # In guix, we have to specify the absolute path for plugins.
16420 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
16423 # Routing ALSA to jack:
16424 # <http://jackaudio.org/faq/routing_alsa.html>.
16428 0 system:playback_1
16429 1 system:playback_2
16446 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
16449 @deffn {Scheme Variable} pulseaudio-service-type
16450 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
16451 sound server. It exists to allow system overrides of the default settings
16452 via @code{pulseaudio-configuration}, see below.
16455 This service overrides per-user configuration files. If you want
16456 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
16457 have to unset the environment variables @env{PULSE_CONFIG} and
16458 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
16462 This service on its own does not ensure, that the @code{pulseaudio} package
16463 exists on your machine. It merely adds configuration files for it, as
16464 detailed below. In the (admittedly unlikely) case, that you find yourself
16465 without a @code{pulseaudio} package, consider enabling it through the
16466 @code{alsa-service-type} above.
16470 @deftp {Data Type} pulseaudio-configuration
16471 Data type representing the configuration for @code{pulseaudio-service}.
16474 @item @var{client-conf} (default: @code{'()})
16475 List of settings to set in @file{client.conf}.
16476 Accepts a list of strings or a symbol-value pairs. A string will be
16477 inserted as-is with a newline added. A pair will be formatted as
16478 ``key = value'', again with a newline added.
16480 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
16481 List of settings to set in @file{daemon.conf}, formatted just like
16484 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
16485 Script file to use as as @file{default.pa}.
16487 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
16488 Script file to use as as @file{system.pa}.
16492 @deffn {Scheme Variable} ladspa-service-type
16493 This service sets the @var{LADSPA_PATH} variable, so that programs, which
16494 respect it, e.g. PulseAudio, can load LADSPA plugins.
16496 The following example will setup the service to enable modules from the
16497 @code{swh-plugins} package:
16500 (service ladspa-service-type
16501 (ladspa-configuration (plugins (list swh-plugins))))
16504 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16509 @node Database Services
16510 @subsection Database Services
16514 The @code{(gnu services databases)} module provides the following services.
16516 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16517 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16518 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16519 Return a service that runs @var{postgresql}, the PostgreSQL database
16522 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16523 creates a database cluster with @var{locale} as the default
16524 locale, stored in @var{data-directory}. It then listens on @var{port}.
16526 @cindex postgresql extension-packages
16527 Additional extensions are loaded from packages listed in
16528 @var{extension-packages}. Extensions are available at runtime. For instance,
16529 to create a geographic database using the @code{postgis} extension, a user can
16530 configure the postgresql-service as in this example:
16534 (use-package-modules databases geo)
16538 ;; postgresql is required to run `psql' but postgis is not required for
16539 ;; proper operation.
16540 (packages (cons* postgresql %base-packages))
16543 (postgresql-service #:extension-packages (list postgis))
16547 Then the extension becomes visible and you can initialise an empty geographic
16548 database in this way:
16552 > create database postgistest;
16553 > \connect postgistest;
16554 > create extension postgis;
16555 > create extension postgis_topology;
16558 There is no need to add this field for contrib extensions such as hstore or
16559 dblink as they are already loadable by postgresql. This field is only
16560 required to add extensions provided by other packages.
16563 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16564 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16567 The optional @var{config} argument specifies the configuration for
16568 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16571 @deftp {Data Type} mysql-configuration
16572 Data type representing the configuration of @var{mysql-service}.
16575 @item @code{mysql} (default: @var{mariadb})
16576 Package object of the MySQL database server, can be either @var{mariadb}
16579 For MySQL, a temporary root password will be displayed at activation time.
16580 For MariaDB, the root password is empty.
16582 @item @code{port} (default: @code{3306})
16583 TCP port on which the database server listens for incoming connections.
16587 @defvr {Scheme Variable} memcached-service-type
16588 This is the service type for the @uref{https://memcached.org/,
16589 Memcached} service, which provides a distributed in memory cache. The
16590 value for the service type is a @code{memcached-configuration} object.
16594 (service memcached-service-type)
16597 @deftp {Data Type} memcached-configuration
16598 Data type representing the configuration of memcached.
16601 @item @code{memcached} (default: @code{memcached})
16602 The Memcached package to use.
16604 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16605 Network interfaces on which to listen.
16607 @item @code{tcp-port} (default: @code{11211})
16608 Port on which to accept connections on,
16610 @item @code{udp-port} (default: @code{11211})
16611 Port on which to accept UDP connections on, a value of 0 will disable
16612 listening on a UDP socket.
16614 @item @code{additional-options} (default: @code{'()})
16615 Additional command line options to pass to @code{memcached}.
16619 @defvr {Scheme Variable} mongodb-service-type
16620 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16621 The value for the service type is a @code{mongodb-configuration} object.
16625 (service mongodb-service-type)
16628 @deftp {Data Type} mongodb-configuration
16629 Data type representing the configuration of mongodb.
16632 @item @code{mongodb} (default: @code{mongodb})
16633 The MongoDB package to use.
16635 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16636 The configuration file for MongoDB.
16638 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16639 This value is used to create the directory, so that it exists and is
16640 owned by the mongodb user. It should match the data-directory which
16641 MongoDB is configured to use through the configuration file.
16645 @defvr {Scheme Variable} redis-service-type
16646 This is the service type for the @uref{https://redis.io/, Redis}
16647 key/value store, whose value is a @code{redis-configuration} object.
16650 @deftp {Data Type} redis-configuration
16651 Data type representing the configuration of redis.
16654 @item @code{redis} (default: @code{redis})
16655 The Redis package to use.
16657 @item @code{bind} (default: @code{"127.0.0.1"})
16658 Network interface on which to listen.
16660 @item @code{port} (default: @code{6379})
16661 Port on which to accept connections on, a value of 0 will disable
16662 listening on a TCP socket.
16664 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16665 Directory in which to store the database and related files.
16669 @node Mail Services
16670 @subsection Mail Services
16674 The @code{(gnu services mail)} module provides Guix service definitions
16675 for email services: IMAP, POP3, and LMTP servers, as well as mail
16676 transport agents (MTAs). Lots of acronyms! These services are detailed
16677 in the subsections below.
16679 @subsubheading Dovecot Service
16681 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16682 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16685 By default, Dovecot does not need much configuration; the default
16686 configuration object created by @code{(dovecot-configuration)} will
16687 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16688 certificate will be generated for TLS-protected connections, though
16689 Dovecot will also listen on cleartext ports by default. There are a
16690 number of options, though, which mail administrators might need to change,
16691 and as is the case with other services, Guix allows the system
16692 administrator to specify these parameters via a uniform Scheme interface.
16694 For example, to specify that mail is located at @code{maildir~/.mail},
16695 one would instantiate the Dovecot service like this:
16698 (dovecot-service #:config
16699 (dovecot-configuration
16700 (mail-location "maildir:~/.mail")))
16703 The available configuration parameters follow. Each parameter
16704 definition is preceded by its type; for example, @samp{string-list foo}
16705 indicates that the @code{foo} parameter should be specified as a list of
16706 strings. There is also a way to specify the configuration as a string,
16707 if you have an old @code{dovecot.conf} file that you want to port over
16708 from some other system; see the end for more details.
16710 @c The following documentation was initially generated by
16711 @c (generate-documentation) in (gnu services mail). Manually maintained
16712 @c documentation is better, so we shouldn't hesitate to edit below as
16713 @c needed. However if the change you want to make to this documentation
16714 @c can be done in an automated way, it's probably easier to change
16715 @c (generate-documentation) than to make it below and have to deal with
16716 @c the churn as dovecot updates.
16718 Available @code{dovecot-configuration} fields are:
16720 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16721 The dovecot package.
16724 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16725 A list of IPs or hosts where to listen for connections. @samp{*}
16726 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16727 interfaces. If you want to specify non-default ports or anything more
16728 complex, customize the address and port fields of the
16729 @samp{inet-listener} of the specific services you are interested in.
16732 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16733 List of protocols we want to serve. Available protocols include
16734 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16736 Available @code{protocol-configuration} fields are:
16738 @deftypevr {@code{protocol-configuration} parameter} string name
16739 The name of the protocol.
16742 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16743 UNIX socket path to the master authentication server to find users.
16744 This is used by imap (for shared users) and lda.
16745 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16748 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16749 Space separated list of plugins to load.
16752 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16753 Maximum number of IMAP connections allowed for a user from each IP
16754 address. NOTE: The username is compared case-sensitively.
16755 Defaults to @samp{10}.
16760 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16761 List of services to enable. Available services include @samp{imap},
16762 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16765 Available @code{service-configuration} fields are:
16767 @deftypevr {@code{service-configuration} parameter} string kind
16768 The service kind. Valid values include @code{director},
16769 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16770 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16771 @code{tcpwrap}, @code{quota-warning}, or anything else.
16774 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16775 Listeners for the service. A listener is either a
16776 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16777 an @code{inet-listener-configuration}.
16778 Defaults to @samp{()}.
16780 Available @code{unix-listener-configuration} fields are:
16782 @deftypevr {@code{unix-listener-configuration} parameter} string path
16783 Path to the file, relative to @code{base-dir} field. This is also used as
16787 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16788 The access mode for the socket.
16789 Defaults to @samp{"0600"}.
16792 @deftypevr {@code{unix-listener-configuration} parameter} string user
16793 The user to own the socket.
16794 Defaults to @samp{""}.
16797 @deftypevr {@code{unix-listener-configuration} parameter} string group
16798 The group to own the socket.
16799 Defaults to @samp{""}.
16803 Available @code{fifo-listener-configuration} fields are:
16805 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16806 Path to the file, relative to @code{base-dir} field. This is also used as
16810 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16811 The access mode for the socket.
16812 Defaults to @samp{"0600"}.
16815 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16816 The user to own the socket.
16817 Defaults to @samp{""}.
16820 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16821 The group to own the socket.
16822 Defaults to @samp{""}.
16826 Available @code{inet-listener-configuration} fields are:
16828 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16829 The protocol to listen for.
16832 @deftypevr {@code{inet-listener-configuration} parameter} string address
16833 The address on which to listen, or empty for all addresses.
16834 Defaults to @samp{""}.
16837 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16838 The port on which to listen.
16841 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16842 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16844 Defaults to @samp{#t}.
16849 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16850 Maximum number of simultaneous client connections per process. Once
16851 this number of connections is received, the next incoming connection
16852 will prompt Dovecot to spawn another process. If set to 0,
16853 @code{default-client-limit} is used instead.
16855 Defaults to @samp{0}.
16859 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16860 Number of connections to handle before starting a new process.
16861 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16862 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16863 Defaults to @samp{1}.
16867 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16868 Maximum number of processes that can exist for this service. If set to
16869 0, @code{default-process-limit} is used instead.
16871 Defaults to @samp{0}.
16875 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16876 Number of processes to always keep waiting for more connections.
16877 Defaults to @samp{0}.
16880 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16881 If you set @samp{service-count 0}, you probably need to grow
16883 Defaults to @samp{256000000}.
16888 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16889 Dict configuration, as created by the @code{dict-configuration}
16892 Available @code{dict-configuration} fields are:
16894 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16895 A list of key-value pairs that this dict should hold.
16896 Defaults to @samp{()}.
16901 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16902 A list of passdb configurations, each one created by the
16903 @code{passdb-configuration} constructor.
16905 Available @code{passdb-configuration} fields are:
16907 @deftypevr {@code{passdb-configuration} parameter} string driver
16908 The driver that the passdb should use. Valid values include
16909 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16911 Defaults to @samp{"pam"}.
16914 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16915 Space separated list of arguments to the passdb driver.
16916 Defaults to @samp{""}.
16921 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16922 List of userdb configurations, each one created by the
16923 @code{userdb-configuration} constructor.
16925 Available @code{userdb-configuration} fields are:
16927 @deftypevr {@code{userdb-configuration} parameter} string driver
16928 The driver that the userdb should use. Valid values include
16929 @samp{passwd} and @samp{static}.
16930 Defaults to @samp{"passwd"}.
16933 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16934 Space separated list of arguments to the userdb driver.
16935 Defaults to @samp{""}.
16938 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16939 Override fields from passwd.
16940 Defaults to @samp{()}.
16945 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16946 Plug-in configuration, created by the @code{plugin-configuration}
16950 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16951 List of namespaces. Each item in the list is created by the
16952 @code{namespace-configuration} constructor.
16954 Available @code{namespace-configuration} fields are:
16956 @deftypevr {@code{namespace-configuration} parameter} string name
16957 Name for this namespace.
16960 @deftypevr {@code{namespace-configuration} parameter} string type
16961 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16962 Defaults to @samp{"private"}.
16965 @deftypevr {@code{namespace-configuration} parameter} string separator
16966 Hierarchy separator to use. You should use the same separator for
16967 all namespaces or some clients get confused. @samp{/} is usually a good
16968 one. The default however depends on the underlying mail storage
16970 Defaults to @samp{""}.
16973 @deftypevr {@code{namespace-configuration} parameter} string prefix
16974 Prefix required to access this namespace. This needs to be
16975 different for all namespaces. For example @samp{Public/}.
16976 Defaults to @samp{""}.
16979 @deftypevr {@code{namespace-configuration} parameter} string location
16980 Physical location of the mailbox. This is in the same format as
16981 mail_location, which is also the default for it.
16982 Defaults to @samp{""}.
16985 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16986 There can be only one INBOX, and this setting defines which
16988 Defaults to @samp{#f}.
16991 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16992 If namespace is hidden, it's not advertised to clients via NAMESPACE
16993 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16994 useful when converting from another server with different namespaces
16995 which you want to deprecate but still keep working. For example you can
16996 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16998 Defaults to @samp{#f}.
17001 @deftypevr {@code{namespace-configuration} parameter} boolean list?
17002 Show the mailboxes under this namespace with the LIST command. This
17003 makes the namespace visible for clients that do not support the NAMESPACE
17004 extension. The special @code{children} value lists child mailboxes, but
17005 hides the namespace prefix.
17006 Defaults to @samp{#t}.
17009 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
17010 Namespace handles its own subscriptions. If set to @code{#f}, the
17011 parent namespace handles them. The empty prefix should always have this
17013 Defaults to @samp{#t}.
17016 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
17017 List of predefined mailboxes in this namespace.
17018 Defaults to @samp{()}.
17020 Available @code{mailbox-configuration} fields are:
17022 @deftypevr {@code{mailbox-configuration} parameter} string name
17023 Name for this mailbox.
17026 @deftypevr {@code{mailbox-configuration} parameter} string auto
17027 @samp{create} will automatically create this mailbox.
17028 @samp{subscribe} will both create and subscribe to the mailbox.
17029 Defaults to @samp{"no"}.
17032 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
17033 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
17034 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
17035 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
17036 Defaults to @samp{()}.
17043 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
17044 Base directory where to store runtime data.
17045 Defaults to @samp{"/var/run/dovecot/"}.
17048 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
17049 Greeting message for clients.
17050 Defaults to @samp{"Dovecot ready."}.
17053 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
17054 List of trusted network ranges. Connections from these IPs are
17055 allowed to override their IP addresses and ports (for logging and for
17056 authentication checks). @samp{disable-plaintext-auth} is also ignored
17057 for these networks. Typically you would specify your IMAP proxy servers
17059 Defaults to @samp{()}.
17062 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
17063 List of login access check sockets (e.g.@: tcpwrap).
17064 Defaults to @samp{()}.
17067 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
17068 Show more verbose process titles (in ps). Currently shows user name
17069 and IP address. Useful for seeing who is actually using the IMAP
17070 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
17072 Defaults to @samp{#f}.
17075 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
17076 Should all processes be killed when Dovecot master process shuts down.
17077 Setting this to @code{#f} means that Dovecot can be upgraded without
17078 forcing existing client connections to close (although that could also
17079 be a problem if the upgrade is e.g.@: due to a security fix).
17080 Defaults to @samp{#t}.
17083 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
17084 If non-zero, run mail commands via this many connections to doveadm
17085 server, instead of running them directly in the same process.
17086 Defaults to @samp{0}.
17089 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
17090 UNIX socket or host:port used for connecting to doveadm server.
17091 Defaults to @samp{"doveadm-server"}.
17094 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
17095 List of environment variables that are preserved on Dovecot startup
17096 and passed down to all of its child processes. You can also give
17097 key=value pairs to always set specific settings.
17100 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
17101 Disable LOGIN command and all other plaintext authentications unless
17102 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
17103 matches the local IP (i.e.@: you're connecting from the same computer),
17104 the connection is considered secure and plaintext authentication is
17105 allowed. See also ssl=required setting.
17106 Defaults to @samp{#t}.
17109 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
17110 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
17111 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
17112 for caching to be used.
17113 Defaults to @samp{0}.
17116 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
17117 Time to live for cached data. After TTL expires the cached record
17118 is no longer used, *except* if the main database lookup returns internal
17119 failure. We also try to handle password changes automatically: If
17120 user's previous authentication was successful, but this one wasn't, the
17121 cache isn't used. For now this works only with plaintext
17123 Defaults to @samp{"1 hour"}.
17126 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
17127 TTL for negative hits (user not found, password mismatch).
17128 0 disables caching them completely.
17129 Defaults to @samp{"1 hour"}.
17132 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
17133 List of realms for SASL authentication mechanisms that need them.
17134 You can leave it empty if you don't want to support multiple realms.
17135 Many clients simply use the first one listed here, so keep the default
17137 Defaults to @samp{()}.
17140 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
17141 Default realm/domain to use if none was specified. This is used for
17142 both SASL realms and appending @@domain to username in plaintext
17144 Defaults to @samp{""}.
17147 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
17148 List of allowed characters in username. If the user-given username
17149 contains a character not listed in here, the login automatically fails.
17150 This is just an extra check to make sure user can't exploit any
17151 potential quote escaping vulnerabilities with SQL/LDAP databases. If
17152 you want to allow all characters, set this value to empty.
17153 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
17156 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
17157 Username character translations before it's looked up from
17158 databases. The value contains series of from -> to characters. For
17159 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
17160 translated to @samp{@@}.
17161 Defaults to @samp{""}.
17164 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
17165 Username formatting before it's looked up from databases. You can
17166 use the standard variables here, e.g.@: %Lu would lowercase the username,
17167 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
17168 change the @samp{@@} into @samp{-AT-}. This translation is done after
17169 @samp{auth-username-translation} changes.
17170 Defaults to @samp{"%Lu"}.
17173 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
17174 If you want to allow master users to log in by specifying the master
17175 username within the normal username string (i.e.@: not using SASL
17176 mechanism's support for it), you can specify the separator character
17177 here. The format is then <username><separator><master username>.
17178 UW-IMAP uses @samp{*} as the separator, so that could be a good
17180 Defaults to @samp{""}.
17183 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
17184 Username to use for users logging in with ANONYMOUS SASL
17186 Defaults to @samp{"anonymous"}.
17189 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
17190 Maximum number of dovecot-auth worker processes. They're used to
17191 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
17192 They're automatically created and destroyed as needed.
17193 Defaults to @samp{30}.
17196 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
17197 Host name to use in GSSAPI principal names. The default is to use
17198 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
17199 allow all keytab entries.
17200 Defaults to @samp{""}.
17203 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
17204 Kerberos keytab to use for the GSSAPI mechanism. Will use the
17205 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
17206 need to change the auth service to run as root to be able to read this
17208 Defaults to @samp{""}.
17211 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
17212 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
17213 and @samp{ntlm-auth} helper.
17214 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
17215 Defaults to @samp{#f}.
17218 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
17219 Path for Samba's @samp{ntlm-auth} helper binary.
17220 Defaults to @samp{"/usr/bin/ntlm_auth"}.
17223 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
17224 Time to delay before replying to failed authentications.
17225 Defaults to @samp{"2 secs"}.
17228 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
17229 Require a valid SSL client certificate or the authentication
17231 Defaults to @samp{#f}.
17234 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
17235 Take the username from client's SSL certificate, using
17236 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
17238 Defaults to @samp{#f}.
17241 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
17242 List of wanted authentication mechanisms. Supported mechanisms are:
17243 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
17244 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
17245 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
17246 @samp{disable-plaintext-auth} setting.
17249 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
17250 List of IPs or hostnames to all director servers, including ourself.
17251 Ports can be specified as ip:port. The default port is the same as what
17252 director service's @samp{inet-listener} is using.
17253 Defaults to @samp{()}.
17256 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
17257 List of IPs or hostnames to all backend mail servers. Ranges are
17258 allowed too, like 10.0.0.10-10.0.0.30.
17259 Defaults to @samp{()}.
17262 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
17263 How long to redirect users to a specific server after it no longer
17264 has any connections.
17265 Defaults to @samp{"15 min"}.
17268 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
17269 How the username is translated before being hashed. Useful values
17270 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
17271 are shared within domain.
17272 Defaults to @samp{"%Lu"}.
17275 @deftypevr {@code{dovecot-configuration} parameter} string log-path
17276 Log file to use for error messages. @samp{syslog} logs to syslog,
17277 @samp{/dev/stderr} logs to stderr.
17278 Defaults to @samp{"syslog"}.
17281 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
17282 Log file to use for informational messages. Defaults to
17284 Defaults to @samp{""}.
17287 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
17288 Log file to use for debug messages. Defaults to
17289 @samp{info-log-path}.
17290 Defaults to @samp{""}.
17293 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
17294 Syslog facility to use if you're logging to syslog. Usually if you
17295 don't want to use @samp{mail}, you'll use local0..local7. Also other
17296 standard facilities are supported.
17297 Defaults to @samp{"mail"}.
17300 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
17301 Log unsuccessful authentication attempts and the reasons why they
17303 Defaults to @samp{#f}.
17306 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
17307 In case of password mismatches, log the attempted password. Valid
17308 values are no, plain and sha1. sha1 can be useful for detecting brute
17309 force password attempts vs. user simply trying the same password over
17310 and over again. You can also truncate the value to n chars by appending
17311 ":n" (e.g.@: sha1:6).
17312 Defaults to @samp{"no"}.
17315 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
17316 Even more verbose logging for debugging purposes. Shows for example
17318 Defaults to @samp{#f}.
17321 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
17322 In case of password mismatches, log the passwords and used scheme so
17323 the problem can be debugged. Enabling this also enables
17325 Defaults to @samp{#f}.
17328 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
17329 Enable mail process debugging. This can help you figure out why
17330 Dovecot isn't finding your mails.
17331 Defaults to @samp{#f}.
17334 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
17335 Show protocol level SSL errors.
17336 Defaults to @samp{#f}.
17339 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
17340 Prefix for each line written to log file. % codes are in
17341 strftime(3) format.
17342 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
17345 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
17346 List of elements we want to log. The elements which have a
17347 non-empty variable value are joined together to form a comma-separated
17351 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
17352 Login log format. %s contains @samp{login-log-format-elements}
17353 string, %$ contains the data we want to log.
17354 Defaults to @samp{"%$: %s"}.
17357 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
17358 Log prefix for mail processes. See doc/wiki/Variables.txt for list
17359 of possible variables you can use.
17360 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
17363 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
17364 Format to use for logging mail deliveries. You can use variables:
17367 Delivery status message (e.g.@: @samp{saved to INBOX})
17379 Defaults to @samp{"msgid=%m: %$"}.
17382 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
17383 Location for users' mailboxes. The default is empty, which means
17384 that Dovecot tries to find the mailboxes automatically. This won't work
17385 if the user doesn't yet have any mail, so you should explicitly tell
17386 Dovecot the full location.
17388 If you're using mbox, giving a path to the INBOX
17389 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
17390 where the other mailboxes are kept. This is called the @emph{root mail
17391 directory}, and it must be the first path given in the
17392 @samp{mail-location} setting.
17394 There are a few special variables you can use, e.g.:
17400 user part in user@@domain, same as %u if there's no domain
17402 domain part in user@@domain, empty if there's no domain
17407 See doc/wiki/Variables.txt for full list. Some examples:
17409 @item maildir:~/Maildir
17410 @item mbox:~/mail:INBOX=/var/mail/%u
17411 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
17413 Defaults to @samp{""}.
17416 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
17417 System user and group used to access mails. If you use multiple,
17418 userdb can override these by returning uid or gid fields. You can use
17419 either numbers or names. <doc/wiki/UserIds.txt>.
17420 Defaults to @samp{""}.
17423 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
17425 Defaults to @samp{""}.
17428 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
17429 Group to enable temporarily for privileged operations. Currently
17430 this is used only with INBOX when either its initial creation or
17431 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
17433 Defaults to @samp{""}.
17436 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
17437 Grant access to these supplementary groups for mail processes.
17438 Typically these are used to set up access to shared mailboxes. Note
17439 that it may be dangerous to set these if users can create symlinks
17440 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
17441 could allow a user to delete others' mailboxes, or @code{ln -s
17442 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
17446 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
17447 Allow full file system access to clients. There's no access checks
17448 other than what the operating system does for the active UID/GID. It
17449 works with both maildir and mboxes, allowing you to prefix mailboxes
17450 names with e.g.@: @file{/path/} or @file{~user/}.
17451 Defaults to @samp{#f}.
17454 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
17455 Don't use @code{mmap()} at all. This is required if you store indexes to
17456 shared file systems (NFS or clustered file system).
17457 Defaults to @samp{#f}.
17460 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
17461 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
17462 supports @samp{O_EXCL} since version 3, so this should be safe to use
17463 nowadays by default.
17464 Defaults to @samp{#t}.
17467 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
17468 When to use fsync() or fdatasync() calls:
17471 Whenever necessary to avoid losing important data
17473 Useful with e.g.@: NFS when @code{write()}s are delayed
17475 Never use it (best performance, but crashes can lose data).
17477 Defaults to @samp{"optimized"}.
17480 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
17481 Mail storage exists in NFS. Set this to yes to make Dovecot flush
17482 NFS caches whenever needed. If you're using only a single mail server
17484 Defaults to @samp{#f}.
17487 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
17488 Mail index files also exist in NFS. Setting this to yes requires
17489 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
17490 Defaults to @samp{#f}.
17493 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
17494 Locking method for index files. Alternatives are fcntl, flock and
17495 dotlock. Dotlocking uses some tricks which may create more disk I/O
17496 than other locking methods. NFS users: flock doesn't work, remember to
17497 change @samp{mmap-disable}.
17498 Defaults to @samp{"fcntl"}.
17501 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17502 Directory in which LDA/LMTP temporarily stores incoming mails >128
17504 Defaults to @samp{"/tmp"}.
17507 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17508 Valid UID range for users. This is mostly to make sure that users can't
17509 log in as daemons or other system users. Note that denying root logins is
17510 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17512 Defaults to @samp{500}.
17515 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17517 Defaults to @samp{0}.
17520 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17521 Valid GID range for users. Users having non-valid GID as primary group ID
17522 aren't allowed to log in. If user belongs to supplementary groups with
17523 non-valid GIDs, those groups are not set.
17524 Defaults to @samp{1}.
17527 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17529 Defaults to @samp{0}.
17532 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17533 Maximum allowed length for mail keyword name. It's only forced when
17534 trying to create new keywords.
17535 Defaults to @samp{50}.
17538 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17539 List of directories under which chrooting is allowed for mail
17540 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
17541 too). This setting doesn't affect @samp{login-chroot}
17542 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17543 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
17544 which local users can modify, that may lead to root exploit. Usually
17545 this should be done only if you don't allow shell access for users.
17546 <doc/wiki/Chrooting.txt>.
17547 Defaults to @samp{()}.
17550 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17551 Default chroot directory for mail processes. This can be overridden
17552 for specific users in user database by giving @samp{/./} in user's home
17553 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
17554 there is no real need to do chrooting, Dovecot doesn't allow users to
17555 access files outside their mail directory anyway. If your home
17556 directories are prefixed with the chroot directory, append @samp{/.} to
17557 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17558 Defaults to @samp{""}.
17561 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17562 UNIX socket path to master authentication server to find users.
17563 This is used by imap (for shared users) and lda.
17564 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17567 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17568 Directory where to look up mail plugins.
17569 Defaults to @samp{"/usr/lib/dovecot"}.
17572 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17573 List of plugins to load for all services. Plugins specific to IMAP,
17574 LDA, etc.@: are added to this list in their own .conf files.
17575 Defaults to @samp{()}.
17578 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17579 The minimum number of mails in a mailbox before updates are done to
17580 cache file. This allows optimizing Dovecot's behavior to do less disk
17581 writes at the cost of more disk reads.
17582 Defaults to @samp{0}.
17585 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17586 When IDLE command is running, mailbox is checked once in a while to
17587 see if there are any new mails or other changes. This setting defines
17588 the minimum time to wait between those checks. Dovecot can also use
17589 dnotify, inotify and kqueue to find out immediately when changes
17591 Defaults to @samp{"30 secs"}.
17594 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17595 Save mails with CR+LF instead of plain LF. This makes sending those
17596 mails take less CPU, especially with sendfile() syscall with Linux and
17597 FreeBSD. But it also creates a bit more disk I/O which may just make it
17598 slower. Also note that if other software reads the mboxes/maildirs,
17599 they may handle the extra CRs wrong and cause problems.
17600 Defaults to @samp{#f}.
17603 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17604 By default LIST command returns all entries in maildir beginning
17605 with a dot. Enabling this option makes Dovecot return only entries
17606 which are directories. This is done by stat()ing each entry, so it
17607 causes more disk I/O.
17608 (For systems setting struct @samp{dirent->d_type} this check is free
17609 and it's done always regardless of this setting).
17610 Defaults to @samp{#f}.
17613 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17614 When copying a message, do it with hard links whenever possible.
17615 This makes the performance much better, and it's unlikely to have any
17617 Defaults to @samp{#t}.
17620 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17621 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17622 directory only when its mtime changes unexpectedly or when we can't find
17623 the mail otherwise.
17624 Defaults to @samp{#f}.
17627 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17628 Which locking methods to use for locking mbox. There are four
17633 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17634 solution. If you want to use /var/mail/ like directory, the users will
17635 need write access to that directory.
17637 Same as dotlock, but if it fails because of permissions or because there
17638 isn't enough disk space, just skip it.
17640 Use this if possible. Works with NFS too if lockd is used.
17642 May not exist in all systems. Doesn't work with NFS.
17644 May not exist in all systems. Doesn't work with NFS.
17647 You can use multiple locking methods; if you do the order they're declared
17648 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17649 locking methods as well. Some operating systems don't allow using some of
17650 them simultaneously.
17653 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17657 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17658 Maximum time to wait for lock (all of them) before aborting.
17659 Defaults to @samp{"5 mins"}.
17662 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17663 If dotlock exists but the mailbox isn't modified in any way,
17664 override the lock file after this much time.
17665 Defaults to @samp{"2 mins"}.
17668 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17669 When mbox changes unexpectedly we have to fully read it to find out
17670 what changed. If the mbox is large this can take a long time. Since
17671 the change is usually just a newly appended mail, it'd be faster to
17672 simply read the new mails. If this setting is enabled, Dovecot does
17673 this but still safely fallbacks to re-reading the whole mbox file
17674 whenever something in mbox isn't how it's expected to be. The only real
17675 downside to this setting is that if some other MUA changes message
17676 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17677 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17678 Defaults to @samp{#t}.
17681 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17682 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17683 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17684 @samp{mbox-dirty-syncs} is ignored.
17685 Defaults to @samp{#f}.
17688 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17689 Delay writing mbox headers until doing a full write sync (EXPUNGE
17690 and CHECK commands and when closing the mailbox). This is especially
17691 useful for POP3 where clients often delete all mails. The downside is
17692 that our changes aren't immediately visible to other MUAs.
17693 Defaults to @samp{#t}.
17696 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17697 If mbox size is smaller than this (e.g.@: 100k), don't write index
17698 files. If an index file already exists it's still read, just not
17700 Defaults to @samp{0}.
17703 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17704 Maximum dbox file size until it's rotated.
17705 Defaults to @samp{10000000}.
17708 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17709 Maximum dbox file age until it's rotated. Typically in days. Day
17710 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17712 Defaults to @samp{"1d"}.
17715 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17716 When creating new mdbox files, immediately preallocate their size to
17717 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17718 with some file systems (ext4, xfs).
17719 Defaults to @samp{#f}.
17722 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17723 sdbox and mdbox support saving mail attachments to external files,
17724 which also allows single instance storage for them. Other backends
17725 don't support this for now.
17727 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17729 Directory root where to store mail attachments. Disabled, if empty.
17730 Defaults to @samp{""}.
17733 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17734 Attachments smaller than this aren't saved externally. It's also
17735 possible to write a plugin to disable saving specific attachments
17737 Defaults to @samp{128000}.
17740 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17741 File system backend to use for saving attachments:
17744 No SiS done by Dovecot (but this might help FS's own deduplication)
17746 SiS with immediate byte-by-byte comparison during saving
17747 @item sis-queue posix
17748 SiS with delayed comparison and deduplication.
17750 Defaults to @samp{"sis posix"}.
17753 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17754 Hash format to use in attachment filenames. You can add any text and
17755 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17756 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17757 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17758 Defaults to @samp{"%@{sha1@}"}.
17761 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17763 Defaults to @samp{100}.
17766 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17768 Defaults to @samp{1000}.
17771 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17772 Default VSZ (virtual memory size) limit for service processes.
17773 This is mainly intended to catch and kill processes that leak memory
17774 before they eat up everything.
17775 Defaults to @samp{256000000}.
17778 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17779 Login user is internally used by login processes. This is the most
17780 untrusted user in Dovecot system. It shouldn't have access to anything
17782 Defaults to @samp{"dovenull"}.
17785 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17786 Internal user is used by unprivileged processes. It should be
17787 separate from login user, so that login processes can't disturb other
17789 Defaults to @samp{"dovecot"}.
17792 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17793 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17794 Defaults to @samp{"required"}.
17797 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17798 PEM encoded X.509 SSL/TLS certificate (public key).
17799 Defaults to @samp{"</etc/dovecot/default.pem"}.
17802 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17803 PEM encoded SSL/TLS private key. The key is opened before
17804 dropping root privileges, so keep the key file unreadable by anyone but
17806 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17809 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17810 If key file is password protected, give the password here.
17811 Alternatively give it when starting dovecot with -p parameter. Since
17812 this file is often world-readable, you may want to place this setting
17813 instead to a different.
17814 Defaults to @samp{""}.
17817 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17818 PEM encoded trusted certificate authority. Set this only if you
17819 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17820 contain the CA certificate(s) followed by the matching
17821 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17822 Defaults to @samp{""}.
17825 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17826 Require that CRL check succeeds for client certificates.
17827 Defaults to @samp{#t}.
17830 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17831 Request client to send a certificate. If you also want to require
17832 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17833 Defaults to @samp{#f}.
17836 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17837 Which field from certificate to use for username. commonName and
17838 x500UniqueIdentifier are the usual choices. You'll also need to set
17839 @samp{auth-ssl-username-from-cert? #t}.
17840 Defaults to @samp{"commonName"}.
17843 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17844 Minimum SSL protocol version to accept.
17845 Defaults to @samp{"TLSv1"}.
17848 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17849 SSL ciphers to use.
17850 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17853 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17854 SSL crypto device to use, for valid values run "openssl engine".
17855 Defaults to @samp{""}.
17858 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17859 Address to use when sending rejection mails.
17860 %d expands to recipient domain.
17861 Defaults to @samp{"postmaster@@%d"}.
17864 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17865 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17866 and in LMTP replies. Default is the system's real hostname@@domain.
17867 Defaults to @samp{""}.
17870 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17871 If user is over quota, return with temporary failure instead of
17873 Defaults to @samp{#f}.
17876 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17877 Binary to use for sending mails.
17878 Defaults to @samp{"/usr/sbin/sendmail"}.
17881 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17882 If non-empty, send mails via this SMTP host[:port] instead of
17884 Defaults to @samp{""}.
17887 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17888 Subject: header to use for rejection mails. You can use the same
17889 variables as for @samp{rejection-reason} below.
17890 Defaults to @samp{"Rejected: %s"}.
17893 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17894 Human readable error message for rejection mails. You can use
17907 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17910 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17911 Delimiter character between local-part and detail in email
17913 Defaults to @samp{"+"}.
17916 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17917 Header where the original recipient address (SMTP's RCPT TO:
17918 address) is taken from if not available elsewhere. With dovecot-lda -a
17919 parameter overrides this. A commonly used header for this is
17921 Defaults to @samp{""}.
17924 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17925 Should saving a mail to a nonexistent mailbox automatically create
17927 Defaults to @samp{#f}.
17930 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17931 Should automatically created mailboxes be also automatically
17933 Defaults to @samp{#f}.
17936 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17937 Maximum IMAP command line length. Some clients generate very long
17938 command lines with huge mailboxes, so you may need to raise this if you
17939 get "Too long argument" or "IMAP command line too large" errors
17941 Defaults to @samp{64000}.
17944 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17945 IMAP logout format string:
17948 total number of bytes read from client
17950 total number of bytes sent to client.
17952 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17953 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@}"}.
17956 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17957 Override the IMAP CAPABILITY response. If the value begins with '+',
17958 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17959 Defaults to @samp{""}.
17962 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17963 How long to wait between "OK Still here" notifications when client
17965 Defaults to @samp{"2 mins"}.
17968 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17969 ID field names and values to send to clients. Using * as the value
17970 makes Dovecot use the default value. The following fields have default
17971 values currently: name, version, os, os-version, support-url,
17973 Defaults to @samp{""}.
17976 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17977 ID fields sent by client to log. * means everything.
17978 Defaults to @samp{""}.
17981 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17982 Workarounds for various client bugs:
17985 @item delay-newmail
17986 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17987 CHECK commands. Some clients ignore them otherwise, for example OSX
17988 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17989 may show user "Message no longer in server" errors. Note that OE6
17990 still breaks even with this workaround if synchronization is set to
17993 @item tb-extra-mailbox-sep
17994 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17995 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17996 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17998 @item tb-lsub-flags
17999 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
18000 This makes Thunderbird realize they aren't selectable and show them
18001 greyed out, instead of only later giving "not selectable" popup error.
18003 Defaults to @samp{()}.
18006 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
18007 Host allowed in URLAUTH URLs sent by client. "*" allows all.
18008 Defaults to @samp{""}.
18012 Whew! Lots of configuration options. The nice thing about it though is
18013 that Guix has a complete interface to Dovecot's configuration
18014 language. This allows not only a nice way to declare configurations,
18015 but also offers reflective capabilities as well: users can write code to
18016 inspect and transform configurations from within Scheme.
18018 However, it could be that you just want to get a @code{dovecot.conf} up
18019 and running. In that case, you can pass an
18020 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
18021 @code{dovecot-service}. As its name indicates, an opaque configuration
18022 does not have easy reflective capabilities.
18024 Available @code{opaque-dovecot-configuration} fields are:
18026 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
18027 The dovecot package.
18030 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
18031 The contents of the @code{dovecot.conf}, as a string.
18034 For example, if your @code{dovecot.conf} is just the empty string, you
18035 could instantiate a dovecot service like this:
18038 (dovecot-service #:config
18039 (opaque-dovecot-configuration
18043 @subsubheading OpenSMTPD Service
18045 @deffn {Scheme Variable} opensmtpd-service-type
18046 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
18047 service, whose value should be an @code{opensmtpd-configuration} object
18048 as in this example:
18051 (service opensmtpd-service-type
18052 (opensmtpd-configuration
18053 (config-file (local-file "./my-smtpd.conf"))))
18057 @deftp {Data Type} opensmtpd-configuration
18058 Data type representing the configuration of opensmtpd.
18061 @item @code{package} (default: @var{opensmtpd})
18062 Package object of the OpenSMTPD SMTP server.
18064 @item @code{config-file} (default: @code{%default-opensmtpd-file})
18065 File-like object of the OpenSMTPD configuration file to use. By default
18066 it listens on the loopback network interface, and allows for mail from
18067 users and daemons on the local machine, as well as permitting email to
18068 remote servers. Run @command{man smtpd.conf} for more information.
18073 @subsubheading Exim Service
18075 @cindex mail transfer agent (MTA)
18076 @cindex MTA (mail transfer agent)
18079 @deffn {Scheme Variable} exim-service-type
18080 This is the type of the @uref{https://exim.org, Exim} mail transfer
18081 agent (MTA), whose value should be an @code{exim-configuration} object
18082 as in this example:
18085 (service exim-service-type
18086 (exim-configuration
18087 (config-file (local-file "./my-exim.conf"))))
18091 In order to use an @code{exim-service-type} service you must also have a
18092 @code{mail-aliases-service-type} service present in your
18093 @code{operating-system} (even if it has no aliases).
18095 @deftp {Data Type} exim-configuration
18096 Data type representing the configuration of exim.
18099 @item @code{package} (default: @var{exim})
18100 Package object of the Exim server.
18102 @item @code{config-file} (default: @code{#f})
18103 File-like object of the Exim configuration file to use. If its value is
18104 @code{#f} then use the default configuration file from the package
18105 provided in @code{package}. The resulting configuration file is loaded
18106 after setting the @code{exim_user} and @code{exim_group} configuration
18112 @subsubheading Getmail service
18117 @deffn {Scheme Variable} getmail-service-type
18118 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
18119 mail retriever, whose value should be an @code{getmail-configuration}.
18122 Available @code{getmail-configuration} fields are:
18124 @deftypevr {@code{getmail-configuration} parameter} symbol name
18125 A symbol to identify the getmail service.
18127 Defaults to @samp{"unset"}.
18131 @deftypevr {@code{getmail-configuration} parameter} package package
18132 The getmail package to use.
18136 @deftypevr {@code{getmail-configuration} parameter} string user
18137 The user to run getmail as.
18139 Defaults to @samp{"getmail"}.
18143 @deftypevr {@code{getmail-configuration} parameter} string group
18144 The group to run getmail as.
18146 Defaults to @samp{"getmail"}.
18150 @deftypevr {@code{getmail-configuration} parameter} string directory
18151 The getmail directory to use.
18153 Defaults to @samp{"/var/lib/getmail/default"}.
18157 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
18158 The getmail configuration file to use.
18160 Available @code{getmail-configuration-file} fields are:
18162 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
18163 What mail account to retrieve mail from, and how to access that account.
18165 Available @code{getmail-retriever-configuration} fields are:
18167 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
18168 The type of mail retriever to use. Valid values include @samp{passwd}
18171 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
18175 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
18176 Username to login to the mail server with.
18178 Defaults to @samp{unset}.
18182 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
18183 Username to login to the mail server with.
18185 Defaults to @samp{unset}.
18189 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
18190 Port number to connect to.
18192 Defaults to @samp{#f}.
18196 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
18197 Override fields from passwd.
18199 Defaults to @samp{""}.
18203 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
18204 Override fields from passwd.
18206 Defaults to @samp{()}.
18210 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
18211 PEM-formatted key file to use for the TLS negotiation.
18213 Defaults to @samp{""}.
18217 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
18218 PEM-formatted certificate file to use for the TLS negotiation.
18220 Defaults to @samp{""}.
18224 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
18225 CA certificates to use.
18227 Defaults to @samp{""}.
18231 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
18232 Extra retriever parameters.
18234 Defaults to @samp{()}.
18240 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
18241 What to do with retrieved messages.
18243 Available @code{getmail-destination-configuration} fields are:
18245 @deftypevr {@code{getmail-destination-configuration} parameter} string type
18246 The type of mail destination. Valid values include @samp{Maildir},
18247 @samp{Mboxrd} and @samp{MDA_external}.
18249 Defaults to @samp{unset}.
18253 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
18254 The path option for the mail destination. The behaviour depends on the
18257 Defaults to @samp{""}.
18261 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
18262 Extra destination parameters
18264 Defaults to @samp{()}.
18270 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
18273 Available @code{getmail-options-configuration} fields are:
18275 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
18276 If set to @samp{0}, getmail will only print warnings and errors. A
18277 value of @samp{1} means that messages will be printed about retrieving
18278 and deleting messages. If set to @samp{2}, getmail will print messages
18279 about each of it's actions.
18281 Defaults to @samp{1}.
18285 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
18286 If true, getmail will retrieve all available messages. Otherwise it
18287 will only retrieve messages it hasn't seen previously.
18289 Defaults to @samp{#t}.
18293 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
18294 If set to true, messages will be deleted from the server after
18295 retrieving and successfully delivering them. Otherwise, messages will
18296 be left on the server.
18298 Defaults to @samp{#f}.
18302 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
18303 Getmail will delete messages this number of days after seeing them, if
18304 they have been delivered. This means messages will be left on the
18305 server this number of days after delivering them. A value of @samp{0}
18306 disabled this feature.
18308 Defaults to @samp{0}.
18312 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
18313 Delete messages larger than this of bytes after retrieving them, even if
18314 the delete and delete-after options are disabled. A value of @samp{0}
18315 disables this feature.
18317 Defaults to @samp{0}.
18321 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
18322 Retrieve messages totalling up to this number of bytes before closing
18323 the session with the server. A value of @samp{0} disables this feature.
18325 Defaults to @samp{0}.
18329 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
18330 Don't retrieve messages larger than this number of bytes. A value of
18331 @samp{0} disables this feature.
18333 Defaults to @samp{0}.
18337 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
18338 If true, getmail will add a Delivered-To header to messages.
18340 Defaults to @samp{#t}.
18344 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
18345 If set, getmail adds a Received header to the messages.
18347 Defaults to @samp{#t}.
18351 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
18352 Getmail will record a log of its actions to the named file. A value of
18353 @samp{""} disables this feature.
18355 Defaults to @samp{""}.
18359 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
18360 If true, getmail will record a log of its actions using the system
18363 Defaults to @samp{#f}.
18367 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
18368 If true, getmail will log information about messages not retrieved and
18369 the reason for not retrieving them, as well as starting and ending
18372 Defaults to @samp{#f}.
18376 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
18377 Extra options to include.
18379 Defaults to @samp{()}.
18387 @deftypevr {@code{getmail-configuration} parameter} list idle
18388 A list of mailboxes that getmail should wait on the server for new mail
18389 notifications. This depends on the server supporting the IDLE
18392 Defaults to @samp{()}.
18396 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
18397 Environment variables to set for getmail.
18399 Defaults to @samp{()}.
18403 @subsubheading Mail Aliases Service
18405 @cindex email aliases
18406 @cindex aliases, for email addresses
18408 @deffn {Scheme Variable} mail-aliases-service-type
18409 This is the type of the service which provides @code{/etc/aliases},
18410 specifying how to deliver mail to users on this system.
18413 (service mail-aliases-service-type
18414 '(("postmaster" "bob")
18415 ("bob" "bob@@example.com" "bob@@example2.com")))
18419 The configuration for a @code{mail-aliases-service-type} service is an
18420 association list denoting how to deliver mail that comes to this
18421 system. Each entry is of the form @code{(alias addresses ...)}, with
18422 @code{alias} specifying the local alias and @code{addresses} specifying
18423 where to deliver this user's mail.
18425 The aliases aren't required to exist as users on the local system. In
18426 the above example, there doesn't need to be a @code{postmaster} entry in
18427 the @code{operating-system}'s @code{user-accounts} in order to deliver
18428 the @code{postmaster} mail to @code{bob} (which subsequently would
18429 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
18431 @subsubheading GNU Mailutils IMAP4 Daemon
18432 @cindex GNU Mailutils IMAP4 Daemon
18434 @deffn {Scheme Variable} imap4d-service-type
18435 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
18436 mailutils, GNU Mailutils Manual}), whose value should be an
18437 @code{imap4d-configuration} object as in this example:
18440 (service imap4d-service-type
18441 (imap4d-configuration
18442 (config-file (local-file "imap4d.conf"))))
18446 @deftp {Data Type} imap4d-configuration
18447 Data type representing the configuration of @command{imap4d}.
18450 @item @code{package} (default: @code{mailutils})
18451 The package that provides @command{imap4d}.
18453 @item @code{config-file} (default: @code{%default-imap4d-config-file})
18454 File-like object of the configuration file to use, by default it will listen
18455 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
18456 Mailutils Manual}, for details.
18461 @node Messaging Services
18462 @subsection Messaging Services
18467 The @code{(gnu services messaging)} module provides Guix service
18468 definitions for messaging services: currently only Prosody is supported.
18470 @subsubheading Prosody Service
18472 @deffn {Scheme Variable} prosody-service-type
18473 This is the type for the @uref{https://prosody.im, Prosody XMPP
18474 communication server}. Its value must be a @code{prosody-configuration}
18475 record as in this example:
18478 (service prosody-service-type
18479 (prosody-configuration
18480 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
18483 (int-component-configuration
18484 (hostname "conference.example.net")
18486 (mod-muc (mod-muc-configuration)))))
18489 (virtualhost-configuration
18490 (domain "example.net"))))))
18493 See below for details about @code{prosody-configuration}.
18497 By default, Prosody does not need much configuration. Only one
18498 @code{virtualhosts} field is needed: it specifies the domain you wish
18501 You can perform various sanity checks on the generated configuration
18502 with the @code{prosodyctl check} command.
18504 Prosodyctl will also help you to import certificates from the
18505 @code{letsencrypt} directory so that the @code{prosody} user can access
18506 them. See @url{https://prosody.im/doc/letsencrypt}.
18509 prosodyctl --root cert import /etc/letsencrypt/live
18512 The available configuration parameters follow. Each parameter
18513 definition is preceded by its type; for example, @samp{string-list foo}
18514 indicates that the @code{foo} parameter should be specified as a list of
18515 strings. Types starting with @code{maybe-} denote parameters that won't
18516 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18518 There is also a way to specify the configuration as a string, if you
18519 have an old @code{prosody.cfg.lua} file that you want to port over from
18520 some other system; see the end for more details.
18522 The @code{file-object} type designates either a file-like object
18523 (@pxref{G-Expressions, file-like objects}) or a file name.
18525 @c The following documentation was initially generated by
18526 @c (generate-documentation) in (gnu services messaging). Manually maintained
18527 @c documentation is better, so we shouldn't hesitate to edit below as
18528 @c needed. However if the change you want to make to this documentation
18529 @c can be done in an automated way, it's probably easier to change
18530 @c (generate-documentation) than to make it below and have to deal with
18531 @c the churn as Prosody updates.
18533 Available @code{prosody-configuration} fields are:
18535 @deftypevr {@code{prosody-configuration} parameter} package prosody
18536 The Prosody package.
18539 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18540 Location of the Prosody data storage directory. See
18541 @url{https://prosody.im/doc/configure}.
18542 Defaults to @samp{"/var/lib/prosody"}.
18545 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18546 Additional plugin directories. They are searched in all the specified
18547 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18548 Defaults to @samp{()}.
18551 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18552 Every virtual host and component needs a certificate so that clients and
18553 servers can securely verify its identity. Prosody will automatically load
18554 certificates/keys from the directory specified here.
18555 Defaults to @samp{"/etc/prosody/certs"}.
18558 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18559 This is a list of accounts that are admins for the server. Note that you
18560 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18561 @url{https://prosody.im/doc/creating_accounts}.
18562 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18563 Defaults to @samp{()}.
18566 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18567 Enable use of libevent for better performance under high load. See
18568 @url{https://prosody.im/doc/libevent}.
18569 Defaults to @samp{#f}.
18572 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18573 This is the list of modules Prosody will load on startup. It looks for
18574 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18575 Documentation on modules can be found at:
18576 @url{https://prosody.im/doc/modules}.
18577 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18580 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18581 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18582 should you want to disable them then add them to this list.
18583 Defaults to @samp{()}.
18586 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18587 Path to a text file where the shared groups are defined. If this path is
18588 empty then @samp{mod_groups} does nothing. See
18589 @url{https://prosody.im/doc/modules/mod_groups}.
18590 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18593 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18594 Disable account creation by default, for security. See
18595 @url{https://prosody.im/doc/creating_accounts}.
18596 Defaults to @samp{#f}.
18599 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18600 These are the SSL/TLS-related settings. Most of them are disabled so to
18601 use Prosody's defaults. If you do not completely understand these options, do
18602 not add them to your config, it is easy to lower the security of your server
18603 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18605 Available @code{ssl-configuration} fields are:
18607 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18608 This determines what handshake to use.
18611 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18612 Path to your private key file.
18615 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18616 Path to your certificate file.
18619 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18620 Path to directory containing root certificates that you wish Prosody to
18621 trust when verifying the certificates of remote servers.
18622 Defaults to @samp{"/etc/ssl/certs"}.
18625 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18626 Path to a file containing root certificates that you wish Prosody to trust.
18627 Similar to @code{capath} but with all certificates concatenated together.
18630 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18631 A list of verification options (these mostly map to OpenSSL's
18632 @code{set_verify()} flags).
18635 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18636 A list of general options relating to SSL/TLS. These map to OpenSSL's
18637 @code{set_options()}. For a full list of options available in LuaSec, see the
18641 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18642 How long a chain of certificate authorities to check when looking for a
18643 trusted root certificate.
18646 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18647 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18648 clients, and in what order.
18651 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18652 A path to a file containing parameters for Diffie-Hellman key exchange. You
18653 can create such a file with:
18654 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18657 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18658 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18659 @samp{"secp384r1"}.
18662 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18663 A list of ``extra'' verification options.
18666 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18667 Password for encrypted private keys.
18672 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18673 Whether to force all client-to-server connections to be encrypted or not.
18674 See @url{https://prosody.im/doc/modules/mod_tls}.
18675 Defaults to @samp{#f}.
18678 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18679 Set of mechanisms that will never be offered. See
18680 @url{https://prosody.im/doc/modules/mod_saslauth}.
18681 Defaults to @samp{("DIGEST-MD5")}.
18684 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18685 Whether to force all server-to-server connections to be encrypted or not.
18686 See @url{https://prosody.im/doc/modules/mod_tls}.
18687 Defaults to @samp{#f}.
18690 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18691 Whether to require encryption and certificate authentication. This
18692 provides ideal security, but requires servers you communicate with to support
18693 encryption AND present valid, trusted certificates. See
18694 @url{https://prosody.im/doc/s2s#security}.
18695 Defaults to @samp{#f}.
18698 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18699 Many servers don't support encryption or have invalid or self-signed
18700 certificates. You can list domains here that will not be required to
18701 authenticate using certificates. They will be authenticated using DNS. See
18702 @url{https://prosody.im/doc/s2s#security}.
18703 Defaults to @samp{()}.
18706 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18707 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18708 valid certificates for some domains by specifying a list here. See
18709 @url{https://prosody.im/doc/s2s#security}.
18710 Defaults to @samp{()}.
18713 @deftypevr {@code{prosody-configuration} parameter} string authentication
18714 Select the authentication backend to use. The default provider stores
18715 passwords in plaintext and uses Prosody's configured data storage to store the
18716 authentication data. If you do not trust your server please see
18717 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18718 about using the hashed backend. See also
18719 @url{https://prosody.im/doc/authentication}
18720 Defaults to @samp{"internal_plain"}.
18723 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18724 Set logging options. Advanced logging configuration is not yet supported
18725 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18726 Defaults to @samp{"*syslog"}.
18729 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18730 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18731 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18734 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18735 Maximum allowed size of the HTTP body (in bytes).
18738 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18739 Some modules expose their own URL in various ways. This URL is built
18740 from the protocol, host and port used. If Prosody sits behind a proxy, the
18741 public URL will be @code{http-external-url} instead. See
18742 @url{https://prosody.im/doc/http#external_url}.
18745 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18746 A host in Prosody is a domain on which user accounts can be created. For
18747 example if you want your users to have addresses like
18748 @samp{"john.smith@@example.com"} then you need to add a host
18749 @samp{"example.com"}. All options in this list will apply only to this host.
18751 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
18752 the actual physical host that Prosody is installed on. A single Prosody
18753 instance can serve many domains, each one defined as a VirtualHost entry in
18754 Prosody's configuration. Conversely a server that hosts a single domain would
18755 have just one VirtualHost entry.
18757 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18759 Available @code{virtualhost-configuration} fields are:
18761 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:
18762 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18763 Domain you wish Prosody to serve.
18768 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18769 Components are extra services on a server which are available to clients,
18770 usually on a subdomain of the main server (such as
18771 @samp{"mycomponent.example.com"}). Example components might be chatroom
18772 servers, user directories, or gateways to other protocols.
18774 Internal components are implemented with Prosody-specific plugins. To add an
18775 internal component, you simply fill the hostname field, and the plugin you wish
18776 to use for the component.
18778 See @url{https://prosody.im/doc/components}.
18779 Defaults to @samp{()}.
18781 Available @code{int-component-configuration} fields are:
18783 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:
18784 @deftypevr {@code{int-component-configuration} parameter} string hostname
18785 Hostname of the component.
18788 @deftypevr {@code{int-component-configuration} parameter} string plugin
18789 Plugin you wish to use for the component.
18792 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18793 Multi-user chat (MUC) is Prosody's module for allowing you to create
18794 hosted chatrooms/conferences for XMPP users.
18796 General information on setting up and using multi-user chatrooms can be found
18797 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
18798 which you should read if you are new to XMPP chatrooms.
18800 See also @url{https://prosody.im/doc/modules/mod_muc}.
18802 Available @code{mod-muc-configuration} fields are:
18804 @deftypevr {@code{mod-muc-configuration} parameter} string name
18805 The name to return in service discovery responses.
18806 Defaults to @samp{"Prosody Chatrooms"}.
18809 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18810 If @samp{#t}, this will only allow admins to create new chatrooms.
18811 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18812 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18813 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18814 restricts to service administrators only.
18815 Defaults to @samp{#f}.
18818 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18819 Maximum number of history messages that will be sent to the member that has
18820 just joined the room.
18821 Defaults to @samp{20}.
18828 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18829 External components use XEP-0114, which most standalone components
18830 support. To add an external component, you simply fill the hostname field. See
18831 @url{https://prosody.im/doc/components}.
18832 Defaults to @samp{()}.
18834 Available @code{ext-component-configuration} fields are:
18836 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:
18837 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18838 Password which the component will use to log in.
18841 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18842 Hostname of the component.
18847 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18848 Port(s) Prosody listens on for component connections.
18849 Defaults to @samp{(5347)}.
18852 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18853 Interface Prosody listens on for component connections.
18854 Defaults to @samp{"127.0.0.1"}.
18857 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18858 Raw content that will be added to the configuration file.
18861 It could be that you just want to get a @code{prosody.cfg.lua}
18862 up and running. In that case, you can pass an
18863 @code{opaque-prosody-configuration} record as the value of
18864 @code{prosody-service-type}. As its name indicates, an opaque configuration
18865 does not have easy reflective capabilities.
18866 Available @code{opaque-prosody-configuration} fields are:
18868 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18869 The prosody package.
18872 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18873 The contents of the @code{prosody.cfg.lua} to use.
18876 For example, if your @code{prosody.cfg.lua} is just the empty
18877 string, you could instantiate a prosody service like this:
18880 (service prosody-service-type
18881 (opaque-prosody-configuration
18882 (prosody.cfg.lua "")))
18885 @c end of Prosody auto-generated documentation
18887 @subsubheading BitlBee Service
18889 @cindex IRC (Internet Relay Chat)
18890 @cindex IRC gateway
18891 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18892 interface to a variety of messaging protocols such as XMPP.
18894 @defvr {Scheme Variable} bitlbee-service-type
18895 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18896 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18899 To have BitlBee listen on port 6667 on localhost, add this line to your
18903 (service bitlbee-service-type)
18907 @deftp {Data Type} bitlbee-configuration
18908 This is the configuration for BitlBee, with the following fields:
18911 @item @code{interface} (default: @code{"127.0.0.1"})
18912 @itemx @code{port} (default: @code{6667})
18913 Listen on the network interface corresponding to the IP address
18914 specified in @var{interface}, on @var{port}.
18916 When @var{interface} is @code{127.0.0.1}, only local clients can
18917 connect; when it is @code{0.0.0.0}, connections can come from any
18918 networking interface.
18920 @item @code{bitlbee} (default: @code{bitlbee})
18921 The BitlBee package to use.
18923 @item @code{plugins} (default: @code{'()})
18924 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18926 @item @code{extra-settings} (default: @code{""})
18927 Configuration snippet added as-is to the BitlBee configuration file.
18931 @subsubheading Quassel Service
18933 @cindex IRC (Internet Relay Chat)
18934 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18935 meaning that one or more clients can attach to and detach from the
18938 @defvr {Scheme Variable} quassel-service-type
18939 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18940 IRC backend daemon. Its value is a @code{quassel-configuration}
18944 @deftp {Data Type} quassel-configuration
18945 This is the configuration for Quassel, with the following fields:
18948 @item @code{quassel} (default: @code{quassel})
18949 The Quassel package to use.
18951 @item @code{interface} (default: @code{"::,0.0.0.0"})
18952 @item @code{port} (default: @code{4242})
18953 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18954 interfaces specified in the comma delimited @var{interface}, on
18957 @item @code{loglevel} (default: @code{"Info"})
18958 The level of logging desired. Accepted values are Debug, Info, Warning
18963 @node Telephony Services
18964 @subsection Telephony Services
18966 @cindex Murmur (VoIP server)
18967 @cindex VoIP server
18968 This section describes how to set up and run a Murmur server. Murmur is
18969 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18972 @deftp {Data Type} murmur-configuration
18973 The service type for the Murmur server. An example configuration can
18977 (service murmur-service-type
18978 (murmur-configuration
18980 "Welcome to this Mumble server running on Guix!")
18981 (cert-required? #t) ;disallow text password logins
18982 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18983 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18986 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18987 password with the command that is printed during the activation phase.
18989 It is recommended to register a normal Mumble user account
18990 and grant it admin or moderator rights.
18991 You can use the @code{mumble} client to
18992 login as new normal user, register yourself, and log out.
18993 For the next step login with the name @code{SuperUser} use
18994 the @code{SuperUser} password that you set previously,
18995 and grant your newly registered mumble user administrator or moderator
18996 rights and create some channels.
18998 Available @code{murmur-configuration} fields are:
19001 @item @code{package} (default: @code{mumble})
19002 Package that contains @code{bin/murmurd}.
19004 @item @code{user} (default: @code{"murmur"})
19005 User who will run the Murmur server.
19007 @item @code{group} (default: @code{"murmur"})
19008 Group of the user who will run the murmur server.
19010 @item @code{port} (default: @code{64738})
19011 Port on which the server will listen.
19013 @item @code{welcome-text} (default: @code{""})
19014 Welcome text sent to clients when they connect.
19016 @item @code{server-password} (default: @code{""})
19017 Password the clients have to enter in order to connect.
19019 @item @code{max-users} (default: @code{100})
19020 Maximum of users that can be connected to the server at once.
19022 @item @code{max-user-bandwidth} (default: @code{#f})
19023 Maximum voice traffic a user can send per second.
19025 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
19026 File name of the sqlite database.
19027 The service's user will become the owner of the directory.
19029 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
19030 File name of the log file.
19031 The service's user will become the owner of the directory.
19033 @item @code{autoban-attempts} (default: @code{10})
19034 Maximum number of logins a user can make in @code{autoban-timeframe}
19035 without getting auto banned for @code{autoban-time}.
19037 @item @code{autoban-timeframe} (default: @code{120})
19038 Timeframe for autoban in seconds.
19040 @item @code{autoban-time} (default: @code{300})
19041 Amount of time in seconds for which a client gets banned
19042 when violating the autoban limits.
19044 @item @code{opus-threshold} (default: @code{100})
19045 Percentage of clients that need to support opus
19046 before switching over to opus audio codec.
19048 @item @code{channel-nesting-limit} (default: @code{10})
19049 How deep channels can be nested at maximum.
19051 @item @code{channelname-regex} (default: @code{#f})
19052 A string in form of a Qt regular expression that channel names must conform to.
19054 @item @code{username-regex} (default: @code{#f})
19055 A string in form of a Qt regular expression that user names must conform to.
19057 @item @code{text-message-length} (default: @code{5000})
19058 Maximum size in bytes that a user can send in one text chat message.
19060 @item @code{image-message-length} (default: @code{(* 128 1024)})
19061 Maximum size in bytes that a user can send in one image message.
19063 @item @code{cert-required?} (default: @code{#f})
19064 If it is set to @code{#t} clients that use weak password authentication
19065 will not be accepted. Users must have completed the certificate wizard to join.
19067 @item @code{remember-channel?} (default: @code{#f})
19068 Should murmur remember the last channel each user was in when they disconnected
19069 and put them into the remembered channel when they rejoin.
19071 @item @code{allow-html?} (default: @code{#f})
19072 Should html be allowed in text messages, user comments, and channel descriptions.
19074 @item @code{allow-ping?} (default: @code{#f})
19075 Setting to true exposes the current user count, the maximum user count, and
19076 the server's maximum bandwidth per client to unauthenticated users. In the
19077 Mumble client, this information is shown in the Connect dialog.
19079 Disabling this setting will prevent public listing of the server.
19081 @item @code{bonjour?} (default: @code{#f})
19082 Should the server advertise itself in the local network through the bonjour protocol.
19084 @item @code{send-version?} (default: @code{#f})
19085 Should the murmur server version be exposed in ping requests.
19087 @item @code{log-days} (default: @code{31})
19088 Murmur also stores logs in the database, which are accessible via RPC.
19089 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
19090 or -1 to disable logging to the database.
19092 @item @code{obfuscate-ips?} (default: @code{#t})
19093 Should logged ips be obfuscated to protect the privacy of users.
19095 @item @code{ssl-cert} (default: @code{#f})
19096 File name of the SSL/TLS certificate used for encrypted connections.
19099 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
19101 @item @code{ssl-key} (default: @code{#f})
19102 Filepath to the ssl private key used for encrypted connections.
19104 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
19107 @item @code{ssl-dh-params} (default: @code{#f})
19108 File name of a PEM-encoded file with Diffie-Hellman parameters
19109 for the SSL/TLS encryption. Alternatively you set it to
19110 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
19111 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
19113 @item @code{ssl-ciphers} (default: @code{#f})
19114 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
19117 This option is specified using
19118 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
19119 OpenSSL cipher list notation}.
19121 It is recommended that you try your cipher string using 'openssl ciphers <string>'
19122 before setting it here, to get a feel for which cipher suites you will get.
19123 After setting this option, it is recommend that you inspect your Murmur log
19124 to ensure that Murmur is using the cipher suites that you expected it to.
19126 Note: Changing this option may impact the backwards compatibility of your
19127 Murmur server, and can remove the ability for older Mumble clients to be able
19130 @item @code{public-registration} (default: @code{#f})
19131 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
19133 You can optionally register your server in the public server list that the
19134 @code{mumble} client shows on startup.
19135 You cannot register your server if you have set a @code{server-password},
19136 or set @code{allow-ping} to @code{#f}.
19138 It might take a few hours until it shows up in the public list.
19140 @item @code{file} (default: @code{#f})
19141 Optional alternative override for this configuration.
19145 @deftp {Data Type} murmur-public-registration-configuration
19146 Configuration for public registration of a murmur service.
19150 This is a display name for your server. Not to be confused with the hostname.
19152 @item @code{password}
19153 A password to identify your registration.
19154 Subsequent updates will need the same password. Don't lose your password.
19157 This should be a @code{http://} or @code{https://} link to your web
19160 @item @code{hostname} (default: @code{#f})
19161 By default your server will be listed by its IP address.
19162 If it is set your server will be linked by this host name instead.
19168 @node Monitoring Services
19169 @subsection Monitoring Services
19171 @subsubheading Tailon Service
19173 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
19174 viewing and searching log files.
19176 The following example will configure the service with default values.
19177 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
19180 (service tailon-service-type)
19183 The following example customises more of the Tailon configuration,
19184 adding @command{sed} to the list of allowed commands.
19187 (service tailon-service-type
19188 (tailon-configuration
19190 (tailon-configuration-file
19191 (allowed-commands '("tail" "grep" "awk" "sed"))))))
19195 @deftp {Data Type} tailon-configuration
19196 Data type representing the configuration of Tailon.
19197 This type has the following parameters:
19200 @item @code{config-file} (default: @code{(tailon-configuration-file)})
19201 The configuration file to use for Tailon. This can be set to a
19202 @dfn{tailon-configuration-file} record value, or any gexp
19203 (@pxref{G-Expressions}).
19205 For example, to instead use a local file, the @code{local-file} function
19209 (service tailon-service-type
19210 (tailon-configuration
19211 (config-file (local-file "./my-tailon.conf"))))
19214 @item @code{package} (default: @code{tailon})
19215 The tailon package to use.
19220 @deftp {Data Type} tailon-configuration-file
19221 Data type representing the configuration options for Tailon.
19222 This type has the following parameters:
19225 @item @code{files} (default: @code{(list "/var/log")})
19226 List of files to display. The list can include strings for a single file
19227 or directory, or a list, where the first item is the name of a
19228 subsection, and the remaining items are the files or directories in that
19231 @item @code{bind} (default: @code{"localhost:8080"})
19232 Address and port to which Tailon should bind on.
19234 @item @code{relative-root} (default: @code{#f})
19235 URL path to use for Tailon, set to @code{#f} to not use a path.
19237 @item @code{allow-transfers?} (default: @code{#t})
19238 Allow downloading the log files in the web interface.
19240 @item @code{follow-names?} (default: @code{#t})
19241 Allow tailing of not-yet existent files.
19243 @item @code{tail-lines} (default: @code{200})
19244 Number of lines to read initially from each file.
19246 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
19247 Commands to allow running. By default, @code{sed} is disabled.
19249 @item @code{debug?} (default: @code{#f})
19250 Set @code{debug?} to @code{#t} to show debug messages.
19252 @item @code{wrap-lines} (default: @code{#t})
19253 Initial line wrapping state in the web interface. Set to @code{#t} to
19254 initially wrap lines (the default), or to @code{#f} to initially not
19257 @item @code{http-auth} (default: @code{#f})
19258 HTTP authentication type to use. Set to @code{#f} to disable
19259 authentication (the default). Supported values are @code{"digest"} or
19262 @item @code{users} (default: @code{#f})
19263 If HTTP authentication is enabled (see @code{http-auth}), access will be
19264 restricted to the credentials provided here. To configure users, use a
19265 list of pairs, where the first element of the pair is the username, and
19266 the 2nd element of the pair is the password.
19269 (tailon-configuration-file
19270 (http-auth "basic")
19271 (users '(("user1" . "password1")
19272 ("user2" . "password2"))))
19279 @subsubheading Darkstat Service
19281 Darkstat is a packet sniffer that captures network traffic, calculates
19282 statistics about usage, and serves reports over HTTP.
19284 @defvar {Scheme Variable} darkstat-service-type
19285 This is the service type for the
19286 @uref{https://unix4lyfe.org/darkstat/, darkstat}
19287 service, its value must be a @code{darkstat-configuration} record as in
19291 (service darkstat-service-type
19292 (darkstat-configuration
19293 (interface "eno1")))
19297 @deftp {Data Type} darkstat-configuration
19298 Data type representing the configuration of @command{darkstat}.
19301 @item @code{package} (default: @code{darkstat})
19302 The darkstat package to use.
19304 @item @code{interface}
19305 Capture traffic on the specified network interface.
19307 @item @code{port} (default: @code{"667"})
19308 Bind the web interface to the specified port.
19310 @item @code{bind-address} (default: @code{"127.0.0.1"})
19311 Bind the web interface to the specified address.
19313 @item @code{base} (default: @code{"/"})
19314 Specify the path of the base URL. This can be useful if
19315 @command{darkstat} is accessed via a reverse proxy.
19320 @subsubheading Prometheus Node Exporter Service
19322 @cindex prometheus-node-exporter
19323 The Prometheus ``node exporter'' makes hardware and operating system statistics
19324 provided by the Linux kernel available for the Prometheus monitoring system.
19325 This service should be deployed on all physical nodes and virtual machines,
19326 where monitoring these statistics is desirable.
19328 @defvar {Scheme variable} prometheus-node-exporter-service-type
19329 This is the service type for the
19330 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
19331 service, its value must be a @code{prometheus-node-exporter-configuration}
19332 record as in this example:
19335 (service prometheus-node-exporter-service-type
19336 (prometheus-node-exporter-configuration
19337 (web-listen-address ":9100")))
19341 @deftp {Data Type} prometheus-node-exporter-configuration
19342 Data type representing the configuration of @command{node_exporter}.
19345 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
19346 The prometheus-node-exporter package to use.
19348 @item @code{web-listen-address} (default: @code{":9100"})
19349 Bind the web interface to the specified address.
19354 @subsubheading Zabbix server
19355 @cindex zabbix zabbix-server
19356 Zabbix provides monitoring metrics, among others network utilization, CPU load
19357 and disk space consumption:
19360 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
19361 @item Auto-discovery of servers and network devices and interfaces.
19362 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
19363 @item Distributed monitoring with centralized web administration.
19364 @item Native high performance agents.
19365 @item SLA, and ITIL KPI metrics on reporting.
19366 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
19367 @item Remote command execution through Zabbix proxies.
19370 @c %start of fragment
19372 Available @code{zabbix-server-configuration} fields are:
19374 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
19375 The zabbix-server package.
19379 @deftypevr {@code{zabbix-server-configuration} parameter} string user
19380 User who will run the Zabbix server.
19382 Defaults to @samp{"zabbix"}.
19386 @deftypevr {@code{zabbix-server-configuration} parameter} group group
19387 Group who will run the Zabbix server.
19389 Defaults to @samp{"zabbix"}.
19393 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
19394 Database host name.
19396 Defaults to @samp{"127.0.0.1"}.
19400 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
19403 Defaults to @samp{"zabbix"}.
19407 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
19410 Defaults to @samp{"zabbix"}.
19414 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
19415 Database password. Please, use @code{include-files} with
19416 @code{DBPassword=SECRET} inside a specified file instead.
19418 Defaults to @samp{""}.
19422 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
19425 Defaults to @samp{5432}.
19429 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
19430 Specifies where log messages are written to:
19434 @code{system} - syslog.
19437 @code{file} - file specified with @code{log-file} parameter.
19440 @code{console} - standard output.
19444 Defaults to @samp{""}.
19448 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
19449 Log file name for @code{log-type} @code{file} parameter.
19451 Defaults to @samp{"/var/log/zabbix/server.log"}.
19455 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
19458 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
19462 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
19463 The location of certificate authority (CA) files for SSL server
19464 certificate verification.
19466 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
19470 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
19471 Location of SSL client certificates.
19473 Defaults to @samp{"/etc/ssl/certs"}.
19477 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
19478 Extra options will be appended to Zabbix server configuration file.
19480 Defaults to @samp{""}.
19484 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
19485 You may include individual files or all files in a directory in the
19486 configuration file.
19488 Defaults to @samp{()}.
19492 @c %end of fragment
19494 @subsubheading Zabbix agent
19495 @cindex zabbix zabbix-agent
19497 Zabbix agent gathers information for Zabbix server.
19499 @c %start of fragment
19501 Available @code{zabbix-agent-configuration} fields are:
19503 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19504 The zabbix-agent package.
19508 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19509 User who will run the Zabbix agent.
19511 Defaults to @samp{"zabbix"}.
19515 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19516 Group who will run the Zabbix agent.
19518 Defaults to @samp{"zabbix"}.
19522 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19523 Unique, case sensitive hostname which is required for active checks and
19524 must match hostname as configured on the server.
19526 Defaults to @samp{"Zabbix server"}.
19530 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19531 Specifies where log messages are written to:
19535 @code{system} - syslog.
19538 @code{file} - file specified with @code{log-file} parameter.
19541 @code{console} - standard output.
19545 Defaults to @samp{""}.
19549 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19550 Log file name for @code{log-type} @code{file} parameter.
19552 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19556 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19559 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19563 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19564 List of IP addresses, optionally in CIDR notation, or hostnames of
19565 Zabbix servers and Zabbix proxies. Incoming connections will be
19566 accepted only from the hosts listed here.
19568 Defaults to @samp{("127.0.0.1")}.
19572 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19573 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19574 proxies for active checks. If port is not specified, default port is
19575 used. If this parameter is not specified, active checks are disabled.
19577 Defaults to @samp{("127.0.0.1")}.
19581 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19582 Extra options will be appended to Zabbix server configuration file.
19584 Defaults to @samp{""}.
19588 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19589 You may include individual files or all files in a directory in the
19590 configuration file.
19592 Defaults to @samp{()}.
19596 @c %end of fragment
19598 @subsubheading Zabbix front-end
19599 @cindex zabbix zabbix-front-end
19601 This service provides a WEB interface to Zabbix server.
19603 @c %start of fragment
19605 Available @code{zabbix-front-end-configuration} fields are:
19607 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19608 NGINX configuration.
19612 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19613 Database host name.
19615 Defaults to @samp{"localhost"}.
19619 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19622 Defaults to @samp{5432}.
19626 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19629 Defaults to @samp{"zabbix"}.
19633 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19636 Defaults to @samp{"zabbix"}.
19640 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19641 Database password. Please, use @code{db-secret-file} instead.
19643 Defaults to @samp{""}.
19647 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19648 Secret file which will be appended to @file{zabbix.conf.php} file. This
19649 file contains credentials for use by Zabbix front-end. You are expected
19650 to create it manually.
19652 Defaults to @samp{""}.
19656 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19657 Zabbix server hostname.
19659 Defaults to @samp{"localhost"}.
19663 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19664 Zabbix server port.
19666 Defaults to @samp{10051}.
19671 @c %end of fragment
19673 @node Kerberos Services
19674 @subsection Kerberos Services
19677 The @code{(gnu services kerberos)} module provides services relating to
19678 the authentication protocol @dfn{Kerberos}.
19680 @subsubheading Krb5 Service
19682 Programs using a Kerberos client library normally
19683 expect a configuration file in @file{/etc/krb5.conf}.
19684 This service generates such a file from a definition provided in the
19685 operating system declaration.
19686 It does not cause any daemon to be started.
19688 No ``keytab'' files are provided by this service---you must explicitly create them.
19689 This service is known to work with the MIT client library, @code{mit-krb5}.
19690 Other implementations have not been tested.
19692 @defvr {Scheme Variable} krb5-service-type
19693 A service type for Kerberos 5 clients.
19697 Here is an example of its use:
19699 (service krb5-service-type
19700 (krb5-configuration
19701 (default-realm "EXAMPLE.COM")
19702 (allow-weak-crypto? #t)
19705 (name "EXAMPLE.COM")
19706 (admin-server "groucho.example.com")
19707 (kdc "karl.example.com"))
19710 (admin-server "kerb-admin.argrx.edu")
19711 (kdc "keys.argrx.edu"))))))
19715 This example provides a Kerberos@tie{}5 client configuration which:
19717 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19718 of which have distinct administration servers and key distribution centers;
19719 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19720 specified by clients;
19721 @item Accepts services which only support encryption types known to be weak.
19724 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19725 Only the most commonly used ones are described here.
19726 For a full list, and more detailed explanation of each, see the MIT
19727 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19731 @deftp {Data Type} krb5-realm
19732 @cindex realm, kerberos
19735 This field is a string identifying the name of the realm.
19736 A common convention is to use the fully qualified DNS name of your organization,
19737 converted to upper case.
19739 @item @code{admin-server}
19740 This field is a string identifying the host where the administration server is
19744 This field is a string identifying the key distribution center
19749 @deftp {Data Type} krb5-configuration
19752 @item @code{allow-weak-crypto?} (default: @code{#f})
19753 If this flag is @code{#t} then services which only offer encryption algorithms
19754 known to be weak will be accepted.
19756 @item @code{default-realm} (default: @code{#f})
19757 This field should be a string identifying the default Kerberos
19758 realm for the client.
19759 You should set this field to the name of your Kerberos realm.
19760 If this value is @code{#f}
19761 then a realm must be specified with every Kerberos principal when invoking programs
19762 such as @command{kinit}.
19764 @item @code{realms}
19765 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19767 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19773 @subsubheading PAM krb5 Service
19776 The @code{pam-krb5} service allows for login authentication and password
19777 management via Kerberos.
19778 You will need this service if you want PAM enabled applications to authenticate
19779 users using Kerberos.
19781 @defvr {Scheme Variable} pam-krb5-service-type
19782 A service type for the Kerberos 5 PAM module.
19785 @deftp {Data Type} pam-krb5-configuration
19786 Data type representing the configuration of the Kerberos 5 PAM module.
19787 This type has the following parameters:
19789 @item @code{pam-krb5} (default: @code{pam-krb5})
19790 The pam-krb5 package to use.
19792 @item @code{minimum-uid} (default: @code{1000})
19793 The smallest user ID for which Kerberos authentications should be attempted.
19794 Local accounts with lower values will silently fail to authenticate.
19799 @node LDAP Services
19800 @subsection LDAP Services
19802 @cindex nslcd, LDAP service
19804 The @code{(gnu services authentication)} module provides the
19805 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19806 server. In addition to configuring the service itself, you may want to add
19807 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19808 Switch} for detailed information.
19810 Here is a simple operating system declaration with a default configuration of
19811 the @code{nslcd-service-type} and a Name Service Switch configuration that
19812 consults the @code{ldap} name service last:
19815 (use-service-modules authentication)
19816 (use-modules (gnu system nss))
19822 (service nslcd-service-type)
19823 (service dhcp-client-service-type)
19825 (name-service-switch
19826 (let ((services (list (name-service (name "db"))
19827 (name-service (name "files"))
19828 (name-service (name "ldap")))))
19829 (name-service-switch
19830 (inherit %mdns-host-lookup-nss)
19831 (password services)
19834 (netgroup services)
19835 (gshadow services)))))
19838 @c %start of generated documentation for nslcd-configuration
19840 Available @code{nslcd-configuration} fields are:
19842 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19843 The @code{nss-pam-ldapd} package to use.
19847 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19848 The number of threads to start that can handle requests and perform LDAP
19849 queries. Each thread opens a separate connection to the LDAP server.
19850 The default is to start 5 threads.
19852 Defaults to @samp{disabled}.
19856 @deftypevr {@code{nslcd-configuration} parameter} string uid
19857 This specifies the user id with which the daemon should be run.
19859 Defaults to @samp{"nslcd"}.
19863 @deftypevr {@code{nslcd-configuration} parameter} string gid
19864 This specifies the group id with which the daemon should be run.
19866 Defaults to @samp{"nslcd"}.
19870 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19871 This option controls the way logging is done via a list containing
19872 SCHEME and LEVEL. The SCHEME argument may either be the symbols
19873 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
19874 argument is optional and specifies the log level. The log level may be
19875 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
19876 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
19877 specified log level or higher are logged.
19879 Defaults to @samp{("/var/log/nslcd" info)}.
19883 @deftypevr {@code{nslcd-configuration} parameter} list uri
19884 The list of LDAP server URIs. Normally, only the first server will be
19885 used with the following servers as fall-back.
19887 Defaults to @samp{("ldap://localhost:389/")}.
19891 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19892 The version of the LDAP protocol to use. The default is to use the
19893 maximum version supported by the LDAP library.
19895 Defaults to @samp{disabled}.
19899 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19900 Specifies the distinguished name with which to bind to the directory
19901 server for lookups. The default is to bind anonymously.
19903 Defaults to @samp{disabled}.
19907 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19908 Specifies the credentials with which to bind. This option is only
19909 applicable when used with binddn.
19911 Defaults to @samp{disabled}.
19915 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19916 Specifies the distinguished name to use when the root user tries to
19917 modify a user's password using the PAM module.
19919 Defaults to @samp{disabled}.
19923 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19924 Specifies the credentials with which to bind if the root user tries to
19925 change a user's password. This option is only applicable when used with
19928 Defaults to @samp{disabled}.
19932 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19933 Specifies the SASL mechanism to be used when performing SASL
19936 Defaults to @samp{disabled}.
19940 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19941 Specifies the SASL realm to be used when performing SASL authentication.
19943 Defaults to @samp{disabled}.
19947 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19948 Specifies the authentication identity to be used when performing SASL
19951 Defaults to @samp{disabled}.
19955 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19956 Specifies the authorization identity to be used when performing SASL
19959 Defaults to @samp{disabled}.
19963 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19964 Determines whether the LDAP server host name should be canonicalised. If
19965 this is enabled the LDAP library will do a reverse host name lookup. By
19966 default, it is left up to the LDAP library whether this check is
19969 Defaults to @samp{disabled}.
19973 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19974 Set the name for the GSS-API Kerberos credentials cache.
19976 Defaults to @samp{disabled}.
19980 @deftypevr {@code{nslcd-configuration} parameter} string base
19981 The directory search base.
19983 Defaults to @samp{"dc=example,dc=com"}.
19987 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19988 Specifies the search scope (subtree, onelevel, base or children). The
19989 default scope is subtree; base scope is almost never useful for name
19990 service lookups; children scope is not supported on all servers.
19992 Defaults to @samp{(subtree)}.
19996 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19997 Specifies the policy for dereferencing aliases. The default policy is
19998 to never dereference aliases.
20000 Defaults to @samp{disabled}.
20004 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
20005 Specifies whether automatic referral chasing should be enabled. The
20006 default behaviour is to chase referrals.
20008 Defaults to @samp{disabled}.
20012 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
20013 This option allows for custom attributes to be looked up instead of the
20014 default RFC 2307 attributes. It is a list of maps, each consisting of
20015 the name of a map, the RFC 2307 attribute to match and the query
20016 expression for the attribute as it is available in the directory.
20018 Defaults to @samp{()}.
20022 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
20023 A list of filters consisting of the name of a map to which the filter
20024 applies and an LDAP search filter expression.
20026 Defaults to @samp{()}.
20030 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
20031 Specifies the time limit in seconds to use when connecting to the
20032 directory server. The default value is 10 seconds.
20034 Defaults to @samp{disabled}.
20038 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
20039 Specifies the time limit (in seconds) to wait for a response from the
20040 LDAP server. A value of zero, which is the default, is to wait
20041 indefinitely for searches to be completed.
20043 Defaults to @samp{disabled}.
20047 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
20048 Specifies the period if inactivity (in seconds) after which the con‐
20049 nection to the LDAP server will be closed. The default is not to time
20052 Defaults to @samp{disabled}.
20056 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
20057 Specifies the number of seconds to sleep when connecting to all LDAP
20058 servers fails. By default one second is waited between the first
20059 failure and the first retry.
20061 Defaults to @samp{disabled}.
20065 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
20066 Specifies the time after which the LDAP server is considered to be
20067 permanently unavailable. Once this time is reached retries will be done
20068 only once per this time period. The default value is 10 seconds.
20070 Defaults to @samp{disabled}.
20074 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
20075 Specifies whether to use SSL/TLS or not (the default is not to). If
20076 'start-tls is specified then StartTLS is used rather than raw LDAP over
20079 Defaults to @samp{disabled}.
20083 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
20084 Specifies what checks to perform on a server-supplied certificate. The
20085 meaning of the values is described in the ldap.conf(5) manual page.
20087 Defaults to @samp{disabled}.
20091 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
20092 Specifies the directory containing X.509 certificates for peer authen‐
20093 tication. This parameter is ignored when using GnuTLS.
20095 Defaults to @samp{disabled}.
20099 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
20100 Specifies the path to the X.509 certificate for peer authentication.
20102 Defaults to @samp{disabled}.
20106 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
20107 Specifies the path to an entropy source. This parameter is ignored when
20110 Defaults to @samp{disabled}.
20114 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
20115 Specifies the ciphers to use for TLS as a string.
20117 Defaults to @samp{disabled}.
20121 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
20122 Specifies the path to the file containing the local certificate for
20123 client TLS authentication.
20125 Defaults to @samp{disabled}.
20129 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
20130 Specifies the path to the file containing the private key for client TLS
20133 Defaults to @samp{disabled}.
20137 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
20138 Set this to a number greater than 0 to request paged results from the
20139 LDAP server in accordance with RFC2696. The default (0) is to not
20140 request paged results.
20142 Defaults to @samp{disabled}.
20146 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
20147 This option prevents group membership lookups through LDAP for the
20148 specified users. Alternatively, the value 'all-local may be used. With
20149 that value nslcd builds a full list of non-LDAP users on startup.
20151 Defaults to @samp{disabled}.
20155 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
20156 This option ensures that LDAP users with a numeric user id lower than
20157 the specified value are ignored.
20159 Defaults to @samp{disabled}.
20163 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
20164 This option specifies an offset that is added to all LDAP numeric user
20165 ids. This can be used to avoid user id collisions with local users.
20167 Defaults to @samp{disabled}.
20171 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
20172 This option specifies an offset that is added to all LDAP numeric group
20173 ids. This can be used to avoid user id collisions with local groups.
20175 Defaults to @samp{disabled}.
20179 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
20180 If this option is set, the member attribute of a group may point to
20181 another group. Members of nested groups are also returned in the higher
20182 level group and parent groups are returned when finding groups for a
20183 specific user. The default is not to perform extra searches for nested
20186 Defaults to @samp{disabled}.
20190 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
20191 If this option is set, the group member list is not retrieved when
20192 looking up groups. Lookups for finding which groups a user belongs to
20193 will remain functional so the user will likely still get the correct
20194 groups assigned on login.
20196 Defaults to @samp{disabled}.
20200 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
20201 If this option is set, functions which cause all user/group entries to
20202 be loaded from the directory will not succeed in doing so. This can
20203 dramatically reduce LDAP server load in situations where there are a
20204 great number of users and/or groups. This option is not recommended for
20205 most configurations.
20207 Defaults to @samp{disabled}.
20211 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
20212 This option can be used to specify how user and group names are verified
20213 within the system. This pattern is used to check all user and group
20214 names that are requested and returned from LDAP.
20216 Defaults to @samp{disabled}.
20220 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
20221 This specifies whether or not to perform searches using case-insensitive
20222 matching. Enabling this could open up the system to authorization
20223 bypass vulnerabilities and introduce nscd cache poisoning
20224 vulnerabilities which allow denial of service.
20226 Defaults to @samp{disabled}.
20230 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
20231 This option specifies whether password policy controls are requested and
20232 handled from the LDAP server when performing user authentication.
20234 Defaults to @samp{disabled}.
20238 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
20239 By default nslcd performs an LDAP search with the user's credentials
20240 after BIND (authentication) to ensure that the BIND operation was
20241 successful. The default search is a simple check to see if the user's
20242 DN exists. A search filter can be specified that will be used instead.
20243 It should return at least one entry.
20245 Defaults to @samp{disabled}.
20249 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
20250 This option allows flexible fine tuning of the authorisation check that
20251 should be performed. The search filter specified is executed and if any
20252 entries match, access is granted, otherwise access is denied.
20254 Defaults to @samp{disabled}.
20258 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
20259 If this option is set password modification using pam_ldap will be
20260 denied and the specified message will be presented to the user instead.
20261 The message can be used to direct the user to an alternative means of
20262 changing their password.
20264 Defaults to @samp{disabled}.
20268 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
20269 List of pam service names for which LDAP authentication should suffice.
20271 Defaults to @samp{()}.
20275 @c %end of generated documentation for nslcd-configuration
20279 @subsection Web Services
20284 The @code{(gnu services web)} module provides the Apache HTTP Server,
20285 the nginx web server, and also a fastcgi wrapper daemon.
20287 @subsubheading Apache HTTP Server
20289 @deffn {Scheme Variable} httpd-service-type
20290 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
20291 (@dfn{httpd}). The value for this service type is a
20292 @code{httpd-configuration} record.
20294 A simple example configuration is given below.
20297 (service httpd-service-type
20298 (httpd-configuration
20301 (server-name "www.example.com")
20302 (document-root "/srv/http/www.example.com")))))
20305 Other services can also extend the @code{httpd-service-type} to add to
20309 (simple-service 'www.example.com-server httpd-service-type
20313 (list (string-join '("ServerName www.example.com"
20314 "DocumentRoot /srv/http/www.example.com")
20319 The details for the @code{httpd-configuration}, @code{httpd-module},
20320 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
20323 @deffn {Data Type} httpd-configuration
20324 This data type represents the configuration for the httpd service.
20327 @item @code{package} (default: @code{httpd})
20328 The httpd package to use.
20330 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20331 The pid file used by the shepherd-service.
20333 @item @code{config} (default: @code{(httpd-config-file)})
20334 The configuration file to use with the httpd service. The default value
20335 is a @code{httpd-config-file} record, but this can also be a different
20336 G-expression that generates a file, for example a @code{plain-file}. A
20337 file outside of the store can also be specified through a string.
20342 @deffn {Data Type} httpd-module
20343 This data type represents a module for the httpd service.
20347 The name of the module.
20350 The file for the module. This can be relative to the httpd package being
20351 used, the absolute location of a file, or a G-expression for a file
20352 within the store, for example @code{(file-append mod-wsgi
20353 "/modules/mod_wsgi.so")}.
20358 @defvr {Scheme Variable} %default-httpd-modules
20359 A default list of @code{httpd-module} objects.
20362 @deffn {Data Type} httpd-config-file
20363 This data type represents a configuration file for the httpd service.
20366 @item @code{modules} (default: @code{%default-httpd-modules})
20367 The modules to load. Additional modules can be added here, or loaded by
20368 additional configuration.
20370 For example, in order to handle requests for PHP files, you can use Apache’s
20371 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
20374 (service httpd-service-type
20375 (httpd-configuration
20380 (name "proxy_module")
20381 (file "modules/mod_proxy.so"))
20383 (name "proxy_fcgi_module")
20384 (file "modules/mod_proxy_fcgi.so"))
20385 %default-httpd-modules))
20386 (extra-config (list "\
20387 <FilesMatch \\.php$>
20388 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
20389 </FilesMatch>"))))))
20390 (service php-fpm-service-type
20391 (php-fpm-configuration
20392 (socket "/var/run/php-fpm.sock")
20393 (socket-group "httpd")))
20396 @item @code{server-root} (default: @code{httpd})
20397 The @code{ServerRoot} in the configuration file, defaults to the httpd
20398 package. Directives including @code{Include} and @code{LoadModule} are
20399 taken as relative to the server root.
20401 @item @code{server-name} (default: @code{#f})
20402 The @code{ServerName} in the configuration file, used to specify the
20403 request scheme, hostname and port that the server uses to identify
20406 This doesn't need to be set in the server config, and can be specified
20407 in virtual hosts. The default is @code{#f} to not specify a
20410 @item @code{document-root} (default: @code{"/srv/http"})
20411 The @code{DocumentRoot} from which files will be served.
20413 @item @code{listen} (default: @code{'("80")})
20414 The list of values for the @code{Listen} directives in the config
20415 file. The value should be a list of strings, when each string can
20416 specify the port number to listen on, and optionally the IP address and
20419 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20420 The @code{PidFile} to use. This should match the @code{pid-file} set in
20421 the @code{httpd-configuration} so that the Shepherd service is
20422 configured correctly.
20424 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
20425 The @code{ErrorLog} to which the server will log errors.
20427 @item @code{user} (default: @code{"httpd"})
20428 The @code{User} which the server will answer requests as.
20430 @item @code{group} (default: @code{"httpd"})
20431 The @code{Group} which the server will answer requests as.
20433 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
20434 A flat list of strings and G-expressions which will be added to the end
20435 of the configuration file.
20437 Any values which the service is extended with will be appended to this
20443 @deffn {Data Type} httpd-virtualhost
20444 This data type represents a virtualhost configuration block for the httpd service.
20446 These should be added to the extra-config for the httpd-service.
20449 (simple-service 'www.example.com-server httpd-service-type
20453 (list (string-join '("ServerName www.example.com"
20454 "DocumentRoot /srv/http/www.example.com")
20459 @item @code{addresses-and-ports}
20460 The addresses and ports for the @code{VirtualHost} directive.
20462 @item @code{contents}
20463 The contents of the @code{VirtualHost} directive, this should be a list
20464 of strings and G-expressions.
20469 @subsubheading NGINX
20471 @deffn {Scheme Variable} nginx-service-type
20472 Service type for the @uref{https://nginx.org/,NGinx} web server. The
20473 value for this service type is a @code{<nginx-configuration>} record.
20475 A simple example configuration is given below.
20478 (service nginx-service-type
20479 (nginx-configuration
20481 (list (nginx-server-configuration
20482 (server-name '("www.example.com"))
20483 (root "/srv/http/www.example.com"))))))
20486 In addition to adding server blocks to the service configuration
20487 directly, this service can be extended by other services to add server
20488 blocks, as in this example:
20491 (simple-service 'my-extra-server nginx-service-type
20492 (list (nginx-server-configuration
20493 (root "/srv/http/extra-website")
20494 (try-files (list "$uri" "$uri/index.html")))))
20498 At startup, @command{nginx} has not yet read its configuration file, so
20499 it uses a default file to log error messages. If it fails to load its
20500 configuration file, that is where error messages are logged. After the
20501 configuration file is loaded, the default error log file changes as per
20502 configuration. In our case, startup error messages can be found in
20503 @file{/var/run/nginx/logs/error.log}, and after configuration in
20504 @file{/var/log/nginx/error.log}. The second location can be changed
20505 with the @var{log-directory} configuration option.
20507 @deffn {Data Type} nginx-configuration
20508 This data type represents the configuration for NGinx. Some
20509 configuration can be done through this and the other provided record
20510 types, or alternatively, a config file can be provided.
20513 @item @code{nginx} (default: @code{nginx})
20514 The nginx package to use.
20516 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20517 The directory to which NGinx will write log files.
20519 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20520 The directory in which NGinx will create a pid file, and write temporary
20523 @item @code{server-blocks} (default: @code{'()})
20524 A list of @dfn{server blocks} to create in the generated configuration
20525 file, the elements should be of type
20526 @code{<nginx-server-configuration>}.
20528 The following example would setup NGinx to serve @code{www.example.com}
20529 from the @code{/srv/http/www.example.com} directory, without using
20532 (service nginx-service-type
20533 (nginx-configuration
20535 (list (nginx-server-configuration
20536 (server-name '("www.example.com"))
20537 (root "/srv/http/www.example.com"))))))
20540 @item @code{upstream-blocks} (default: @code{'()})
20541 A list of @dfn{upstream blocks} to create in the generated configuration
20542 file, the elements should be of type
20543 @code{<nginx-upstream-configuration>}.
20545 Configuring upstreams through the @code{upstream-blocks} can be useful
20546 when combined with @code{locations} in the
20547 @code{<nginx-server-configuration>} records. The following example
20548 creates a server configuration with one location configuration, that
20549 will proxy requests to a upstream configuration, which will handle
20550 requests with two servers.
20555 (nginx-configuration
20557 (list (nginx-server-configuration
20558 (server-name '("www.example.com"))
20559 (root "/srv/http/www.example.com")
20562 (nginx-location-configuration
20564 (body '("proxy_pass http://server-proxy;"))))))))
20566 (list (nginx-upstream-configuration
20567 (name "server-proxy")
20568 (servers (list "server1.example.com"
20569 "server2.example.com")))))))
20572 @item @code{file} (default: @code{#f})
20573 If a configuration @var{file} is provided, this will be used, rather than
20574 generating a configuration file from the provided @code{log-directory},
20575 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20576 proper operation, these arguments should match what is in @var{file} to ensure
20577 that the directories are created when the service is activated.
20579 This can be useful if you have an existing configuration file, or it's
20580 not possible to do what is required through the other parts of the
20581 nginx-configuration record.
20583 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20584 Bucket size for the server names hash tables, defaults to @code{#f} to
20585 use the size of the processors cache line.
20587 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20588 Maximum bucket size for the server names hash tables.
20590 @item @code{modules} (default: @code{'()})
20591 List of nginx dynamic modules to load. This should be a list of file
20592 names of loadable modules, as in this example:
20597 (file-append nginx-accept-language-module "\
20598 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20601 @item @code{global-directives} (default: @code{'((events . ()))})
20602 Association list of global directives for the top level of the nginx
20603 configuration. Values may themselves be association lists.
20607 `((worker_processes . 16)
20609 (events . ((worker_connections . 1024)))))
20612 @item @code{extra-content} (default: @code{""})
20613 Extra content for the @code{http} block. Should be string or a string
20614 valued G-expression.
20619 @deftp {Data Type} nginx-server-configuration
20620 Data type representing the configuration of an nginx server block.
20621 This type has the following parameters:
20624 @item @code{listen} (default: @code{'("80" "443 ssl")})
20625 Each @code{listen} directive sets the address and port for IP, or the
20626 path for a UNIX-domain socket on which the server will accept requests.
20627 Both address and port, or only address or only port can be specified.
20628 An address may also be a hostname, for example:
20631 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20634 @item @code{server-name} (default: @code{(list 'default)})
20635 A list of server names this server represents. @code{'default} represents the
20636 default server for connections matching no other server.
20638 @item @code{root} (default: @code{"/srv/http"})
20639 Root of the website nginx will serve.
20641 @item @code{locations} (default: @code{'()})
20642 A list of @dfn{nginx-location-configuration} or
20643 @dfn{nginx-named-location-configuration} records to use within this
20646 @item @code{index} (default: @code{(list "index.html")})
20647 Index files to look for when clients ask for a directory. If it cannot be found,
20648 Nginx will send the list of files in the directory.
20650 @item @code{try-files} (default: @code{'()})
20651 A list of files whose existence is checked in the specified order.
20652 @code{nginx} will use the first file it finds to process the request.
20654 @item @code{ssl-certificate} (default: @code{#f})
20655 Where to find the certificate for secure connections. Set it to @code{#f} if
20656 you don't have a certificate or you don't want to use HTTPS.
20658 @item @code{ssl-certificate-key} (default: @code{#f})
20659 Where to find the private key for secure connections. Set it to @code{#f} if
20660 you don't have a key or you don't want to use HTTPS.
20662 @item @code{server-tokens?} (default: @code{#f})
20663 Whether the server should add its configuration to response.
20665 @item @code{raw-content} (default: @code{'()})
20666 A list of raw lines added to the server block.
20671 @deftp {Data Type} nginx-upstream-configuration
20672 Data type representing the configuration of an nginx @code{upstream}
20673 block. This type has the following parameters:
20677 Name for this group of servers.
20679 @item @code{servers}
20680 Specify the addresses of the servers in the group. The address can be
20681 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20682 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20683 prefix @samp{unix:}. For addresses using an IP address or domain name,
20684 the default port is 80, and a different port can be specified
20690 @deftp {Data Type} nginx-location-configuration
20691 Data type representing the configuration of an nginx @code{location}
20692 block. This type has the following parameters:
20696 URI which this location block matches.
20698 @anchor{nginx-location-configuration body}
20700 Body of the location block, specified as a list of strings. This can contain
20702 configuration directives. For example, to pass requests to a upstream
20703 server group defined using an @code{nginx-upstream-configuration} block,
20704 the following directive would be specified in the body @samp{(list "proxy_pass
20705 http://upstream-name;")}.
20710 @deftp {Data Type} nginx-named-location-configuration
20711 Data type representing the configuration of an nginx named location
20712 block. Named location blocks are used for request redirection, and not
20713 used for regular request processing. This type has the following
20718 Name to identify this location block.
20721 @xref{nginx-location-configuration body}, as the body for named location
20722 blocks can be used in a similar way to the
20723 @code{nginx-location-configuration body}. One restriction is that the
20724 body of a named location block cannot contain location blocks.
20729 @subsubheading Varnish Cache
20731 Varnish is a fast cache server that sits in between web applications
20732 and end users. It proxies requests from clients and caches the
20733 accessed URLs such that multiple requests for the same resource only
20734 creates one request to the back-end.
20736 @defvr {Scheme Variable} varnish-service-type
20737 Service type for the Varnish daemon.
20740 @deftp {Data Type} varnish-configuration
20741 Data type representing the @code{varnish} service configuration.
20742 This type has the following parameters:
20745 @item @code{package} (default: @code{varnish})
20746 The Varnish package to use.
20748 @item @code{name} (default: @code{"default"})
20749 A name for this Varnish instance. Varnish will create a directory in
20750 @file{/var/varnish/} with this name and keep temporary files there. If
20751 the name starts with a forward slash, it is interpreted as an absolute
20754 Pass the @code{-n} argument to other Varnish programs to connect to the
20755 named instance, e.g.@: @command{varnishncsa -n default}.
20757 @item @code{backend} (default: @code{"localhost:8080"})
20758 The backend to use. This option has no effect if @code{vcl} is set.
20760 @item @code{vcl} (default: #f)
20761 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20762 is @code{#f}, Varnish will proxy @code{backend} using the default
20763 configuration. Otherwise this must be a file-like object with valid
20766 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20767 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
20768 can do something along these lines:
20771 (define %gnu-mirror
20772 (plain-file "gnu.vcl"
20774 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20778 (services (cons (service varnish-service-type
20779 (varnish-configuration
20781 (vcl %gnu-mirror)))
20785 The configuration of an already running Varnish instance can be inspected
20786 and changed using the @command{varnishadm} program.
20788 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20789 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20790 comprehensive documentation on Varnish and its configuration language.
20792 @item @code{listen} (default: @code{'("localhost:80")})
20793 List of addresses Varnish will listen on.
20795 @item @code{storage} (default: @code{'("malloc,128m")})
20796 List of storage backends that will be available in VCL.
20798 @item @code{parameters} (default: @code{'()})
20799 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20801 @item @code{extra-options} (default: @code{'()})
20802 Additional arguments to pass to the @command{varnishd} process.
20807 @subsubheading Patchwork
20809 Patchwork is a patch tracking system. It can collect patches sent to a
20810 mailing list, and display them in a web interface.
20812 @defvr {Scheme Variable} patchwork-service-type
20813 Service type for Patchwork.
20816 The following example is an example of a minimal service for Patchwork, for
20817 the @code{patchwork.example.com} domain.
20820 (service patchwork-service-type
20821 (patchwork-configuration
20822 (domain "patchwork.example.com")
20824 (patchwork-settings-module
20825 (allowed-hosts (list domain))
20826 (default-from-email "patchwork@@patchwork.example.com")))
20827 (getmail-retriever-config
20828 (getmail-retriever-configuration
20829 (type "SimpleIMAPSSLRetriever")
20830 (server "imap.example.com")
20832 (username "patchwork")
20834 (list (file-append coreutils "/bin/cat")
20835 "/etc/getmail-patchwork-imap-password"))
20837 '((mailboxes . ("Patches"))))))))
20841 There are three records for configuring the Patchwork service. The
20842 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20843 within the HTTPD service.
20845 The @code{settings-module} field within the @code{<patchwork-configuration>}
20846 record can be populated with the @code{<patchwork-settings-module>} record,
20847 which describes a settings module that is generated within the Guix store.
20849 For the @code{database-configuration} field within the
20850 @code{<patchwork-settings-module>}, the
20851 @code{<patchwork-database-configuration>} must be used.
20853 @deftp {Data Type} patchwork-configuration
20854 Data type representing the Patchwork service configuration. This type has the
20855 following parameters:
20858 @item @code{patchwork} (default: @code{patchwork})
20859 The Patchwork package to use.
20861 @item @code{domain}
20862 The domain to use for Patchwork, this is used in the HTTPD service virtual
20865 @item @code{settings-module}
20866 The settings module to use for Patchwork. As a Django application, Patchwork
20867 is configured with a Python module containing the settings. This can either be
20868 an instance of the @code{<patchwork-settings-module>} record, any other record
20869 that represents the settings in the store, or a directory outside of the
20872 @item @code{static-path} (default: @code{"/static/"})
20873 The path under which the HTTPD service should serve the static files.
20875 @item @code{getmail-retriever-config}
20876 The getmail-retriever-configuration record value to use with
20877 Patchwork. Getmail will be configured with this value, the messages will be
20878 delivered to Patchwork.
20883 @deftp {Data Type} patchwork-settings-module
20884 Data type representing a settings module for Patchwork. Some of these
20885 settings relate directly to Patchwork, but others relate to Django, the web
20886 framework used by Patchwork, or the Django Rest Framework library. This type
20887 has the following parameters:
20890 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20891 The database connection settings used for Patchwork. See the
20892 @code{<patchwork-database-configuration>} record type for more information.
20894 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20895 Patchwork, as a Django web application uses a secret key for cryptographically
20896 signing values. This file should contain a unique unpredictable value.
20898 If this file does not exist, it will be created and populated with a random
20899 value by the patchwork-setup shepherd service.
20901 This setting relates to Django.
20903 @item @code{allowed-hosts}
20904 A list of valid hosts for this Patchwork service. This should at least include
20905 the domain specified in the @code{<patchwork-configuration>} record.
20907 This is a Django setting.
20909 @item @code{default-from-email}
20910 The email address from which Patchwork should send email by default.
20912 This is a Patchwork setting.
20914 @item @code{static-url} (default: @code{#f})
20915 The URL to use when serving static assets. It can be part of a URL, or a full
20916 URL, but must end in a @code{/}.
20918 If the default value is used, the @code{static-path} value from the
20919 @code{<patchwork-configuration>} record will be used.
20921 This is a Django setting.
20923 @item @code{admins} (default: @code{'()})
20924 Email addresses to send the details of errors that occur. Each value should
20925 be a list containing two elements, the name and then the email address.
20927 This is a Django setting.
20929 @item @code{debug?} (default: @code{#f})
20930 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20931 messages will be shown.
20933 This is a Django setting.
20935 @item @code{enable-rest-api?} (default: @code{#t})
20936 Whether to enable the Patchwork REST API.
20938 This is a Patchwork setting.
20940 @item @code{enable-xmlrpc?} (default: @code{#t})
20941 Whether to enable the XML RPC API.
20943 This is a Patchwork setting.
20945 @item @code{force-https-links?} (default: @code{#t})
20946 Whether to use HTTPS links on Patchwork pages.
20948 This is a Patchwork setting.
20950 @item @code{extra-settings} (default: @code{""})
20951 Extra code to place at the end of the Patchwork settings module.
20956 @deftp {Data Type} patchwork-database-configuration
20957 Data type representing the database configuration for Patchwork.
20960 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20961 The database engine to use.
20963 @item @code{name} (default: @code{"patchwork"})
20964 The name of the database to use.
20966 @item @code{user} (default: @code{"httpd"})
20967 The user to connect to the database as.
20969 @item @code{password} (default: @code{""})
20970 The password to use when connecting to the database.
20972 @item @code{host} (default: @code{""})
20973 The host to make the database connection to.
20975 @item @code{port} (default: @code{""})
20976 The port on which to connect to the database.
20981 @subsubheading Mumi
20983 @cindex Mumi, Debbugs Web interface
20984 @cindex Debbugs, Mumi Web interface
20985 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
20986 Web interface to the Debbugs bug tracker, by default for
20987 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
20988 but it also fetches and indexes mail retrieved from Debbugs.
20990 @defvr {Scheme Variable} mumi-service-type
20991 This is the service type for Mumi.
20994 @deftp {Data Type} mumi-configuration
20995 Data type representing the Mumi service configuration. This type has the
20999 @item @code{mumi} (default: @code{mumi})
21000 The Mumi package to use.
21002 @item @code{mailer?} (default: @code{#true})
21003 Whether to enable or disable the mailer component.
21005 @item @code{mumi-configuration-sender}
21006 The email address used as the sender for comments.
21008 @item @code{mumi-configuration-smtp}
21009 A URI to configure the SMTP settings for Mailutils. This could be
21010 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
21011 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
21012 mailutils, GNU@tie{}Mailutils}.
21018 @subsubheading FastCGI
21021 FastCGI is an interface between the front-end and the back-end of a web
21022 service. It is a somewhat legacy facility; new web services should
21023 generally just talk HTTP between the front-end and the back-end.
21024 However there are a number of back-end services such as PHP or the
21025 optimized HTTP Git repository access that use FastCGI, so we have
21026 support for it in Guix.
21028 To use FastCGI, you configure the front-end web server (e.g., nginx) to
21029 dispatch some subset of its requests to the fastcgi backend, which
21030 listens on a local TCP or UNIX socket. There is an intermediary
21031 @code{fcgiwrap} program that sits between the actual backend process and
21032 the web server. The front-end indicates which backend program to run,
21033 passing that information to the @code{fcgiwrap} process.
21035 @defvr {Scheme Variable} fcgiwrap-service-type
21036 A service type for the @code{fcgiwrap} FastCGI proxy.
21039 @deftp {Data Type} fcgiwrap-configuration
21040 Data type representing the configuration of the @code{fcgiwrap} service.
21041 This type has the following parameters:
21043 @item @code{package} (default: @code{fcgiwrap})
21044 The fcgiwrap package to use.
21046 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
21047 The socket on which the @code{fcgiwrap} process should listen, as a
21048 string. Valid @var{socket} values include
21049 @code{unix:@var{/path/to/unix/socket}},
21050 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
21051 @code{tcp6:[@var{ipv6_addr}]:port}.
21053 @item @code{user} (default: @code{fcgiwrap})
21054 @itemx @code{group} (default: @code{fcgiwrap})
21055 The user and group names, as strings, under which to run the
21056 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
21057 the user asks for the specific user or group names @code{fcgiwrap} that
21058 the corresponding user and/or group is present on the system.
21060 It is possible to configure a FastCGI-backed web service to pass HTTP
21061 authentication information from the front-end to the back-end, and to
21062 allow @code{fcgiwrap} to run the back-end process as a corresponding
21063 local user. To enable this capability on the back-end, run
21064 @code{fcgiwrap} as the @code{root} user and group. Note that this
21065 capability also has to be configured on the front-end as well.
21070 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
21071 with some additional features useful for sites of any size.
21073 These features include:
21075 @item Adaptive process spawning
21076 @item Basic statistics (similar to Apache's mod_status)
21077 @item Advanced process management with graceful stop/start
21078 @item Ability to start workers with different uid/gid/chroot/environment
21079 and different php.ini (replaces safe_mode)
21080 @item Stdout & stderr logging
21081 @item Emergency restart in case of accidental opcode cache destruction
21082 @item Accelerated upload support
21083 @item Support for a "slowlog"
21084 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
21085 a special function to finish request & flush all data while continuing to do
21086 something time-consuming (video converting, stats processing, etc.)
21088 ...@: and much more.
21090 @defvr {Scheme Variable} php-fpm-service-type
21091 A Service type for @code{php-fpm}.
21094 @deftp {Data Type} php-fpm-configuration
21095 Data Type for php-fpm service configuration.
21097 @item @code{php} (default: @code{php})
21098 The php package to use.
21099 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
21100 The address on which to accept FastCGI requests. Valid syntaxes are:
21102 @item @code{"ip.add.re.ss:port"}
21103 Listen on a TCP socket to a specific address on a specific port.
21104 @item @code{"port"}
21105 Listen on a TCP socket to all addresses on a specific port.
21106 @item @code{"/path/to/unix/socket"}
21107 Listen on a unix socket.
21110 @item @code{user} (default: @code{php-fpm})
21111 User who will own the php worker processes.
21112 @item @code{group} (default: @code{php-fpm})
21113 Group of the worker processes.
21114 @item @code{socket-user} (default: @code{php-fpm})
21115 User who can speak to the php-fpm socket.
21116 @item @code{socket-group} (default: @code{nginx})
21117 Group that can speak to the php-fpm socket.
21118 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
21119 The process id of the php-fpm process is written to this file
21120 once the service has started.
21121 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
21122 Log for the php-fpm master process.
21123 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
21124 Detailed settings for the php-fpm process manager.
21127 @item @code{<php-fpm-dynamic-process-manager-configuration>}
21128 @item @code{<php-fpm-static-process-manager-configuration>}
21129 @item @code{<php-fpm-on-demand-process-manager-configuration>}
21131 @item @code{display-errors} (default @code{#f})
21132 Determines whether php errors and warning should be sent to clients
21133 and displayed in their browsers.
21134 This is useful for local php development, but a security risk for public sites,
21135 as error messages can reveal passwords and personal data.
21136 @item @code{timezone} (default @code{#f})
21137 Specifies @code{php_admin_value[date.timezone]} parameter.
21138 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
21139 This file will log the @code{stderr} outputs of php worker processes.
21140 Can be set to @code{#f} to disable logging.
21141 @item @code{file} (default @code{#f})
21142 An optional override of the whole configuration.
21143 You can use the @code{mixed-text-file} function or an absolute filepath for it.
21147 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
21148 Data Type for the @code{dynamic} php-fpm process manager. With the
21149 @code{dynamic} process manager, spare worker processes are kept around
21150 based on it's configured limits.
21152 @item @code{max-children} (default: @code{5})
21153 Maximum of worker processes.
21154 @item @code{start-servers} (default: @code{2})
21155 How many worker processes should be started on start-up.
21156 @item @code{min-spare-servers} (default: @code{1})
21157 How many spare worker processes should be kept around at minimum.
21158 @item @code{max-spare-servers} (default: @code{3})
21159 How many spare worker processes should be kept around at maximum.
21163 @deftp {Data type} php-fpm-static-process-manager-configuration
21164 Data Type for the @code{static} php-fpm process manager. With the
21165 @code{static} process manager, an unchanging number of worker processes
21168 @item @code{max-children} (default: @code{5})
21169 Maximum of worker processes.
21173 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
21174 Data Type for the @code{on-demand} php-fpm process manager. With the
21175 @code{on-demand} process manager, worker processes are only created as
21178 @item @code{max-children} (default: @code{5})
21179 Maximum of worker processes.
21180 @item @code{process-idle-timeout} (default: @code{10})
21181 The time in seconds after which a process with no requests is killed.
21186 @deffn {Scheme Procedure} nginx-php-location @
21187 [#:nginx-package nginx] @
21188 [socket (string-append "/var/run/php" @
21189 (version-major (package-version php)) @
21191 A helper function to quickly add php to an @code{nginx-server-configuration}.
21194 A simple services setup for nginx with php can look like this:
21196 (services (cons* (service dhcp-client-service-type)
21197 (service php-fpm-service-type)
21198 (service nginx-service-type
21199 (nginx-server-configuration
21200 (server-name '("example.com"))
21201 (root "/srv/http/")
21203 (list (nginx-php-location)))
21205 (ssl-certificate #f)
21206 (ssl-certificate-key #f)))
21210 @cindex cat-avatar-generator
21211 The cat avatar generator is a simple service to demonstrate the use of php-fpm
21212 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
21213 the hash of a user's email address.
21215 @deffn {Scheme Procedure} cat-avatar-generator-service @
21216 [#:cache-dir "/var/cache/cat-avatar-generator"] @
21217 [#:package cat-avatar-generator] @
21218 [#:configuration (nginx-server-configuration)]
21219 Returns an nginx-server-configuration that inherits @code{configuration}. It
21220 extends the nginx configuration to add a server block that serves @code{package},
21221 a version of cat-avatar-generator. During execution, cat-avatar-generator will
21222 be able to use @code{cache-dir} as its cache directory.
21225 A simple setup for cat-avatar-generator can look like this:
21227 (services (cons* (cat-avatar-generator-service
21229 (nginx-server-configuration
21230 (server-name '("example.com"))))
21235 @subsubheading Hpcguix-web
21237 @cindex hpcguix-web
21238 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
21239 program is a customizable web interface to browse Guix packages,
21240 initially designed for users of high-performance computing (HPC)
21243 @defvr {Scheme Variable} hpcguix-web-service-type
21244 The service type for @code{hpcguix-web}.
21247 @deftp {Data Type} hpcguix-web-configuration
21248 Data type for the hpcguix-web service configuration.
21252 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
21253 configuration. The main items available in this spec are:
21256 @item @code{title-prefix} (default: @code{"hpcguix | "})
21257 The page title prefix.
21259 @item @code{guix-command} (default: @code{"guix"})
21260 The @command{guix} command.
21262 @item @code{package-filter-proc} (default: @code{(const #t)})
21263 A procedure specifying how to filter packages that are displayed.
21265 @item @code{package-page-extension-proc} (default: @code{(const '())})
21266 Extension package for @code{hpcguix-web}.
21268 @item @code{menu} (default: @code{'()})
21269 Additional entry in page @code{menu}.
21271 @item @code{channels} (default: @code{%default-channels})
21272 List of channels from which the package list is built (@pxref{Channels}).
21274 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
21275 The expiration time, in seconds, after which the package list is rebuilt from
21276 the latest instances of the given channels.
21279 See the hpcguix-web repository for a
21280 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
21283 @item @code{package} (default: @code{hpcguix-web})
21284 The hpcguix-web package to use.
21288 A typical hpcguix-web service declaration looks like this:
21291 (service hpcguix-web-service-type
21292 (hpcguix-web-configuration
21294 #~(define site-config
21295 (hpcweb-configuration
21296 (title-prefix "Guix-HPC - ")
21297 (menu '(("/about" "ABOUT"))))))))
21301 The hpcguix-web service periodically updates the package list it publishes by
21302 pulling channels from Git. To that end, it needs to access X.509 certificates
21303 so that it can authenticate Git servers when communicating over HTTPS, and it
21304 assumes that @file{/etc/ssl/certs} contains those certificates.
21306 Thus, make sure to add @code{nss-certs} or another certificate package to the
21307 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
21308 more information on X.509 certificates.
21311 @node Certificate Services
21312 @subsection Certificate Services
21315 @cindex HTTP, HTTPS
21316 @cindex Let's Encrypt
21317 @cindex TLS certificates
21318 The @code{(gnu services certbot)} module provides a service to
21319 automatically obtain a valid TLS certificate from the Let's Encrypt
21320 certificate authority. These certificates can then be used to serve
21321 content securely over HTTPS or other TLS-based protocols, with the
21322 knowledge that the client will be able to verify the server's
21325 @url{https://letsencrypt.org/, Let's Encrypt} provides the
21326 @code{certbot} tool to automate the certification process. This tool
21327 first securely generates a key on the server. It then makes a request
21328 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
21329 checks that the request originates from the host in question by using a
21330 challenge-response protocol, requiring the server to provide its
21331 response over HTTP. If that protocol completes successfully, the CA
21332 signs the key, resulting in a certificate. That certificate is valid
21333 for a limited period of time, and therefore to continue to provide TLS
21334 services, the server needs to periodically ask the CA to renew its
21337 The certbot service automates this process: the initial key
21338 generation, the initial certification request to the Let's Encrypt
21339 service, the web server challenge/response integration, writing the
21340 certificate to disk, the automated periodic renewals, and the deployment
21341 tasks associated with the renewal (e.g.@: reloading services, copying keys
21342 with different permissions).
21344 Certbot is run twice a day, at a random minute within the hour. It
21345 won't do anything until your certificates are due for renewal or
21346 revoked, but running it regularly would give your service a chance of
21347 staying online in case a Let's Encrypt-initiated revocation happened for
21350 By using this service, you agree to the ACME Subscriber Agreement, which
21351 can be found there:
21352 @url{https://acme-v01.api.letsencrypt.org/directory}.
21354 @defvr {Scheme Variable} certbot-service-type
21355 A service type for the @code{certbot} Let's Encrypt client. Its value
21356 must be a @code{certbot-configuration} record as in this example:
21359 (define %nginx-deploy-hook
21361 "nginx-deploy-hook"
21362 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
21363 (kill pid SIGHUP))))
21365 (service certbot-service-type
21366 (certbot-configuration
21367 (email "foo@@example.net")
21370 (certificate-configuration
21371 (domains '("example.net" "www.example.net"))
21372 (deploy-hook %nginx-deploy-hook))
21373 (certificate-configuration
21374 (domains '("bar.example.net")))))))
21377 See below for details about @code{certbot-configuration}.
21380 @deftp {Data Type} certbot-configuration
21381 Data type representing the configuration of the @code{certbot} service.
21382 This type has the following parameters:
21385 @item @code{package} (default: @code{certbot})
21386 The certbot package to use.
21388 @item @code{webroot} (default: @code{/var/www})
21389 The directory from which to serve the Let's Encrypt challenge/response
21392 @item @code{certificates} (default: @code{()})
21393 A list of @code{certificates-configuration}s for which to generate
21394 certificates and request signatures. Each certificate has a @code{name}
21395 and several @code{domains}.
21398 Mandatory email used for registration, recovery contact, and important
21399 account notifications.
21401 @item @code{server} (default: @code{#f})
21402 Optional URL of ACME server. Setting this overrides certbot's default,
21403 which is the Let's Encrypt server.
21405 @item @code{rsa-key-size} (default: @code{2048})
21406 Size of the RSA key.
21408 @item @code{default-location} (default: @i{see below})
21409 The default @code{nginx-location-configuration}. Because @code{certbot}
21410 needs to be able to serve challenges and responses, it needs to be able
21411 to run a web server. It does so by extending the @code{nginx} web
21412 service with an @code{nginx-server-configuration} listening on the
21413 @var{domains} on port 80, and which has a
21414 @code{nginx-location-configuration} for the @code{/.well-known/} URI
21415 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
21416 these nginx configuration data types.
21418 Requests to other URL paths will be matched by the
21419 @code{default-location}, which if present is added to all
21420 @code{nginx-server-configuration}s.
21422 By default, the @code{default-location} will issue a redirect from
21423 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
21424 you to define what to serve on your site via @code{https}.
21426 Pass @code{#f} to not issue a default location.
21430 @deftp {Data Type} certificate-configuration
21431 Data type representing the configuration of a certificate.
21432 This type has the following parameters:
21435 @item @code{name} (default: @i{see below})
21436 This name is used by Certbot for housekeeping and in file paths; it
21437 doesn't affect the content of the certificate itself. To see
21438 certificate names, run @code{certbot certificates}.
21440 Its default is the first provided domain.
21442 @item @code{domains} (default: @code{()})
21443 The first domain provided will be the subject CN of the certificate, and
21444 all domains will be Subject Alternative Names on the certificate.
21446 @item @code{challenge} (default: @code{#f})
21447 The challenge type that has to be run by certbot. If @code{#f} is specified,
21448 default to the HTTP challenge. If a value is specified, defaults to the
21449 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
21450 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
21451 and gives Let's Encrypt permission to log the public IP address of the
21452 requesting machine.
21454 @item @code{authentication-hook} (default: @code{#f})
21455 Command to be run in a shell once for each certificate challenge to be
21456 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
21457 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
21458 contains the validation string and @code{$CERTBOT_TOKEN} contains the
21459 file name of the resource requested when performing an HTTP-01 challenge.
21461 @item @code{cleanup-hook} (default: @code{#f})
21462 Command to be run in a shell once for each certificate challenge that
21463 have been answered by the @code{auth-hook}. For this command, the shell
21464 variables available in the @code{auth-hook} script are still available, and
21465 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
21466 of the @code{auth-hook} script.
21468 @item @code{deploy-hook} (default: @code{#f})
21469 Command to be run in a shell once for each successfully issued
21470 certificate. For this command, the shell variable
21471 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
21472 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
21473 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
21474 contain a space-delimited list of renewed certificate domains (for
21475 example, @samp{"example.com www.example.com"}.
21480 For each @code{certificate-configuration}, the certificate is saved to
21481 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
21482 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
21484 @subsection DNS Services
21485 @cindex DNS (domain name system)
21486 @cindex domain name system (DNS)
21488 The @code{(gnu services dns)} module provides services related to the
21489 @dfn{domain name system} (DNS). It provides a server service for hosting
21490 an @emph{authoritative} DNS server for multiple zones, slave or master.
21491 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
21492 caching and forwarding DNS server for the LAN, which uses
21493 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
21495 @subsubheading Knot Service
21497 An example configuration of an authoritative server for two zones, one master
21501 (define-zone-entries example.org.zone
21502 ;; Name TTL Class Type Data
21503 ("@@" "" "IN" "A" "127.0.0.1")
21504 ("@@" "" "IN" "NS" "ns")
21505 ("ns" "" "IN" "A" "127.0.0.1"))
21507 (define master-zone
21508 (knot-zone-configuration
21509 (domain "example.org")
21511 (origin "example.org")
21512 (entries example.org.zone)))))
21515 (knot-zone-configuration
21516 (domain "plop.org")
21517 (dnssec-policy "default")
21518 (master (list "plop-master"))))
21520 (define plop-master
21521 (knot-remote-configuration
21523 (address (list "208.76.58.171"))))
21527 (services (cons* (service knot-service-type
21528 (knot-configuration
21529 (remotes (list plop-master))
21530 (zones (list master-zone slave-zone))))
21535 @deffn {Scheme Variable} knot-service-type
21536 This is the type for the Knot DNS server.
21538 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
21539 zones, that is to say domain names you would buy from a registrar. This server
21540 is not a resolver, meaning that it can only resolve names for which it is
21541 authoritative. This server can be configured to serve zones as a master server
21542 or a slave server as a per-zone basis. Slave zones will get their data from
21543 masters, and will serve it as an authoritative server. From the point of view
21544 of a resolver, there is no difference between master and slave.
21546 The following data types are used to configure the Knot DNS server:
21549 @deftp {Data Type} knot-key-configuration
21550 Data type representing a key.
21551 This type has the following parameters:
21554 @item @code{id} (default: @code{""})
21555 An identifier for other configuration fields to refer to this key. IDs must
21556 be unique and must not be empty.
21558 @item @code{algorithm} (default: @code{#f})
21559 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21560 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21561 and @code{'hmac-sha512}.
21563 @item @code{secret} (default: @code{""})
21564 The secret key itself.
21569 @deftp {Data Type} knot-acl-configuration
21570 Data type representing an Access Control List (ACL) configuration.
21571 This type has the following parameters:
21574 @item @code{id} (default: @code{""})
21575 An identifier for ether configuration fields to refer to this key. IDs must be
21576 unique and must not be empty.
21578 @item @code{address} (default: @code{'()})
21579 An ordered list of IP addresses, network subnets, or network ranges represented
21580 with strings. The query must match one of them. Empty value means that
21581 address match is not required.
21583 @item @code{key} (default: @code{'()})
21584 An ordered list of references to keys represented with strings. The string
21585 must match a key ID defined in a @code{knot-key-configuration}. No key means
21586 that a key is not require to match that ACL.
21588 @item @code{action} (default: @code{'()})
21589 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21590 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21591 and @code{'update}.
21593 @item @code{deny?} (default: @code{#f})
21594 When true, the ACL defines restrictions. Listed actions are forbidden. When
21595 false, listed actions are allowed.
21600 @deftp {Data Type} zone-entry
21601 Data type representing a record entry in a zone file.
21602 This type has the following parameters:
21605 @item @code{name} (default: @code{"@@"})
21606 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21607 are relative to the origin of the zone. For example, in the @code{example.org}
21608 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21609 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21610 refers to @code{ns.example.org}.
21612 @item @code{ttl} (default: @code{""})
21613 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21615 @item @code{class} (default: @code{"IN"})
21616 The class of the record. Knot currently supports only @code{"IN"} and
21617 partially @code{"CH"}.
21619 @item @code{type} (default: @code{"A"})
21620 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21621 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21624 @item @code{data} (default: @code{""})
21625 The data contained in the record. For instance an IP address associated with
21626 an A record, or a domain name associated with an NS record. Remember that
21627 domain names are relative to the origin unless they end with a dot.
21632 @deftp {Data Type} zone-file
21633 Data type representing the content of a zone file.
21634 This type has the following parameters:
21637 @item @code{entries} (default: @code{'()})
21638 The list of entries. The SOA record is taken care of, so you don't need to
21639 put it in the list of entries. This list should probably contain an entry
21640 for your primary authoritative DNS server. Other than using a list of entries
21641 directly, you can use @code{define-zone-entries} to define a object containing
21642 the list of entries more easily, that you can later pass to the @code{entries}
21643 field of the @code{zone-file}.
21645 @item @code{origin} (default: @code{""})
21646 The name of your zone. This parameter cannot be empty.
21648 @item @code{ns} (default: @code{"ns"})
21649 The domain of your primary authoritative DNS server. The name is relative to
21650 the origin, unless it ends with a dot. It is mandatory that this primary
21651 DNS server corresponds to an NS record in the zone and that it is associated
21652 to an IP address in the list of entries.
21654 @item @code{mail} (default: @code{"hostmaster"})
21655 An email address people can contact you at, as the owner of the zone. This
21656 is translated as @code{<mail>@@<origin>}.
21658 @item @code{serial} (default: @code{1})
21659 The serial number of the zone. As this is used to keep track of changes by
21660 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21661 Always increment it when you make a change in your zone.
21663 @item @code{refresh} (default: @code{(* 2 24 3600)})
21664 The frequency at which slaves will do a zone transfer. This value is a number
21665 of seconds. It can be computed by multiplications or with
21666 @code{(string->duration)}.
21668 @item @code{retry} (default: @code{(* 15 60)})
21669 The period after which a slave will retry to contact its master when it fails
21670 to do so a first time.
21672 @item @code{expiry} (default: @code{(* 14 24 3600)})
21673 Default TTL of records. Existing records are considered correct for at most
21674 this amount of time. After this period, resolvers will invalidate their cache
21675 and check again that it still exists.
21677 @item @code{nx} (default: @code{3600})
21678 Default TTL of inexistant records. This delay is usually short because you want
21679 your new domains to reach everyone quickly.
21684 @deftp {Data Type} knot-remote-configuration
21685 Data type representing a remote configuration.
21686 This type has the following parameters:
21689 @item @code{id} (default: @code{""})
21690 An identifier for other configuration fields to refer to this remote. IDs must
21691 be unique and must not be empty.
21693 @item @code{address} (default: @code{'()})
21694 An ordered list of destination IP addresses. Addresses are tried in sequence.
21695 An optional port can be given with the @@ separator. For instance:
21696 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21698 @item @code{via} (default: @code{'()})
21699 An ordered list of source IP addresses. An empty list will have Knot choose
21700 an appropriate source IP. An optional port can be given with the @@ separator.
21701 The default is to choose at random.
21703 @item @code{key} (default: @code{#f})
21704 A reference to a key, that is a string containing the identifier of a key
21705 defined in a @code{knot-key-configuration} field.
21710 @deftp {Data Type} knot-keystore-configuration
21711 Data type representing a keystore to hold dnssec keys.
21712 This type has the following parameters:
21715 @item @code{id} (default: @code{""})
21716 The id of the keystore. It must not be empty.
21718 @item @code{backend} (default: @code{'pem})
21719 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21721 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21722 The configuration string of the backend. An example for the PKCS#11 is:
21723 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21724 For the pem backend, the string represents a path in the file system.
21729 @deftp {Data Type} knot-policy-configuration
21730 Data type representing a dnssec policy. Knot DNS is able to automatically
21731 sign your zones. It can either generate and manage your keys automatically or
21732 use keys that you generate.
21734 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21735 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21736 zone. In order to be trusted, the KSK needs to be present in the parent zone
21737 (usually a top-level domain). If your registrar supports dnssec, you will
21738 have to send them your KSK's hash so they can add a DS record in their zone.
21739 This is not automated and need to be done each time you change your KSK.
21741 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21742 easily and use weaker cryptographic functions (they use lower parameters) in
21743 order to sign records quickly, so they are changed often. The KSK however
21744 requires manual interaction with the registrar, so they are changed less often
21745 and use stronger parameters because they sign only one record.
21747 This type has the following parameters:
21750 @item @code{id} (default: @code{""})
21751 The id of the policy. It must not be empty.
21753 @item @code{keystore} (default: @code{"default"})
21754 A reference to a keystore, that is a string containing the identifier of a
21755 keystore defined in a @code{knot-keystore-configuration} field. The
21756 @code{"default"} identifier means the default keystore (a kasp database that
21757 was setup by this service).
21759 @item @code{manual?} (default: @code{#f})
21760 Whether the key management is manual or automatic.
21762 @item @code{single-type-signing?} (default: @code{#f})
21763 When @code{#t}, use the Single-Type Signing Scheme.
21765 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21766 An algorithm of signing keys and issued signatures.
21768 @item @code{ksk-size} (default: @code{256})
21769 The length of the KSK. Note that this value is correct for the default
21770 algorithm, but would be unsecure for other algorithms.
21772 @item @code{zsk-size} (default: @code{256})
21773 The length of the ZSK. Note that this value is correct for the default
21774 algorithm, but would be unsecure for other algorithms.
21776 @item @code{dnskey-ttl} (default: @code{'default})
21777 The TTL value for DNSKEY records added into zone apex. The special
21778 @code{'default} value means same as the zone SOA TTL.
21780 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21781 The period between ZSK publication and the next rollover initiation.
21783 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21784 An extra delay added for each key rollover step. This value should be high
21785 enough to cover propagation of data from the master server to all slaves.
21787 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21788 A validity period of newly issued signatures.
21790 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21791 A period how long before a signature expiration the signature will be refreshed.
21793 @item @code{nsec3?} (default: @code{#f})
21794 When @code{#t}, NSEC3 will be used instead of NSEC.
21796 @item @code{nsec3-iterations} (default: @code{5})
21797 The number of additional times the hashing is performed.
21799 @item @code{nsec3-salt-length} (default: @code{8})
21800 The length of a salt field in octets, which is appended to the original owner
21801 name before hashing.
21803 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21804 The validity period of newly issued salt field.
21809 @deftp {Data Type} knot-zone-configuration
21810 Data type representing a zone served by Knot.
21811 This type has the following parameters:
21814 @item @code{domain} (default: @code{""})
21815 The domain served by this configuration. It must not be empty.
21817 @item @code{file} (default: @code{""})
21818 The file where this zone is saved. This parameter is ignored by master zones.
21819 Empty means default location that depends on the domain name.
21821 @item @code{zone} (default: @code{(zone-file)})
21822 The content of the zone file. This parameter is ignored by slave zones. It
21823 must contain a zone-file record.
21825 @item @code{master} (default: @code{'()})
21826 A list of master remotes. When empty, this zone is a master. When set, this
21827 zone is a slave. This is a list of remotes identifiers.
21829 @item @code{ddns-master} (default: @code{#f})
21830 The main master. When empty, it defaults to the first master in the list of
21833 @item @code{notify} (default: @code{'()})
21834 A list of slave remote identifiers.
21836 @item @code{acl} (default: @code{'()})
21837 A list of acl identifiers.
21839 @item @code{semantic-checks?} (default: @code{#f})
21840 When set, this adds more semantic checks to the zone.
21842 @item @code{disable-any?} (default: @code{#f})
21843 When set, this forbids queries of the ANY type.
21845 @item @code{zonefile-sync} (default: @code{0})
21846 The delay between a modification in memory and on disk. 0 means immediate
21849 @item @code{zonefile-load} (default: @code{#f})
21850 The way the zone file contents are applied during zone load. Possible values
21854 @item @code{#f} for using the default value from Knot,
21855 @item @code{'none} for not using the zone file at all,
21856 @item @code{'difference} for computing the difference between already available
21857 contents and zone contents and applying it to the current zone contents,
21858 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21859 ignoring the SOA serial in the zone file, while the server takes care of it
21861 @item @code{'whole} for loading zone contents from the zone file.
21864 @item @code{journal-content} (default: @code{#f})
21865 The way the journal is used to store zone and its changes. Possible values
21866 are @code{'none} to not use it at all, @code{'changes} to store changes and
21867 @code{'all} to store contents. @code{#f} does not set this option, so the
21868 default value from Knot is used.
21870 @item @code{max-journal-usage} (default: @code{#f})
21871 The maximum size for the journal on disk. @code{#f} does not set this option,
21872 so the default value from Knot is used.
21874 @item @code{max-journal-depth} (default: @code{#f})
21875 The maximum size of the history. @code{#f} does not set this option, so the
21876 default value from Knot is used.
21878 @item @code{max-zone-size} (default: @code{#f})
21879 The maximum size of the zone file. This limit is enforced for incoming
21880 transfer and updates. @code{#f} does not set this option, so the default
21881 value from Knot is used.
21883 @item @code{dnssec-policy} (default: @code{#f})
21884 A reference to a @code{knot-policy-configuration} record, or the special
21885 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21888 @item @code{serial-policy} (default: @code{'increment})
21889 A policy between @code{'increment} and @code{'unixtime}.
21894 @deftp {Data Type} knot-configuration
21895 Data type representing the Knot configuration.
21896 This type has the following parameters:
21899 @item @code{knot} (default: @code{knot})
21902 @item @code{run-directory} (default: @code{"/var/run/knot"})
21903 The run directory. This directory will be used for pid file and sockets.
21905 @item @code{includes} (default: @code{'()})
21906 A list of strings or file-like objects denoting other files that must be
21907 included at the top of the configuration file.
21909 @cindex secrets, Knot service
21910 This can be used to manage secrets out-of-band. For example, secret
21911 keys may be stored in an out-of-band file not managed by Guix, and
21912 thus not visible in @file{/gnu/store}---e.g., you could store secret
21913 key configuration in @file{/etc/knot/secrets.conf} and add this file
21914 to the @code{includes} list.
21916 One can generate a secret tsig key (for nsupdate and zone transfers with the
21917 keymgr command from the knot package. Note that the package is not automatically
21918 installed by the service. The following example shows how to generate a new
21922 keymgr -t mysecret > /etc/knot/secrets.conf
21923 chmod 600 /etc/knot/secrets.conf
21926 Also note that the generated key will be named @var{mysecret}, so it is the
21927 name that needs to be used in the @var{key} field of the
21928 @code{knot-acl-configuration} record and in other places that need to refer
21931 It can also be used to add configuration not supported by this interface.
21933 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21934 An ip address on which to listen.
21936 @item @code{listen-v6} (default: @code{"::"})
21937 An ip address on which to listen.
21939 @item @code{listen-port} (default: @code{53})
21940 A port on which to listen.
21942 @item @code{keys} (default: @code{'()})
21943 The list of knot-key-configuration used by this configuration.
21945 @item @code{acls} (default: @code{'()})
21946 The list of knot-acl-configuration used by this configuration.
21948 @item @code{remotes} (default: @code{'()})
21949 The list of knot-remote-configuration used by this configuration.
21951 @item @code{zones} (default: @code{'()})
21952 The list of knot-zone-configuration used by this configuration.
21957 @subsubheading Knot Resolver Service
21959 @deffn {Scheme Variable} knot-resolver-service-type
21960 This this the type of the knot resolver service, whose value should be
21961 an @code{knot-resolver-configuration} object as in this example:
21964 (service knot-resolver-service-type
21965 (knot-resolver-configuration
21966 (kresd-config-file (plain-file "kresd.conf" "
21967 net.listen('192.168.0.1', 5353)
21968 user('knot-resolver', 'knot-resolver')
21969 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21970 cache.size = 100 * MB
21974 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21977 @deftp {Data Type} knot-resolver-configuration
21978 Data type representing the configuration of knot-resolver.
21981 @item @code{package} (default: @var{knot-resolver})
21982 Package object of the knot DNS resolver.
21984 @item @code{kresd-config-file} (default: %kresd.conf)
21985 File-like object of the kresd configuration file to use, by default it
21986 will listen on @code{127.0.0.1} and @code{::1}.
21988 @item @code{garbage-collection-interval} (default: 1000)
21989 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21995 @subsubheading Dnsmasq Service
21997 @deffn {Scheme Variable} dnsmasq-service-type
21998 This is the type of the dnsmasq service, whose value should be an
21999 @code{dnsmasq-configuration} object as in this example:
22002 (service dnsmasq-service-type
22003 (dnsmasq-configuration
22005 (servers '("192.168.1.1"))))
22009 @deftp {Data Type} dnsmasq-configuration
22010 Data type representing the configuration of dnsmasq.
22013 @item @code{package} (default: @var{dnsmasq})
22014 Package object of the dnsmasq server.
22016 @item @code{no-hosts?} (default: @code{#f})
22017 When true, don't read the hostnames in /etc/hosts.
22019 @item @code{port} (default: @code{53})
22020 The port to listen on. Setting this to zero completely disables DNS
22021 responses, leaving only DHCP and/or TFTP functions.
22023 @item @code{local-service?} (default: @code{#t})
22024 Accept DNS queries only from hosts whose address is on a local subnet,
22025 ie a subnet for which an interface exists on the server.
22027 @item @code{listen-addresses} (default: @code{'()})
22028 Listen on the given IP addresses.
22030 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
22031 The file to read the IP address of the upstream nameservers from.
22033 @item @code{no-resolv?} (default: @code{#f})
22034 When true, don't read @var{resolv-file}.
22036 @item @code{servers} (default: @code{'()})
22037 Specify IP address of upstream servers directly.
22039 @item @code{addresses} (default: @code{'()})
22040 For each entry, specify an IP address to return for any host in the
22041 given domains. Queries in the domains are never forwarded and always
22042 replied to with the specified IP address.
22044 This is useful for redirecting hosts locally, for example:
22047 (service dnsmasq-service-type
22048 (dnsmasq-configuration
22050 '(; Redirect to a local web-server.
22051 "/example.org/127.0.0.1"
22052 ; Redirect subdomain to a specific IP.
22053 "/subdomain.example.org/192.168.1.42"))))
22056 Note that rules in @file{/etc/hosts} take precedence over this.
22058 @item @code{cache-size} (default: @code{150})
22059 Set the size of dnsmasq's cache. Setting the cache size to zero
22062 @item @code{negative-cache?} (default: @code{#t})
22063 When false, disable negative caching.
22068 @subsubheading ddclient Service
22071 The ddclient service described below runs the ddclient daemon, which takes
22072 care of automatically updating DNS entries for service providers such as
22073 @uref{https://dyn.com/dns/, Dyn}.
22075 The following example show instantiates the service with its default
22079 (service ddclient-service-type)
22082 Note that ddclient needs to access credentials that are stored in a
22083 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
22084 @code{secret-file} below.) You are expected to create this file manually, in
22085 an ``out-of-band'' fashion (you @emph{could} make this file part of the
22086 service configuration, for instance by using @code{plain-file}, but it will be
22087 world-readable @i{via} @file{/gnu/store}.) See the examples in the
22088 @file{share/ddclient} directory of the @code{ddclient} package.
22090 @c %start of fragment
22092 Available @code{ddclient-configuration} fields are:
22094 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
22095 The ddclient package.
22099 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
22100 The period after which ddclient will retry to check IP and domain name.
22102 Defaults to @samp{300}.
22106 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
22107 Use syslog for the output.
22109 Defaults to @samp{#t}.
22113 @deftypevr {@code{ddclient-configuration} parameter} string mail
22116 Defaults to @samp{"root"}.
22120 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
22121 Mail failed update to user.
22123 Defaults to @samp{"root"}.
22127 @deftypevr {@code{ddclient-configuration} parameter} string pid
22128 The ddclient PID file.
22130 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
22134 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
22135 Enable SSL support.
22137 Defaults to @samp{#t}.
22141 @deftypevr {@code{ddclient-configuration} parameter} string user
22142 Specifies the user name or ID that is used when running ddclient
22145 Defaults to @samp{"ddclient"}.
22149 @deftypevr {@code{ddclient-configuration} parameter} string group
22150 Group of the user who will run the ddclient program.
22152 Defaults to @samp{"ddclient"}.
22156 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
22157 Secret file which will be appended to @file{ddclient.conf} file. This
22158 file contains credentials for use by ddclient. You are expected to
22159 create it manually.
22161 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
22165 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
22166 Extra options will be appended to @file{ddclient.conf} file.
22168 Defaults to @samp{()}.
22173 @c %end of fragment
22177 @subsection VPN Services
22178 @cindex VPN (virtual private network)
22179 @cindex virtual private network (VPN)
22181 The @code{(gnu services vpn)} module provides services related to
22182 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
22183 your machine to connect to a VPN, and a @emph{server} service for your machine
22184 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
22186 @deffn {Scheme Procedure} openvpn-client-service @
22187 [#:config (openvpn-client-configuration)]
22189 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
22192 @deffn {Scheme Procedure} openvpn-server-service @
22193 [#:config (openvpn-server-configuration)]
22195 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
22197 Both can be run simultaneously.
22200 @c %automatically generated documentation
22202 Available @code{openvpn-client-configuration} fields are:
22204 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
22205 The OpenVPN package.
22209 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
22210 The OpenVPN pid file.
22212 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22216 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
22217 The protocol (UDP or TCP) used to open a channel between clients and
22220 Defaults to @samp{udp}.
22224 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
22225 The device type used to represent the VPN connection.
22227 Defaults to @samp{tun}.
22231 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
22232 The certificate authority to check connections against.
22234 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22238 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
22239 The certificate of the machine the daemon is running on. It should be
22240 signed by the authority given in @code{ca}.
22242 Defaults to @samp{"/etc/openvpn/client.crt"}.
22246 @deftypevr {@code{openvpn-client-configuration} parameter} string key
22247 The key of the machine the daemon is running on. It must be the key whose
22248 certificate is @code{cert}.
22250 Defaults to @samp{"/etc/openvpn/client.key"}.
22254 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
22255 Whether to use the lzo compression algorithm.
22257 Defaults to @samp{#t}.
22261 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
22262 Don't re-read key files across SIGUSR1 or --ping-restart.
22264 Defaults to @samp{#t}.
22268 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
22269 Don't close and reopen TUN/TAP device or run up/down scripts across
22270 SIGUSR1 or --ping-restart restarts.
22272 Defaults to @samp{#t}.
22276 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
22277 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22278 poll/epoll/select prior to the write operation.
22280 Defaults to @samp{#f}.
22283 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
22286 Defaults to @samp{3}.
22290 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
22291 Add an additional layer of HMAC authentication on top of the TLS control
22292 channel to protect against DoS attacks.
22294 Defaults to @samp{#f}.
22298 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
22299 Authenticate with server using username/password. The option is a file
22300 containing username/password on 2 lines. Do not use a file-like object as it
22301 would be added to the store and readable by any user.
22303 Defaults to @samp{'disabled}.
22306 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
22307 Whether to check the server certificate has server usage extension.
22309 Defaults to @samp{#t}.
22313 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
22314 Bind to a specific local port number.
22316 Defaults to @samp{#f}.
22320 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
22321 Retry resolving server address.
22323 Defaults to @samp{#t}.
22327 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
22328 A list of remote servers to connect to.
22330 Defaults to @samp{()}.
22332 Available @code{openvpn-remote-configuration} fields are:
22334 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
22337 Defaults to @samp{"my-server"}.
22341 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
22342 Port number the server listens to.
22344 Defaults to @samp{1194}.
22349 @c %end of automatic openvpn-client documentation
22351 @c %automatically generated documentation
22353 Available @code{openvpn-server-configuration} fields are:
22355 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
22356 The OpenVPN package.
22360 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
22361 The OpenVPN pid file.
22363 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22367 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
22368 The protocol (UDP or TCP) used to open a channel between clients and
22371 Defaults to @samp{udp}.
22375 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
22376 The device type used to represent the VPN connection.
22378 Defaults to @samp{tun}.
22382 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
22383 The certificate authority to check connections against.
22385 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22389 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
22390 The certificate of the machine the daemon is running on. It should be
22391 signed by the authority given in @code{ca}.
22393 Defaults to @samp{"/etc/openvpn/client.crt"}.
22397 @deftypevr {@code{openvpn-server-configuration} parameter} string key
22398 The key of the machine the daemon is running on. It must be the key whose
22399 certificate is @code{cert}.
22401 Defaults to @samp{"/etc/openvpn/client.key"}.
22405 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
22406 Whether to use the lzo compression algorithm.
22408 Defaults to @samp{#t}.
22412 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
22413 Don't re-read key files across SIGUSR1 or --ping-restart.
22415 Defaults to @samp{#t}.
22419 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
22420 Don't close and reopen TUN/TAP device or run up/down scripts across
22421 SIGUSR1 or --ping-restart restarts.
22423 Defaults to @samp{#t}.
22427 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
22428 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22429 poll/epoll/select prior to the write operation.
22431 Defaults to @samp{#f}.
22434 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
22437 Defaults to @samp{3}.
22441 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
22442 Add an additional layer of HMAC authentication on top of the TLS control
22443 channel to protect against DoS attacks.
22445 Defaults to @samp{#f}.
22449 @deftypevr {@code{openvpn-server-configuration} parameter} number port
22450 Specifies the port number on which the server listens.
22452 Defaults to @samp{1194}.
22456 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
22457 An ip and mask specifying the subnet inside the virtual network.
22459 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
22463 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
22464 A CIDR notation specifying the IPv6 subnet inside the virtual network.
22466 Defaults to @samp{#f}.
22470 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
22471 The Diffie-Hellman parameters file.
22473 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
22477 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
22478 The file that records client IPs.
22480 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
22484 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
22485 When true, the server will act as a gateway for its clients.
22487 Defaults to @samp{#f}.
22491 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
22492 When true, clients are allowed to talk to each other inside the VPN.
22494 Defaults to @samp{#f}.
22498 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
22499 Causes ping-like messages to be sent back and forth over the link so
22500 that each side knows when the other side has gone down. @code{keepalive}
22501 requires a pair. The first element is the period of the ping sending,
22502 and the second element is the timeout before considering the other side
22507 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
22508 The maximum number of clients.
22510 Defaults to @samp{100}.
22514 @deftypevr {@code{openvpn-server-configuration} parameter} string status
22515 The status file. This file shows a small report on current connection.
22516 It is truncated and rewritten every minute.
22518 Defaults to @samp{"/var/run/openvpn/status"}.
22522 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
22523 The list of configuration for some clients.
22525 Defaults to @samp{()}.
22527 Available @code{openvpn-ccd-configuration} fields are:
22529 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
22532 Defaults to @samp{"client"}.
22536 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
22539 Defaults to @samp{#f}.
22543 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
22546 Defaults to @samp{#f}.
22553 @c %end of automatic openvpn-server documentation
22556 @node Network File System
22557 @subsection Network File System
22560 The @code{(gnu services nfs)} module provides the following services,
22561 which are most commonly used in relation to mounting or exporting
22562 directory trees as @dfn{network file systems} (NFS).
22564 While it is possible to use the individual components that together make
22565 up a Network File System service, we recommended to configure an NFS
22566 server with the @code{nfs-service-type}.
22568 @subsubheading NFS Service
22569 @cindex NFS, server
22571 The NFS service takes care of setting up all NFS component services,
22572 kernel configuration file systems, and installs configuration files in
22573 the locations that NFS expects.
22575 @defvr {Scheme Variable} nfs-service-type
22576 A service type for a complete NFS server.
22579 @deftp {Data Type} nfs-configuration
22580 This data type represents the configuration of the NFS service and all
22583 It has the following parameters:
22585 @item @code{nfs-utils} (default: @code{nfs-utils})
22586 The nfs-utils package to use.
22588 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
22589 If a list of string values is provided, the @command{rpc.nfsd} daemon
22590 will be limited to supporting the given versions of the NFS protocol.
22592 @item @code{exports} (default: @code{'()})
22593 This is a list of directories the NFS server should export. Each entry
22594 is a list consisting of two elements: a directory name and a string
22595 containing all options. This is an example in which the directory
22596 @file{/export} is served to all NFS clients as a read-only share:
22602 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22605 @item @code{rpcmountd-port} (default: @code{#f})
22606 The network port that the @command{rpc.mountd} daemon should use.
22608 @item @code{rpcstatd-port} (default: @code{#f})
22609 The network port that the @command{rpc.statd} daemon should use.
22611 @item @code{rpcbind} (default: @code{rpcbind})
22612 The rpcbind package to use.
22614 @item @code{idmap-domain} (default: @code{"localdomain"})
22615 The local NFSv4 domain name.
22617 @item @code{nfsd-port} (default: @code{2049})
22618 The network port that the @command{nfsd} daemon should use.
22620 @item @code{nfsd-threads} (default: @code{8})
22621 The number of threads used by the @command{nfsd} daemon.
22623 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22624 The directory where the pipefs file system is mounted.
22626 @item @code{debug} (default: @code{'()"})
22627 A list of subsystems for which debugging output should be enabled. This
22628 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22629 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22633 If you don't need a complete NFS service or prefer to build it yourself
22634 you can use the individual component services that are documented below.
22636 @subsubheading RPC Bind Service
22639 The RPC Bind service provides a facility to map program numbers into
22640 universal addresses.
22641 Many NFS related services use this facility. Hence it is automatically
22642 started when a dependent service starts.
22644 @defvr {Scheme Variable} rpcbind-service-type
22645 A service type for the RPC portmapper daemon.
22649 @deftp {Data Type} rpcbind-configuration
22650 Data type representing the configuration of the RPC Bind Service.
22651 This type has the following parameters:
22653 @item @code{rpcbind} (default: @code{rpcbind})
22654 The rpcbind package to use.
22656 @item @code{warm-start?} (default: @code{#t})
22657 If this parameter is @code{#t}, then the daemon will read a
22658 state file on startup thus reloading state information saved by a previous
22664 @subsubheading Pipefs Pseudo File System
22668 The pipefs file system is used to transfer NFS related data
22669 between the kernel and user space programs.
22671 @defvr {Scheme Variable} pipefs-service-type
22672 A service type for the pipefs pseudo file system.
22675 @deftp {Data Type} pipefs-configuration
22676 Data type representing the configuration of the pipefs pseudo file system service.
22677 This type has the following parameters:
22679 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22680 The directory to which the file system is to be attached.
22685 @subsubheading GSS Daemon Service
22688 @cindex global security system
22690 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22692 Before exchanging RPC requests an RPC client must establish a security
22693 context. Typically this is done using the Kerberos command @command{kinit}
22694 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22696 @defvr {Scheme Variable} gss-service-type
22697 A service type for the Global Security System (GSS) daemon.
22700 @deftp {Data Type} gss-configuration
22701 Data type representing the configuration of the GSS daemon service.
22702 This type has the following parameters:
22704 @item @code{nfs-utils} (default: @code{nfs-utils})
22705 The package in which the @command{rpc.gssd} command is to be found.
22707 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22708 The directory where the pipefs file system is mounted.
22714 @subsubheading IDMAP Daemon Service
22716 @cindex name mapper
22718 The idmap daemon service provides mapping between user IDs and user names.
22719 Typically it is required in order to access file systems mounted via NFSv4.
22721 @defvr {Scheme Variable} idmap-service-type
22722 A service type for the Identity Mapper (IDMAP) daemon.
22725 @deftp {Data Type} idmap-configuration
22726 Data type representing the configuration of the IDMAP daemon service.
22727 This type has the following parameters:
22729 @item @code{nfs-utils} (default: @code{nfs-utils})
22730 The package in which the @command{rpc.idmapd} command is to be found.
22732 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22733 The directory where the pipefs file system is mounted.
22735 @item @code{domain} (default: @code{#f})
22736 The local NFSv4 domain name.
22737 This must be a string or @code{#f}.
22738 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22740 @item @code{verbosity} (default: @code{0})
22741 The verbosity level of the daemon.
22746 @node Continuous Integration
22747 @subsection Continuous Integration
22749 @cindex continuous integration
22750 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22751 continuous integration tool for Guix. It can be used both for development and
22752 for providing substitutes to others (@pxref{Substitutes}).
22754 The @code{(gnu services cuirass)} module provides the following service.
22756 @defvr {Scheme Procedure} cuirass-service-type
22757 The type of the Cuirass service. Its value must be a
22758 @code{cuirass-configuration} object, as described below.
22761 To add build jobs, you have to set the @code{specifications} field of the
22762 configuration. Here is an example of a service that polls the Guix repository
22763 and builds the packages from a manifest. Some of the packages are defined in
22764 the @code{"custom-packages"} input, which is the equivalent of
22765 @env{GUIX_PACKAGE_PATH}.
22768 (define %cuirass-specs
22770 '((#:name . "my-manifest")
22771 (#:load-path-inputs . ("guix"))
22772 (#:package-path-inputs . ("custom-packages"))
22773 (#:proc-input . "guix")
22774 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22775 (#:proc . cuirass-jobs)
22776 (#:proc-args . ((subset . "manifests")
22777 (systems . ("x86_64-linux"))
22778 (manifests . (("config" . "guix/manifest.scm")))))
22779 (#:inputs . (((#:name . "guix")
22780 (#:url . "git://git.savannah.gnu.org/guix.git")
22781 (#:load-path . ".")
22782 (#:branch . "master")
22783 (#:no-compile? . #t))
22784 ((#:name . "config")
22785 (#:url . "https://git.example.org/config.git")
22786 (#:load-path . ".")
22787 (#:branch . "master")
22788 (#:no-compile? . #t))
22789 ((#:name . "custom-packages")
22790 (#:url . "https://git.example.org/custom-packages.git")
22791 (#:load-path . ".")
22792 (#:branch . "master")
22793 (#:no-compile? . #t)))))))
22795 (service cuirass-service-type
22796 (cuirass-configuration
22797 (specifications %cuirass-specs)))
22800 While information related to build jobs is located directly in the
22801 specifications, global settings for the @command{cuirass} process are
22802 accessible in other @code{cuirass-configuration} fields.
22804 @deftp {Data Type} cuirass-configuration
22805 Data type representing the configuration of Cuirass.
22808 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22809 Location of the log file.
22811 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22812 Location of the log file used by the web interface.
22814 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22815 Location of the repository cache.
22817 @item @code{user} (default: @code{"cuirass"})
22818 Owner of the @code{cuirass} process.
22820 @item @code{group} (default: @code{"cuirass"})
22821 Owner's group of the @code{cuirass} process.
22823 @item @code{interval} (default: @code{60})
22824 Number of seconds between the poll of the repositories followed by the
22827 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22828 Location of sqlite database which contains the build results and previously
22829 added specifications.
22831 @item @code{ttl} (default: @code{(* 30 24 3600)})
22832 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22833 are registered for build results. This means that build results are protected
22834 from garbage collection for at least @var{ttl} seconds.
22836 @item @code{port} (default: @code{8081})
22837 Port number used by the HTTP server.
22839 @item @code{host} (default: @code{"localhost"})
22840 Listen on the network interface for @var{host}. The default is to
22841 accept connections from localhost.
22843 @item @code{specifications} (default: @code{#~'()})
22844 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22845 where a specification is an association list
22846 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22847 keys are keywords (@code{#:keyword-example}) as shown in the example
22850 @item @code{use-substitutes?} (default: @code{#f})
22851 This allows using substitutes to avoid building every dependencies of a job
22854 @item @code{one-shot?} (default: @code{#f})
22855 Only evaluate specifications and build derivations once.
22857 @item @code{fallback?} (default: @code{#f})
22858 When substituting a pre-built binary fails, fall back to building
22861 @item @code{extra-options} (default: @code{'()})
22862 Extra options to pass when running the Cuirass processes.
22864 @item @code{cuirass} (default: @code{cuirass})
22865 The Cuirass package to use.
22869 @node Power Management Services
22870 @subsection Power Management Services
22873 @cindex power management with TLP
22874 @subsubheading TLP daemon
22876 The @code{(gnu services pm)} module provides a Guix service definition
22877 for the Linux power management tool TLP.
22879 TLP enables various powersaving modes in userspace and kernel.
22880 Contrary to @code{upower-service}, it is not a passive,
22881 monitoring tool, as it will apply custom settings each time a new power
22882 source is detected. More information can be found at
22883 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22885 @deffn {Scheme Variable} tlp-service-type
22886 The service type for the TLP tool. Its value should be a valid
22887 TLP configuration (see below). To use the default settings, simply
22890 (service tlp-service-type)
22894 By default TLP does not need much configuration but most TLP parameters
22895 can be tweaked using @code{tlp-configuration}.
22897 Each parameter definition is preceded by its type; for example,
22898 @samp{boolean foo} indicates that the @code{foo} parameter
22899 should be specified as a boolean. Types starting with
22900 @code{maybe-} denote parameters that won't show up in TLP config file
22901 when their value is @code{'disabled}.
22903 @c The following documentation was initially generated by
22904 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22905 @c documentation is better, so we shouldn't hesitate to edit below as
22906 @c needed. However if the change you want to make to this documentation
22907 @c can be done in an automated way, it's probably easier to change
22908 @c (generate-documentation) than to make it below and have to deal with
22909 @c the churn as TLP updates.
22911 Available @code{tlp-configuration} fields are:
22913 @deftypevr {@code{tlp-configuration} parameter} package tlp
22918 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22919 Set to true if you wish to enable TLP.
22921 Defaults to @samp{#t}.
22925 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22926 Default mode when no power supply can be detected. Alternatives are AC
22929 Defaults to @samp{"AC"}.
22933 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22934 Number of seconds Linux kernel has to wait after the disk goes idle,
22935 before syncing on AC.
22937 Defaults to @samp{0}.
22941 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22942 Same as @code{disk-idle-ac} but on BAT mode.
22944 Defaults to @samp{2}.
22948 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22949 Dirty pages flushing periodicity, expressed in seconds.
22951 Defaults to @samp{15}.
22955 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22956 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22958 Defaults to @samp{60}.
22962 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22963 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22964 alternatives are powersave and performance. With acpi-cpufreq driver,
22965 alternatives are ondemand, powersave, performance and conservative.
22967 Defaults to @samp{disabled}.
22971 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22972 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22974 Defaults to @samp{disabled}.
22978 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22979 Set the min available frequency for the scaling governor on AC.
22981 Defaults to @samp{disabled}.
22985 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22986 Set the max available frequency for the scaling governor on AC.
22988 Defaults to @samp{disabled}.
22992 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22993 Set the min available frequency for the scaling governor on BAT.
22995 Defaults to @samp{disabled}.
22999 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
23000 Set the max available frequency for the scaling governor on BAT.
23002 Defaults to @samp{disabled}.
23006 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
23007 Limit the min P-state to control the power dissipation of the CPU, in AC
23008 mode. Values are stated as a percentage of the available performance.
23010 Defaults to @samp{disabled}.
23014 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
23015 Limit the max P-state to control the power dissipation of the CPU, in AC
23016 mode. Values are stated as a percentage of the available performance.
23018 Defaults to @samp{disabled}.
23022 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
23023 Same as @code{cpu-min-perf-on-ac} on BAT mode.
23025 Defaults to @samp{disabled}.
23029 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
23030 Same as @code{cpu-max-perf-on-ac} on BAT mode.
23032 Defaults to @samp{disabled}.
23036 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
23037 Enable CPU turbo boost feature on AC mode.
23039 Defaults to @samp{disabled}.
23043 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
23044 Same as @code{cpu-boost-on-ac?} on BAT mode.
23046 Defaults to @samp{disabled}.
23050 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
23051 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
23052 used under light load conditions.
23054 Defaults to @samp{#f}.
23058 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
23059 Same as @code{sched-powersave-on-ac?} but on BAT mode.
23061 Defaults to @samp{#t}.
23065 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
23066 Enable Linux kernel NMI watchdog.
23068 Defaults to @samp{#f}.
23072 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
23073 For Linux kernels with PHC patch applied, change CPU voltages. An
23074 example value would be @samp{"F:V F:V F:V F:V"}.
23076 Defaults to @samp{disabled}.
23080 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
23081 Set CPU performance versus energy saving policy on AC. Alternatives are
23082 performance, normal, powersave.
23084 Defaults to @samp{"performance"}.
23088 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
23089 Same as @code{energy-perf-policy-ac} but on BAT mode.
23091 Defaults to @samp{"powersave"}.
23095 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
23100 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
23101 Hard disk advanced power management level.
23105 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
23106 Same as @code{disk-apm-bat} but on BAT mode.
23110 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
23111 Hard disk spin down timeout. One value has to be specified for each
23112 declared hard disk.
23114 Defaults to @samp{disabled}.
23118 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
23119 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
23121 Defaults to @samp{disabled}.
23125 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
23126 Select IO scheduler for disk devices. One value has to be specified for
23127 each declared hard disk. Example alternatives are cfq, deadline and
23130 Defaults to @samp{disabled}.
23134 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
23135 SATA aggressive link power management (ALPM) level. Alternatives are
23136 min_power, medium_power, max_performance.
23138 Defaults to @samp{"max_performance"}.
23142 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
23143 Same as @code{sata-linkpwr-ac} but on BAT mode.
23145 Defaults to @samp{"min_power"}.
23149 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
23150 Exclude specified SATA host devices for link power management.
23152 Defaults to @samp{disabled}.
23156 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
23157 Enable Runtime Power Management for AHCI controller and disks on AC
23160 Defaults to @samp{disabled}.
23164 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
23165 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
23167 Defaults to @samp{disabled}.
23171 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
23172 Seconds of inactivity before disk is suspended.
23174 Defaults to @samp{15}.
23178 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
23179 PCI Express Active State Power Management level. Alternatives are
23180 default, performance, powersave.
23182 Defaults to @samp{"performance"}.
23186 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
23187 Same as @code{pcie-aspm-ac} but on BAT mode.
23189 Defaults to @samp{"powersave"}.
23193 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
23194 Radeon graphics clock speed level. Alternatives are low, mid, high,
23197 Defaults to @samp{"high"}.
23201 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
23202 Same as @code{radeon-power-ac} but on BAT mode.
23204 Defaults to @samp{"low"}.
23208 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
23209 Radeon dynamic power management method (DPM). Alternatives are battery,
23212 Defaults to @samp{"performance"}.
23216 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
23217 Same as @code{radeon-dpm-state-ac} but on BAT mode.
23219 Defaults to @samp{"battery"}.
23223 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
23224 Radeon DPM performance level. Alternatives are auto, low, high.
23226 Defaults to @samp{"auto"}.
23230 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
23231 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
23233 Defaults to @samp{"auto"}.
23237 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
23238 Wifi power saving mode.
23240 Defaults to @samp{#f}.
23244 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
23245 Same as @code{wifi-power-ac?} but on BAT mode.
23247 Defaults to @samp{#t}.
23251 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
23252 Disable wake on LAN.
23254 Defaults to @samp{#t}.
23258 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
23259 Timeout duration in seconds before activating audio power saving on
23260 Intel HDA and AC97 devices. A value of 0 disables power saving.
23262 Defaults to @samp{0}.
23266 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
23267 Same as @code{sound-powersave-ac} but on BAT mode.
23269 Defaults to @samp{1}.
23273 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
23274 Disable controller in powersaving mode on Intel HDA devices.
23276 Defaults to @samp{#t}.
23280 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
23281 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
23282 powered on again by releasing (and reinserting) the eject lever or by
23283 pressing the disc eject button on newer models.
23285 Defaults to @samp{#f}.
23289 @deftypevr {@code{tlp-configuration} parameter} string bay-device
23290 Name of the optical drive device to power off.
23292 Defaults to @samp{"sr0"}.
23296 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
23297 Runtime Power Management for PCI(e) bus devices. Alternatives are on
23300 Defaults to @samp{"on"}.
23304 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
23305 Same as @code{runtime-pm-ac} but on BAT mode.
23307 Defaults to @samp{"auto"}.
23311 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
23312 Runtime Power Management for all PCI(e) bus devices, except blacklisted
23315 Defaults to @samp{#t}.
23319 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
23320 Exclude specified PCI(e) device addresses from Runtime Power Management.
23322 Defaults to @samp{disabled}.
23326 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
23327 Exclude PCI(e) devices assigned to the specified drivers from Runtime
23332 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
23333 Enable USB autosuspend feature.
23335 Defaults to @samp{#t}.
23339 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
23340 Exclude specified devices from USB autosuspend.
23342 Defaults to @samp{disabled}.
23346 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
23347 Exclude WWAN devices from USB autosuspend.
23349 Defaults to @samp{#t}.
23353 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
23354 Include specified devices into USB autosuspend, even if they are already
23355 excluded by the driver or via @code{usb-blacklist-wwan?}.
23357 Defaults to @samp{disabled}.
23361 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
23362 Enable USB autosuspend before shutdown.
23364 Defaults to @samp{disabled}.
23368 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
23369 Restore radio device state (bluetooth, wifi, wwan) from previous
23370 shutdown on system startup.
23372 Defaults to @samp{#f}.
23377 @cindex CPU frequency scaling with thermald
23378 @subsubheading Thermald daemon
23380 The @code{(gnu services pm)} module provides an interface to
23381 thermald, a CPU frequency scaling service which helps prevent overheating.
23383 @defvr {Scheme Variable} thermald-service-type
23384 This is the service type for
23385 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
23386 Thermal Daemon, which is responsible for controlling the thermal state
23387 of processors and preventing overheating.
23390 @deftp {Data Type} thermald-configuration
23391 Data type representing the configuration of @code{thermald-service-type}.
23394 @item @code{ignore-cpuid-check?} (default: @code{#f})
23395 Ignore cpuid check for supported CPU models.
23397 @item @code{thermald} (default: @var{thermald})
23398 Package object of thermald.
23403 @node Audio Services
23404 @subsection Audio Services
23406 The @code{(gnu services audio)} module provides a service to start MPD
23407 (the Music Player Daemon).
23410 @subsubheading Music Player Daemon
23412 The Music Player Daemon (MPD) is a service that can play music while
23413 being controlled from the local machine or over the network by a variety
23416 The following example shows how one might run @code{mpd} as user
23417 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
23420 (service mpd-service-type
23426 @defvr {Scheme Variable} mpd-service-type
23427 The service type for @command{mpd}
23430 @deftp {Data Type} mpd-configuration
23431 Data type representing the configuration of @command{mpd}.
23434 @item @code{user} (default: @code{"mpd"})
23435 The user to run mpd as.
23437 @item @code{music-dir} (default: @code{"~/Music"})
23438 The directory to scan for music files.
23440 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
23441 The directory to store playlists.
23443 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
23444 The location of the music database.
23446 @item @code{state-file} (default: @code{"~/.mpd/state"})
23447 The location of the file that stores current MPD's state.
23449 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
23450 The location of the sticker database.
23452 @item @code{port} (default: @code{"6600"})
23453 The port to run mpd on.
23455 @item @code{address} (default: @code{"any"})
23456 The address that mpd will bind to. To use a Unix domain socket,
23457 an absolute path can be specified here.
23459 @item @code{outputs} (default: @code{"(list (mpd-output))"})
23460 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
23465 @deftp {Data Type} mpd-output
23466 Data type representing an @command{mpd} audio output.
23469 @item @code{name} (default: @code{"MPD"})
23470 The name of the audio output.
23472 @item @code{type} (default: @code{"pulse"})
23473 The type of audio output.
23475 @item @code{enabled?} (default: @code{#t})
23476 Specifies whether this audio output is enabled when MPD is started. By
23477 default, all audio outputs are enabled. This is just the default
23478 setting when there is no state file; with a state file, the previous
23481 @item @code{tags?} (default: @code{#t})
23482 If set to @code{#f}, then MPD will not send tags to this output. This
23483 is only useful for output plugins that can receive tags, for example the
23484 @code{httpd} output plugin.
23486 @item @code{always-on?} (default: @code{#f})
23487 If set to @code{#t}, then MPD attempts to keep this audio output always
23488 open. This may be useful for streaming servers, when you don’t want to
23489 disconnect all listeners even when playback is accidentally stopped.
23491 @item @code{mixer-type}
23492 This field accepts a symbol that specifies which mixer should be used
23493 for this audio output: the @code{hardware} mixer, the @code{software}
23494 mixer, the @code{null} mixer (allows setting the volume, but with no
23495 effect; this can be used as a trick to implement an external mixer
23496 External Mixer) or no mixer (@code{none}).
23498 @item @code{extra-options} (default: @code{'()"})
23499 An association list of option symbols to string values to be appended to
23500 the audio output configuration.
23505 The following example shows a configuration of @code{mpd} that provides
23506 an HTTP audio streaming output.
23509 (service mpd-service-type
23517 `((encoder . "vorbis")
23518 (port . "8080"))))))))
23522 @node Virtualization Services
23523 @subsection Virtualization services
23525 The @code{(gnu services virtualization)} module provides services for
23526 the libvirt and virtlog daemons, as well as other virtualization-related
23529 @subsubheading Libvirt daemon
23530 @code{libvirtd} is the server side daemon component of the libvirt
23531 virtualization management system. This daemon runs on host servers
23532 and performs required management tasks for virtualized guests.
23534 @deffn {Scheme Variable} libvirt-service-type
23535 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
23536 Its value must be a @code{libvirt-configuration}.
23539 (service libvirt-service-type
23540 (libvirt-configuration
23541 (unix-sock-group "libvirt")
23542 (tls-port "16555")))
23546 @c Auto-generated with (generate-libvirt-documentation)
23547 Available @code{libvirt-configuration} fields are:
23549 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
23554 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
23555 Flag listening for secure TLS connections on the public TCP/IP port.
23556 must set @code{listen} for this to have any effect.
23558 It is necessary to setup a CA and issue server certificates before using
23561 Defaults to @samp{#t}.
23565 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
23566 Listen for unencrypted TCP connections on the public TCP/IP port. must
23567 set @code{listen} for this to have any effect.
23569 Using the TCP socket requires SASL authentication by default. Only SASL
23570 mechanisms which support data encryption are allowed. This is
23571 DIGEST_MD5 and GSSAPI (Kerberos5)
23573 Defaults to @samp{#f}.
23577 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
23578 Port for accepting secure TLS connections This can be a port number, or
23581 Defaults to @samp{"16514"}.
23585 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23586 Port for accepting insecure TCP connections This can be a port number,
23589 Defaults to @samp{"16509"}.
23593 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23594 IP address or hostname used for client connections.
23596 Defaults to @samp{"0.0.0.0"}.
23600 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23601 Flag toggling mDNS advertisement of the libvirt service.
23603 Alternatively can disable for all services on a host by stopping the
23606 Defaults to @samp{#f}.
23610 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23611 Default mDNS advertisement name. This must be unique on the immediate
23614 Defaults to @samp{"Virtualization Host <hostname>"}.
23618 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23619 UNIX domain socket group ownership. This can be used to allow a
23620 'trusted' set of users access to management capabilities without
23623 Defaults to @samp{"root"}.
23627 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23628 UNIX socket permissions for the R/O socket. This is used for monitoring
23631 Defaults to @samp{"0777"}.
23635 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23636 UNIX socket permissions for the R/W socket. Default allows only root.
23637 If PolicyKit is enabled on the socket, the default will change to allow
23638 everyone (eg, 0777)
23640 Defaults to @samp{"0770"}.
23644 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23645 UNIX socket permissions for the admin socket. Default allows only owner
23646 (root), do not change it unless you are sure to whom you are exposing
23649 Defaults to @samp{"0777"}.
23653 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23654 The directory in which sockets will be found/created.
23656 Defaults to @samp{"/var/run/libvirt"}.
23660 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23661 Authentication scheme for UNIX read-only sockets. By default socket
23662 permissions allow anyone to connect
23664 Defaults to @samp{"polkit"}.
23668 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23669 Authentication scheme for UNIX read-write sockets. By default socket
23670 permissions only allow root. If PolicyKit support was compiled into
23671 libvirt, the default will be to use 'polkit' auth.
23673 Defaults to @samp{"polkit"}.
23677 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23678 Authentication scheme for TCP sockets. If you don't enable SASL, then
23679 all TCP traffic is cleartext. Don't do this outside of a dev/test
23682 Defaults to @samp{"sasl"}.
23686 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23687 Authentication scheme for TLS sockets. TLS sockets already have
23688 encryption provided by the TLS layer, and limited authentication is done
23691 It is possible to make use of any SASL authentication mechanism as well,
23692 by using 'sasl' for this option
23694 Defaults to @samp{"none"}.
23698 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23699 API access control scheme.
23701 By default an authenticated user is allowed access to all APIs. Access
23702 drivers can place restrictions on this.
23704 Defaults to @samp{()}.
23708 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23709 Server key file path. If set to an empty string, then no private key is
23712 Defaults to @samp{""}.
23716 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23717 Server key file path. If set to an empty string, then no certificate is
23720 Defaults to @samp{""}.
23724 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23725 Server key file path. If set to an empty string, then no CA certificate
23728 Defaults to @samp{""}.
23732 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23733 Certificate revocation list path. If set to an empty string, then no
23736 Defaults to @samp{""}.
23740 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23741 Disable verification of our own server certificates.
23743 When libvirtd starts it performs some sanity checks against its own
23746 Defaults to @samp{#f}.
23750 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23751 Disable verification of client certificates.
23753 Client certificate verification is the primary authentication mechanism.
23754 Any client which does not present a certificate signed by the CA will be
23757 Defaults to @samp{#f}.
23761 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23762 Whitelist of allowed x509 Distinguished Name.
23764 Defaults to @samp{()}.
23768 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23769 Whitelist of allowed SASL usernames. The format for username depends on
23770 the SASL authentication mechanism.
23772 Defaults to @samp{()}.
23776 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23777 Override the compile time default TLS priority string. The default is
23778 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
23779 is desired for libvirt to deviate from the global default settings.
23781 Defaults to @samp{"NORMAL"}.
23785 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23786 Maximum number of concurrent client connections to allow over all
23789 Defaults to @samp{5000}.
23793 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23794 Maximum length of queue of connections waiting to be accepted by the
23795 daemon. Note, that some protocols supporting retransmission may obey
23796 this so that a later reattempt at connection succeeds.
23798 Defaults to @samp{1000}.
23802 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23803 Maximum length of queue of accepted but not yet authenticated clients.
23804 Set this to zero to turn this feature off
23806 Defaults to @samp{20}.
23810 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23811 Number of workers to start up initially.
23813 Defaults to @samp{5}.
23817 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23818 Maximum number of worker threads.
23820 If the number of active clients exceeds @code{min-workers}, then more
23821 threads are spawned, up to max_workers limit. Typically you'd want
23822 max_workers to equal maximum number of clients allowed.
23824 Defaults to @samp{20}.
23828 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23829 Number of priority workers. If all workers from above pool are stuck,
23830 some calls marked as high priority (notably domainDestroy) can be
23831 executed in this pool.
23833 Defaults to @samp{5}.
23837 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23838 Total global limit on concurrent RPC calls.
23840 Defaults to @samp{20}.
23844 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23845 Limit on concurrent requests from a single client connection. To avoid
23846 one client monopolizing the server this should be a small fraction of
23847 the global max_requests and max_workers parameter.
23849 Defaults to @samp{5}.
23853 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23854 Same as @code{min-workers} but for the admin interface.
23856 Defaults to @samp{1}.
23860 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23861 Same as @code{max-workers} but for the admin interface.
23863 Defaults to @samp{5}.
23867 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23868 Same as @code{max-clients} but for the admin interface.
23870 Defaults to @samp{5}.
23874 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23875 Same as @code{max-queued-clients} but for the admin interface.
23877 Defaults to @samp{5}.
23881 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23882 Same as @code{max-client-requests} but for the admin interface.
23884 Defaults to @samp{5}.
23888 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23889 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23891 Defaults to @samp{3}.
23895 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23898 A filter allows to select a different logging level for a given category
23899 of logs The format for a filter is one of:
23910 where @code{name} is a string which is matched against the category
23911 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23912 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
23913 name in the filter can be a substring of the full category name, in
23914 order to match multiple similar categories), the optional @samp{"+"}
23915 prefix tells libvirt to log stack trace for each message matching name,
23916 and @code{x} is the minimal level where matching messages should be
23934 Multiple filters can be defined in a single filters statement, they just
23935 need to be separated by spaces.
23937 Defaults to @samp{"3:remote 4:event"}.
23941 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23944 An output is one of the places to save logging information. The format
23945 for an output can be:
23949 output goes to stderr
23951 @item x:syslog:name
23952 use syslog for the output and use the given name as the ident
23954 @item x:file:file_path
23955 output to a file, with the given filepath
23958 output to journald logging system
23962 In all case the x prefix is the minimal level, acting as a filter
23979 Multiple outputs can be defined, they just need to be separated by
23982 Defaults to @samp{"3:stderr"}.
23986 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23987 Allows usage of the auditing subsystem to be altered
23991 0: disable all auditing
23994 1: enable auditing, only if enabled on host
23997 2: enable auditing, and exit if disabled on host.
24001 Defaults to @samp{1}.
24005 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
24006 Send audit messages via libvirt logging infrastructure.
24008 Defaults to @samp{#f}.
24012 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
24013 Host UUID. UUID must not have all digits be the same.
24015 Defaults to @samp{""}.
24019 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
24020 Source to read host UUID.
24024 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
24027 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
24031 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
24034 Defaults to @samp{"smbios"}.
24038 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
24039 A keepalive message is sent to a client after @code{keepalive_interval}
24040 seconds of inactivity to check if the client is still responding. If
24041 set to -1, libvirtd will never send keepalive requests; however clients
24042 can still send them and the daemon will send responses.
24044 Defaults to @samp{5}.
24048 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
24049 Maximum number of keepalive messages that are allowed to be sent to the
24050 client without getting any response before the connection is considered
24053 In other words, the connection is automatically closed approximately
24054 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
24055 the last message received from the client. When @code{keepalive-count}
24056 is set to 0, connections will be automatically closed after
24057 @code{keepalive-interval} seconds of inactivity without sending any
24058 keepalive messages.
24060 Defaults to @samp{5}.
24064 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
24065 Same as above but for admin interface.
24067 Defaults to @samp{5}.
24071 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
24072 Same as above but for admin interface.
24074 Defaults to @samp{5}.
24078 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
24079 Timeout for Open vSwitch calls.
24081 The @code{ovs-vsctl} utility is used for the configuration and its
24082 timeout option is set by default to 5 seconds to avoid potential
24083 infinite waits blocking libvirt.
24085 Defaults to @samp{5}.
24089 @c %end of autogenerated docs
24091 @subsubheading Virtlog daemon
24092 The virtlogd service is a server side daemon component of libvirt that is
24093 used to manage logs from virtual machine consoles.
24095 This daemon is not used directly by libvirt client applications, rather it
24096 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
24097 standalone daemon, the main @code{libvirtd} daemon can be restarted without
24098 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
24099 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
24101 @deffn {Scheme Variable} virtlog-service-type
24102 This is the type of the virtlog daemon.
24103 Its value must be a @code{virtlog-configuration}.
24106 (service virtlog-service-type
24107 (virtlog-configuration
24108 (max-clients 1000)))
24112 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
24113 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24115 Defaults to @samp{3}.
24119 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
24122 A filter allows to select a different logging level for a given category
24123 of logs The format for a filter is one of:
24134 where @code{name} is a string which is matched against the category
24135 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24136 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
24137 be a substring of the full category name, in order to match multiple
24138 similar categories), the optional "+" prefix tells libvirt to log stack
24139 trace for each message matching name, and @code{x} is the minimal level
24140 where matching messages should be logged:
24157 Multiple filters can be defined in a single filters statement, they just
24158 need to be separated by spaces.
24160 Defaults to @samp{"3:remote 4:event"}.
24164 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
24167 An output is one of the places to save logging information The format
24168 for an output can be:
24172 output goes to stderr
24174 @item x:syslog:name
24175 use syslog for the output and use the given name as the ident
24177 @item x:file:file_path
24178 output to a file, with the given filepath
24181 output to journald logging system
24185 In all case the x prefix is the minimal level, acting as a filter
24202 Multiple outputs can be defined, they just need to be separated by
24205 Defaults to @samp{"3:stderr"}.
24209 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
24210 Maximum number of concurrent client connections to allow over all
24213 Defaults to @samp{1024}.
24217 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
24218 Maximum file size before rolling over.
24220 Defaults to @samp{2MB}
24224 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
24225 Maximum number of backup files to keep.
24227 Defaults to @samp{3}
24231 @subsubheading Transparent Emulation with QEMU
24234 @cindex @code{binfmt_misc}
24235 @code{qemu-binfmt-service-type} provides support for transparent
24236 emulation of program binaries built for different architectures---e.g.,
24237 it allows you to transparently execute an ARMv7 program on an x86_64
24238 machine. It achieves this by combining the @uref{https://www.qemu.org,
24239 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
24241 @defvr {Scheme Variable} qemu-binfmt-service-type
24242 This is the type of the QEMU/binfmt service for transparent emulation.
24243 Its value must be a @code{qemu-binfmt-configuration} object, which
24244 specifies the QEMU package to use as well as the architecture we want to
24248 (service qemu-binfmt-service-type
24249 (qemu-binfmt-configuration
24250 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
24253 In this example, we enable transparent emulation for the ARM and aarch64
24254 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
24255 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
24256 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
24259 @deftp {Data Type} qemu-binfmt-configuration
24260 This is the configuration for the @code{qemu-binfmt} service.
24263 @item @code{platforms} (default: @code{'()})
24264 The list of emulated QEMU platforms. Each item must be a @dfn{platform
24265 object} as returned by @code{lookup-qemu-platforms} (see below).
24267 @item @code{guix-support?} (default: @code{#f})
24268 When it is true, QEMU and all its dependencies are added to the build
24269 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
24270 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
24271 handlers to be used within the build environment, which in turn means
24272 that you can transparently build programs for another architecture.
24274 For example, let's suppose you're on an x86_64 machine and you have this
24278 (service qemu-binfmt-service-type
24279 (qemu-binfmt-configuration
24280 (platforms (lookup-qemu-platforms "arm"))
24281 (guix-support? #t)))
24287 guix build -s armhf-linux inkscape
24291 and it will build Inkscape for ARMv7 @emph{as if it were a native
24292 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
24293 if you'd like to test a package build for an architecture you don't have
24296 @item @code{qemu} (default: @code{qemu})
24297 The QEMU package to use.
24301 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
24302 Return the list of QEMU platform objects corresponding to
24303 @var{platforms}@dots{}. @var{platforms} must be a list of strings
24304 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
24305 @code{"mips64el"}, and so on.
24308 @deffn {Scheme Procedure} qemu-platform? @var{obj}
24309 Return true if @var{obj} is a platform object.
24312 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
24313 Return the name of @var{platform}---a string such as @code{"arm"}.
24316 @node Version Control Services
24317 @subsection Version Control Services
24319 The @code{(gnu services version-control)} module provides a service to
24320 allow remote access to local Git repositories. There are three options:
24321 the @code{git-daemon-service}, which provides access to repositories via
24322 the @code{git://} unsecured TCP-based protocol, extending the
24323 @code{nginx} web server to proxy some requests to
24324 @code{git-http-backend}, or providing a web interface with
24325 @code{cgit-service-type}.
24327 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
24329 Return a service that runs @command{git daemon}, a simple TCP server to
24330 expose repositories over the Git protocol for anonymous access.
24332 The optional @var{config} argument should be a
24333 @code{<git-daemon-configuration>} object, by default it allows read-only
24334 access to exported@footnote{By creating the magic file
24335 @file{git-daemon-export-ok} in the repository directory.} repositories under
24340 @deftp {Data Type} git-daemon-configuration
24341 Data type representing the configuration for @code{git-daemon-service}.
24344 @item @code{package} (default: @var{git})
24345 Package object of the Git distributed version control system.
24347 @item @code{export-all?} (default: @var{#f})
24348 Whether to allow access for all Git repositories, even if they do not
24349 have the @file{git-daemon-export-ok} file.
24351 @item @code{base-path} (default: @file{/srv/git})
24352 Whether to remap all the path requests as relative to the given path.
24353 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
24354 then if you later try to pull @code{git://example.com/hello.git}, git
24355 daemon will interpret the path as @code{/srv/git/hello.git}.
24357 @item @code{user-path} (default: @var{#f})
24358 Whether to allow @code{~user} notation to be used in requests. When
24359 specified with empty string, requests to @code{git://host/~alice/foo} is
24360 taken as a request to access @code{foo} repository in the home directory
24361 of user @code{alice}. If @var{(user-path "path")} is specified, the
24362 same request is taken as a request to access @code{path/foo} repository
24363 in the home directory of user @code{alice}.
24365 @item @code{listen} (default: @var{'()})
24366 Whether to listen on specific IP addresses or hostnames, defaults to
24369 @item @code{port} (default: @var{#f})
24370 Whether to listen on an alternative port, which defaults to 9418.
24372 @item @code{whitelist} (default: @var{'()})
24373 If not empty, only allow access to this list of directories.
24375 @item @code{extra-options} (default: @var{'()})
24376 Extra options will be passed to @code{git daemon}, please run
24377 @command{man git-daemon} for more information.
24382 The @code{git://} protocol lacks authentication. When you pull from a
24383 repository fetched via @code{git://}, you don't know whether the data you
24384 receive was modified or is even coming from the specified host, and your
24385 connection is subject to eavesdropping. It's better to use an authenticated
24386 and encrypted transport, such as @code{https}. Although Git allows you
24387 to serve repositories using unsophisticated file-based web servers,
24388 there is a faster protocol implemented by the @code{git-http-backend}
24389 program. This program is the back-end of a proper Git web service. It
24390 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
24391 on running the necessary @code{fcgiwrap} daemon.
24393 Guix has a separate configuration data type for serving Git repositories
24396 @deftp {Data Type} git-http-configuration
24397 Data type representing the configuration for a future
24398 @code{git-http-service-type}; can currently be used to configure Nginx
24399 trough @code{git-http-nginx-location-configuration}.
24402 @item @code{package} (default: @var{git})
24403 Package object of the Git distributed version control system.
24405 @item @code{git-root} (default: @file{/srv/git})
24406 Directory containing the Git repositories to expose to the world.
24408 @item @code{export-all?} (default: @var{#f})
24409 Whether to expose access for all Git repositories in @var{git-root},
24410 even if they do not have the @file{git-daemon-export-ok} file.
24412 @item @code{uri-path} (default: @file{/git/})
24413 Path prefix for Git access. With the default @code{/git/} prefix, this
24414 will map @code{http://@var{server}/git/@var{repo}.git} to
24415 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
24416 with this prefix are not passed on to this Git instance.
24418 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
24419 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
24424 There is no @code{git-http-service-type}, currently; instead you can
24425 create an @code{nginx-location-configuration} from a
24426 @code{git-http-configuration} and then add that location to a web
24429 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
24430 [config=(git-http-configuration)]
24431 Compute an @code{nginx-location-configuration} that corresponds to the
24432 given Git http configuration. An example nginx service definition to
24433 serve the default @file{/srv/git} over HTTPS might be:
24436 (service nginx-service-type
24437 (nginx-configuration
24440 (nginx-server-configuration
24441 (listen '("443 ssl"))
24442 (server-name "git.my-host.org")
24444 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
24445 (ssl-certificate-key
24446 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
24449 (git-http-nginx-location-configuration
24450 (git-http-configuration (uri-path "/"))))))))))
24453 This example assumes that you are using Let's Encrypt to get your TLS
24454 certificate. @xref{Certificate Services}. The default @code{certbot}
24455 service will redirect all HTTP traffic on @code{git.my-host.org} to
24456 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
24457 system services. @xref{Web Services}.
24460 @subsubheading Cgit Service
24462 @cindex Cgit service
24463 @cindex Git, web interface
24464 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
24465 repositories written in C.
24467 The following example will configure the service with default values.
24468 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
24471 (service cgit-service-type)
24474 The @code{file-object} type designates either a file-like object
24475 (@pxref{G-Expressions, file-like objects}) or a string.
24477 @c %start of fragment
24479 Available @code{cgit-configuration} fields are:
24481 @deftypevr {@code{cgit-configuration} parameter} package package
24486 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
24487 NGINX configuration.
24491 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
24492 Specifies a command which will be invoked to format the content of about
24493 pages (both top-level and for each repository).
24495 Defaults to @samp{""}.
24499 @deftypevr {@code{cgit-configuration} parameter} string agefile
24500 Specifies a path, relative to each repository path, which can be used to
24501 specify the date and time of the youngest commit in the repository.
24503 Defaults to @samp{""}.
24507 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
24508 Specifies a command that will be invoked for authenticating repository
24511 Defaults to @samp{""}.
24515 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
24516 Flag which, when set to @samp{age}, enables date ordering in the branch
24517 ref list, and when set @samp{name} enables ordering by branch name.
24519 Defaults to @samp{"name"}.
24523 @deftypevr {@code{cgit-configuration} parameter} string cache-root
24524 Path used to store the cgit cache entries.
24526 Defaults to @samp{"/var/cache/cgit"}.
24530 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
24531 Number which specifies the time-to-live, in minutes, for the cached
24532 version of repository pages accessed with a fixed SHA1.
24534 Defaults to @samp{-1}.
24538 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
24539 Number which specifies the time-to-live, in minutes, for the cached
24540 version of repository pages accessed without a fixed SHA1.
24542 Defaults to @samp{5}.
24546 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
24547 Number which specifies the time-to-live, in minutes, for the cached
24548 version of the repository summary page.
24550 Defaults to @samp{5}.
24554 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
24555 Number which specifies the time-to-live, in minutes, for the cached
24556 version of the repository index page.
24558 Defaults to @samp{5}.
24562 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
24563 Number which specifies the time-to-live, in minutes, for the result of
24564 scanning a path for Git repositories.
24566 Defaults to @samp{15}.
24570 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
24571 Number which specifies the time-to-live, in minutes, for the cached
24572 version of the repository about page.
24574 Defaults to @samp{15}.
24578 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
24579 Number which specifies the time-to-live, in minutes, for the cached
24580 version of snapshots.
24582 Defaults to @samp{5}.
24586 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
24587 The maximum number of entries in the cgit cache. When set to @samp{0},
24588 caching is disabled.
24590 Defaults to @samp{0}.
24594 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24595 Sort items in the repo list case sensitively.
24597 Defaults to @samp{#t}.
24601 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24602 List of common prefixes which, when combined with a repository URL,
24603 generates valid clone URLs for the repository.
24605 Defaults to @samp{()}.
24609 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24610 List of @code{clone-url} templates.
24612 Defaults to @samp{()}.
24616 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24617 Command which will be invoked to format commit messages.
24619 Defaults to @samp{""}.
24623 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24624 Flag which, when set to @samp{date}, enables strict date ordering in the
24625 commit log, and when set to @samp{topo} enables strict topological
24628 Defaults to @samp{"git log"}.
24632 @deftypevr {@code{cgit-configuration} parameter} file-object css
24633 URL which specifies the css document to include in all cgit pages.
24635 Defaults to @samp{"/share/cgit/cgit.css"}.
24639 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24640 Specifies a command which will be invoked to format names and email
24641 address of committers, authors, and taggers, as represented in various
24642 places throughout the cgit interface.
24644 Defaults to @samp{""}.
24648 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24649 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24650 fragment suitable for embedding in other HTML pages.
24652 Defaults to @samp{#f}.
24656 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24657 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24658 commit history graph to the left of the commit messages in the
24659 repository log page.
24661 Defaults to @samp{#f}.
24665 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24666 Flag which, when set to @samp{#t}, allows all filter settings to be
24667 overridden in repository-specific cgitrc files.
24669 Defaults to @samp{#f}.
24673 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24674 Flag which, when set to @samp{#t}, allows users to follow a file in the
24677 Defaults to @samp{#f}.
24681 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24682 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24685 Defaults to @samp{#t}.
24689 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24690 Flag which, when set to @samp{#t}, will make cgit generate extra links
24691 "summary", "commit", "tree" for each repo in the repository index.
24693 Defaults to @samp{#f}.
24697 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24698 Flag which, when set to @samp{#t}, will make cgit display the owner of
24699 each repo in the repository index.
24701 Defaults to @samp{#t}.
24705 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24706 Flag which, when set to @samp{#t}, will make cgit print the number of
24707 modified files for each commit on the repository log page.
24709 Defaults to @samp{#f}.
24713 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24714 Flag which, when set to @samp{#t}, will make cgit print the number of
24715 added and removed lines for each commit on the repository log page.
24717 Defaults to @samp{#f}.
24721 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24722 Flag which, when set to @code{#t}, will make cgit display remote
24723 branches in the summary and refs views.
24725 Defaults to @samp{#f}.
24729 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24730 Flag which, when set to @code{1}, will make cgit use the subject of the
24731 parent commit as link text when generating links to parent commits in
24734 Defaults to @samp{#f}.
24738 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24739 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24740 parent commit as link text when generating links to parent commits in
24743 Defaults to @samp{#f}.
24747 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24748 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24749 links for plaintext blobs printed in the tree view.
24751 Defaults to @samp{#t}.
24755 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24756 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24757 set any repo specific settings.
24759 Defaults to @samp{#f}.
24763 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24764 URL used as link to a shortcut icon for cgit.
24766 Defaults to @samp{"/favicon.ico"}.
24770 @deftypevr {@code{cgit-configuration} parameter} string footer
24771 The content of the file specified with this option will be included
24772 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24773 "generated by..."@: message).
24775 Defaults to @samp{""}.
24779 @deftypevr {@code{cgit-configuration} parameter} string head-include
24780 The content of the file specified with this option will be included
24781 verbatim in the HTML HEAD section on all pages.
24783 Defaults to @samp{""}.
24787 @deftypevr {@code{cgit-configuration} parameter} string header
24788 The content of the file specified with this option will be included
24789 verbatim at the top of all pages.
24791 Defaults to @samp{""}.
24795 @deftypevr {@code{cgit-configuration} parameter} file-object include
24796 Name of a configfile to include before the rest of the current config-
24799 Defaults to @samp{""}.
24803 @deftypevr {@code{cgit-configuration} parameter} string index-header
24804 The content of the file specified with this option will be included
24805 verbatim above the repository index.
24807 Defaults to @samp{""}.
24811 @deftypevr {@code{cgit-configuration} parameter} string index-info
24812 The content of the file specified with this option will be included
24813 verbatim below the heading on the repository index page.
24815 Defaults to @samp{""}.
24819 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24820 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24821 in the servers timezone.
24823 Defaults to @samp{#f}.
24827 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24828 URL which specifies the source of an image which will be used as a logo
24831 Defaults to @samp{"/share/cgit/cgit.png"}.
24835 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24836 URL loaded when clicking on the cgit logo image.
24838 Defaults to @samp{""}.
24842 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24843 Command which will be invoked to format the Owner column of the main
24846 Defaults to @samp{""}.
24850 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24851 Number of items to display in atom feeds view.
24853 Defaults to @samp{10}.
24857 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24858 Number of entries to list per page in "log" view.
24860 Defaults to @samp{50}.
24864 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24865 Number of commit message characters to display in "log" view.
24867 Defaults to @samp{80}.
24871 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24872 Specifies the number of entries to list per page on the repository index
24875 Defaults to @samp{50}.
24879 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24880 Specifies the maximum number of repo description characters to display
24881 on the repository index page.
24883 Defaults to @samp{80}.
24887 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24888 Specifies the maximum size of a blob to display HTML for in KBytes.
24890 Defaults to @samp{0}.
24894 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24895 Maximum statistics period. Valid values are @samp{week},@samp{month},
24896 @samp{quarter} and @samp{year}.
24898 Defaults to @samp{""}.
24902 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24903 Mimetype for the specified filename extension.
24905 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24906 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24907 "image/png") (svg "image/svg+xml"))}.
24911 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24912 Specifies the file to use for automatic mimetype lookup.
24914 Defaults to @samp{""}.
24918 @deftypevr {@code{cgit-configuration} parameter} string module-link
24919 Text which will be used as the formatstring for a hyperlink when a
24920 submodule is printed in a directory listing.
24922 Defaults to @samp{""}.
24926 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24927 If set to the value @samp{#t} caching will be disabled.
24929 Defaults to @samp{#f}.
24933 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24934 If set to @samp{#t} showing full author email addresses will be
24937 Defaults to @samp{#f}.
24941 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24942 Flag which, when set to @samp{#t}, will make cgit omit the standard
24943 header on all pages.
24945 Defaults to @samp{#f}.
24949 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24950 A list of subdirectories inside of @code{repository-directory}, relative
24951 to it, that should loaded as Git repositories. An empty list means that
24952 all subdirectories will be loaded.
24954 Defaults to @samp{()}.
24958 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24959 Text which will be used as default value for @code{cgit-repo-readme}.
24961 Defaults to @samp{""}.
24965 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24966 If set to @code{#t} and @code{repository-directory} is enabled, if any
24967 repositories are found with a suffix of @code{.git}, this suffix will be
24968 removed for the URL and name.
24970 Defaults to @samp{#f}.
24974 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24975 Maximum number of files to consider when detecting renames.
24977 Defaults to @samp{-1}.
24981 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24982 The way in which repositories in each section are sorted.
24984 Defaults to @samp{""}.
24988 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24989 Text used as content for the @code{robots} meta-tag.
24991 Defaults to @samp{("noindex" "nofollow")}.
24995 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24996 Text printed below the heading on the repository index page.
24998 Defaults to @samp{"a fast webinterface for the git dscm"}.
25002 @deftypevr {@code{cgit-configuration} parameter} string root-readme
25003 The content of the file specified with this option will be included
25004 verbatim below the ``about'' link on the repository index page.
25006 Defaults to @samp{""}.
25010 @deftypevr {@code{cgit-configuration} parameter} string root-title
25011 Text printed as heading on the repository index page.
25013 Defaults to @samp{""}.
25017 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
25018 If set to @samp{#t} and repository-directory is enabled,
25019 repository-directory will recurse into directories whose name starts
25020 with a period. Otherwise, repository-directory will stay away from such
25021 directories, considered as ``hidden''. Note that this does not apply to
25022 the @file{.git} directory in non-bare repos.
25024 Defaults to @samp{#f}.
25028 @deftypevr {@code{cgit-configuration} parameter} list snapshots
25029 Text which specifies the default set of snapshot formats that cgit
25030 generates links for.
25032 Defaults to @samp{()}.
25036 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
25037 Name of the directory to scan for repositories (represents
25040 Defaults to @samp{"/srv/git"}.
25044 @deftypevr {@code{cgit-configuration} parameter} string section
25045 The name of the current repository section - all repositories defined
25046 after this option will inherit the current section name.
25048 Defaults to @samp{""}.
25052 @deftypevr {@code{cgit-configuration} parameter} string section-sort
25053 Flag which, when set to @samp{1}, will sort the sections on the
25054 repository listing by name.
25056 Defaults to @samp{""}.
25060 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
25061 A number which, if defined prior to repository-directory, specifies how
25062 many path elements from each repo path to use as a default section name.
25064 Defaults to @samp{0}.
25068 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
25069 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
25072 Defaults to @samp{#f}.
25076 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
25077 Specifies a command which will be invoked to format plaintext blobs in
25080 Defaults to @samp{""}.
25084 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
25085 Specifies the number of branches to display in the repository ``summary''
25088 Defaults to @samp{10}.
25092 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
25093 Specifies the number of log entries to display in the repository
25096 Defaults to @samp{10}.
25100 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
25101 Specifies the number of tags to display in the repository ``summary''
25104 Defaults to @samp{10}.
25108 @deftypevr {@code{cgit-configuration} parameter} string strict-export
25109 Filename which, if specified, needs to be present within the repository
25110 for cgit to allow access to that repository.
25112 Defaults to @samp{""}.
25116 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
25117 URL which, if specified, will be used as root for all cgit links.
25119 Defaults to @samp{"/"}.
25123 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
25124 A list of @dfn{cgit-repo} records to use with config.
25126 Defaults to @samp{()}.
25128 Available @code{repository-cgit-configuration} fields are:
25130 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
25131 A mask of snapshot formats for this repo that cgit generates links for,
25132 restricted by the global @code{snapshots} setting.
25134 Defaults to @samp{()}.
25138 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
25139 Override the default @code{source-filter}.
25141 Defaults to @samp{""}.
25145 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
25146 The relative URL used to access the repository.
25148 Defaults to @samp{""}.
25152 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
25153 Override the default @code{about-filter}.
25155 Defaults to @samp{""}.
25159 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
25160 Flag which, when set to @samp{age}, enables date ordering in the branch
25161 ref list, and when set to @samp{name} enables ordering by branch name.
25163 Defaults to @samp{""}.
25167 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
25168 A list of URLs which can be used to clone repo.
25170 Defaults to @samp{()}.
25174 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
25175 Override the default @code{commit-filter}.
25177 Defaults to @samp{""}.
25181 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
25182 Flag which, when set to @samp{date}, enables strict date ordering in the
25183 commit log, and when set to @samp{topo} enables strict topological
25186 Defaults to @samp{""}.
25190 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
25191 The name of the default branch for this repository. If no such branch
25192 exists in the repository, the first branch name (when sorted) is used as
25193 default instead. By default branch pointed to by HEAD, or ``master'' if
25194 there is no suitable HEAD.
25196 Defaults to @samp{""}.
25200 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
25201 The value to show as repository description.
25203 Defaults to @samp{""}.
25207 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
25208 The value to show as repository homepage.
25210 Defaults to @samp{""}.
25214 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
25215 Override the default @code{email-filter}.
25217 Defaults to @samp{""}.
25221 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
25222 A flag which can be used to disable the global setting
25223 @code{enable-commit-graph?}.
25225 Defaults to @samp{disabled}.
25229 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
25230 A flag which can be used to disable the global setting
25231 @code{enable-log-filecount?}.
25233 Defaults to @samp{disabled}.
25237 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
25238 A flag which can be used to disable the global setting
25239 @code{enable-log-linecount?}.
25241 Defaults to @samp{disabled}.
25245 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
25246 Flag which, when set to @code{#t}, will make cgit display remote
25247 branches in the summary and refs views.
25249 Defaults to @samp{disabled}.
25253 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
25254 A flag which can be used to override the global setting
25255 @code{enable-subject-links?}.
25257 Defaults to @samp{disabled}.
25261 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
25262 A flag which can be used to override the global setting
25263 @code{enable-html-serving?}.
25265 Defaults to @samp{disabled}.
25269 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
25270 Flag which, when set to @code{#t}, hides the repository from the
25273 Defaults to @samp{#f}.
25277 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
25278 Flag which, when set to @samp{#t}, ignores the repository.
25280 Defaults to @samp{#f}.
25284 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
25285 URL which specifies the source of an image which will be used as a logo
25286 on this repo’s pages.
25288 Defaults to @samp{""}.
25292 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
25293 URL loaded when clicking on the cgit logo image.
25295 Defaults to @samp{""}.
25299 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
25300 Override the default @code{owner-filter}.
25302 Defaults to @samp{""}.
25306 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
25307 Text which will be used as the formatstring for a hyperlink when a
25308 submodule is printed in a directory listing. The arguments for the
25309 formatstring are the path and SHA1 of the submodule commit.
25311 Defaults to @samp{""}.
25315 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
25316 Text which will be used as the formatstring for a hyperlink when a
25317 submodule with the specified subdirectory path is printed in a directory
25320 Defaults to @samp{()}.
25324 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
25325 Override the default maximum statistics period.
25327 Defaults to @samp{""}.
25331 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
25332 The value to show as repository name.
25334 Defaults to @samp{""}.
25338 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
25339 A value used to identify the owner of the repository.
25341 Defaults to @samp{""}.
25345 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
25346 An absolute path to the repository directory.
25348 Defaults to @samp{""}.
25352 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
25353 A path (relative to repo) which specifies a file to include verbatim as
25354 the ``About'' page for this repo.
25356 Defaults to @samp{""}.
25360 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
25361 The name of the current repository section - all repositories defined
25362 after this option will inherit the current section name.
25364 Defaults to @samp{""}.
25368 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
25369 Extra options will be appended to cgitrc file.
25371 Defaults to @samp{()}.
25377 @deftypevr {@code{cgit-configuration} parameter} list extra-options
25378 Extra options will be appended to cgitrc file.
25380 Defaults to @samp{()}.
25385 @c %end of fragment
25387 However, it could be that you just want to get a @code{cgitrc} up and
25388 running. In that case, you can pass an @code{opaque-cgit-configuration}
25389 as a record to @code{cgit-service-type}. As its name indicates, an
25390 opaque configuration does not have easy reflective capabilities.
25392 Available @code{opaque-cgit-configuration} fields are:
25394 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
25398 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
25399 The contents of the @code{cgitrc}, as a string.
25402 For example, if your @code{cgitrc} is just the empty string, you
25403 could instantiate a cgit service like this:
25406 (service cgit-service-type
25407 (opaque-cgit-configuration
25411 @subsubheading Gitolite Service
25413 @cindex Gitolite service
25414 @cindex Git, hosting
25415 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
25416 repositories on a central server.
25418 Gitolite can handle multiple repositories and users, and supports flexible
25419 configuration of the permissions for the users on the repositories.
25421 The following example will configure Gitolite using the default @code{git}
25422 user, and the provided SSH public key.
25425 (service gitolite-service-type
25426 (gitolite-configuration
25427 (admin-pubkey (plain-file
25429 "ssh-rsa AAAA... guix@@example.com"))))
25432 Gitolite is configured through a special admin repository which you can clone,
25433 for example, if you setup Gitolite on @code{example.com}, you would run the
25434 following command to clone the admin repository.
25437 git clone git@@example.com:gitolite-admin
25440 When the Gitolite service is activated, the provided @code{admin-pubkey} will
25441 be inserted in to the @file{keydir} directory in the gitolite-admin
25442 repository. If this results in a change in the repository, it will be
25443 committed using the message ``gitolite setup by GNU Guix''.
25445 @deftp {Data Type} gitolite-configuration
25446 Data type representing the configuration for @code{gitolite-service-type}.
25449 @item @code{package} (default: @var{gitolite})
25450 Gitolite package to use.
25452 @item @code{user} (default: @var{git})
25453 User to use for Gitolite. This will be user that you use when accessing
25456 @item @code{group} (default: @var{git})
25457 Group to use for Gitolite.
25459 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
25460 Directory in which to store the Gitolite configuration and repositories.
25462 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
25463 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
25464 representing the configuration for Gitolite.
25466 @item @code{admin-pubkey} (default: @var{#f})
25467 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
25468 setup Gitolite. This will be inserted in to the @file{keydir} directory
25469 within the gitolite-admin repository.
25471 To specify the SSH key as a string, use the @code{plain-file} function.
25474 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
25480 @deftp {Data Type} gitolite-rc-file
25481 Data type representing the Gitolite RC file.
25484 @item @code{umask} (default: @code{#o0077})
25485 This controls the permissions Gitolite sets on the repositories and their
25488 A value like @code{#o0027} will give read access to the group used by Gitolite
25489 (by default: @code{git}). This is necessary when using Gitolite with software
25490 like cgit or gitweb.
25492 @item @code{git-config-keys} (default: @code{""})
25493 Gitolite allows you to set git config values using the @samp{config} keyword. This
25494 setting allows control over the config keys to accept.
25496 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
25497 Set the role names allowed to be used by users running the perms command.
25499 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
25500 This setting controls the commands and features to enable within Gitolite.
25506 @node Game Services
25507 @subsection Game Services
25509 @subsubheading The Battle for Wesnoth Service
25511 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
25512 based tactical strategy game, with several single player campaigns, and
25513 multiplayer games (both networked and local).
25515 @defvar {Scheme Variable} wesnothd-service-type
25516 Service type for the wesnothd service. Its value must be a
25517 @code{wesnothd-configuration} object. To run wesnothd in the default
25518 configuration, instantiate it as:
25521 (service wesnothd-service-type)
25525 @deftp {Data Type} wesnothd-configuration
25526 Data type representing the configuration of @command{wesnothd}.
25529 @item @code{package} (default: @code{wesnoth-server})
25530 The wesnoth server package to use.
25532 @item @code{port} (default: @code{15000})
25533 The port to bind the server to.
25538 @node PAM Mount Service
25539 @subsection PAM Mount Service
25542 The @code{(gnu services pam-mount)} module provides a service allowing
25543 users to mount volumes when they log in. It should be able to mount any
25544 volume format supported by the system.
25546 @defvar {Scheme Variable} pam-mount-service-type
25547 Service type for PAM Mount support.
25550 @deftp {Data Type} pam-mount-configuration
25551 Data type representing the configuration of PAM Mount.
25553 It takes the following parameters:
25557 The configuration rules that will be used to generate
25558 @file{/etc/security/pam_mount.conf.xml}.
25560 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
25561 Guile Reference Manual}), and the the default ones don't mount anything
25562 for anyone at login:
25565 `((debug (@@ (enable "0")))
25566 (mntoptions (@@ (allow ,(string-join
25567 '("nosuid" "nodev" "loop"
25568 "encryption" "fsck" "nonempty"
25569 "allow_root" "allow_other")
25571 (mntoptions (@@ (require "nosuid,nodev")))
25572 (logout (@@ (wait "0")
25576 (mkmountpoint (@@ (enable "1")
25580 Some @code{volume} elements must be added to automatically mount volumes
25581 at login. Here's an example allowing the user @code{alice} to mount her
25582 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
25583 the partition where he stores his data:
25586 (define pam-mount-rules
25587 `((debug (@@ (enable "0")))
25588 (volume (@@ (user "alice")
25591 (mountpoint "/home/alice")))
25592 (volume (@@ (user "bob")
25595 (mountpoint "/home/bob/data")
25596 (options "defaults,autodefrag,compress")))
25597 (mntoptions (@@ (allow ,(string-join
25598 '("nosuid" "nodev" "loop"
25599 "encryption" "fsck" "nonempty"
25600 "allow_root" "allow_other")
25602 (mntoptions (@@ (require "nosuid,nodev")))
25603 (logout (@@ (wait "0")
25607 (mkmountpoint (@@ (enable "1")
25608 (remove "true")))))
25610 (service pam-mount-service-type
25611 (pam-mount-configuration
25612 (rules pam-mount-rules)))
25615 The complete list of possible options can be found in the man page for
25616 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25621 @node Guix Services
25622 @subsection Guix Services
25624 @subsubheading Guix Data Service
25625 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25626 and provides data about GNU Guix. This includes information about
25627 packages, derivations and lint warnings.
25629 The data is stored in a PostgreSQL database, and available through a web
25632 @defvar {Scheme Variable} guix-data-service-type
25633 Service type for the Guix Data Service. Its value must be a
25634 @code{guix-data-service-configuration} object. The service optionally
25635 extends the getmail service, as the guix-commits mailing list is used to
25636 find out about changes in the Guix git repository.
25639 @deftp {Data Type} guix-data-service-configuration
25640 Data type representing the configuration of the Guix Data Service.
25643 @item @code{package} (default: @code{guix-data-service})
25644 The Guix Data Service package to use.
25646 @item @code{user} (default: @code{"guix-data-service"})
25647 The system user to run the service as.
25649 @item @code{group} (default: @code{"guix-data-service"})
25650 The system group to run the service as.
25652 @item @code{port} (default: @code{8765})
25653 The port to bind the web service to.
25655 @item @code{host} (default: @code{"127.0.0.1"})
25656 The host to bind the web service to.
25658 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25659 If set, this is the list of mailboxes that the getmail service will be
25660 configured to listen to.
25662 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25663 If set, this is the @code{getmail-retriever-configuration} object with
25664 which to configure getmail to fetch mail from the guix-commits mailing
25667 @item @code{extra-options} (default: @var{'()})
25668 Extra command line options for @code{guix-data-service}.
25670 @item @code{extra-process-jobs-options} (default: @var{'()})
25671 Extra command line options for @code{guix-data-service-process-jobs}.
25676 @node Linux Services
25677 @subsection Linux Services
25680 @cindex out of memory killer
25682 @cindex early out of memory daemon
25683 @subsubheading Early OOM Service
25685 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
25686 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
25687 space and provides a more responsive and configurable alternative to the
25688 in-kernel OOM killer. It is useful to prevent the system from becoming
25689 unresponsive when it runs out of memory.
25691 @deffn {Scheme Variable} earlyoom-service-type
25692 The service type for running @command{earlyoom}, the Early OOM daemon.
25693 Its value must be a @code{earlyoom-configuration} object, described
25694 below. The service can be instantiated in its default configuration
25698 (service earlyoom-service-type)
25702 @deftp {Data Type} earlyoom-configuration
25703 This is the configuration record for the @code{earlyoom-service-type}.
25706 @item @code{earlyoom} (default: @var{earlyoom})
25707 The Earlyoom package to use.
25709 @item @code{minimum-available-memory} (default: @code{10})
25710 The threshold for the minimum @emph{available} memory, in percentages.
25712 @item @code{minimum-free-swap} (default: @code{10})
25713 The threshold for the minimum free swap memory, in percentages.
25715 @item @code{prefer-regexp} (default: @code{#f})
25716 A regular expression (as a string) to match the names of the processes
25717 that should be preferably killed.
25719 @item @code{avoid-regexp} (default: @code{#f})
25720 A regular expression (as a string) to match the names of the processes
25721 that should @emph{not} be killed.
25723 @item @code{memory-report-interval} (default: @code{0})
25724 The interval in seconds at which a memory report is printed. It is
25725 disabled by default.
25727 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
25728 A boolean indicating whether the positive adjustments set in
25729 @file{/proc/*/oom_score_adj}.
25731 @item @code{show-debug-messages?} (default: @code{#f})
25732 A boolean indicating whether debug messages should be printed. The logs
25733 are saved at @file{/var/log/earlyoom.log}.
25735 @item @code{send-notification-command} (default: @code{#f})
25736 This can be used to provide a custom command used for sending
25742 @cindex kernel module loader
25743 @subsubheading Kernel Module Loader Service
25745 The kernel module loader service allows one to load loadable kernel
25746 modules at boot. This is especially useful for modules that don't
25747 autoload and need to be manually loaded, as it's the case with
25750 @deffn {Scheme Variable} kernel-module-loader-service-type
25751 The service type for loading loadable kernel modules at boot with
25752 @command{modprobe}. Its value must be a list of strings representing
25753 module names. For example loading the drivers provided by
25754 @code{ddcci-driver-linux}, in debugging mode by passing some module
25755 parameters, can be done as follow:
25758 (use-modules (gnu) (gnu services))
25759 (use-package-modules linux)
25760 (use-service-modules linux)
25762 (define ddcci-config
25763 (plain-file "ddcci.conf"
25764 "options ddcci dyndbg delay=120"))
25768 (services (cons* (service kernel-module-loader-service-type
25769 '("ddcci" "ddcci_backlight"))
25770 (simple-service 'ddcci-config etc-service-type
25771 (list `("modprobe.d/ddcci.conf"
25774 (kernel-loadable-modules (list ddcci-driver-linux)))
25778 @node Miscellaneous Services
25779 @subsection Miscellaneous Services
25781 @cindex fingerprint
25782 @subsubheading Fingerprint Service
25784 The @code{(gnu services authentication)} module provides a DBus service to
25785 read and identify fingerprints via a fingerprint sensor.
25787 @defvr {Scheme Variable} fprintd-service-type
25788 The service type for @command{fprintd}, which provides the fingerprint
25789 reading capability.
25792 (service fprintd-service-type)
25797 @subsubheading System Control Service
25799 The @code{(gnu services sysctl)} provides a service to configure kernel
25800 parameters at boot.
25802 @defvr {Scheme Variable} sysctl-service-type
25803 The service type for @command{sysctl}, which modifies kernel parameters
25804 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25808 (service sysctl-service-type
25809 (sysctl-configuration
25810 (settings '(("net.ipv4.ip_forward" . "1")))))
25814 @deftp {Data Type} sysctl-configuration
25815 The data type representing the configuration of @command{sysctl}.
25818 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25819 The @command{sysctl} executable to use.
25821 @item @code{settings} (default: @code{'()})
25822 An association list specifies kernel parameters and their values.
25827 @subsubheading PC/SC Smart Card Daemon Service
25829 The @code{(gnu services security-token)} module provides the following service
25830 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25831 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25832 manager that coordinates communications with smart card readers, smart cards
25833 and cryptographic tokens that are connected to the system.
25835 @defvr {Scheme Variable} pcscd-service-type
25836 Service type for the @command{pcscd} service. Its value must be a
25837 @code{pcscd-configuration} object. To run pcscd in the default
25838 configuration, instantiate it as:
25841 (service pcscd-service-type)
25845 @deftp {Data Type} pcscd-configuration
25846 The data type representing the configuration of @command{pcscd}.
25849 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25850 The pcsc-lite package that provides pcscd.
25851 @item @code{usb-drivers} (default: @code{(list ccid)})
25852 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25853 under @file{pcsc/drivers} in the store directory of the package.
25858 @subsubheading Lirc Service
25860 The @code{(gnu services lirc)} module provides the following service.
25862 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25863 [#:device #f] [#:driver #f] [#:config-file #f] @
25864 [#:extra-options '()]
25865 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25866 decodes infrared signals from remote controls.
25868 Optionally, @var{device}, @var{driver} and @var{config-file}
25869 (configuration file name) may be specified. See @command{lircd} manual
25872 Finally, @var{extra-options} is a list of additional command-line options
25873 passed to @command{lircd}.
25877 @subsubheading Spice Service
25879 The @code{(gnu services spice)} module provides the following service.
25881 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25882 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25883 that enables sharing the clipboard with a vm and setting the guest display
25884 resolution when the graphical console window resizes.
25887 @cindex inputattach
25888 @subsubheading inputattach Service
25890 @cindex tablet input, for Xorg
25891 @cindex touchscreen input, for Xorg
25892 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25893 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25894 Xorg display server.
25896 @deffn {Scheme Variable} inputattach-service-type
25897 Type of a service that runs @command{inputattach} on a device and
25898 dispatches events from it.
25901 @deftp {Data Type} inputattach-configuration
25903 @item @code{device-type} (default: @code{"wacom"})
25904 The type of device to connect to. Run @command{inputattach --help}, from the
25905 @code{inputattach} package, to see the list of supported device types.
25907 @item @code{device} (default: @code{"/dev/ttyS0"})
25908 The device file to connect to the device.
25910 @item @code{baud-rate} (default: @code{#f})
25911 Baud rate to use for the serial connection.
25912 Should be a number or @code{#f}.
25914 @item @code{log-file} (default: @code{#f})
25915 If true, this must be the name of a file to log messages to.
25919 @subsubheading Dictionary Service
25921 The @code{(gnu services dict)} module provides the following service:
25923 @defvr {Scheme Variable} dicod-service-type
25924 This is the type of the service that runs the @command{dicod} daemon, an
25925 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25928 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25929 Return a service that runs the @command{dicod} daemon, an implementation
25930 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25932 The optional @var{config} argument specifies the configuration for
25933 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25934 default it serves the GNU Collaborative International Dictionary of English.
25936 You can add @command{open localhost} to your @file{~/.dico} file to make
25937 @code{localhost} the default server for @command{dico} client
25938 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25941 @deftp {Data Type} dicod-configuration
25942 Data type representing the configuration of dicod.
25945 @item @code{dico} (default: @var{dico})
25946 Package object of the GNU Dico dictionary server.
25948 @item @code{interfaces} (default: @var{'("localhost")})
25949 This is the list of IP addresses and ports and possibly socket file
25950 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25951 dico, GNU Dico Manual}).
25953 @item @code{handlers} (default: @var{'()})
25954 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25956 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25957 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25961 @deftp {Data Type} dicod-handler
25962 Data type representing a dictionary handler (module instance).
25966 Name of the handler (module instance).
25968 @item @code{module} (default: @var{#f})
25969 Name of the dicod module of the handler (instance). If it is @code{#f},
25970 the module has the same name as the handler.
25971 (@pxref{Modules,,, dico, GNU Dico Manual}).
25973 @item @code{options}
25974 List of strings or gexps representing the arguments for the module handler
25978 @deftp {Data Type} dicod-database
25979 Data type representing a dictionary database.
25983 Name of the database, will be used in DICT commands.
25985 @item @code{handler}
25986 Name of the dicod handler (module instance) used by this database
25987 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25989 @item @code{complex?} (default: @var{#f})
25990 Whether the database configuration complex. The complex configuration
25991 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25993 @item @code{options}
25994 List of strings or gexps representing the arguments for the database
25995 (@pxref{Databases,,, dico, GNU Dico Manual}).
25999 @defvr {Scheme Variable} %dicod-database:gcide
26000 A @code{<dicod-database>} object serving the GNU Collaborative International
26001 Dictionary of English using the @code{gcide} package.
26004 The following is an example @code{dicod-service} configuration.
26007 (dicod-service #:config
26008 (dicod-configuration
26009 (handlers (list (dicod-handler
26013 (list #~(string-append "dbdir=" #$wordnet))))))
26014 (databases (list (dicod-database
26017 (handler "wordnet")
26018 (options '("database=wn")))
26019 %dicod-database:gcide))))
26023 @subsubheading Docker Service
26025 The @code{(gnu services docker)} module provides the following services.
26027 @defvr {Scheme Variable} docker-service-type
26029 This is the type of the service that runs @url{https://www.docker.com,Docker},
26030 a daemon that can execute application bundles (sometimes referred to as
26031 ``containers'') in isolated environments.
26035 @deftp {Data Type} docker-configuration
26036 This is the data type representing the configuration of Docker and Containerd.
26040 @item @code{package} (default: @code{docker})
26041 The Docker package to use.
26043 @item @code{containerd} (default: @var{containerd})
26044 The Containerd package to use.
26050 @subsubheading Auditd Service
26052 The @code{(gnu services auditd)} module provides the following service.
26054 @defvr {Scheme Variable} auditd-service-type
26056 This is the type of the service that runs
26057 @url{https://people.redhat.com/sgrubb/audit/,auditd},
26058 a daemon that tracks security-relevant information on your system.
26060 Examples of things that can be tracked:
26070 Failed login attempts
26077 @command{auditctl} from the @code{audit} package can be used in order
26078 to add or remove events to be tracked (until the next reboot).
26079 In order to permanently track events, put the command line arguments
26080 of auditctl into @file{/etc/audit/audit.rules}.
26081 @command{aureport} from the @code{audit} package can be used in order
26082 to view a report of all recorded events.
26083 The audit daemon usually logs into the directory @file{/var/log/audit}.
26087 @deftp {Data Type} auditd-configuration
26088 This is the data type representing the configuration of auditd.
26092 @item @code{audit} (default: @code{audit})
26093 The audit package to use.
26098 @defvr {Scheme Variable} singularity-service-type
26099 This is the type of the service that allows you to run
26100 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
26101 create and run application bundles (aka. ``containers''). The value for this
26102 service is the Singularity package to use.
26104 The service does not install a daemon; instead, it installs helper programs as
26105 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
26106 @command{singularity run} and similar commands.
26110 @subsubheading Nix service
26112 The @code{(gnu services nix)} module provides the following service.
26114 @defvr {Scheme Variable} nix-service-type
26116 This is the type of the service that runs build daemon of the
26117 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
26121 (use-modules (gnu))
26122 (use-service-modules nix)
26123 (use-package-modules package-management)
26127 (packages (append (list nix)
26130 (services (append (list (service nix-service-type))
26134 After @command{guix system reconfigure} configure Nix for your user:
26137 @item Add a Nix channel and update it. See
26138 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
26140 @item Create a symlink to your profile and activate Nix profile:
26144 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
26145 $ source /run/current-system/profile/etc/profile.d/nix.sh
26150 @node Setuid Programs
26151 @section Setuid Programs
26153 @cindex setuid programs
26154 Some programs need to run with ``root'' privileges, even when they are
26155 launched by unprivileged users. A notorious example is the
26156 @command{passwd} program, which users can run to change their
26157 password, and which needs to access the @file{/etc/passwd} and
26158 @file{/etc/shadow} files---something normally restricted to root, for
26159 obvious security reasons. To address that, these executables are
26160 @dfn{setuid-root}, meaning that they always run with root privileges
26161 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
26162 for more info about the setuid mechanism.)
26164 The store itself @emph{cannot} contain setuid programs: that would be a
26165 security issue since any user on the system can write derivations that
26166 populate the store (@pxref{The Store}). Thus, a different mechanism is
26167 used: instead of changing the setuid bit directly on files that are in
26168 the store, we let the system administrator @emph{declare} which programs
26169 should be setuid root.
26171 The @code{setuid-programs} field of an @code{operating-system}
26172 declaration contains a list of G-expressions denoting the names of
26173 programs to be setuid-root (@pxref{Using the Configuration System}).
26174 For instance, the @command{passwd} program, which is part of the Shadow
26175 package, can be designated by this G-expression (@pxref{G-Expressions}):
26178 #~(string-append #$shadow "/bin/passwd")
26181 A default set of setuid programs is defined by the
26182 @code{%setuid-programs} variable of the @code{(gnu system)} module.
26184 @defvr {Scheme Variable} %setuid-programs
26185 A list of G-expressions denoting common programs that are setuid-root.
26187 The list includes commands such as @command{passwd}, @command{ping},
26188 @command{su}, and @command{sudo}.
26191 Under the hood, the actual setuid programs are created in the
26192 @file{/run/setuid-programs} directory at system activation time. The
26193 files in this directory refer to the ``real'' binaries, which are in the
26196 @node X.509 Certificates
26197 @section X.509 Certificates
26199 @cindex HTTPS, certificates
26200 @cindex X.509 certificates
26202 Web servers available over HTTPS (that is, HTTP over the transport-layer
26203 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
26204 that the client can then use to @emph{authenticate} the server. To do
26205 that, clients verify that the server's certificate is signed by a
26206 so-called @dfn{certificate authority} (CA). But to verify the CA's
26207 signature, clients must have first acquired the CA's certificate.
26209 Web browsers such as GNU@tie{}IceCat include their own set of CA
26210 certificates, such that they are able to verify CA signatures
26213 However, most other programs that can talk HTTPS---@command{wget},
26214 @command{git}, @command{w3m}, etc.---need to be told where CA
26215 certificates can be found.
26217 @cindex @code{nss-certs}
26218 In Guix, this is done by adding a package that provides certificates
26219 to the @code{packages} field of the @code{operating-system} declaration
26220 (@pxref{operating-system Reference}). Guix includes one such package,
26221 @code{nss-certs}, which is a set of CA certificates provided as part of
26222 Mozilla's Network Security Services.
26224 Note that it is @emph{not} part of @code{%base-packages}, so you need to
26225 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
26226 most applications and libraries look for certificates by default, points
26227 to the certificates installed globally.
26229 Unprivileged users, including users of Guix on a foreign distro,
26230 can also install their own certificate package in
26231 their profile. A number of environment variables need to be defined so
26232 that applications and libraries know where to find them. Namely, the
26233 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
26234 variables. Some applications add their own environment variables; for
26235 instance, the Git version control system honors the certificate bundle
26236 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
26237 would typically run something like:
26240 guix install nss-certs
26241 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
26242 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26243 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
26246 As another example, R requires the @env{CURL_CA_BUNDLE} environment
26247 variable to point to a certificate bundle, so you would have to run
26248 something like this:
26251 guix install nss-certs
26252 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26255 For other applications you may want to look up the required environment
26256 variable in the relevant documentation.
26259 @node Name Service Switch
26260 @section Name Service Switch
26262 @cindex name service switch
26264 The @code{(gnu system nss)} module provides bindings to the
26265 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
26266 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
26267 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
26268 extended with new ``name'' lookup methods for system databases, which
26269 includes host names, service names, user accounts, and more (@pxref{Name
26270 Service Switch, System Databases and Name Service Switch,, libc, The GNU
26271 C Library Reference Manual}).
26273 The NSS configuration specifies, for each system database, which lookup
26274 method is to be used, and how the various methods are chained
26275 together---for instance, under which circumstances NSS should try the
26276 next method in the list. The NSS configuration is given in the
26277 @code{name-service-switch} field of @code{operating-system} declarations
26278 (@pxref{operating-system Reference, @code{name-service-switch}}).
26281 @cindex .local, host name lookup
26282 As an example, the declaration below configures the NSS to use the
26283 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
26284 back-end}, which supports host name lookups over multicast DNS (mDNS)
26285 for host names ending in @code{.local}:
26288 (name-service-switch
26289 (hosts (list %files ;first, check /etc/hosts
26291 ;; If the above did not succeed, try
26292 ;; with 'mdns_minimal'.
26294 (name "mdns_minimal")
26296 ;; 'mdns_minimal' is authoritative for
26297 ;; '.local'. When it returns "not found",
26298 ;; no need to try the next methods.
26299 (reaction (lookup-specification
26300 (not-found => return))))
26302 ;; Then fall back to DNS.
26306 ;; Finally, try with the "full" 'mdns'.
26311 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
26312 contains this configuration, so you will not have to type it if all you
26313 want is to have @code{.local} host lookup working.
26315 Note that, in this case, in addition to setting the
26316 @code{name-service-switch} of the @code{operating-system} declaration,
26317 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
26318 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
26319 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
26320 to the name service cache daemon (@pxref{Base Services,
26321 @code{nscd-service}}).
26323 For convenience, the following variables provide typical NSS
26326 @defvr {Scheme Variable} %default-nss
26327 This is the default name service switch configuration, a
26328 @code{name-service-switch} object.
26331 @defvr {Scheme Variable} %mdns-host-lookup-nss
26332 This is the name service switch configuration with support for host name
26333 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
26336 The reference for name service switch configuration is given below. It
26337 is a direct mapping of the configuration file format of the C library , so
26338 please refer to the C library manual for more information (@pxref{NSS
26339 Configuration File,,, libc, The GNU C Library Reference Manual}).
26340 Compared to the configuration file format of libc NSS, it has the advantage
26341 not only of adding this warm parenthetic feel that we like, but also
26342 static checks: you will know about syntax errors and typos as soon as you
26343 run @command{guix system}.
26345 @deftp {Data Type} name-service-switch
26347 This is the data type representation the configuration of libc's name
26348 service switch (NSS). Each field below represents one of the supported
26365 The system databases handled by the NSS. Each of these fields must be a
26366 list of @code{<name-service>} objects (see below).
26370 @deftp {Data Type} name-service
26372 This is the data type representing an actual name service and the
26373 associated lookup action.
26377 A string denoting the name service (@pxref{Services in the NSS
26378 configuration,,, libc, The GNU C Library Reference Manual}).
26380 Note that name services listed here must be visible to nscd. This is
26381 achieved by passing the @code{#:name-services} argument to
26382 @code{nscd-service} the list of packages providing the needed name
26383 services (@pxref{Base Services, @code{nscd-service}}).
26386 An action specified using the @code{lookup-specification} macro
26387 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
26388 Reference Manual}). For example:
26391 (lookup-specification (unavailable => continue)
26392 (success => return))
26397 @node Initial RAM Disk
26398 @section Initial RAM Disk
26401 @cindex initial RAM disk
26402 For bootstrapping purposes, the Linux-Libre kernel is passed an
26403 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
26404 root file system as well as an initialization script. The latter is
26405 responsible for mounting the real root file system, and for loading any
26406 kernel modules that may be needed to achieve that.
26408 The @code{initrd-modules} field of an @code{operating-system}
26409 declaration allows you to specify Linux-libre kernel modules that must
26410 be available in the initrd. In particular, this is where you would list
26411 modules needed to actually drive the hard disk where your root partition
26412 is---although the default value of @code{initrd-modules} should cover
26413 most use cases. For example, assuming you need the @code{megaraid_sas}
26414 module in addition to the default modules to be able to access your root
26415 file system, you would write:
26420 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
26423 @defvr {Scheme Variable} %base-initrd-modules
26424 This is the list of kernel modules included in the initrd by default.
26427 Furthermore, if you need lower-level customization, the @code{initrd}
26428 field of an @code{operating-system} declaration allows
26429 you to specify which initrd you would like to use. The @code{(gnu
26430 system linux-initrd)} module provides three ways to build an initrd: the
26431 high-level @code{base-initrd} procedure and the low-level
26432 @code{raw-initrd} and @code{expression->initrd} procedures.
26434 The @code{base-initrd} procedure is intended to cover most common uses.
26435 For example, if you want to add a bunch of kernel modules to be loaded
26436 at boot time, you can define the @code{initrd} field of the operating
26437 system declaration like this:
26440 (initrd (lambda (file-systems . rest)
26441 ;; Create a standard initrd but set up networking
26442 ;; with the parameters QEMU expects by default.
26443 (apply base-initrd file-systems
26444 #:qemu-networking? #t
26448 The @code{base-initrd} procedure also handles common use cases that
26449 involves using the system as a QEMU guest, or as a ``live'' system with
26450 volatile root file system.
26452 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
26453 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
26454 such as trying to guess which kernel modules and packages should be included
26455 to the initrd. An example use of @code{raw-initrd} is when a user has
26456 a custom Linux kernel configuration and default kernel modules included by
26457 @code{base-initrd} are not available.
26459 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
26460 honors several options passed on the Linux kernel command line
26461 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
26462 @code{-append} option of QEMU), notably:
26465 @item --load=@var{boot}
26466 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
26467 program, once it has mounted the root file system.
26469 Guix uses this option to yield control to a boot program that runs the
26470 service activation programs and then spawns the GNU@tie{}Shepherd, the
26471 initialization system.
26473 @item --root=@var{root}
26474 Mount @var{root} as the root file system. @var{root} can be a
26475 device name like @code{/dev/sda1}, a file system label, or a file system
26478 @item --system=@var{system}
26479 Have @file{/run/booted-system} and @file{/run/current-system} point to
26482 @item modprobe.blacklist=@var{modules}@dots{}
26483 @cindex module, black-listing
26484 @cindex black list, of kernel modules
26485 Instruct the initial RAM disk as well as the @command{modprobe} command
26486 (from the kmod package) to refuse to load @var{modules}. @var{modules}
26487 must be a comma-separated list of module names---e.g.,
26488 @code{usbkbd,9pnet}.
26491 Start a read-eval-print loop (REPL) from the initial RAM disk before it
26492 tries to load kernel modules and to mount the root file system. Our
26493 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
26494 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
26495 Manual}, for more information on Guile's REPL.
26499 Now that you know all the features that initial RAM disks produced by
26500 @code{base-initrd} and @code{raw-initrd} provide,
26501 here is how to use it and customize it further.
26504 @cindex initial RAM disk
26505 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
26506 [#:linux-modules '()] [#:mapped-devices '()] @
26507 [#:keyboard-layout #f] @
26508 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
26509 Return a derivation that builds a raw initrd. @var{file-systems} is
26510 a list of file systems to be mounted by the initrd, possibly in addition to
26511 the root file system specified on the kernel command line via @option{--root}.
26512 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
26513 @var{mapped-devices} is a list of device mappings to realize before
26514 @var{file-systems} are mounted (@pxref{Mapped Devices}).
26515 @var{helper-packages} is a list of packages to be copied in the initrd. It may
26516 include @code{e2fsck/static} or other packages needed by the initrd to check
26517 the root file system.
26519 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26520 the desired console keyboard layout. This is done before @var{mapped-devices}
26521 are set up and before @var{file-systems} are mounted such that, should the
26522 user need to enter a passphrase or use the REPL, this happens using the
26523 intended keyboard layout.
26525 When @var{qemu-networking?} is true, set up networking with the standard QEMU
26526 parameters. When @var{virtio?} is true, load additional modules so that the
26527 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
26529 When @var{volatile-root?} is true, the root file system is writable but any changes
26533 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
26534 [#:mapped-devices '()] [#:keyboard-layout #f] @
26535 [#:qemu-networking? #f] [#:volatile-root? #f] @
26536 [#:linux-modules '()]
26537 Return as a file-like object a generic initrd, with kernel
26538 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
26539 mounted by the initrd, possibly in addition to the root file system specified
26540 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
26541 mappings to realize before @var{file-systems} are mounted.
26543 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26544 the desired console keyboard layout. This is done before @var{mapped-devices}
26545 are set up and before @var{file-systems} are mounted such that, should the
26546 user need to enter a passphrase or use the REPL, this happens using the
26547 intended keyboard layout.
26549 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
26551 The initrd is automatically populated with all the kernel modules necessary
26552 for @var{file-systems} and for the given options. Additional kernel
26553 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
26554 loaded at boot time in the order in which they appear.
26557 Needless to say, the initrds we produce and use embed a
26558 statically-linked Guile, and the initialization program is a Guile
26559 program. That gives a lot of flexibility. The
26560 @code{expression->initrd} procedure builds such an initrd, given the
26561 program to run in that initrd.
26563 @deffn {Scheme Procedure} expression->initrd @var{exp} @
26564 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
26565 Return as a file-like object a Linux initrd (a gzipped cpio archive)
26566 containing @var{guile} and that evaluates @var{exp}, a G-expression,
26567 upon booting. All the derivations referenced by @var{exp} are
26568 automatically copied to the initrd.
26571 @node Bootloader Configuration
26572 @section Bootloader Configuration
26575 @cindex boot loader
26577 The operating system supports multiple bootloaders. The bootloader is
26578 configured using @code{bootloader-configuration} declaration. All the
26579 fields of this structure are bootloader agnostic except for one field,
26580 @code{bootloader} that indicates the bootloader to be configured and
26583 Some of the bootloaders do not honor every field of
26584 @code{bootloader-configuration}. For instance, the extlinux
26585 bootloader does not support themes and thus ignores the @code{theme}
26588 @deftp {Data Type} bootloader-configuration
26589 The type of a bootloader configuration declaration.
26593 @item @code{bootloader}
26594 @cindex EFI, bootloader
26595 @cindex UEFI, bootloader
26596 @cindex BIOS, bootloader
26597 The bootloader to use, as a @code{bootloader} object. For now
26598 @code{grub-bootloader}, @code{grub-efi-bootloader},
26599 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
26601 @vindex grub-efi-bootloader
26602 @code{grub-efi-bootloader} allows to boot on modern systems using the
26603 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
26604 use if the installation image contains a @file{/sys/firmware/efi} directory
26605 when you boot it on your system.
26607 @vindex grub-bootloader
26608 @code{grub-bootloader} allows you to boot in particular Intel-based machines
26609 in ``legacy'' BIOS mode.
26611 @cindex ARM, bootloaders
26612 @cindex AArch64, bootloaders
26613 Available bootloaders are described in @code{(gnu bootloader @dots{})}
26614 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
26615 of bootloaders for a wide range of ARM and AArch64 systems, using the
26616 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
26618 @item @code{target}
26619 This is a string denoting the target onto which to install the
26622 The interpretation depends on the bootloader in question. For
26623 @code{grub-bootloader}, for example, it should be a device name understood by
26624 the bootloader @command{installer} command, such as @code{/dev/sda} or
26625 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
26626 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
26627 system, usually @file{/boot/efi}.
26629 @item @code{menu-entries} (default: @code{()})
26630 A possibly empty list of @code{menu-entry} objects (see below), denoting
26631 entries to appear in the bootloader menu, in addition to the current
26632 system entry and the entry pointing to previous system generations.
26634 @item @code{default-entry} (default: @code{0})
26635 The index of the default boot menu entry. Index 0 is for the entry of the
26638 @item @code{timeout} (default: @code{5})
26639 The number of seconds to wait for keyboard input before booting. Set to
26640 0 to boot immediately, and to -1 to wait indefinitely.
26642 @cindex keyboard layout, for the bootloader
26643 @item @code{keyboard-layout} (default: @code{#f})
26644 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
26645 layout, usually US@tie{}English (``qwerty'').
26647 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
26651 This option is currently ignored by bootloaders other than @code{grub} and
26655 @item @code{theme} (default: @var{#f})
26656 The bootloader theme object describing the theme to use. If no theme
26657 is provided, some bootloaders might use a default theme, that's true
26660 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
26661 The output terminals used for the bootloader boot menu, as a list of
26662 symbols. GRUB accepts the values: @code{console}, @code{serial},
26663 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
26664 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
26665 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
26666 configuration,,, grub,GNU GRUB manual}).
26668 @item @code{terminal-inputs} (default: @code{'()})
26669 The input terminals used for the bootloader boot menu, as a list of
26670 symbols. For GRUB, the default is the native platform terminal as
26671 determined at run-time. GRUB accepts the values: @code{console},
26672 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
26673 @code{usb_keyboard}. This field corresponds to the GRUB variable
26674 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
26677 @item @code{serial-unit} (default: @code{#f})
26678 The serial unit used by the bootloader, as an integer from 0 to 3.
26679 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
26680 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26682 @item @code{serial-speed} (default: @code{#f})
26683 The speed of the serial interface, as an integer. For GRUB, the
26684 default value is chosen at run-time; currently GRUB chooses
26685 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26692 Should you want to list additional boot menu entries @i{via} the
26693 @code{menu-entries} field above, you will need to create them with the
26694 @code{menu-entry} form. For example, imagine you want to be able to
26695 boot another distro (hard to imagine!), you can define a menu entry
26700 (label "The Other Distro")
26701 (linux "/boot/old/vmlinux-2.6.32")
26702 (linux-arguments '("root=/dev/sda2"))
26703 (initrd "/boot/old/initrd"))
26708 @deftp {Data Type} menu-entry
26709 The type of an entry in the bootloader menu.
26714 The label to show in the menu---e.g., @code{"GNU"}.
26717 The Linux kernel image to boot, for example:
26720 (file-append linux-libre "/bzImage")
26723 For GRUB, it is also possible to specify a device explicitly in the
26724 file path using GRUB's device naming convention (@pxref{Naming
26725 convention,,, grub, GNU GRUB manual}), for example:
26728 "(hd0,msdos1)/boot/vmlinuz"
26731 If the device is specified explicitly as above, then the @code{device}
26732 field is ignored entirely.
26734 @item @code{linux-arguments} (default: @code{()})
26735 The list of extra Linux kernel command-line arguments---e.g.,
26736 @code{("console=ttyS0")}.
26738 @item @code{initrd}
26739 A G-Expression or string denoting the file name of the initial RAM disk
26740 to use (@pxref{G-Expressions}).
26741 @item @code{device} (default: @code{#f})
26742 The device where the kernel and initrd are to be found---i.e., for GRUB,
26743 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26745 This may be a file system label (a string), a file system UUID (a
26746 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26747 the bootloader will search the device containing the file specified by
26748 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26749 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26757 @c FIXME: Write documentation once it's stable.
26758 For now only GRUB has theme support. GRUB themes are created using
26759 the @code{grub-theme} form, which is not fully documented yet.
26761 @deftp {Data Type} grub-theme
26762 Data type representing the configuration of the GRUB theme.
26765 @item @code{gfxmode} (default: @code{'("auto")})
26766 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
26767 @pxref{gfxmode,,, grub, GNU GRUB manual}).
26771 @defvr {Scheme Variable} %default-theme
26772 This is the default GRUB theme used by the operating system if no
26773 @code{theme} field is specified in @code{bootloader-configuration}
26776 It comes with a fancy background image displaying the GNU and Guix
26780 For example, to override the default resolution, you may use something
26785 (bootloader-configuration
26788 (inherit %default-theme)
26789 (gfxmode '("1024x786x32" "auto"))))))
26792 @node Invoking guix system
26793 @section Invoking @code{guix system}
26795 Once you have written an operating system declaration as seen in the
26796 previous section, it can be @dfn{instantiated} using the @command{guix
26797 system} command. The synopsis is:
26800 guix system @var{options}@dots{} @var{action} @var{file}
26803 @var{file} must be the name of a file containing an
26804 @code{operating-system} declaration. @var{action} specifies how the
26805 operating system is instantiated. Currently the following values are
26810 Display available service type definitions that match the given regular
26811 expressions, sorted by relevance:
26817 $ guix system search console
26818 name: console-fonts
26819 location: gnu/services/base.scm:806:2
26820 extends: shepherd-root
26821 description: Install the given fonts on the specified ttys (fonts are per
26822 + virtual console on GNU/Linux). The value of this service is a list of
26823 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26824 + package or any valid argument to `setfont', as in this example:
26826 + '(("tty1" . "LatGrkCyr-8x16")
26827 + ("tty2" . (file-append
26829 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26830 + ("tty3" . (file-append
26832 + "/share/consolefonts/ter-132n"))) ; for HDPI
26836 location: gnu/services/base.scm:1190:2
26837 extends: shepherd-root
26838 description: Provide console login using the `mingetty' program.
26842 location: gnu/services/base.scm:860:2
26844 description: Provide a console log-in service as specified by its
26845 + configuration value, a `login-configuration' object.
26851 As for @command{guix package --search}, the result is written in
26852 @code{recutils} format, which makes it easy to filter the output
26853 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26856 Build the operating system described in @var{file}, activate it, and
26857 switch to it@footnote{This action (and the related actions
26858 @code{switch-generation} and @code{roll-back}) are usable only on
26859 systems already running Guix System.}.
26862 @c The paragraph below refers to the problem discussed at
26863 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26864 It is highly recommended to run @command{guix pull} once before you run
26865 @command{guix system reconfigure} for the first time (@pxref{Invoking
26866 guix pull}). Failing to do that you would see an older version of Guix
26867 once @command{reconfigure} has completed.
26870 This effects all the configuration specified in @var{file}: user
26871 accounts, system services, global package list, setuid programs, etc.
26872 The command starts system services specified in @var{file} that are not
26873 currently running; if a service is currently running this command will
26874 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26875 @code{herd stop X} or @code{herd restart X}).
26877 This command creates a new generation whose number is one greater than
26878 the current generation (as reported by @command{guix system
26879 list-generations}). If that generation already exists, it will be
26880 overwritten. This behavior mirrors that of @command{guix package}
26881 (@pxref{Invoking guix package}).
26883 It also adds a bootloader menu entry for the new OS configuration,
26884 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26885 entries for older configurations to a submenu, allowing you to choose
26886 an older system generation at boot time should you need it.
26888 @cindex provenance tracking, of the operating system
26889 Upon completion, the new system is deployed under
26890 @file{/run/current-system}. This directory contains @dfn{provenance
26891 meta-data}: the list of channels in use (@pxref{Channels}) and
26892 @var{file} itself, when available. This information is useful should
26893 you later want to inspect how this particular generation was built.
26895 In fact, assuming @var{file} is self-contained, you can later rebuild
26896 generation @var{n} of your operating system with:
26899 guix time-machine \
26900 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26901 system reconfigure \
26902 /var/guix/profiles/system-@var{n}-link/configuration.scm
26905 You can think of it as some sort of built-in version control! Your
26906 system is not just a binary artifact: @emph{it carries its own source}.
26907 @xref{Service Reference, @code{provenance-service-type}}, for more
26908 information on provenance tracking.
26910 @item switch-generation
26911 @cindex generations
26912 Switch to an existing system generation. This action atomically
26913 switches the system profile to the specified system generation. It
26914 also rearranges the system's existing bootloader menu entries. It
26915 makes the menu entry for the specified system generation the default,
26916 and it moves the entries for the other generations to a submenu, if
26917 supported by the bootloader being used. The next time the system
26918 boots, it will use the specified system generation.
26920 The bootloader itself is not being reinstalled when using this
26921 command. Thus, the installed bootloader is used with an updated
26922 configuration file.
26924 The target generation can be specified explicitly by its generation
26925 number. For example, the following invocation would switch to system
26929 guix system switch-generation 7
26932 The target generation can also be specified relative to the current
26933 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26934 ``3 generations ahead of the current generation,'' and @code{-1} means
26935 ``1 generation prior to the current generation.'' When specifying a
26936 negative value such as @code{-1}, you must precede it with @code{--} to
26937 prevent it from being parsed as an option. For example:
26940 guix system switch-generation -- -1
26943 Currently, the effect of invoking this action is @emph{only} to switch
26944 the system profile to an existing generation and rearrange the
26945 bootloader menu entries. To actually start using the target system
26946 generation, you must reboot after running this action. In the future,
26947 it will be updated to do the same things as @command{reconfigure},
26948 like activating and deactivating services.
26950 This action will fail if the specified generation does not exist.
26953 @cindex rolling back
26954 Switch to the preceding system generation. The next time the system
26955 boots, it will use the preceding system generation. This is the inverse
26956 of @command{reconfigure}, and it is exactly the same as invoking
26957 @command{switch-generation} with an argument of @code{-1}.
26959 Currently, as with @command{switch-generation}, you must reboot after
26960 running this action to actually start using the preceding system
26963 @item delete-generations
26964 @cindex deleting system generations
26965 @cindex saving space
26966 Delete system generations, making them candidates for garbage collection
26967 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
26970 This works in the same way as @samp{guix package --delete-generations}
26971 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
26972 arguments, all system generations but the current one are deleted:
26975 guix system delete-generations
26978 You can also select the generations you want to delete. The example below
26979 deletes all the system generations that are more than two month old:
26982 guix system delete-generations 2m
26985 Running this command automatically reinstalls the bootloader with an updated
26986 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26987 longer lists the generations that have been deleted.
26990 Build the derivation of the operating system, which includes all the
26991 configuration files and programs needed to boot and run the system.
26992 This action does not actually install anything.
26995 Populate the given directory with all the files necessary to run the
26996 operating system specified in @var{file}. This is useful for first-time
26997 installations of Guix System. For instance:
27000 guix system init my-os-config.scm /mnt
27003 copies to @file{/mnt} all the store items required by the configuration
27004 specified in @file{my-os-config.scm}. This includes configuration
27005 files, packages, and so on. It also creates other essential files
27006 needed for the system to operate correctly---e.g., the @file{/etc},
27007 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
27009 This command also installs bootloader on the target specified in
27010 @file{my-os-config}, unless the @option{--no-bootloader} option was
27014 @cindex virtual machine
27016 @anchor{guix system vm}
27017 Build a virtual machine that contains the operating system declared in
27018 @var{file}, and return a script to run that virtual machine (VM).
27021 The @code{vm} action and others below
27022 can use KVM support in the Linux-libre kernel. Specifically, if the
27023 machine has hardware virtualization support, the corresponding
27024 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
27025 must exist and be readable and writable by the user and by the
27026 build users of the daemon (@pxref{Build Environment Setup}).
27029 Arguments given to the script are passed to QEMU as in the example
27030 below, which enables networking and requests 1@tie{}GiB of RAM for the
27034 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
27037 The VM shares its store with the host system.
27039 Additional file systems can be shared between the host and the VM using
27040 the @option{--share} and @option{--expose} command-line options: the former
27041 specifies a directory to be shared with write access, while the latter
27042 provides read-only access to the shared directory.
27044 The example below creates a VM in which the user's home directory is
27045 accessible read-only, and where the @file{/exchange} directory is a
27046 read-write mapping of @file{$HOME/tmp} on the host:
27049 guix system vm my-config.scm \
27050 --expose=$HOME --share=$HOME/tmp=/exchange
27053 On GNU/Linux, the default is to boot directly to the kernel; this has
27054 the advantage of requiring only a very tiny root disk image since the
27055 store of the host can then be mounted.
27057 The @option{--full-boot} option forces a complete boot sequence, starting
27058 with the bootloader. This requires more disk space since a root image
27059 containing at least the kernel, initrd, and bootloader data files must
27060 be created. The @option{--image-size} option can be used to specify the
27063 @cindex System images, creation in various formats
27064 @cindex Creating system images in various formats
27067 @itemx docker-image
27068 Return a virtual machine, disk image, or Docker image of the operating
27069 system declared in @var{file} that stands alone. By default,
27070 @command{guix system} estimates the size of the image needed to store
27071 the system, but you can use the @option{--image-size} option to specify
27072 a value. Docker images are built to contain exactly what they need, so
27073 the @option{--image-size} option is ignored in the case of
27074 @code{docker-image}.
27076 You can specify the root file system type by using the
27077 @option{--file-system-type} option. It defaults to @code{ext4}.
27079 When using @code{vm-image}, the returned image is in qcow2 format, which
27080 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
27081 for more information on how to run the image in a virtual machine.
27083 When using @code{disk-image}, a raw disk image is produced; it can be
27084 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
27085 the device corresponding to a USB stick, one can copy the image to it
27086 using the following command:
27089 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
27092 When using @code{docker-image}, a Docker image is produced. Guix builds
27093 the image from scratch, not from a pre-existing Docker base image. As a
27094 result, it contains @emph{exactly} what you define in the operating
27095 system configuration file. You can then load the image and launch a
27096 Docker container using commands like the following:
27099 image_id="`docker load < guix-system-docker-image.tar.gz`"
27100 container_id="`docker create $image_id`"
27101 docker start $container_id
27104 This command starts a new Docker container from the specified image. It
27105 will boot the Guix system in the usual manner, which means it will
27106 start any services you have defined in the operating system
27107 configuration. You can get an interactive shell running in the container
27108 using @command{docker exec}:
27111 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
27114 Depending on what you run in the Docker container, it
27115 may be necessary to give the container additional permissions. For
27116 example, if you intend to build software using Guix inside of the Docker
27117 container, you may need to pass the @option{--privileged} option to
27118 @code{docker create}.
27120 Last, the @option{--network} option applies to @command{guix system
27121 docker-image}: it produces an image where network is supposedly shared
27122 with the host, and thus without services like nscd or NetworkManager.
27125 Return a script to run the operating system declared in @var{file}
27126 within a container. Containers are a set of lightweight isolation
27127 mechanisms provided by the kernel Linux-libre. Containers are
27128 substantially less resource-demanding than full virtual machines since
27129 the kernel, shared objects, and other resources can be shared with the
27130 host system; this also means they provide thinner isolation.
27132 Currently, the script must be run as root in order to support more than
27133 a single user and group. The container shares its store with the host
27136 As with the @code{vm} action (@pxref{guix system vm}), additional file
27137 systems to be shared between the host and container can be specified
27138 using the @option{--share} and @option{--expose} options:
27141 guix system container my-config.scm \
27142 --expose=$HOME --share=$HOME/tmp=/exchange
27146 This option requires Linux-libre 3.19 or newer.
27151 @var{options} can contain any of the common build options (@pxref{Common
27152 Build Options}). In addition, @var{options} can contain one of the
27156 @item --expression=@var{expr}
27157 @itemx -e @var{expr}
27158 Consider the operating-system @var{expr} evaluates to.
27159 This is an alternative to specifying a file which evaluates to an
27161 This is used to generate the Guix system installer @pxref{Building the
27162 Installation Image}).
27164 @item --system=@var{system}
27165 @itemx -s @var{system}
27166 Attempt to build for @var{system} instead of the host system type.
27167 This works as per @command{guix build} (@pxref{Invoking guix build}).
27171 Return the derivation file name of the given operating system without
27174 @cindex provenance tracking, of the operating system
27175 @item --save-provenance
27176 As discussed above, @command{guix system init} and @command{guix system
27177 reconfigure} always save provenance information @i{via} a dedicated
27178 service (@pxref{Service Reference, @code{provenance-service-type}}).
27179 However, other commands don't do that by default. If you wish to, say,
27180 create a virtual machine image that contains provenance information, you
27184 guix system vm-image --save-provenance config.scm
27187 That way, the resulting image will effectively ``embed its own source''
27188 in the form of meta-data in @file{/run/current-system}. With that
27189 information, one can rebuild the image to make sure it really contains
27190 what it pretends to contain; or they could use that to derive a variant
27193 @item --file-system-type=@var{type}
27194 @itemx -t @var{type}
27195 For the @code{disk-image} action, create a file system of the given
27196 @var{type} on the image.
27198 When this option is omitted, @command{guix system} uses @code{ext4}.
27200 @cindex ISO-9660 format
27201 @cindex CD image format
27202 @cindex DVD image format
27203 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
27204 for burning on CDs and DVDs.
27206 @item --image-size=@var{size}
27207 For the @code{vm-image} and @code{disk-image} actions, create an image
27208 of the given @var{size}. @var{size} may be a number of bytes, or it may
27209 include a unit as a suffix (@pxref{Block size, size specifications,,
27210 coreutils, GNU Coreutils}).
27212 When this option is omitted, @command{guix system} computes an estimate
27213 of the image size as a function of the size of the system declared in
27218 For the @code{container} action, allow containers to access the host network,
27219 that is, do not create a network namespace.
27221 @item --root=@var{file}
27222 @itemx -r @var{file}
27223 Make @var{file} a symlink to the result, and register it as a garbage
27226 @item --skip-checks
27227 Skip pre-installation safety checks.
27229 By default, @command{guix system init} and @command{guix system
27230 reconfigure} perform safety checks: they make sure the file systems that
27231 appear in the @code{operating-system} declaration actually exist
27232 (@pxref{File Systems}), and that any Linux kernel modules that may be
27233 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
27234 RAM Disk}). Passing this option skips these tests altogether.
27237 @cindex on-error strategy
27238 @cindex error strategy
27239 @item --on-error=@var{strategy}
27240 Apply @var{strategy} when an error occurs when reading @var{file}.
27241 @var{strategy} may be one of the following:
27244 @item nothing-special
27245 Report the error concisely and exit. This is the default strategy.
27248 Likewise, but also display a backtrace.
27251 Report the error and enter Guile's debugger. From there, you can run
27252 commands such as @code{,bt} to get a backtrace, @code{,locals} to
27253 display local variable values, and more generally inspect the state of the
27254 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
27255 a list of available debugging commands.
27259 Once you have built, configured, re-configured, and re-re-configured
27260 your Guix installation, you may find it useful to list the operating
27261 system generations available on disk---and that you can choose from the
27262 bootloader boot menu:
27267 Describe the current system generation: its file name, the kernel and
27268 bootloader used, etc., as well as provenance information when available.
27270 @item list-generations
27271 List a summary of each generation of the operating system available on
27272 disk, in a human-readable way. This is similar to the
27273 @option{--list-generations} option of @command{guix package}
27274 (@pxref{Invoking guix package}).
27276 Optionally, one can specify a pattern, with the same syntax that is used
27277 in @command{guix package --list-generations}, to restrict the list of
27278 generations displayed. For instance, the following command displays
27279 generations that are up to 10 days old:
27282 $ guix system list-generations 10d
27287 The @command{guix system} command has even more to offer! The following
27288 sub-commands allow you to visualize how your system services relate to
27291 @anchor{system-extension-graph}
27294 @item extension-graph
27295 Emit in Dot/Graphviz format to standard output the @dfn{service
27296 extension graph} of the operating system defined in @var{file}
27297 (@pxref{Service Composition}, for more information on service
27303 $ guix system extension-graph @var{file} | xdot -
27306 shows the extension relations among services.
27308 @anchor{system-shepherd-graph}
27309 @item shepherd-graph
27310 Emit in Dot/Graphviz format to standard output the @dfn{dependency
27311 graph} of shepherd services of the operating system defined in
27312 @var{file}. @xref{Shepherd Services}, for more information and for an
27317 @node Invoking guix deploy
27318 @section Invoking @code{guix deploy}
27320 We've already seen @code{operating-system} declarations used to manage a
27321 machine's configuration locally. Suppose you need to configure multiple
27322 machines, though---perhaps you're managing a service on the web that's
27323 comprised of several servers. @command{guix deploy} enables you to use those
27324 same @code{operating-system} declarations to manage multiple remote hosts at
27325 once as a logical ``deployment''.
27328 The functionality described in this section is still under development
27329 and is subject to change. Get in touch with us on
27330 @email{guix-devel@@gnu.org}!
27334 guix deploy @var{file}
27337 Such an invocation will deploy the machines that the code within @var{file}
27338 evaluates to. As an example, @var{file} might contain a definition like this:
27341 ;; This is a Guix deployment of a "bare bones" setup, with
27342 ;; no X11 display server, to a machine with an SSH daemon
27343 ;; listening on localhost:2222. A configuration such as this
27344 ;; may be appropriate for virtual machine with ports
27345 ;; forwarded to the host's loopback interface.
27347 (use-service-modules networking ssh)
27348 (use-package-modules bootloaders)
27352 (host-name "gnu-deployed")
27353 (timezone "Etc/UTC")
27354 (bootloader (bootloader-configuration
27355 (bootloader grub-bootloader)
27356 (target "/dev/vda")
27357 (terminal-outputs '(console))))
27358 (file-systems (cons (file-system
27360 (device "/dev/vda1")
27362 %base-file-systems))
27364 (append (list (service dhcp-client-service-type)
27365 (service openssh-service-type
27366 (openssh-configuration
27367 (permit-root-login #t)
27368 (allow-empty-passwords? #t))))
27372 (operating-system %system)
27373 (environment managed-host-environment-type)
27374 (configuration (machine-ssh-configuration
27375 (host-name "localhost")
27376 (system "x86_64-linux")
27378 (identity "./id_rsa")
27382 The file should evaluate to a list of @var{machine} objects. This example,
27383 upon being deployed, will create a new generation on the remote system
27384 realizing the @code{operating-system} declaration @code{%system}.
27385 @code{environment} and @code{configuration} specify how the machine should be
27386 provisioned---that is, how the computing resources should be created and
27387 managed. The above example does not create any resources, as a
27388 @code{'managed-host} is a machine that is already running the Guix system and
27389 available over the network. This is a particularly simple case; a more
27390 complex deployment may involve, for example, starting virtual machines through
27391 a Virtual Private Server (VPS) provider. In such a case, a different
27392 @var{environment} type would be used.
27394 Do note that you first need to generate a key pair on the coordinator machine
27395 to allow the daemon to export signed archives of files from the store
27396 (@pxref{Invoking guix archive}).
27399 # guix archive --generate-key
27403 Each target machine must authorize the key of the master machine so that it
27404 accepts store items it receives from the coordinator:
27407 # guix archive --authorize < coordinator-public-key.txt
27410 @code{user}, in this example, specifies the name of the user account to log in
27411 as to perform the deployment. Its default value is @code{root}, but root
27412 login over SSH may be forbidden in some cases. To work around this,
27413 @command{guix deploy} can log in as an unprivileged user and employ
27414 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
27415 currently installed on the remote and can be invoked non-interactively as
27416 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
27417 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
27418 be accomplished with the following operating system configuration snippet:
27422 (gnu system)) ;for %sudoers-specification
27424 (define %user "username")
27429 (plain-file "sudoers"
27430 (string-append (plain-file-content %sudoers-specification)
27431 (format #f "~a ALL = NOPASSWD: ALL~%"
27436 For more information regarding the format of the @file{sudoers} file,
27437 consult @command{man sudoers}.
27439 @deftp {Data Type} machine
27440 This is the data type representing a single machine in a heterogeneous Guix
27444 @item @code{operating-system}
27445 The object of the operating system configuration to deploy.
27447 @item @code{environment}
27448 An @code{environment-type} describing how the machine should be provisioned.
27450 @item @code{configuration} (default: @code{#f})
27451 An object describing the configuration for the machine's @code{environment}.
27452 If the @code{environment} has a default configuration, @code{#f} may be used.
27453 If @code{#f} is used for an environment with no default configuration,
27454 however, an error will be thrown.
27458 @deftp {Data Type} machine-ssh-configuration
27459 This is the data type representing the SSH client parameters for a machine
27460 with an @code{environment} of @code{managed-host-environment-type}.
27463 @item @code{host-name}
27464 @item @code{build-locally?} (default: @code{#t})
27465 If false, system derivations will be built on the machine being deployed to.
27466 @item @code{system}
27467 The system type describing the architecture of the machine being deployed
27468 to---e.g., @code{"x86_64-linux"}.
27469 @item @code{authorize?} (default: @code{#t})
27470 If true, the coordinator's signing key will be added to the remote's ACL
27472 @item @code{port} (default: @code{22})
27473 @item @code{user} (default: @code{"root"})
27474 @item @code{identity} (default: @code{#f})
27475 If specified, the path to the SSH private key to use to authenticate with the
27478 @item @code{host-key} (default: @code{#f})
27479 This should be the SSH host key of the machine, which looks like this:
27482 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
27485 When @code{host-key} is @code{#f}, the server is authenticated against
27486 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
27492 @deftp {Data Type} digital-ocean-configuration
27493 This is the data type describing the Droplet that should be created for a
27494 machine with an @code{environment} of @code{digital-ocean-environment-type}.
27497 @item @code{ssh-key}
27498 The path to the SSH private key to use to authenticate with the remote
27499 host. In the future, this field may not exist.
27501 A list of string ``tags'' that uniquely identify the machine. Must be given
27502 such that no two machines in the deployment have the same set of tags.
27503 @item @code{region}
27504 A Digital Ocean region slug, such as @code{"nyc3"}.
27506 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
27507 @item @code{enable-ipv6?}
27508 Whether or not the droplet should be created with IPv6 networking.
27512 @node Running Guix in a VM
27513 @section Running Guix in a Virtual Machine
27515 @cindex virtual machine
27516 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
27518 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
27519 This image is a compressed image in QCOW format. You will first need to
27520 decompress with @command{xz -d}, and then you can pass it to an emulator such
27521 as QEMU (see below for details).
27523 This image boots the Xfce graphical environment and it contains some
27524 commonly-used tools. You can install more software in the image by running
27525 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
27526 also reconfigure the system based on its initial configuration file available
27527 as @file{/run/current-system/configuration.scm} (@pxref{Using the
27528 Configuration System}).
27530 Instead of using this pre-built image, one can also build their own virtual
27531 machine image using @command{guix system vm-image} (@pxref{Invoking guix
27532 system}). The returned image is in qcow2 format, which the
27533 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
27536 If you built your own image, you must copy it out of the store
27537 (@pxref{The Store}) and give yourself permission to write to the copy
27538 before you can use it. When invoking QEMU, you must choose a system
27539 emulator that is suitable for your hardware platform. Here is a minimal
27540 QEMU invocation that will boot the result of @command{guix system
27541 vm-image} on x86_64 hardware:
27544 $ qemu-system-x86_64 \
27545 -nic user,model=virtio-net-pci \
27546 -enable-kvm -m 1024 \
27547 -device virtio-blk,drive=myhd \
27548 -drive if=none,file=/tmp/qemu-image,id=myhd
27551 Here is what each of these options means:
27554 @item qemu-system-x86_64
27555 This specifies the hardware platform to emulate. This should match the
27558 @item -nic user,model=virtio-net-pci
27559 Enable the unprivileged user-mode network stack. The guest OS can
27560 access the host but not vice versa. This is the simplest way to get the
27561 guest OS online. @code{model} specifies which network device to emulate:
27562 @code{virtio-net-pci} is a special device made for virtualized operating
27563 systems and recommended for most uses. Assuming your hardware platform is
27564 x86_64, you can get a list of available NIC models by running
27565 @command{qemu-system-x86_64 -nic model=help}.
27568 If your system has hardware virtualization extensions, enabling the
27569 virtual machine support (KVM) of the Linux kernel will make things run
27572 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
27574 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
27575 which may be insufficient for some operations.
27577 @item -device virtio-blk,drive=myhd
27578 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
27579 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
27580 better performance than if it were emulating a complete disk drive. See the
27581 QEMU and KVM documentation for more info.
27583 @item -drive if=none,file=/tmp/qemu-image,id=myhd
27584 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
27585 the ``myhd'' drive.
27588 The default @command{run-vm.sh} script that is returned by an invocation of
27589 @command{guix system vm} does not add a @command{-nic user} flag by default.
27590 To get network access from within the vm add the @code{(dhcp-client-service)}
27591 to your system definition and start the VM using
27592 @command{`guix system vm config.scm` -nic user}. An important caveat of using
27593 @command{-nic user} for networking is that @command{ping} will not work, because
27594 it uses the ICMP protocol. You'll have to use a different command to check for
27595 network connectivity, for example @command{guix download}.
27597 @subsection Connecting Through SSH
27601 To enable SSH inside a VM you need to add an SSH server like
27602 @code{openssh-service-type} to your VM (@pxref{Networking Services,
27603 @code{openssh-service-type}}). In addition you need to forward the SSH port,
27604 22 by default, to the host. You can do this with
27607 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
27610 To connect to the VM you can run
27613 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
27616 The @command{-p} tells @command{ssh} the port you want to connect to.
27617 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
27618 every time you modify your @command{config.scm} file and the
27619 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
27620 connection to an unknown host every time you connect.
27622 @subsection Using @command{virt-viewer} with Spice
27624 As an alternative to the default @command{qemu} graphical client you can
27625 use the @command{remote-viewer} from the @command{virt-viewer} package. To
27626 connect pass the @command{-spice port=5930,disable-ticketing} flag to
27627 @command{qemu}. See previous section for further information on how to do this.
27629 Spice also allows you to do some nice stuff like share your clipboard with your
27630 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
27633 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
27634 -chardev spicevmc,name=vdagent,id=vdagent
27635 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
27636 name=com.redhat.spice.0
27639 You'll also need to add the @code{(spice-vdagent-service)} to your
27640 system definition (@pxref{Miscellaneous Services, Spice service}).
27642 @node Defining Services
27643 @section Defining Services
27645 The previous sections show the available services and how one can combine
27646 them in an @code{operating-system} declaration. But how do we define
27647 them in the first place? And what is a service anyway?
27650 * Service Composition:: The model for composing services.
27651 * Service Types and Services:: Types and services.
27652 * Service Reference:: API reference.
27653 * Shepherd Services:: A particular type of service.
27656 @node Service Composition
27657 @subsection Service Composition
27661 Here we define a @dfn{service} as, broadly, something that extends the
27662 functionality of the operating system. Often a service is a process---a
27663 @dfn{daemon}---started when the system boots: a secure shell server, a
27664 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
27665 whose execution can be triggered by another daemon---e.g., an FTP server
27666 started by @command{inetd} or a D-Bus service activated by
27667 @command{dbus-daemon}. Occasionally, a service does not map to a
27668 daemon. For instance, the ``account'' service collects user accounts
27669 and makes sure they exist when the system runs; the ``udev'' service
27670 collects device management rules and makes them available to the eudev
27671 daemon; the @file{/etc} service populates the @file{/etc} directory
27674 @cindex service extensions
27675 Guix system services are connected by @dfn{extensions}. For instance, the
27676 secure shell service @emph{extends} the Shepherd---the
27677 initialization system, running as PID@tie{}1---by giving it the command
27678 lines to start and stop the secure shell daemon (@pxref{Networking
27679 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
27680 service by passing it its @file{.service} specification, and extends the
27681 udev service by passing it device management rules (@pxref{Desktop
27682 Services, @code{upower-service}}); the Guix daemon service extends the
27683 Shepherd by passing it the command lines to start and stop the daemon,
27684 and extends the account service by passing it a list of required build
27685 user accounts (@pxref{Base Services}).
27687 All in all, services and their ``extends'' relations form a directed
27688 acyclic graph (DAG). If we represent services as boxes and extensions
27689 as arrows, a typical system might provide something like this:
27691 @image{images/service-graph,,5in,Typical service extension graph.}
27693 @cindex system service
27694 At the bottom, we see the @dfn{system service}, which produces the
27695 directory containing everything to run and boot the system, as returned
27696 by the @command{guix system build} command. @xref{Service Reference},
27697 to learn about the other service types shown here.
27698 @xref{system-extension-graph, the @command{guix system extension-graph}
27699 command}, for information on how to generate this representation for a
27700 particular operating system definition.
27702 @cindex service types
27703 Technically, developers can define @dfn{service types} to express these
27704 relations. There can be any number of services of a given type on the
27705 system---for instance, a system running two instances of the GNU secure
27706 shell server (lsh) has two instances of @code{lsh-service-type}, with
27707 different parameters.
27709 The following section describes the programming interface for service
27710 types and services.
27712 @node Service Types and Services
27713 @subsection Service Types and Services
27715 A @dfn{service type} is a node in the DAG described above. Let us start
27716 with a simple example, the service type for the Guix build daemon
27717 (@pxref{Invoking guix-daemon}):
27720 (define guix-service-type
27724 (list (service-extension shepherd-root-service-type guix-shepherd-service)
27725 (service-extension account-service-type guix-accounts)
27726 (service-extension activation-service-type guix-activation)))
27727 (default-value (guix-configuration))))
27731 It defines three things:
27735 A name, whose sole purpose is to make inspection and debugging easier.
27738 A list of @dfn{service extensions}, where each extension designates the
27739 target service type and a procedure that, given the parameters of the
27740 service, returns a list of objects to extend the service of that type.
27742 Every service type has at least one service extension. The only
27743 exception is the @dfn{boot service type}, which is the ultimate service.
27746 Optionally, a default value for instances of this type.
27749 In this example, @code{guix-service-type} extends three services:
27752 @item shepherd-root-service-type
27753 The @code{guix-shepherd-service} procedure defines how the Shepherd
27754 service is extended. Namely, it returns a @code{<shepherd-service>}
27755 object that defines how @command{guix-daemon} is started and stopped
27756 (@pxref{Shepherd Services}).
27758 @item account-service-type
27759 This extension for this service is computed by @code{guix-accounts},
27760 which returns a list of @code{user-group} and @code{user-account}
27761 objects representing the build user accounts (@pxref{Invoking
27764 @item activation-service-type
27765 Here @code{guix-activation} is a procedure that returns a gexp, which is
27766 a code snippet to run at ``activation time''---e.g., when the service is
27770 A service of this type is instantiated like this:
27773 (service guix-service-type
27774 (guix-configuration
27776 (use-substitutes? #f)))
27779 The second argument to the @code{service} form is a value representing
27780 the parameters of this specific service instance.
27781 @xref{guix-configuration-type, @code{guix-configuration}}, for
27782 information about the @code{guix-configuration} data type. When the
27783 value is omitted, the default value specified by
27784 @code{guix-service-type} is used:
27787 (service guix-service-type)
27790 @code{guix-service-type} is quite simple because it extends other
27791 services but is not extensible itself.
27793 @c @subsubsubsection Extensible Service Types
27795 The service type for an @emph{extensible} service looks like this:
27798 (define udev-service-type
27799 (service-type (name 'udev)
27801 (list (service-extension shepherd-root-service-type
27802 udev-shepherd-service)))
27804 (compose concatenate) ;concatenate the list of rules
27805 (extend (lambda (config rules)
27807 (($ <udev-configuration> udev initial-rules)
27808 (udev-configuration
27809 (udev udev) ;the udev package to use
27810 (rules (append initial-rules rules)))))))))
27813 This is the service type for the
27814 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27815 management daemon}. Compared to the previous example, in addition to an
27816 extension of @code{shepherd-root-service-type}, we see two new fields:
27820 This is the procedure to @dfn{compose} the list of extensions to
27821 services of this type.
27823 Services can extend the udev service by passing it lists of rules; we
27824 compose those extensions simply by concatenating them.
27827 This procedure defines how the value of the service is @dfn{extended} with
27828 the composition of the extensions.
27830 Udev extensions are composed into a list of rules, but the udev service
27831 value is itself a @code{<udev-configuration>} record. So here, we
27832 extend that record by appending the list of rules it contains to the
27833 list of contributed rules.
27836 This is a string giving an overview of the service type. The string can
27837 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27838 @command{guix system search} command searches these strings and displays
27839 them (@pxref{Invoking guix system}).
27842 There can be only one instance of an extensible service type such as
27843 @code{udev-service-type}. If there were more, the
27844 @code{service-extension} specifications would be ambiguous.
27846 Still here? The next section provides a reference of the programming
27847 interface for services.
27849 @node Service Reference
27850 @subsection Service Reference
27852 We have seen an overview of service types (@pxref{Service Types and
27853 Services}). This section provides a reference on how to manipulate
27854 services and service types. This interface is provided by the
27855 @code{(gnu services)} module.
27857 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27858 Return a new service of @var{type}, a @code{<service-type>} object (see
27859 below.) @var{value} can be any object; it represents the parameters of
27860 this particular service instance.
27862 When @var{value} is omitted, the default value specified by @var{type}
27863 is used; if @var{type} does not specify a default value, an error is
27866 For instance, this:
27869 (service openssh-service-type)
27873 is equivalent to this:
27876 (service openssh-service-type
27877 (openssh-configuration))
27880 In both cases the result is an instance of @code{openssh-service-type}
27881 with the default configuration.
27884 @deffn {Scheme Procedure} service? @var{obj}
27885 Return true if @var{obj} is a service.
27888 @deffn {Scheme Procedure} service-kind @var{service}
27889 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27892 @deffn {Scheme Procedure} service-value @var{service}
27893 Return the value associated with @var{service}. It represents its
27897 Here is an example of how a service is created and manipulated:
27901 (service nginx-service-type
27902 (nginx-configuration
27904 (log-directory log-directory)
27905 (run-directory run-directory)
27906 (file config-file))))
27911 (eq? (service-kind s) nginx-service-type)
27915 The @code{modify-services} form provides a handy way to change the
27916 parameters of some of the services of a list such as
27917 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27918 evaluates to a list of services. Of course, you could always use
27919 standard list combinators such as @code{map} and @code{fold} to do that
27920 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27921 @code{modify-services} simply provides a more concise form for this
27924 @deffn {Scheme Syntax} modify-services @var{services} @
27925 (@var{type} @var{variable} => @var{body}) @dots{}
27927 Modify the services listed in @var{services} according to the given
27928 clauses. Each clause has the form:
27931 (@var{type} @var{variable} => @var{body})
27934 where @var{type} is a service type---e.g.,
27935 @code{guix-service-type}---and @var{variable} is an identifier that is
27936 bound within the @var{body} to the service parameters---e.g., a
27937 @code{guix-configuration} instance---of the original service of that
27940 The @var{body} should evaluate to the new service parameters, which will
27941 be used to configure the new service. This new service will replace the
27942 original in the resulting list. Because a service's service parameters
27943 are created using @code{define-record-type*}, you can write a succinct
27944 @var{body} that evaluates to the new service parameters by using the
27945 @code{inherit} feature that @code{define-record-type*} provides.
27947 @xref{Using the Configuration System}, for example usage.
27951 Next comes the programming interface for service types. This is
27952 something you want to know when writing new service definitions, but not
27953 necessarily when simply looking for ways to customize your
27954 @code{operating-system} declaration.
27956 @deftp {Data Type} service-type
27957 @cindex service type
27958 This is the representation of a @dfn{service type} (@pxref{Service Types
27963 This is a symbol, used only to simplify inspection and debugging.
27965 @item @code{extensions}
27966 A non-empty list of @code{<service-extension>} objects (see below).
27968 @item @code{compose} (default: @code{#f})
27969 If this is @code{#f}, then the service type denotes services that cannot
27970 be extended---i.e., services that do not receive ``values'' from other
27973 Otherwise, it must be a one-argument procedure. The procedure is called
27974 by @code{fold-services} and is passed a list of values collected from
27975 extensions. It may return any single value.
27977 @item @code{extend} (default: @code{#f})
27978 If this is @code{#f}, services of this type cannot be extended.
27980 Otherwise, it must be a two-argument procedure: @code{fold-services}
27981 calls it, passing it the initial value of the service as the first
27982 argument and the result of applying @code{compose} to the extension
27983 values as the second argument. It must return a value that is a valid
27984 parameter value for the service instance.
27987 @xref{Service Types and Services}, for examples.
27990 @deffn {Scheme Procedure} service-extension @var{target-type} @
27992 Return a new extension for services of type @var{target-type}.
27993 @var{compute} must be a one-argument procedure: @code{fold-services}
27994 calls it, passing it the value associated with the service that provides
27995 the extension; it must return a valid value for the target service.
27998 @deffn {Scheme Procedure} service-extension? @var{obj}
27999 Return true if @var{obj} is a service extension.
28002 Occasionally, you might want to simply extend an existing service. This
28003 involves creating a new service type and specifying the extension of
28004 interest, which can be verbose; the @code{simple-service} procedure
28005 provides a shorthand for this.
28007 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
28008 Return a service that extends @var{target} with @var{value}. This works
28009 by creating a singleton service type @var{name}, of which the returned
28010 service is an instance.
28012 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
28016 (simple-service 'my-mcron-job mcron-service-type
28017 #~(job '(next-hour (3)) "guix gc -F 2G"))
28021 At the core of the service abstraction lies the @code{fold-services}
28022 procedure, which is responsible for ``compiling'' a list of services
28023 down to a single directory that contains everything needed to boot and
28024 run the system---the directory shown by the @command{guix system build}
28025 command (@pxref{Invoking guix system}). In essence, it propagates
28026 service extensions down the service graph, updating each node parameters
28027 on the way, until it reaches the root node.
28029 @deffn {Scheme Procedure} fold-services @var{services} @
28030 [#:target-type @var{system-service-type}]
28031 Fold @var{services} by propagating their extensions down to the root of
28032 type @var{target-type}; return the root service adjusted accordingly.
28035 Lastly, the @code{(gnu services)} module also defines several essential
28036 service types, some of which are listed below.
28038 @defvr {Scheme Variable} system-service-type
28039 This is the root of the service graph. It produces the system directory
28040 as returned by the @command{guix system build} command.
28043 @defvr {Scheme Variable} boot-service-type
28044 The type of the ``boot service'', which produces the @dfn{boot script}.
28045 The boot script is what the initial RAM disk runs when booting.
28048 @defvr {Scheme Variable} etc-service-type
28049 The type of the @file{/etc} service. This service is used to create
28050 files under @file{/etc} and can be extended by
28051 passing it name/file tuples such as:
28054 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
28057 In this example, the effect would be to add an @file{/etc/issue} file
28058 pointing to the given file.
28061 @defvr {Scheme Variable} setuid-program-service-type
28062 Type for the ``setuid-program service''. This service collects lists of
28063 executable file names, passed as gexps, and adds them to the set of
28064 setuid-root programs on the system (@pxref{Setuid Programs}).
28067 @defvr {Scheme Variable} profile-service-type
28068 Type of the service that populates the @dfn{system profile}---i.e., the
28069 programs under @file{/run/current-system/profile}. Other services can
28070 extend it by passing it lists of packages to add to the system profile.
28073 @cindex provenance tracking, of the operating system
28074 @defvr {Scheme Variable} provenance-service-type
28075 This is the type of the service that records @dfn{provenance meta-data}
28076 in the system itself. It creates several files under
28077 @file{/run/current-system}:
28081 This is a ``channel file'' that can be passed to @command{guix pull -C}
28082 or @command{guix time-machine -C}, and which describes the channels used
28083 to build the system, if that information was available
28084 (@pxref{Channels}).
28086 @item configuration.scm
28087 This is the file that was passed as the value for this
28088 @code{provenance-service-type} service. By default, @command{guix
28089 system reconfigure} automatically passes the OS configuration file it
28090 received on the command line.
28093 This contains the same information as the two other files but in a
28094 format that is more readily processable.
28097 In general, these two pieces of information (channels and configuration
28098 file) are enough to reproduce the operating system ``from source''.
28101 This information is necessary to rebuild your operating system, but it
28102 is not always sufficient. In particular, @file{configuration.scm}
28103 itself is insufficient if it is not self-contained---if it refers to
28104 external Guile modules or to extra files. If you want
28105 @file{configuration.scm} to be self-contained, we recommend that modules
28106 or files it refers to be part of a channel.
28108 Besides, provenance meta-data is ``silent'' in the sense that it does
28109 not change the bits contained in your system, @emph{except for the
28110 meta-data bits themselves}. Two different OS configurations or sets of
28111 channels can lead to the same system, bit-for-bit; when
28112 @code{provenance-service-type} is used, these two systems will have
28113 different meta-data and thus different store file names, which makes
28114 comparison less trivial.
28117 This service is automatically added to your operating system
28118 configuration when you use @command{guix system reconfigure},
28119 @command{guix system init}, or @command{guix deploy}.
28122 @node Shepherd Services
28123 @subsection Shepherd Services
28125 @cindex shepherd services
28127 @cindex init system
28128 The @code{(gnu services shepherd)} module provides a way to define
28129 services managed by the GNU@tie{}Shepherd, which is the
28130 initialization system---the first process that is started when the
28131 system boots, also known as PID@tie{}1
28132 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
28134 Services in the Shepherd can depend on each other. For instance, the
28135 SSH daemon may need to be started after the syslog daemon has been
28136 started, which in turn can only happen once all the file systems have
28137 been mounted. The simple operating system defined earlier (@pxref{Using
28138 the Configuration System}) results in a service graph like this:
28140 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
28142 You can actually generate such a graph for any operating system
28143 definition using the @command{guix system shepherd-graph} command
28144 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
28146 The @code{%shepherd-root-service} is a service object representing
28147 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
28148 by passing it lists of @code{<shepherd-service>} objects.
28150 @deftp {Data Type} shepherd-service
28151 The data type representing a service managed by the Shepherd.
28154 @item @code{provision}
28155 This is a list of symbols denoting what the service provides.
28157 These are the names that may be passed to @command{herd start},
28158 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
28159 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
28160 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
28162 @item @code{requirement} (default: @code{'()})
28163 List of symbols denoting the Shepherd services this one depends on.
28165 @cindex one-shot services, for the Shepherd
28166 @item @code{one-shot?} (default: @code{#f})
28167 Whether this service is @dfn{one-shot}. One-shot services stop immediately
28168 after their @code{start} action has completed. @xref{Slots of services,,,
28169 shepherd, The GNU Shepherd Manual}, for more info.
28171 @item @code{respawn?} (default: @code{#t})
28172 Whether to restart the service when it stops, for instance when the
28173 underlying process dies.
28176 @itemx @code{stop} (default: @code{#~(const #f)})
28177 The @code{start} and @code{stop} fields refer to the Shepherd's
28178 facilities to start and stop processes (@pxref{Service De- and
28179 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
28180 G-expressions that get expanded in the Shepherd configuration file
28181 (@pxref{G-Expressions}).
28183 @item @code{actions} (default: @code{'()})
28184 @cindex actions, of Shepherd services
28185 This is a list of @code{shepherd-action} objects (see below) defining
28186 @dfn{actions} supported by the service, in addition to the standard
28187 @code{start} and @code{stop} actions. Actions listed here become available as
28188 @command{herd} sub-commands:
28191 herd @var{action} @var{service} [@var{arguments}@dots{}]
28194 @item @code{auto-start?} (default: @code{#t})
28195 Whether this service should be started automatically by the Shepherd. If it
28196 is @code{#f} the service has to be started manually with @code{herd start}.
28198 @item @code{documentation}
28199 A documentation string, as shown when running:
28202 herd doc @var{service-name}
28205 where @var{service-name} is one of the symbols in @code{provision}
28206 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
28208 @item @code{modules} (default: @code{%default-modules})
28209 This is the list of modules that must be in scope when @code{start} and
28210 @code{stop} are evaluated.
28215 @deftp {Data Type} shepherd-action
28216 This is the data type that defines additional actions implemented by a
28217 Shepherd service (see above).
28221 Symbol naming the action.
28223 @item documentation
28224 This is a documentation string for the action. It can be viewed by running:
28227 herd doc @var{service} action @var{action}
28231 This should be a gexp that evaluates to a procedure of at least one argument,
28232 which is the ``running value'' of the service (@pxref{Slots of services,,,
28233 shepherd, The GNU Shepherd Manual}).
28236 The following example defines an action called @code{say-hello} that kindly
28242 (documentation "Say hi!")
28243 (procedure #~(lambda (running . args)
28244 (format #t "Hello, friend! arguments: ~s\n"
28249 Assuming this action is added to the @code{example} service, then you can do:
28252 # herd say-hello example
28253 Hello, friend! arguments: ()
28254 # herd say-hello example a b c
28255 Hello, friend! arguments: ("a" "b" "c")
28258 This, as you can see, is a fairly sophisticated way to say hello.
28259 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
28263 @defvr {Scheme Variable} shepherd-root-service-type
28264 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
28266 This is the service type that extensions target when they want to create
28267 shepherd services (@pxref{Service Types and Services}, for an example).
28268 Each extension must pass a list of @code{<shepherd-service>}.
28271 @defvr {Scheme Variable} %shepherd-root-service
28272 This service represents PID@tie{}1.
28276 @node Documentation
28277 @chapter Documentation
28279 @cindex documentation, searching for
28280 @cindex searching for documentation
28281 @cindex Info, documentation format
28283 @cindex manual pages
28284 In most cases packages installed with Guix come with documentation.
28285 There are two main documentation formats: ``Info'', a browseable
28286 hypertext format used for GNU software, and ``manual pages'' (or ``man
28287 pages''), the linear documentation format traditionally found on Unix.
28288 Info manuals are accessed with the @command{info} command or with Emacs,
28289 and man pages are accessed using @command{man}.
28291 You can look for documentation of software installed on your system by
28292 keyword. For example, the following command searches for information
28293 about ``TLS'' in Info manuals:
28297 "(emacs)Network Security" -- STARTTLS
28298 "(emacs)Network Security" -- TLS
28299 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
28300 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
28305 The command below searches for the same keyword in man pages:
28309 SSL (7) - OpenSSL SSL/TLS library
28310 certtool (1) - GnuTLS certificate tool
28314 These searches are purely local to your computer so you have the
28315 guarantee that documentation you find corresponds to what you have
28316 actually installed, you can access it off-line, and your privacy is
28319 Once you have these results, you can view the relevant documentation by
28323 $ info "(gnutls)Core TLS API"
28333 Info manuals contain sections and indices as well as hyperlinks like
28334 those found in Web pages. The @command{info} reader (@pxref{Top, Info
28335 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
28336 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
28337 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
28338 Introduction}, for an introduction to Info navigation.
28340 @node Installing Debugging Files
28341 @chapter Installing Debugging Files
28343 @cindex debugging files
28344 Program binaries, as produced by the GCC compilers for instance, are
28345 typically written in the ELF format, with a section containing
28346 @dfn{debugging information}. Debugging information is what allows the
28347 debugger, GDB, to map binary code to source code; it is required to
28348 debug a compiled program in good conditions.
28350 The problem with debugging information is that is takes up a fair amount
28351 of disk space. For example, debugging information for the GNU C Library
28352 weighs in at more than 60 MiB. Thus, as a user, keeping all the
28353 debugging info of all the installed programs is usually not an option.
28354 Yet, space savings should not come at the cost of an impediment to
28355 debugging---especially in the GNU system, which should make it easier
28356 for users to exert their computing freedom (@pxref{GNU Distribution}).
28358 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
28359 mechanism that allows users to get the best of both worlds: debugging
28360 information can be stripped from the binaries and stored in separate
28361 files. GDB is then able to load debugging information from those files,
28362 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
28365 The GNU distribution takes advantage of this by storing debugging
28366 information in the @code{lib/debug} sub-directory of a separate package
28367 output unimaginatively called @code{debug} (@pxref{Packages with
28368 Multiple Outputs}). Users can choose to install the @code{debug} output
28369 of a package when they need it. For instance, the following command
28370 installs the debugging information for the GNU C Library and for GNU
28374 guix install glibc:debug guile:debug
28377 GDB must then be told to look for debug files in the user's profile, by
28378 setting the @code{debug-file-directory} variable (consider setting it
28379 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
28383 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
28386 From there on, GDB will pick up debugging information from the
28387 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
28389 In addition, you will most likely want GDB to be able to show the source
28390 code being debugged. To do that, you will have to unpack the source
28391 code of the package of interest (obtained with @code{guix build
28392 --source}, @pxref{Invoking guix build}), and to point GDB to that source
28393 directory using the @code{directory} command (@pxref{Source Path,
28394 @code{directory},, gdb, Debugging with GDB}).
28396 @c XXX: keep me up-to-date
28397 The @code{debug} output mechanism in Guix is implemented by the
28398 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
28399 opt-in---debugging information is available only for the packages
28400 with definitions explicitly declaring a @code{debug} output. This may be
28401 changed to opt-out in the future if our build farm servers can handle
28402 the load. To check whether a package has a @code{debug} output, use
28403 @command{guix package --list-available} (@pxref{Invoking guix package}).
28406 @node Security Updates
28407 @chapter Security Updates
28409 @cindex security updates
28410 @cindex security vulnerabilities
28411 Occasionally, important security vulnerabilities are discovered in software
28412 packages and must be patched. Guix developers try hard to keep track of
28413 known vulnerabilities and to apply fixes as soon as possible in the
28414 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
28415 containing only security updates.) The @command{guix lint} tool helps
28416 developers find out about vulnerable versions of software packages in the
28421 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
28422 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
28423 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
28427 @xref{Invoking guix lint}, for more information.
28429 Guix follows a functional
28430 package management discipline (@pxref{Introduction}), which implies
28431 that, when a package is changed, @emph{every package that depends on it}
28432 must be rebuilt. This can significantly slow down the deployment of
28433 fixes in core packages such as libc or Bash, since basically the whole
28434 distribution would need to be rebuilt. Using pre-built binaries helps
28435 (@pxref{Substitutes}), but deployment may still take more time than
28439 To address this, Guix implements @dfn{grafts}, a mechanism that allows
28440 for fast deployment of critical updates without the costs associated
28441 with a whole-distribution rebuild. The idea is to rebuild only the
28442 package that needs to be patched, and then to ``graft'' it onto packages
28443 explicitly installed by the user and that were previously referring to
28444 the original package. The cost of grafting is typically very low, and
28445 order of magnitudes lower than a full rebuild of the dependency chain.
28447 @cindex replacements of packages, for grafts
28448 For instance, suppose a security update needs to be applied to Bash.
28449 Guix developers will provide a package definition for the ``fixed''
28450 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
28451 Packages}). Then, the original package definition is augmented with a
28452 @code{replacement} field pointing to the package containing the bug fix:
28459 (replacement bash-fixed)))
28462 From there on, any package depending directly or indirectly on Bash---as
28463 reported by @command{guix gc --requisites} (@pxref{Invoking guix
28464 gc})---that is installed is automatically ``rewritten'' to refer to
28465 @code{bash-fixed} instead of @code{bash}. This grafting process takes
28466 time proportional to the size of the package, usually less than a
28467 minute for an ``average'' package on a recent machine. Grafting is
28468 recursive: when an indirect dependency requires grafting, then grafting
28469 ``propagates'' up to the package that the user is installing.
28471 Currently, the length of the name and version of the graft and that of
28472 the package it replaces (@code{bash-fixed} and @code{bash} in the example
28473 above) must be equal. This restriction mostly comes from the fact that
28474 grafting works by patching files, including binary files, directly.
28475 Other restrictions may apply: for instance, when adding a graft to a
28476 package providing a shared library, the original shared library and its
28477 replacement must have the same @code{SONAME} and be binary-compatible.
28479 The @option{--no-grafts} command-line option allows you to forcefully
28480 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
28484 guix build bash --no-grafts
28488 returns the store file name of the original Bash, whereas:
28495 returns the store file name of the ``fixed'', replacement Bash. This
28496 allows you to distinguish between the two variants of Bash.
28498 To verify which Bash your whole profile refers to, you can run
28499 (@pxref{Invoking guix gc}):
28502 guix gc -R `readlink -f ~/.guix-profile` | grep bash
28506 @dots{} and compare the store file names that you get with those above.
28507 Likewise for a complete Guix system generation:
28510 guix gc -R `guix system build my-config.scm` | grep bash
28513 Lastly, to check which Bash running processes are using, you can use the
28514 @command{lsof} command:
28517 lsof | grep /gnu/store/.*bash
28521 @node Bootstrapping
28522 @chapter Bootstrapping
28524 @c Adapted from the ELS 2013 paper.
28526 @cindex bootstrapping
28528 Bootstrapping in our context refers to how the distribution gets built
28529 ``from nothing''. Remember that the build environment of a derivation
28530 contains nothing but its declared inputs (@pxref{Introduction}). So
28531 there's an obvious chicken-and-egg problem: how does the first package
28532 get built? How does the first compiler get compiled? Note that this is
28533 a question of interest only to the curious hacker, not to the regular
28534 user, so you can shamelessly skip this section if you consider yourself
28535 a ``regular user''.
28537 @cindex bootstrap binaries
28538 The GNU system is primarily made of C code, with libc at its core. The
28539 GNU build system itself assumes the availability of a Bourne shell and
28540 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
28541 `grep'. Furthermore, build programs---programs that run
28542 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
28543 (@pxref{Derivations}). Consequently, to be able to build anything at
28544 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
28545 Binutils, libc, and the other packages mentioned above---the
28546 @dfn{bootstrap binaries}.
28548 These bootstrap binaries are ``taken for granted'', though we can also
28549 re-create them if needed (more on that later).
28551 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
28552 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
28555 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
28556 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
28559 @node Reduced Binary Seed Bootstrap
28560 @section The Reduced Binary Seed Bootstrap
28562 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
28563 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
28564 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
28565 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
28566 ``taken for granted.''
28568 Taking these binaries for granted means that we consider them to be a correct
28569 and trustworthy `seed' for building the complete system. Therein lies a
28570 problem: the current combined size of these bootstrap binaries is about 250MB
28571 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
28572 these is next to impossible.
28574 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
28575 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
28576 Bootstrap'' and while we are working towards that goal it would be hyperbole
28577 to use that term for what we do now.}.
28579 The Reduced Binary Seed bootstrap removes the most critical tools---from a
28580 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
28581 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
28582 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
28583 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
28584 these new binary seeds and a new set of
28586 packages@footnote{@c
28601 gcc-mesboot1-wrapper,
28602 glibc-headers-mesboot,
28606 gcc-mesboot-wrapper.
28609 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
28610 From here on the more traditional bootstrap process resumes. This approach
28611 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
28612 reduce this further. If you are interested, join us on @code{#bootstrappable}
28613 on the Freenode IRC network.
28615 @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
28616 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
28618 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
28619 compiler used to build the rest of GuixSD.
28621 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
28623 @node Preparing to Use the Bootstrap Binaries
28624 @section Preparing to Use the Bootstrap Binaries
28626 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
28627 @c large image, it's hard to scroll. Oh well.
28628 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
28630 The figure above shows the very beginning of the dependency graph of the
28631 distribution, corresponding to the package definitions of the @code{(gnu
28632 packages bootstrap)} module. A similar figure can be generated with
28633 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
28636 guix graph -t derivation \
28637 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
28638 | dot -Tps > gcc.ps
28641 or, for the Reduced Binary Seed bootstrap
28644 guix graph -t derivation \
28645 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
28646 | dot -Tps > mes.ps
28649 At this level of detail, things are
28650 slightly complex. First, Guile itself consists of an ELF executable,
28651 along with many source and compiled Scheme files that are dynamically
28652 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
28653 tarball shown in this graph. This tarball is part of Guix's ``source''
28654 distribution, and gets inserted into the store with @code{add-to-store}
28655 (@pxref{The Store}).
28657 But how do we write a derivation that unpacks this tarball and adds it
28658 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
28659 derivation---the first one that gets built---uses @code{bash} as its
28660 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
28661 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
28662 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
28663 the Guix source distribution, whose sole purpose is to allow the Guile
28664 tarball to be unpacked.
28666 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
28667 Guile that can be used to run subsequent build programs. Its first task
28668 is to download tarballs containing the other pre-built binaries---this
28669 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
28670 @code{ftp-client.scm} are used for this purpose. The
28671 @code{module-import.drv} derivations import those modules in a directory
28672 in the store, using the original layout. The
28673 @code{module-import-compiled.drv} derivations compile those modules, and
28674 write them in an output directory with the right layout. This
28675 corresponds to the @code{#:modules} argument of
28676 @code{build-expression->derivation} (@pxref{Derivations}).
28678 Finally, the various tarballs are unpacked by the derivations
28679 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
28680 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
28681 point we have a working C tool chain.
28683 @unnumberedsec Building the Build Tools
28685 Bootstrapping is complete when we have a full tool chain that does not
28686 depend on the pre-built bootstrap tools discussed above. This
28687 no-dependency requirement is verified by checking whether the files of
28688 the final tool chain contain references to the @file{/gnu/store}
28689 directories of the bootstrap inputs. The process that leads to this
28690 ``final'' tool chain is described by the package definitions found in
28691 the @code{(gnu packages commencement)} module.
28693 The @command{guix graph} command allows us to ``zoom out'' compared to
28694 the graph above, by looking at the level of package objects instead of
28695 individual derivations---remember that a package may translate to
28696 several derivations, typically one derivation to download its source,
28697 one to build the Guile modules it needs, and one to actually build the
28698 package from source. The command:
28701 guix graph -t bag \
28702 -e '(@@@@ (gnu packages commencement)
28703 glibc-final-with-bootstrap-bash)' | xdot -
28707 displays the dependency graph leading to the ``final'' C
28708 library@footnote{You may notice the @code{glibc-intermediate} label,
28709 suggesting that it is not @emph{quite} final, but as a good
28710 approximation, we will consider it final.}, depicted below.
28712 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
28714 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
28715 The first tool that gets built with the bootstrap binaries is
28716 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
28717 for all the following packages. From there Findutils and Diffutils get
28720 Then come the first-stage Binutils and GCC, built as pseudo cross
28721 tools---i.e., with @option{--target} equal to @option{--host}. They are
28722 used to build libc. Thanks to this cross-build trick, this libc is
28723 guaranteed not to hold any reference to the initial tool chain.
28725 From there the final Binutils and GCC (not shown above) are built. GCC
28726 uses @command{ld} from the final Binutils, and links programs against
28727 the just-built libc. This tool chain is used to build the other
28728 packages used by Guix and by the GNU Build System: Guile, Bash,
28731 And voilà! At this point we have the complete set of build tools that
28732 the GNU Build System expects. These are in the @code{%final-inputs}
28733 variable of the @code{(gnu packages commencement)} module, and are
28734 implicitly used by any package that uses @code{gnu-build-system}
28735 (@pxref{Build Systems, @code{gnu-build-system}}).
28738 @unnumberedsec Building the Bootstrap Binaries
28740 @cindex bootstrap binaries
28741 Because the final tool chain does not depend on the bootstrap binaries,
28742 those rarely need to be updated. Nevertheless, it is useful to have an
28743 automated way to produce them, should an update occur, and this is what
28744 the @code{(gnu packages make-bootstrap)} module provides.
28746 The following command builds the tarballs containing the bootstrap binaries
28747 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
28748 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
28749 and Guile, and a tarball containing a mixture of Coreutils and other basic
28750 command-line tools):
28753 guix build bootstrap-tarballs
28756 The generated tarballs are those that should be referred to in the
28757 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28760 Still here? Then perhaps by now you've started to wonder: when do we
28761 reach a fixed point? That is an interesting question! The answer is
28762 unknown, but if you would like to investigate further (and have
28763 significant computational and storage resources to do so), then let us
28766 @unnumberedsec Reducing the Set of Bootstrap Binaries
28768 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28769 binary code! Why is that a problem? It's a problem because these big chunks
28770 of binary code are practically non-auditable, which makes it hard to establish
28771 what source code produced them. Every unauditable binary also leaves us
28772 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28773 paper @emph{Reflections on Trusting Trust}.
28775 This is mitigated by the fact that our bootstrap binaries were generated
28776 from an earlier Guix revision. Nevertheless it lacks the level of
28777 transparency that we get in the rest of the package dependency graph,
28778 where Guix always gives us a source-to-binary mapping. Thus, our goal
28779 is to reduce the set of bootstrap binaries to the bare minimum.
28781 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
28782 on-going projects to do that. One of these is about replacing the
28783 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28784 of increasing complexity, which could be built from source starting from
28785 a simple and auditable assembler.
28787 Our first major achievement is the replacement of of GCC, the GNU C Library
28788 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28789 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28790 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28791 bootstrapped yet and thus we inject them as binary seeds. We call this the
28792 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28793 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28794 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28796 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28797 also looking at any other bootstrap binaries. Your help is welcome!
28800 @chapter Porting to a New Platform
28802 As discussed above, the GNU distribution is self-contained, and
28803 self-containment is achieved by relying on pre-built ``bootstrap
28804 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28805 operating system kernel, CPU architecture, and application binary
28806 interface (ABI). Thus, to port the distribution to a platform that is
28807 not yet supported, one must build those bootstrap binaries, and update
28808 the @code{(gnu packages bootstrap)} module to use them on that platform.
28810 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28811 When everything goes well, and assuming the GNU tool chain supports the
28812 target platform, this can be as simple as running a command like this
28816 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28819 For this to work, the @code{glibc-dynamic-linker} procedure in
28820 @code{(gnu packages bootstrap)} must be augmented to return the right
28821 file name for libc's dynamic linker on that platform; likewise,
28822 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28823 taught about the new platform.
28825 Once these are built, the @code{(gnu packages bootstrap)} module needs
28826 to be updated to refer to these binaries on the target platform. That
28827 is, the hashes and URLs of the bootstrap tarballs for the new platform
28828 must be added alongside those of the currently supported platforms. The
28829 bootstrap Guile tarball is treated specially: it is expected to be
28830 available locally, and @file{gnu/local.mk} has rules to download it for
28831 the supported architectures; a rule for the new platform must be added
28834 In practice, there may be some complications. First, it may be that the
28835 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28836 above) is not recognized by all the GNU tools. Typically, glibc
28837 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
28838 configure flag (see @code{gcc.scm} for examples of how to handle this).
28839 Second, some of the required packages could fail to build for that
28840 platform. Lastly, the generated binaries could be broken for some
28843 @c *********************************************************************
28844 @include contributing.texi
28846 @c *********************************************************************
28847 @node Acknowledgments
28848 @chapter Acknowledgments
28850 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28851 which was designed and
28852 implemented by Eelco Dolstra, with contributions from other people (see
28853 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28854 management, and promoted unprecedented features, such as transactional
28855 package upgrades and rollbacks, per-user profiles, and referentially
28856 transparent build processes. Without this work, Guix would not exist.
28858 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28859 an inspiration for Guix.
28861 GNU@tie{}Guix itself is a collective work with contributions from a
28862 number of people. See the @file{AUTHORS} file in Guix for more
28863 information on these fine people. The @file{THANKS} file lists people
28864 who have helped by reporting bugs, taking care of the infrastructure,
28865 providing artwork and themes, making suggestions, and more---thank you!
28868 @c *********************************************************************
28869 @node GNU Free Documentation License
28870 @appendix GNU Free Documentation License
28871 @cindex license, GNU Free Documentation License
28872 @include fdl-1.3.texi
28874 @c *********************************************************************
28875 @node Concept Index
28876 @unnumbered Concept Index
28879 @node Programming Index
28880 @unnumbered Programming Index
28881 @syncodeindex tp fn
28882 @syncodeindex vr fn
28887 @c Local Variables:
28888 @c ispell-local-dictionary: "american";