6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set KEY-SERVER pool.sks-keyservers.net
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
68 Permission is granted to copy, distribute and/or modify this document
69 under the terms of the GNU Free Documentation License, Version 1.3 or
70 any later version published by the Free Software Foundation; with no
71 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
72 copy of the license is included in the section entitled ``GNU Free
73 Documentation License''.
76 @dircategory System administration
78 * Guix: (guix). Manage installed software and system configuration.
79 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
80 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
81 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
82 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
85 @dircategory Software development
87 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
88 * guix build: (guix)Invoking guix build. Building packages.
89 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
93 @title GNU Guix Reference Manual
94 @subtitle Using the GNU Guix Functional Package Manager
95 @author The GNU Guix Developers
98 @vskip 0pt plus 1filll
99 Edition @value{EDITION} @*
107 @c *********************************************************************
111 This document describes GNU Guix version @value{VERSION}, a functional
112 package management tool written for the GNU system.
114 @c TRANSLATORS: You can replace the following paragraph with information on
115 @c how to join your own translation team and how to report issues with the
117 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
118 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
119 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
120 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
121 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
122 would like to translate it in your native language, consider joining the
123 @uref{https://translationproject.org/domain/guix-manual.html, Translation
127 * Introduction:: What is Guix about?
128 * Installation:: Installing Guix.
129 * System Installation:: Installing the whole operating system.
130 * Package Management:: Package installation, upgrade, etc.
131 * Development:: Guix-aided software development.
132 * Programming Interface:: Using Guix in Scheme.
133 * Utilities:: Package management commands.
134 * System Configuration:: Configuring the operating system.
135 * Documentation:: Browsing software user manuals.
136 * Installing Debugging Files:: Feeding the debugger.
137 * Security Updates:: Deploying security fixes quickly.
138 * Bootstrapping:: GNU/Linux built from scratch.
139 * Porting:: Targeting another platform or kernel.
140 * Contributing:: Your help needed!
142 * Acknowledgments:: Thanks!
143 * GNU Free Documentation License:: The license of this manual.
144 * Concept Index:: Concepts.
145 * Programming Index:: Data types, functions, and variables.
148 --- The Detailed Node Listing ---
152 * Managing Software the Guix Way:: What's special.
153 * GNU Distribution:: The packages and tools.
157 * Binary Installation:: Getting Guix running in no time!
158 * Requirements:: Software needed to build and run Guix.
159 * Running the Test Suite:: Testing Guix.
160 * Setting Up the Daemon:: Preparing the build daemon's environment.
161 * Invoking guix-daemon:: Running the build daemon.
162 * Application Setup:: Application-specific setup.
164 Setting Up the Daemon
166 * Build Environment Setup:: Preparing the isolated build environment.
167 * Daemon Offload Setup:: Offloading builds to remote machines.
168 * SELinux Support:: Using an SELinux policy for the daemon.
172 * Limitations:: What you can expect.
173 * Hardware Considerations:: Supported hardware.
174 * USB Stick and DVD Installation:: Preparing the installation medium.
175 * Preparing for Installation:: Networking, partitioning, etc.
176 * Guided Graphical Installation:: Easy graphical installation.
177 * Manual Installation:: Manual installation for wizards.
178 * After System Installation:: When installation succeeded.
179 * Installing Guix in a VM:: Guix System playground.
180 * Building the Installation Image:: How this comes to be.
184 * Keyboard Layout and Networking and Partitioning:: Initial setup.
185 * Proceeding with the Installation:: Installing.
189 * Features:: How Guix will make your life brighter.
190 * Invoking guix package:: Package installation, removal, etc.
191 * Substitutes:: Downloading pre-built binaries.
192 * Packages with Multiple Outputs:: Single source package, multiple outputs.
193 * Invoking guix gc:: Running the garbage collector.
194 * Invoking guix pull:: Fetching the latest Guix and distribution.
195 * Channels:: Customizing the package collection.
196 * Inferiors:: Interacting with another revision of Guix.
197 * Invoking guix describe:: Display information about your Guix revision.
198 * Invoking guix archive:: Exporting and importing store files.
202 * Official Substitute Server:: One particular source of substitutes.
203 * Substitute Server Authorization:: How to enable or disable substitutes.
204 * Substitute Authentication:: How Guix verifies substitutes.
205 * Proxy Settings:: How to get substitutes via proxy.
206 * Substitution Failure:: What happens when substitution fails.
207 * On Trusting Binaries:: How can you trust that binary blob?
211 * Invoking guix environment:: Setting up development environments.
212 * Invoking guix pack:: Creating software bundles.
214 Programming Interface
216 * Package Modules:: Packages from the programmer's viewpoint.
217 * Defining Packages:: Defining new packages.
218 * Build Systems:: Specifying how packages are built.
219 * The Store:: Manipulating the package store.
220 * Derivations:: Low-level interface to package derivations.
221 * The Store Monad:: Purely functional interface to the store.
222 * G-Expressions:: Manipulating build expressions.
223 * Invoking guix repl:: Fiddling with Guix interactively.
227 * package Reference:: The package data type.
228 * origin Reference:: The origin data type.
232 * Invoking guix build:: Building packages from the command line.
233 * Invoking guix edit:: Editing package definitions.
234 * Invoking guix download:: Downloading a file and printing its hash.
235 * Invoking guix hash:: Computing the cryptographic hash of a file.
236 * Invoking guix import:: Importing package definitions.
237 * Invoking guix refresh:: Updating package definitions.
238 * Invoking guix lint:: Finding errors in package definitions.
239 * Invoking guix size:: Profiling disk usage.
240 * Invoking guix graph:: Visualizing the graph of packages.
241 * Invoking guix publish:: Sharing substitutes.
242 * Invoking guix challenge:: Challenging substitute servers.
243 * Invoking guix copy:: Copying to and from a remote store.
244 * Invoking guix container:: Process isolation.
245 * Invoking guix weather:: Assessing substitute availability.
246 * Invoking guix processes:: Listing client processes.
248 Invoking @command{guix build}
250 * Common Build Options:: Build options for most commands.
251 * Package Transformation Options:: Creating variants of packages.
252 * Additional Build Options:: Options specific to 'guix build'.
253 * Debugging Build Failures:: Real life packaging experience.
257 * Using the Configuration System:: Customizing your GNU system.
258 * operating-system Reference:: Detail of operating-system declarations.
259 * File Systems:: Configuring file system mounts.
260 * Mapped Devices:: Block device extra processing.
261 * User Accounts:: Specifying user accounts.
262 * Keyboard Layout:: How the system interprets key strokes.
263 * Locales:: Language and cultural convention settings.
264 * Services:: Specifying system services.
265 * Setuid Programs:: Programs running with root privileges.
266 * X.509 Certificates:: Authenticating HTTPS servers.
267 * Name Service Switch:: Configuring libc's name service switch.
268 * Initial RAM Disk:: Linux-Libre bootstrapping.
269 * Bootloader Configuration:: Configuring the boot loader.
270 * Invoking guix system:: Instantiating a system configuration.
271 * Running Guix in a VM:: How to run Guix System in a virtual machine.
272 * Defining Services:: Adding new service definitions.
276 * Base Services:: Essential system services.
277 * Scheduled Job Execution:: The mcron service.
278 * Log Rotation:: The rottlog service.
279 * Networking Services:: Network setup, SSH daemon, etc.
280 * X Window:: Graphical display.
281 * Printing Services:: Local and remote printer support.
282 * Desktop Services:: D-Bus and desktop services.
283 * Sound Services:: ALSA and Pulseaudio services.
284 * Database Services:: SQL databases, key-value stores, etc.
285 * Mail Services:: IMAP, POP3, SMTP, and all that.
286 * Messaging Services:: Messaging services.
287 * Telephony Services:: Telephony services.
288 * Monitoring Services:: Monitoring services.
289 * Kerberos Services:: Kerberos services.
290 * Web Services:: Web servers.
291 * Certificate Services:: TLS certificates via Let's Encrypt.
292 * DNS Services:: DNS daemons.
293 * VPN Services:: VPN daemons.
294 * Network File System:: NFS related services.
295 * Continuous Integration:: The Cuirass service.
296 * Power Management Services:: Extending battery life.
297 * Audio Services:: The MPD.
298 * Virtualization Services:: Virtualization services.
299 * Version Control Services:: Providing remote access to Git repositories.
300 * Game Services:: Game servers.
301 * Miscellaneous Services:: Other services.
305 * Service Composition:: The model for composing services.
306 * Service Types and Services:: Types and services.
307 * Service Reference:: API reference.
308 * Shepherd Services:: A particular type of service.
313 @c *********************************************************************
315 @chapter Introduction
318 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
319 using the international phonetic alphabet (IPA).} is a package
320 management tool for and distribution of the GNU system.
321 Guix makes it easy for unprivileged
322 users to install, upgrade, or remove software packages, to roll back to a
323 previous package set, to build packages from source, and generally
324 assists with the creation and maintenance of software environments.
327 @cindex GuixSD, now Guix System
328 @cindex Guix System Distribution, now Guix System
329 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
330 complements the available tools without interference (@pxref{Installation}),
331 or you can use it as a standalone operating system distribution,
332 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
333 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
334 group everything under the ``Guix'' banner since, after all, Guix System is
335 readily available through the @command{guix system} command, even if you're
336 using a different distro underneath!}. @xref{GNU Distribution}.
339 * Managing Software the Guix Way:: What's special.
340 * GNU Distribution:: The packages and tools.
343 @node Managing Software the Guix Way
344 @section Managing Software the Guix Way
346 @cindex user interfaces
347 Guix provides a command-line package management interface
348 (@pxref{Package Management}), tools to help with software development
349 (@pxref{Development}), command-line utilities for more advanced usage,
350 (@pxref{Utilities}), as well as Scheme programming interfaces
351 (@pxref{Programming Interface}).
353 Its @dfn{build daemon} is responsible for building packages on behalf of
354 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
355 binaries from authorized sources (@pxref{Substitutes}).
357 @cindex extensibility of the distribution
358 @cindex customization, of packages
359 Guix includes package definitions for many GNU and non-GNU packages, all
360 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
361 user's computing freedom}. It is @emph{extensible}: users can write
362 their own package definitions (@pxref{Defining Packages}) and make them
363 available as independent package modules (@pxref{Package Modules}). It
364 is also @emph{customizable}: users can @emph{derive} specialized package
365 definitions from existing ones, including from the command line
366 (@pxref{Package Transformation Options}).
368 @cindex functional package management
370 Under the hood, Guix implements the @dfn{functional package management}
371 discipline pioneered by Nix (@pxref{Acknowledgments}).
372 In Guix, the package build and installation process is seen
373 as a @emph{function}, in the mathematical sense. That function takes inputs,
374 such as build scripts, a compiler, and libraries, and
375 returns an installed package. As a pure function, its result depends
376 solely on its inputs---for instance, it cannot refer to software or
377 scripts that were not explicitly passed as inputs. A build function
378 always produces the same result when passed a given set of inputs. It
379 cannot alter the environment of the running system in
380 any way; for instance, it cannot create, modify, or delete files outside
381 of its build and installation directories. This is achieved by running
382 build processes in isolated environments (or @dfn{containers}), where only their
383 explicit inputs are visible.
386 The result of package build functions is @dfn{cached} in the file
387 system, in a special directory called @dfn{the store} (@pxref{The
388 Store}). Each package is installed in a directory of its own in the
389 store---by default under @file{/gnu/store}. The directory name contains
390 a hash of all the inputs used to build that package; thus, changing an
391 input yields a different directory name.
393 This approach is the foundation for the salient features of Guix: support
394 for transactional package upgrade and rollback, per-user installation, and
395 garbage collection of packages (@pxref{Features}).
398 @node GNU Distribution
399 @section GNU Distribution
402 Guix comes with a distribution of the GNU system consisting entirely of
403 free software@footnote{The term ``free'' here refers to the
404 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
405 users of that software}.}. The
406 distribution can be installed on its own (@pxref{System Installation}),
407 but it is also possible to install Guix as a package manager on top of
408 an installed GNU/Linux system (@pxref{Installation}). When we need to
409 distinguish between the two, we refer to the standalone distribution as
412 The distribution provides core GNU packages such as GNU libc, GCC, and
413 Binutils, as well as many GNU and non-GNU applications. The complete
414 list of available packages can be browsed
415 @url{https://www.gnu.org/software/guix/packages,on-line} or by
416 running @command{guix package} (@pxref{Invoking guix package}):
419 guix package --list-available
422 Our goal is to provide a practical 100% free software distribution of
423 Linux-based and other variants of GNU, with a focus on the promotion and
424 tight integration of GNU components, and an emphasis on programs and
425 tools that help users exert that freedom.
427 Packages are currently available on the following platforms:
432 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
435 Intel 32-bit architecture (IA32), Linux-Libre kernel;
438 ARMv7-A architecture with hard float, Thumb-2 and NEON,
439 using the EABI hard-float application binary interface (ABI),
440 and Linux-Libre kernel.
443 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
446 little-endian 64-bit MIPS processors, specifically the Loongson series,
447 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
448 supported; in particular, the project's build farms no longer provide
449 substitutes for this architecture.
453 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
454 configuration and Guix takes care of instantiating the configuration in a
455 transactional, reproducible, and stateless fashion (@pxref{System
456 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
457 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
458 Manual}), the well-known GNU utilities and tool chain, as well as the
459 graphical environment or system services of your choice.
461 Guix System is available on all the above platforms except
462 @code{mips64el-linux}.
465 For information on porting to other architectures or kernels,
468 Building this distribution is a cooperative effort, and you are invited
469 to join! @xref{Contributing}, for information about how you can help.
472 @c *********************************************************************
474 @chapter Installation
476 @cindex installing Guix
479 We recommend the use of this
480 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
481 shell installer script} to install Guix on top of a running GNU/Linux system,
482 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
483 with the installation of the package manager, which can be done on top of a
484 running GNU/Linux system. If, instead, you want to install the complete GNU
485 operating system, @pxref{System Installation}.} The script automates the
486 download, installation, and initial configuration of Guix. It should be run
490 @cindex foreign distro
491 @cindex directories related to foreign distro
492 When installed on a foreign distro, GNU@tie{}Guix complements the available
493 tools without interference. Its data lives exclusively in two directories,
494 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
495 such as @file{/etc}, are left untouched.
497 Once installed, Guix can be updated by running @command{guix pull}
498 (@pxref{Invoking guix pull}).
500 If you prefer to perform the installation steps manually or want to tweak
501 them, you may find the following subsections useful. They describe the
502 software requirements of Guix, as well as how to install it manually and get
506 * Binary Installation:: Getting Guix running in no time!
507 * Requirements:: Software needed to build and run Guix.
508 * Running the Test Suite:: Testing Guix.
509 * Setting Up the Daemon:: Preparing the build daemon's environment.
510 * Invoking guix-daemon:: Running the build daemon.
511 * Application Setup:: Application-specific setup.
514 @node Binary Installation
515 @section Binary Installation
517 @cindex installing Guix from binaries
518 @cindex installer script
519 This section describes how to install Guix on an arbitrary system from a
520 self-contained tarball providing binaries for Guix and for all its
521 dependencies. This is often quicker than installing from source, which
522 is described in the next sections. The only requirement is to have
525 @c Note duplicated from the ``Installation'' node.
527 We recommend the use of this
528 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
529 shell installer script}. The script automates the download, installation, and
530 initial configuration steps described below. It should be run as the root
534 Installing goes along these lines:
538 @cindex downloading Guix binary
539 Download the binary tarball from
540 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
541 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
542 already running the kernel Linux, and so on.
544 @c The following is somewhat duplicated in ``System Installation''.
545 Make sure to download the associated @file{.sig} file and to verify the
546 authenticity of the tarball against it, along these lines:
549 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
550 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
553 If that command fails because you do not have the required public key,
554 then run this command to import it:
557 $ gpg --keyserver @value{KEY-SERVER} \
558 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
562 and rerun the @code{gpg --verify} command.
563 @c end authentication part
566 Now, you need to become the @code{root} user. Depending on your distribution,
567 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
571 # tar --warning=no-timestamp -xf \
572 guix-binary-@value{VERSION}.@var{system}.tar.xz
573 # mv var/guix /var/ && mv gnu /
576 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
577 The latter contains a ready-to-use profile for @code{root} (see next
580 Do @emph{not} unpack the tarball on a working Guix system since that
581 would overwrite its own essential files.
583 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
584 not emit warnings about ``implausibly old time stamps'' (such
585 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
587 They stem from the fact that all the
588 files in the archive have their modification time set to zero (which
589 means January 1st, 1970.) This is done on purpose to make sure the
590 archive content is independent of its creation time, thus making it
594 Make the profile available under @file{~root/.config/guix/current}, which is
595 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
598 # mkdir -p ~root/.config/guix
599 # ln -sf /var/guix/profiles/per-user/root/current-guix \
600 ~root/.config/guix/current
603 Source @file{etc/profile} to augment @code{PATH} and other relevant
604 environment variables:
607 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
608 source $GUIX_PROFILE/etc/profile
612 Create the group and user accounts for build users as explained below
613 (@pxref{Build Environment Setup}).
616 Run the daemon, and set it to automatically start on boot.
618 If your host distro uses the systemd init system, this can be achieved
621 @c Versions of systemd that supported symlinked service files are not
622 @c yet widely deployed, so we should suggest that users copy the service
625 @c See this thread for more information:
626 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
629 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
631 # systemctl start guix-daemon && systemctl enable guix-daemon
634 If your host distro uses the Upstart init system:
637 # initctl reload-configuration
638 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
643 Otherwise, you can still start the daemon manually with:
646 # ~root/.config/guix/current/bin/guix-daemon \
647 --build-users-group=guixbuild
651 Make the @command{guix} command available to other users on the machine,
655 # mkdir -p /usr/local/bin
657 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
660 It is also a good idea to make the Info version of this manual available
664 # mkdir -p /usr/local/share/info
665 # cd /usr/local/share/info
666 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
670 That way, assuming @file{/usr/local/share/info} is in the search path,
671 running @command{info guix} will open this manual (@pxref{Other Info
672 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
676 @cindex substitutes, authorization thereof
677 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
678 (@pxref{Substitutes}), authorize them:
681 # guix archive --authorize < \
682 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
686 Each user may need to perform a few additional steps to make their Guix
687 environment ready for use, @pxref{Application Setup}.
690 Voilà, the installation is complete!
692 You can confirm that Guix is working by installing a sample package into
699 The binary installation tarball can be (re)produced and verified simply
700 by running the following command in the Guix source tree:
703 make guix-binary.@var{system}.tar.xz
707 ...@: which, in turn, runs:
710 guix pack -s @var{system} --localstatedir \
711 --profile-name=current-guix guix
714 @xref{Invoking guix pack}, for more info on this handy tool.
717 @section Requirements
719 This section lists requirements when building Guix from source. The
720 build procedure for Guix is the same as for other GNU software, and is
721 not covered here. Please see the files @file{README} and @file{INSTALL}
722 in the Guix source tree for additional details.
724 @cindex official website
725 GNU Guix is available for download from its website at
726 @url{https://www.gnu.org/software/guix/}.
728 GNU Guix depends on the following packages:
731 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
732 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
735 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
736 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
737 Guile,, gnutls-guile, GnuTLS-Guile});
739 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
742 @c FIXME: Specify a version number once a release has been made.
743 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
745 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
746 @item @url{https://zlib.net, zlib};
747 @item @url{https://www.gnu.org/software/make/, GNU Make}.
750 The following dependencies are optional:
754 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
755 Support for build offloading (@pxref{Daemon Offload Setup}) and
756 @command{guix copy} (@pxref{Invoking guix copy}) depends on
757 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
758 version 0.10.2 or later.
761 When @url{http://www.bzip.org, libbz2} is available,
762 @command{guix-daemon} can use it to compress build logs.
765 Unless @code{--disable-daemon} was passed to @command{configure}, the
766 following packages are also needed:
769 @item @url{https://gnupg.org/, GNU libgcrypt};
770 @item @url{https://sqlite.org, SQLite 3};
771 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
775 @cindex state directory
776 When configuring Guix on a system that already has a Guix installation,
777 be sure to specify the same state directory as the existing installation
778 using the @code{--localstatedir} option of the @command{configure}
779 script (@pxref{Directory Variables, @code{localstatedir},, standards,
780 GNU Coding Standards}). The @command{configure} script protects against
781 unintended misconfiguration of @var{localstatedir} so you do not
782 inadvertently corrupt your store (@pxref{The Store}).
784 @cindex Nix, compatibility
785 When a working installation of @url{https://nixos.org/nix/, the Nix package
786 manager} is available, you
787 can instead configure Guix with @code{--disable-daemon}. In that case,
788 Nix replaces the three dependencies above.
790 Guix is compatible with Nix, so it is possible to share the same store
791 between both. To do so, you must pass @command{configure} not only the
792 same @code{--with-store-dir} value, but also the same
793 @code{--localstatedir} value. The latter is essential because it
794 specifies where the database that stores metadata about the store is
795 located, among other things. The default values for Nix are
796 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
797 Note that @code{--disable-daemon} is not required if
798 your goal is to share the store with Nix.
800 @node Running the Test Suite
801 @section Running the Test Suite
804 After a successful @command{configure} and @code{make} run, it is a good
805 idea to run the test suite. It can help catch issues with the setup or
806 environment, or bugs in Guix itself---and really, reporting test
807 failures is a good way to help improve the software. To run the test
814 Test cases can run in parallel: you can use the @code{-j} option of
815 GNU@tie{}make to speed things up. The first run may take a few minutes
816 on a recent machine; subsequent runs will be faster because the store
817 that is created for test purposes will already have various things in
820 It is also possible to run a subset of the tests by defining the
821 @code{TESTS} makefile variable as in this example:
824 make check TESTS="tests/store.scm tests/cpio.scm"
827 By default, tests results are displayed at a file level. In order to
828 see the details of every individual test cases, it is possible to define
829 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
832 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
835 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
836 @file{test-suite.log} file. Please specify the Guix version being used
837 as well as version numbers of the dependencies (@pxref{Requirements}) in
840 Guix also comes with a whole-system test suite that tests complete
841 Guix System instances. It can only run on systems where
842 Guix is already installed, using:
849 or, again, by defining @code{TESTS} to select a subset of tests to run:
852 make check-system TESTS="basic mcron"
855 These system tests are defined in the @code{(gnu tests @dots{})}
856 modules. They work by running the operating systems under test with
857 lightweight instrumentation in a virtual machine (VM). They can be
858 computationally intensive or rather cheap, depending on whether
859 substitutes are available for their dependencies (@pxref{Substitutes}).
860 Some of them require a lot of storage space to hold VM images.
862 Again in case of test failures, please send @email{bug-guix@@gnu.org}
865 @node Setting Up the Daemon
866 @section Setting Up the Daemon
869 Operations such as building a package or running the garbage collector
870 are all performed by a specialized process, the @dfn{build daemon}, on
871 behalf of clients. Only the daemon may access the store and its
872 associated database. Thus, any operation that manipulates the store
873 goes through the daemon. For instance, command-line tools such as
874 @command{guix package} and @command{guix build} communicate with the
875 daemon (@i{via} remote procedure calls) to instruct it what to do.
877 The following sections explain how to prepare the build daemon's
878 environment. See also @ref{Substitutes}, for information on how to allow
879 the daemon to download pre-built binaries.
882 * Build Environment Setup:: Preparing the isolated build environment.
883 * Daemon Offload Setup:: Offloading builds to remote machines.
884 * SELinux Support:: Using an SELinux policy for the daemon.
887 @node Build Environment Setup
888 @subsection Build Environment Setup
890 @cindex build environment
891 In a standard multi-user setup, Guix and its daemon---the
892 @command{guix-daemon} program---are installed by the system
893 administrator; @file{/gnu/store} is owned by @code{root} and
894 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
895 Guix tools to build packages or otherwise access the store, and the
896 daemon will do it on their behalf, ensuring that the store is kept in a
897 consistent state, and allowing built packages to be shared among users.
900 When @command{guix-daemon} runs as @code{root}, you may not want package
901 build processes themselves to run as @code{root} too, for obvious
902 security reasons. To avoid that, a special pool of @dfn{build users}
903 should be created for use by build processes started by the daemon.
904 These build users need not have a shell and a home directory: they will
905 just be used when the daemon drops @code{root} privileges in build
906 processes. Having several such users allows the daemon to launch
907 distinct build processes under separate UIDs, which guarantees that they
908 do not interfere with each other---an essential feature since builds are
909 regarded as pure functions (@pxref{Introduction}).
911 On a GNU/Linux system, a build user pool may be created like this (using
912 Bash syntax and the @code{shadow} commands):
914 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
915 @c for why `-G' is needed.
917 # groupadd --system guixbuild
918 # for i in `seq -w 1 10`;
920 useradd -g guixbuild -G guixbuild \
921 -d /var/empty -s `which nologin` \
922 -c "Guix build user $i" --system \
928 The number of build users determines how many build jobs may run in
929 parallel, as specified by the @option{--max-jobs} option
930 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
931 @command{guix system vm} and related commands, you may need to add the
932 build users to the @code{kvm} group so they can access @file{/dev/kvm},
933 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
934 (@pxref{Invoking guix system}).
936 The @code{guix-daemon} program may then be run as @code{root} with the
937 following command@footnote{If your machine uses the systemd init system,
938 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
939 file in @file{/etc/systemd/system} will ensure that
940 @command{guix-daemon} is automatically started. Similarly, if your
941 machine uses the Upstart init system, drop the
942 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
943 file in @file{/etc/init}.}:
946 # guix-daemon --build-users-group=guixbuild
951 This way, the daemon starts build processes in a chroot, under one of
952 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
953 environment contains nothing but:
955 @c Keep this list in sync with libstore/build.cc! -----------------------
958 a minimal @code{/dev} directory, created mostly independently from the
959 host @code{/dev}@footnote{``Mostly'', because while the set of files
960 that appear in the chroot's @code{/dev} is fixed, most of these files
961 can only be created if the host has them.};
964 the @code{/proc} directory; it only shows the processes of the container
965 since a separate PID name space is used;
968 @file{/etc/passwd} with an entry for the current user and an entry for
972 @file{/etc/group} with an entry for the user's group;
975 @file{/etc/hosts} with an entry that maps @code{localhost} to
979 a writable @file{/tmp} directory.
982 You can influence the directory where the daemon stores build trees
983 @i{via} the @code{TMPDIR} environment variable. However, the build tree
984 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
985 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
986 This way, the value of @code{TMPDIR} does not leak inside build
987 environments, which avoids discrepancies in cases where build processes
988 capture the name of their build tree.
991 The daemon also honors the @code{http_proxy} environment variable for
992 HTTP downloads it performs, be it for fixed-output derivations
993 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
995 If you are installing Guix as an unprivileged user, it is still possible
996 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
997 However, build processes will not be isolated from one another, and not
998 from the rest of the system. Thus, build processes may interfere with
999 each other, and may access programs, libraries, and other files
1000 available on the system---making it much harder to view them as
1001 @emph{pure} functions.
1004 @node Daemon Offload Setup
1005 @subsection Using the Offload Facility
1009 When desired, the build daemon can @dfn{offload} derivation builds to
1010 other machines running Guix, using the @code{offload} @dfn{build
1011 hook}@footnote{This feature is available only when
1012 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1013 present.}. When that
1014 feature is enabled, a list of user-specified build machines is read from
1015 @file{/etc/guix/machines.scm}; every time a build is requested, for
1016 instance via @code{guix build}, the daemon attempts to offload it to one
1017 of the machines that satisfy the constraints of the derivation, in
1018 particular its system type---e.g., @file{x86_64-linux}. Missing
1019 prerequisites for the build are copied over SSH to the target machine,
1020 which then proceeds with the build; upon success the output(s) of the
1021 build are copied back to the initial machine.
1023 The @file{/etc/guix/machines.scm} file typically looks like this:
1026 (list (build-machine
1027 (name "eightysix.example.org")
1028 (system "x86_64-linux")
1029 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1031 (speed 2.)) ;incredibly fast!
1034 (name "meeps.example.org")
1035 (system "mips64el-linux")
1036 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1039 (string-append (getenv "HOME")
1040 "/.ssh/identity-for-guix"))))
1044 In the example above we specify a list of two build machines, one for
1045 the @code{x86_64} architecture and one for the @code{mips64el}
1048 In fact, this file is---not surprisingly!---a Scheme file that is
1049 evaluated when the @code{offload} hook is started. Its return value
1050 must be a list of @code{build-machine} objects. While this example
1051 shows a fixed list of build machines, one could imagine, say, using
1052 DNS-SD to return a list of potential build machines discovered in the
1053 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1054 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1057 @deftp {Data Type} build-machine
1058 This data type represents build machines to which the daemon may offload
1059 builds. The important fields are:
1064 The host name of the remote machine.
1067 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1070 The user account to use when connecting to the remote machine over SSH.
1071 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1072 allow non-interactive logins.
1075 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1076 This is used to authenticate the machine when we connect to it. It is a
1077 long string that looks like this:
1080 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1083 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1084 key can be found in a file such as
1085 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1087 If the machine is running the SSH daemon of GNU@tie{}lsh,
1088 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1089 similar file. It can be converted to the OpenSSH format using
1090 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1093 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1094 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1099 A number of optional fields may be specified:
1103 @item @code{port} (default: @code{22})
1104 Port number of SSH server on the machine.
1106 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1107 The SSH private key file to use when connecting to the machine, in
1108 OpenSSH format. This key must not be protected with a passphrase.
1110 Note that the default value is the private key @emph{of the root
1111 account}. Make sure it exists if you use the default.
1113 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1114 @itemx @code{compression-level} (default: @code{3})
1115 The SSH-level compression methods and compression level requested.
1117 Note that offloading relies on SSH compression to reduce bandwidth usage
1118 when transferring files to and from build machines.
1120 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1121 File name of the Unix-domain socket @command{guix-daemon} is listening
1124 @item @code{parallel-builds} (default: @code{1})
1125 The number of builds that may run in parallel on the machine.
1127 @item @code{speed} (default: @code{1.0})
1128 A ``relative speed factor''. The offload scheduler will tend to prefer
1129 machines with a higher speed factor.
1131 @item @code{features} (default: @code{'()})
1132 A list of strings denoting specific features supported by the machine.
1133 An example is @code{"kvm"} for machines that have the KVM Linux modules
1134 and corresponding hardware support. Derivations can request features by
1135 name, and they will be scheduled on matching build machines.
1140 The @command{guix} command must be in the search path on the build
1141 machines. You can check whether this is the case by running:
1144 ssh build-machine guix repl --version
1147 There is one last thing to do once @file{machines.scm} is in place. As
1148 explained above, when offloading, files are transferred back and forth
1149 between the machine stores. For this to work, you first need to
1150 generate a key pair on each machine to allow the daemon to export signed
1151 archives of files from the store (@pxref{Invoking guix archive}):
1154 # guix archive --generate-key
1158 Each build machine must authorize the key of the master machine so that
1159 it accepts store items it receives from the master:
1162 # guix archive --authorize < master-public-key.txt
1166 Likewise, the master machine must authorize the key of each build machine.
1168 All the fuss with keys is here to express pairwise mutual trust
1169 relations between the master and the build machines. Concretely, when
1170 the master receives files from a build machine (and @i{vice versa}), its
1171 build daemon can make sure they are genuine, have not been tampered
1172 with, and that they are signed by an authorized key.
1174 @cindex offload test
1175 To test whether your setup is operational, run this command on the
1182 This will attempt to connect to each of the build machines specified in
1183 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1184 available on each machine, attempt to export to the machine and import
1185 from it, and report any error in the process.
1187 If you want to test a different machine file, just specify it on the
1191 # guix offload test machines-qualif.scm
1194 Last, you can test the subset of the machines whose name matches a
1195 regular expression like this:
1198 # guix offload test machines.scm '\.gnu\.org$'
1201 @cindex offload status
1202 To display the current load of all build hosts, run this command on the
1206 # guix offload status
1210 @node SELinux Support
1211 @subsection SELinux Support
1213 @cindex SELinux, daemon policy
1214 @cindex mandatory access control, SELinux
1215 @cindex security, guix-daemon
1216 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1217 can be installed on a system where SELinux is enabled, in order to label
1218 Guix files and to specify the expected behavior of the daemon. Since
1219 Guix System does not provide an SELinux base policy, the daemon policy cannot
1220 be used on Guix System.
1222 @subsubsection Installing the SELinux policy
1223 @cindex SELinux, policy installation
1224 To install the policy run this command as root:
1227 semodule -i etc/guix-daemon.cil
1230 Then relabel the file system with @code{restorecon} or by a different
1231 mechanism provided by your system.
1233 Once the policy is installed, the file system has been relabeled, and
1234 the daemon has been restarted, it should be running in the
1235 @code{guix_daemon_t} context. You can confirm this with the following
1239 ps -Zax | grep guix-daemon
1242 Monitor the SELinux log files as you run a command like @code{guix build
1243 hello} to convince yourself that SELinux permits all necessary
1246 @subsubsection Limitations
1247 @cindex SELinux, limitations
1249 This policy is not perfect. Here is a list of limitations or quirks
1250 that should be considered when deploying the provided SELinux policy for
1255 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1256 operations involve contexts that have anything to do with
1257 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1258 but it would be preferrable to define socket rules for only this label.
1261 @code{guix gc} cannot access arbitrary links to profiles. By design,
1262 the file label of the destination of a symlink is independent of the
1263 file label of the link itself. Although all profiles under
1264 $localstatedir are labelled, the links to these profiles inherit the
1265 label of the directory they are in. For links in the user’s home
1266 directory this will be @code{user_home_t}. But for links from the root
1267 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1268 directory, etc, this won’t work. @code{guix gc} would be prevented from
1269 reading and following these links.
1272 The daemon’s feature to listen for TCP connections might no longer work.
1273 This might require extra rules, because SELinux treats network sockets
1274 differently from files.
1277 Currently all files with a name matching the regular expression
1278 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1279 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1280 that name in any profile would be permitted to run in the
1281 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1282 build a package that provides this executable and convince a user to
1283 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1284 At that point SELinux could not prevent it from accessing files that are
1285 allowed for processes in that domain.
1287 We could generate a much more restrictive policy at installation time,
1288 so that only the @emph{exact} file name of the currently installed
1289 @code{guix-daemon} executable would be labelled with
1290 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1291 The downside is that root would have to install or upgrade the policy at
1292 installation time whenever the Guix package that provides the
1293 effectively running @code{guix-daemon} executable is upgraded.
1296 @node Invoking guix-daemon
1297 @section Invoking @command{guix-daemon}
1299 The @command{guix-daemon} program implements all the functionality to
1300 access the store. This includes launching build processes, running the
1301 garbage collector, querying the availability of a build result, etc. It
1302 is normally run as @code{root} like this:
1305 # guix-daemon --build-users-group=guixbuild
1309 For details on how to set it up, @pxref{Setting Up the Daemon}.
1312 @cindex container, build environment
1313 @cindex build environment
1314 @cindex reproducible builds
1315 By default, @command{guix-daemon} launches build processes under
1316 different UIDs, taken from the build group specified with
1317 @code{--build-users-group}. In addition, each build process is run in a
1318 chroot environment that only contains the subset of the store that the
1319 build process depends on, as specified by its derivation
1320 (@pxref{Programming Interface, derivation}), plus a set of specific
1321 system directories. By default, the latter contains @file{/dev} and
1322 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1323 @dfn{container}: in addition to having its own file system tree, it has
1324 a separate mount name space, its own PID name space, network name space,
1325 etc. This helps achieve reproducible builds (@pxref{Features}).
1327 When the daemon performs a build on behalf of the user, it creates a
1328 build directory under @file{/tmp} or under the directory specified by
1329 its @code{TMPDIR} environment variable. This directory is shared with
1330 the container for the duration of the build, though within the container,
1331 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1333 The build directory is automatically deleted upon completion, unless the
1334 build failed and the client specified @option{--keep-failed}
1335 (@pxref{Invoking guix build, @option{--keep-failed}}).
1337 The daemon listens for connections and spawns one sub-process for each session
1338 started by a client (one of the @command{guix} sub-commands.) The
1339 @command{guix processes} command allows you to get an overview of the activity
1340 on your system by viewing each of the active sessions and clients.
1341 @xref{Invoking guix processes}, for more information.
1343 The following command-line options are supported:
1346 @item --build-users-group=@var{group}
1347 Take users from @var{group} to run build processes (@pxref{Setting Up
1348 the Daemon, build users}).
1350 @item --no-substitutes
1352 Do not use substitutes for build products. That is, always build things
1353 locally instead of allowing downloads of pre-built binaries
1354 (@pxref{Substitutes}).
1356 When the daemon runs with @code{--no-substitutes}, clients can still
1357 explicitly enable substitution @i{via} the @code{set-build-options}
1358 remote procedure call (@pxref{The Store}).
1360 @item --substitute-urls=@var{urls}
1361 @anchor{daemon-substitute-urls}
1362 Consider @var{urls} the default whitespace-separated list of substitute
1363 source URLs. When this option is omitted,
1364 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1366 This means that substitutes may be downloaded from @var{urls}, as long
1367 as they are signed by a trusted signature (@pxref{Substitutes}).
1370 @item --no-build-hook
1371 Do not use the @dfn{build hook}.
1373 The build hook is a helper program that the daemon can start and to
1374 which it submits build requests. This mechanism is used to offload
1375 builds to other machines (@pxref{Daemon Offload Setup}).
1377 @item --cache-failures
1378 Cache build failures. By default, only successful builds are cached.
1380 When this option is used, @command{guix gc --list-failures} can be used
1381 to query the set of store items marked as failed; @command{guix gc
1382 --clear-failures} removes store items from the set of cached failures.
1383 @xref{Invoking guix gc}.
1385 @item --cores=@var{n}
1387 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1390 The default value is @code{0}, but it may be overridden by clients, such
1391 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1394 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1395 in the build process, which can then use it to exploit internal
1396 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1398 @item --max-jobs=@var{n}
1400 Allow at most @var{n} build jobs in parallel. The default value is
1401 @code{1}. Setting it to @code{0} means that no builds will be performed
1402 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1403 Setup}), or simply fail.
1405 @item --max-silent-time=@var{seconds}
1406 When the build or substitution process remains silent for more than
1407 @var{seconds}, terminate it and report a build failure.
1409 The default value is @code{0}, which disables the timeout.
1411 The value specified here can be overridden by clients (@pxref{Common
1412 Build Options, @code{--max-silent-time}}).
1414 @item --timeout=@var{seconds}
1415 Likewise, when the build or substitution process lasts for more than
1416 @var{seconds}, terminate it and report a build failure.
1418 The default value is @code{0}, which disables the timeout.
1420 The value specified here can be overridden by clients (@pxref{Common
1421 Build Options, @code{--timeout}}).
1423 @item --rounds=@var{N}
1424 Build each derivation @var{n} times in a row, and raise an error if
1425 consecutive build results are not bit-for-bit identical. Note that this
1426 setting can be overridden by clients such as @command{guix build}
1427 (@pxref{Invoking guix build}).
1429 When used in conjunction with @option{--keep-failed}, the differing
1430 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1431 This makes it easy to look for differences between the two results.
1434 Produce debugging output.
1436 This is useful to debug daemon start-up issues, but then it may be
1437 overridden by clients, for example the @code{--verbosity} option of
1438 @command{guix build} (@pxref{Invoking guix build}).
1440 @item --chroot-directory=@var{dir}
1441 Add @var{dir} to the build chroot.
1443 Doing this may change the result of build processes---for instance if
1444 they use optional dependencies found in @var{dir} when it is available,
1445 and not otherwise. For that reason, it is not recommended to do so.
1446 Instead, make sure that each derivation declares all the inputs that it
1449 @item --disable-chroot
1450 Disable chroot builds.
1452 Using this option is not recommended since, again, it would allow build
1453 processes to gain access to undeclared dependencies. It is necessary,
1454 though, when @command{guix-daemon} is running under an unprivileged user
1457 @item --log-compression=@var{type}
1458 Compress build logs according to @var{type}, one of @code{gzip},
1459 @code{bzip2}, or @code{none}.
1461 Unless @code{--lose-logs} is used, all the build logs are kept in the
1462 @var{localstatedir}. To save space, the daemon automatically compresses
1463 them with bzip2 by default.
1465 @item --disable-deduplication
1466 @cindex deduplication
1467 Disable automatic file ``deduplication'' in the store.
1469 By default, files added to the store are automatically ``deduplicated'':
1470 if a newly added file is identical to another one found in the store,
1471 the daemon makes the new file a hard link to the other file. This can
1472 noticeably reduce disk usage, at the expense of slightly increased
1473 input/output load at the end of a build process. This option disables
1476 @item --gc-keep-outputs[=yes|no]
1477 Tell whether the garbage collector (GC) must keep outputs of live
1481 @cindex garbage collector roots
1482 When set to ``yes'', the GC will keep the outputs of any live derivation
1483 available in the store---the @code{.drv} files. The default is ``no'',
1484 meaning that derivation outputs are kept only if they are reachable from a GC
1485 root. @xref{Invoking guix gc}, for more on GC roots.
1487 @item --gc-keep-derivations[=yes|no]
1488 Tell whether the garbage collector (GC) must keep derivations
1489 corresponding to live outputs.
1491 When set to ``yes'', as is the case by default, the GC keeps
1492 derivations---i.e., @code{.drv} files---as long as at least one of their
1493 outputs is live. This allows users to keep track of the origins of
1494 items in their store. Setting it to ``no'' saves a bit of disk space.
1496 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1497 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1498 ``yes'' causes liveness to flow from derivations to outputs. When both are
1499 set to ``yes'', the effect is to keep all the build prerequisites (the
1500 sources, compiler, libraries, and other build-time tools) of live objects in
1501 the store, regardless of whether these prerequisites are reachable from a GC
1502 root. This is convenient for developers since it saves rebuilds or downloads.
1504 @item --impersonate-linux-2.6
1505 On Linux-based systems, impersonate Linux 2.6. This means that the
1506 kernel's @code{uname} system call will report 2.6 as the release number.
1508 This might be helpful to build programs that (usually wrongfully) depend
1509 on the kernel version number.
1512 Do not keep build logs. By default they are kept under
1513 @code{@var{localstatedir}/guix/log}.
1515 @item --system=@var{system}
1516 Assume @var{system} as the current system type. By default it is the
1517 architecture/kernel pair found at configure time, such as
1518 @code{x86_64-linux}.
1520 @item --listen=@var{endpoint}
1521 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1522 as the file name of a Unix-domain socket if it starts with
1523 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1524 host name or host name and port to listen to. Here are a few examples:
1527 @item --listen=/gnu/var/daemon
1528 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1529 creating it if needed.
1531 @item --listen=localhost
1532 @cindex daemon, remote access
1533 @cindex remote access to the daemon
1534 @cindex daemon, cluster setup
1535 @cindex clusters, daemon setup
1536 Listen for TCP connections on the network interface corresponding to
1537 @code{localhost}, on port 44146.
1539 @item --listen=128.0.0.42:1234
1540 Listen for TCP connections on the network interface corresponding to
1541 @code{128.0.0.42}, on port 1234.
1544 This option can be repeated multiple times, in which case
1545 @command{guix-daemon} accepts connections on all the specified
1546 endpoints. Users can tell client commands what endpoint to connect to
1547 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1548 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1551 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1552 @code{--listen=@var{host}} is suitable on local networks, such as
1553 clusters, where only trusted nodes may connect to the build daemon. In
1554 other cases where remote access to the daemon is needed, we recommend
1555 using Unix-domain sockets along with SSH.
1558 When @code{--listen} is omitted, @command{guix-daemon} listens for
1559 connections on the Unix-domain socket located at
1560 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1564 @node Application Setup
1565 @section Application Setup
1567 @cindex foreign distro
1568 When using Guix on top of GNU/Linux distribution other than Guix System---a
1569 so-called @dfn{foreign distro}---a few additional steps are needed to
1570 get everything in place. Here are some of them.
1574 @anchor{locales-and-locpath}
1575 @cindex locales, when not on Guix System
1577 @vindex GUIX_LOCPATH
1578 Packages installed @i{via} Guix will not use the locale data of the
1579 host system. Instead, you must first install one of the locale packages
1580 available with Guix and then define the @code{GUIX_LOCPATH} environment
1584 $ guix install glibc-locales
1585 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1588 Note that the @code{glibc-locales} package contains data for all the
1589 locales supported by the GNU@tie{}libc and weighs in at around
1590 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1591 limited to a few UTF-8 locales.
1593 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1594 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1595 Manual}). There are two important differences though:
1599 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1600 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1601 to make sure the programs of the foreign distro will not end up loading
1602 incompatible locale data.
1605 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1606 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1607 should your Guix profile contain a mixture of programs linked against
1608 different libc version, each libc version will only try to load locale
1609 data in the right format.
1612 This is important because the locale data format used by different libc
1613 versions may be incompatible.
1615 @subsection Name Service Switch
1617 @cindex name service switch, glibc
1618 @cindex NSS (name service switch), glibc
1619 @cindex nscd (name service caching daemon)
1620 @cindex name service caching daemon (nscd)
1621 When using Guix on a foreign distro, we @emph{strongly recommend} that
1622 the system run the GNU C library's @dfn{name service cache daemon},
1623 @command{nscd}, which should be listening on the
1624 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1625 installed with Guix may fail to look up host names or user accounts, or
1626 may even crash. The next paragraphs explain why.
1628 @cindex @file{nsswitch.conf}
1629 The GNU C library implements a @dfn{name service switch} (NSS), which is
1630 an extensible mechanism for ``name lookups'' in general: host name
1631 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1632 The GNU C Library Reference Manual}).
1634 @cindex Network information service (NIS)
1635 @cindex NIS (Network information service)
1636 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1637 lookup implementations: for example, the @code{nss-mdns} plugin allow
1638 resolution of @code{.local} host names, the @code{nis} plugin allows
1639 user account lookup using the Network information service (NIS), and so
1640 on. These extra ``lookup services'' are configured system-wide in
1641 @file{/etc/nsswitch.conf}, and all the programs running on the system
1642 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1645 When they perform a name lookup---for instance by calling the
1646 @code{getaddrinfo} function in C---applications first try to connect to
1647 the nscd; on success, nscd performs name lookups on their behalf. If
1648 the nscd is not running, then they perform the name lookup by
1649 themselves, by loading the name lookup services into their own address
1650 space and running it. These name lookup services---the
1651 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1652 the host system's C library, rather than from the C library the
1653 application is linked against (the C library coming from Guix).
1655 And this is where the problem is: if your application is linked against
1656 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1657 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1658 likely crash or have its name lookups fail unexpectedly.
1660 Running @command{nscd} on the system, among other advantages, eliminates
1661 this binary incompatibility problem because those @code{libnss_*.so}
1662 files are loaded in the @command{nscd} process, not in applications
1665 @subsection X11 Fonts
1668 The majority of graphical applications use Fontconfig to locate and
1669 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1670 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1671 by default. Thus, to allow graphical applications installed with Guix
1672 to display fonts, you have to install fonts with Guix as well.
1673 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1674 @code{font-gnu-freefont-ttf}.
1676 To display text written in Chinese languages, Japanese, or Korean in
1677 graphical applications, consider installing
1678 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1679 has multiple outputs, one per language family (@pxref{Packages with
1680 Multiple Outputs}). For instance, the following command installs fonts
1681 for Chinese languages:
1684 guix install font-adobe-source-han-sans:cn
1687 @cindex @code{xterm}
1688 Older programs such as @command{xterm} do not use Fontconfig and instead
1689 rely on server-side font rendering. Such programs require to specify a
1690 full name of a font using XLFD (X Logical Font Description), like this:
1693 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1696 To be able to use such full names for the TrueType fonts installed in
1697 your Guix profile, you need to extend the font path of the X server:
1699 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1700 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1702 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1705 @cindex @code{xlsfonts}
1706 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1707 to make sure your TrueType fonts are listed there.
1709 @cindex @code{fc-cache}
1711 After installing fonts you may have to refresh the font cache to use
1712 them in applications. The same applies when applications installed via
1713 Guix do not seem to find fonts. To force rebuilding of the font cache
1714 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1715 @code{fontconfig} package.
1717 @subsection X.509 Certificates
1719 @cindex @code{nss-certs}
1720 The @code{nss-certs} package provides X.509 certificates, which allow
1721 programs to authenticate Web servers accessed over HTTPS.
1723 When using Guix on a foreign distro, you can install this package and
1724 define the relevant environment variables so that packages know where to
1725 look for certificates. @xref{X.509 Certificates}, for detailed
1728 @subsection Emacs Packages
1730 @cindex @code{emacs}
1731 When you install Emacs packages with Guix, the elisp files may be placed
1732 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1734 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1735 directory exists because potentially there may exist thousands of Emacs
1736 packages and storing all their files in a single directory may not be
1737 reliable (because of name conflicts). So we think using a separate
1738 directory for each package is a good idea. It is very similar to how
1739 the Emacs package system organizes the file structure (@pxref{Package
1740 Files,,, emacs, The GNU Emacs Manual}).
1742 By default, Emacs (installed with Guix) ``knows'' where these packages
1743 are placed, so you do not need to perform any configuration. If, for
1744 some reason, you want to avoid auto-loading Emacs packages installed
1745 with Guix, you can do so by running Emacs with @code{--no-site-file}
1746 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1748 @subsection The GCC toolchain
1753 Guix offers individual compiler packages such as @code{gcc} but if you
1754 are in need of a complete toolchain for compiling and linking source
1755 code what you really want is the @code{gcc-toolchain} package. This
1756 package provides a complete GCC toolchain for C/C++ development,
1757 including GCC itself, the GNU C Library (headers and binaries, plus
1758 debugging symbols in the @code{debug} output), Binutils, and a linker
1761 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1762 passed to the linker, add corresponding @code{-rpath} arguments, and
1763 invoke the actual linker with this new set of arguments. You can instruct the
1764 wrapper to refuse to link against libraries not in the store by setting the
1765 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1769 @c *********************************************************************
1770 @node System Installation
1771 @chapter System Installation
1773 @cindex installing Guix System
1774 @cindex Guix System, installation
1775 This section explains how to install Guix System
1776 on a machine. Guix, as a package manager, can
1777 also be installed on top of a running GNU/Linux system,
1778 @pxref{Installation}.
1782 @c This paragraph is for people reading this from tty2 of the
1783 @c installation image.
1784 You are reading this documentation with an Info reader. For details on
1785 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1786 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1787 Info}. Hit @kbd{l} afterwards to come back here.
1789 Alternately, run @command{info info} in another tty to keep the manual
1795 * Limitations:: What you can expect.
1796 * Hardware Considerations:: Supported hardware.
1797 * USB Stick and DVD Installation:: Preparing the installation medium.
1798 * Preparing for Installation:: Networking, partitioning, etc.
1799 * Guided Graphical Installation:: Easy graphical installation.
1800 * Manual Installation:: Manual installation for wizards.
1801 * After System Installation:: When installation succeeded.
1802 * Installing Guix in a VM:: Guix System playground.
1803 * Building the Installation Image:: How this comes to be.
1807 @section Limitations
1809 We consider Guix System to be ready for a wide range of ``desktop'' and server
1810 use cases. The reliability guarantees it provides---transactional upgrades
1811 and rollbacks, reproducibility---make it a solid foundation.
1813 Nevertheless, before you proceed with the installation, be aware of the
1814 following noteworthy limitations applicable to version @value{VERSION}:
1818 Support for the Logical Volume Manager (LVM) is missing.
1821 More and more system services are provided (@pxref{Services}), but some
1825 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1826 as well as a number of X11 window managers. However, KDE is currently
1830 More than a disclaimer, this is an invitation to report issues (and success
1831 stories!), and to join us in improving it. @xref{Contributing}, for more
1835 @node Hardware Considerations
1836 @section Hardware Considerations
1838 @cindex hardware support on Guix System
1839 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1840 builds around the kernel Linux-libre, which means that only hardware for
1841 which free software drivers and firmware exist is supported. Nowadays,
1842 a wide range of off-the-shelf hardware is supported on
1843 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1844 Ethernet controllers. Unfortunately, there are still areas where
1845 hardware vendors deny users control over their own computing, and such
1846 hardware is not supported on Guix System.
1848 @cindex WiFi, hardware support
1849 One of the main areas where free drivers or firmware are lacking is WiFi
1850 devices. WiFi devices known to work include those using Atheros chips
1851 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1852 driver, and those using Broadcom/AirForce chips (BCM43xx with
1853 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1854 Linux-libre driver. Free firmware exists for both and is available
1855 out-of-the-box on Guix System, as part of @code{%base-firmware}
1856 (@pxref{operating-system Reference, @code{firmware}}).
1858 @cindex RYF, Respects Your Freedom
1859 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1860 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1861 certification program for hardware products that respect your freedom
1862 and your privacy and ensure that you have control over your device. We
1863 encourage you to check the list of RYF-certified devices.
1865 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1866 web site. It contains a catalog of hardware devices with information
1867 about their support in GNU/Linux.
1870 @node USB Stick and DVD Installation
1871 @section USB Stick and DVD Installation
1873 An ISO-9660 installation image that can be written to a USB stick or
1874 burnt to a DVD can be downloaded from
1875 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1876 where @var{system} is one of:
1880 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1883 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1886 @c start duplication of authentication part from ``Binary Installation''
1887 Make sure to download the associated @file{.sig} file and to verify the
1888 authenticity of the image against it, along these lines:
1891 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1892 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1895 If that command fails because you do not have the required public key,
1896 then run this command to import it:
1899 $ gpg --keyserver @value{KEY-SERVER} \
1900 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1904 and rerun the @code{gpg --verify} command.
1907 This image contains the tools necessary for an installation.
1908 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1910 @unnumberedsubsec Copying to a USB Stick
1912 To copy the image to a USB stick, follow these steps:
1916 Decompress the image using the @command{xz} command:
1919 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1923 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1924 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1925 copy the image with:
1928 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1932 Access to @file{/dev/sdX} usually requires root privileges.
1935 @unnumberedsubsec Burning on a DVD
1937 To copy the image to a DVD, follow these steps:
1941 Decompress the image using the @command{xz} command:
1944 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1948 Insert a blank DVD into your machine, and determine
1949 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1950 copy the image with:
1953 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1956 Access to @file{/dev/srX} usually requires root privileges.
1959 @unnumberedsubsec Booting
1961 Once this is done, you should be able to reboot the system and boot from
1962 the USB stick or DVD. The latter usually requires you to get in the
1963 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1965 @xref{Installing Guix in a VM}, if, instead, you would like to install
1966 Guix System in a virtual machine (VM).
1969 @node Preparing for Installation
1970 @section Preparing for Installation
1972 Once you have booted, you can use the guided graphical installer, which makes
1973 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1974 if you are already familiar with GNU/Linux and if you want more control than
1975 what the graphical installer provides, you can choose the ``manual''
1976 installation process (@pxref{Manual Installation}).
1978 The graphical installer is available on TTY1. You can obtain root shells on
1979 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1980 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1981 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1982 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1983 which allows you to select text with the left mouse button and to paste it
1984 with the middle button.
1987 Installation requires access to the Internet so that any missing
1988 dependencies of your system configuration can be downloaded. See the
1989 ``Networking'' section below.
1992 @node Guided Graphical Installation
1993 @section Guided Graphical Installation
1995 The graphical installer is a text-based user interface. It will guide you,
1996 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
1998 The first dialog boxes allow you to set up the system as you use it during the
1999 installation: you can choose the language, keyboard layout, and set up
2000 networking, which will be used during the installation. The image below shows
2001 the networking dialog.
2003 @image{images/installer-network,5in,, networking setup with the graphical installer}
2005 Later steps allow you to partition your hard disk, as shown in the image
2006 below, to choose whether or not to use encrypted file systems, to enter the
2007 host name and root password, and to create an additional account, among other
2010 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2012 Note that, at any time, the installer allows you to exit the current
2013 installation step and resume at a previous step, as show in the image below.
2015 @image{images/installer-resume,5in,, resuming the installation process}
2017 Once you're done, the installer produces an operating system configuration and
2018 displays it (@pxref{Using the Configuration System}). At that point you can
2019 hit ``OK'' and installation will proceed. On success, you can reboot into the
2020 new system and enjoy. @xref{After System Installation}, for what's next!
2023 @node Manual Installation
2024 @section Manual Installation
2026 This section describes how you would ``manually'' install GNU@tie{}Guix System
2027 on your machine. This option requires familiarity with GNU/Linux, with the
2028 shell, and with common administration tools. If you think this is not for
2029 you, consider using the guided graphical installer (@pxref{Guided Graphical
2032 The installation system provides root shells on TTYs 3 to 6; press
2033 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2034 many common tools needed to install the system. But it is also a full-blown
2035 Guix System, which means that you can install additional packages, should you
2036 need it, using @command{guix package} (@pxref{Invoking guix package}).
2039 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2040 * Proceeding with the Installation:: Installing.
2043 @node Keyboard Layout and Networking and Partitioning
2044 @subsection Keyboard Layout, Networking, and Partitioning
2046 Before you can install the system, you may want to adjust the keyboard layout,
2047 set up networking, and partition your target hard disk. This section will
2048 guide you through this.
2050 @subsubsection Keyboard Layout
2052 @cindex keyboard layout
2053 The installation image uses the US qwerty keyboard layout. If you want
2054 to change it, you can use the @command{loadkeys} command. For example,
2055 the following command selects the Dvorak keyboard layout:
2061 See the files under @file{/run/current-system/profile/share/keymaps} for
2062 a list of available keyboard layouts. Run @command{man loadkeys} for
2065 @subsubsection Networking
2067 Run the following command to see what your network interfaces are called:
2074 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2080 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2081 Wired interfaces have a name starting with @samp{e}; for example, the
2082 interface corresponding to the first on-board Ethernet controller is
2083 called @samp{eno1}. Wireless interfaces have a name starting with
2084 @samp{w}, like @samp{w1p2s0}.
2087 @item Wired connection
2088 To configure a wired network run the following command, substituting
2089 @var{interface} with the name of the wired interface you want to use.
2092 ifconfig @var{interface} up
2095 @item Wireless connection
2098 To configure wireless networking, you can create a configuration file
2099 for the @command{wpa_supplicant} configuration tool (its location is not
2100 important) using one of the available text editors such as
2104 nano wpa_supplicant.conf
2107 As an example, the following stanza can go to this file and will work
2108 for many wireless networks, provided you give the actual SSID and
2109 passphrase for the network you are connecting to:
2113 ssid="@var{my-ssid}"
2115 psk="the network's secret passphrase"
2119 Start the wireless service and run it in the background with the
2120 following command (substitute @var{interface} with the name of the
2121 network interface you want to use):
2124 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2127 Run @command{man wpa_supplicant} for more information.
2131 At this point, you need to acquire an IP address. On a network where IP
2132 addresses are automatically assigned @i{via} DHCP, you can run:
2135 dhclient -v @var{interface}
2138 Try to ping a server to see if networking is up and running:
2144 Setting up network access is almost always a requirement because the
2145 image does not contain all the software and tools that may be needed.
2147 @cindex installing over SSH
2148 If you want to, you can continue the installation remotely by starting
2152 herd start ssh-daemon
2155 Make sure to either set a password with @command{passwd}, or configure
2156 OpenSSH public key authentication before logging in.
2158 @subsubsection Disk Partitioning
2160 Unless this has already been done, the next step is to partition, and
2161 then format the target partition(s).
2163 The installation image includes several partitioning tools, including
2164 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2165 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2166 the partition layout you want:
2172 If your disk uses the GUID Partition Table (GPT) format and you plan to
2173 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2174 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2177 @cindex EFI, installation
2178 @cindex UEFI, installation
2179 @cindex ESP, EFI system partition
2180 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2181 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2182 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2185 parted /dev/sda set 1 esp on
2189 @vindex grub-bootloader
2190 @vindex grub-efi-bootloader
2191 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2192 @file{/sys/firmware/efi} exists in the installation image, then you should
2193 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2194 Otherwise you should use the BIOS-based GRUB, known as
2195 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2199 Once you are done partitioning the target hard disk drive, you have to
2200 create a file system on the relevant partition(s)@footnote{Currently
2201 Guix System only supports ext4 and btrfs file systems. In particular, code
2202 that reads file system UUIDs and labels only works for these file system
2203 types.}. For the ESP, if you have one and assuming it is
2204 @file{/dev/sda1}, run:
2207 mkfs.fat -F32 /dev/sda1
2210 Preferably, assign file systems a label so that you can easily and
2211 reliably refer to them in @code{file-system} declarations (@pxref{File
2212 Systems}). This is typically done using the @code{-L} option of
2213 @command{mkfs.ext4} and related commands. So, assuming the target root
2214 partition lives at @file{/dev/sda2}, a file system with the label
2215 @code{my-root} can be created with:
2218 mkfs.ext4 -L my-root /dev/sda2
2221 @cindex encrypted disk
2222 If you are instead planning to encrypt the root partition, you can use
2223 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2224 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2225 @code{man cryptsetup}} for more information.) Assuming you want to
2226 store the root partition on @file{/dev/sda2}, the command sequence would
2227 be along these lines:
2230 cryptsetup luksFormat /dev/sda2
2231 cryptsetup open --type luks /dev/sda2 my-partition
2232 mkfs.ext4 -L my-root /dev/mapper/my-partition
2235 Once that is done, mount the target file system under @file{/mnt}
2236 with a command like (again, assuming @code{my-root} is the label of the
2240 mount LABEL=my-root /mnt
2243 Also mount any other file systems you would like to use on the target
2244 system relative to this path. If you have opted for @file{/boot/efi} as an
2245 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2246 found by @code{guix system init} afterwards.
2248 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2249 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2250 sure to initialize them with @command{mkswap}. Assuming you have one
2251 swap partition on @file{/dev/sda3}, you would run:
2258 Alternatively, you may use a swap file. For example, assuming that in
2259 the new system you want to use the file @file{/swapfile} as a swap file,
2260 you would run@footnote{This example will work for many types of file
2261 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2262 btrfs), the required steps may be different. For details, see the
2263 manual pages for @command{mkswap} and @command{swapon}.}:
2266 # This is 10 GiB of swap space. Adjust "count" to change the size.
2267 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2268 # For security, make the file readable and writable only by root.
2269 chmod 600 /mnt/swapfile
2270 mkswap /mnt/swapfile
2271 swapon /mnt/swapfile
2274 Note that if you have encrypted the root partition and created a swap
2275 file in its file system as described above, then the encryption also
2276 protects the swap file, just like any other file in that file system.
2278 @node Proceeding with the Installation
2279 @subsection Proceeding with the Installation
2281 With the target partitions ready and the target root mounted on
2282 @file{/mnt}, we're ready to go. First, run:
2285 herd start cow-store /mnt
2288 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2289 during the installation phase are written to the target disk on @file{/mnt}
2290 rather than kept in memory. This is necessary because the first phase of
2291 the @command{guix system init} command (see below) entails downloads or
2292 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2294 Next, you have to edit a file and
2295 provide the declaration of the operating system to be installed. To
2296 that end, the installation system comes with three text editors. We
2297 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2298 supports syntax highlighting and parentheses matching; other editors
2299 include GNU Zile (an Emacs clone), and
2300 nvi (a clone of the original BSD @command{vi} editor).
2301 We strongly recommend storing that file on the target root file system, say,
2302 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2303 configuration file once you have rebooted into the newly-installed system.
2305 @xref{Using the Configuration System}, for an overview of the
2306 configuration file. The example configurations discussed in that
2307 section are available under @file{/etc/configuration} in the
2308 installation image. Thus, to get started with a system configuration
2309 providing a graphical display server (a ``desktop'' system), you can run
2310 something along these lines:
2314 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2315 # nano /mnt/etc/config.scm
2318 You should pay attention to what your configuration file contains, and
2323 Make sure the @code{bootloader-configuration} form refers to the target
2324 you want to install GRUB on. It should mention @code{grub-bootloader} if
2325 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2326 for newer UEFI systems. For legacy systems, the @code{target} field
2327 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2328 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2329 currently mounted and a @code{file-system} entry is specified in your
2333 Be sure that your file system labels match the value of their respective
2334 @code{device} fields in your @code{file-system} configuration, assuming
2335 your @code{file-system} configuration uses the @code{file-system-label}
2336 procedure in its @code{device} field.
2339 If there are encrypted or RAID partitions, make sure to add a
2340 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2343 Once you are done preparing the configuration file, the new system must
2344 be initialized (remember that the target root file system is mounted
2348 guix system init /mnt/etc/config.scm /mnt
2352 This copies all the necessary files and installs GRUB on
2353 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2354 more information, @pxref{Invoking guix system}. This command may trigger
2355 downloads or builds of missing packages, which can take some time.
2357 Once that command has completed---and hopefully succeeded!---you can run
2358 @command{reboot} and boot into the new system. The @code{root} password
2359 in the new system is initially empty; other users' passwords need to be
2360 initialized by running the @command{passwd} command as @code{root},
2361 unless your configuration specifies otherwise
2362 (@pxref{user-account-password, user account passwords}).
2363 @xref{After System Installation}, for what's next!
2366 @node After System Installation
2367 @section After System Installation
2369 Success, you've now booted into Guix System! From then on, you can update the
2370 system whenever you want by running, say:
2374 sudo guix system reconfigure /etc/config.scm
2378 This builds a new system generation with the latest packages and services
2379 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2380 your system includes the latest security updates (@pxref{Security Updates}).
2382 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2384 @cindex sudo vs. @command{guix pull}
2385 Note that @command{sudo guix} runs your user's @command{guix} command and
2386 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2387 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2390 Join us on @code{#guix} on the Freenode IRC network or on
2391 @email{guix-devel@@gnu.org} to share your experience!
2394 @node Installing Guix in a VM
2395 @section Installing Guix in a Virtual Machine
2397 @cindex virtual machine, Guix System installation
2398 @cindex virtual private server (VPS)
2399 @cindex VPS (virtual private server)
2400 If you'd like to install Guix System in a virtual machine (VM) or on a
2401 virtual private server (VPS) rather than on your beloved machine, this
2404 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2405 disk image, follow these steps:
2409 First, retrieve and decompress the Guix system installation image as
2410 described previously (@pxref{USB Stick and DVD Installation}).
2413 Create a disk image that will hold the installed system. To make a
2414 qcow2-formatted disk image, use the @command{qemu-img} command:
2417 qemu-img create -f qcow2 guixsd.img 50G
2420 The resulting file will be much smaller than 50 GB (typically less than
2421 1 MB), but it will grow as the virtualized storage device is filled up.
2424 Boot the USB installation image in an VM:
2427 qemu-system-x86_64 -m 1024 -smp 1 \
2428 -net user -net nic,model=virtio -boot menu=on \
2429 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2430 -drive file=guixsd.img
2433 The ordering of the drives matters.
2435 In the VM console, quickly press the @kbd{F12} key to enter the boot
2436 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2440 You're now root in the VM, proceed with the installation process.
2441 @xref{Preparing for Installation}, and follow the instructions.
2444 Once installation is complete, you can boot the system that's on your
2445 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2448 @node Building the Installation Image
2449 @section Building the Installation Image
2451 @cindex installation image
2452 The installation image described above was built using the @command{guix
2453 system} command, specifically:
2456 guix system disk-image --file-system-type=iso9660 \
2457 gnu/system/install.scm
2460 Have a look at @file{gnu/system/install.scm} in the source tree,
2461 and see also @ref{Invoking guix system} for more information
2462 about the installation image.
2464 @section Building the Installation Image for ARM Boards
2466 Many ARM boards require a specific variant of the
2467 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2469 If you build a disk image and the bootloader is not available otherwise
2470 (on another boot drive etc), it's advisable to build an image that
2471 includes the bootloader, specifically:
2474 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2477 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2478 board, a list of possible boards will be printed.
2480 @c *********************************************************************
2481 @node Package Management
2482 @chapter Package Management
2485 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2486 remove software packages, without having to know about their build
2487 procedures or dependencies. Guix also goes beyond this obvious set of
2490 This chapter describes the main features of Guix, as well as the
2491 package management tools it provides. Along with the command-line
2492 interface described below (@pxref{Invoking guix package, @code{guix
2493 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2494 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2495 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2499 guix install emacs-guix
2503 * Features:: How Guix will make your life brighter.
2504 * Invoking guix package:: Package installation, removal, etc.
2505 * Substitutes:: Downloading pre-built binaries.
2506 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2507 * Invoking guix gc:: Running the garbage collector.
2508 * Invoking guix pull:: Fetching the latest Guix and distribution.
2509 * Channels:: Customizing the package collection.
2510 * Inferiors:: Interacting with another revision of Guix.
2511 * Invoking guix describe:: Display information about your Guix revision.
2512 * Invoking guix archive:: Exporting and importing store files.
2518 When using Guix, each package ends up in the @dfn{package store}, in its
2519 own directory---something that resembles
2520 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2522 Instead of referring to these directories, users have their own
2523 @dfn{profile}, which points to the packages that they actually want to
2524 use. These profiles are stored within each user's home directory, at
2525 @code{$HOME/.guix-profile}.
2527 For example, @code{alice} installs GCC 4.7.2. As a result,
2528 @file{/home/alice/.guix-profile/bin/gcc} points to
2529 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2530 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2531 simply continues to point to
2532 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2533 coexist on the same system without any interference.
2535 The @command{guix package} command is the central tool to manage
2536 packages (@pxref{Invoking guix package}). It operates on the per-user
2537 profiles, and can be used @emph{with normal user privileges}.
2539 @cindex transactions
2540 The command provides the obvious install, remove, and upgrade
2541 operations. Each invocation is actually a @emph{transaction}: either
2542 the specified operation succeeds, or nothing happens. Thus, if the
2543 @command{guix package} process is terminated during the transaction,
2544 or if a power outage occurs during the transaction, then the user's
2545 profile remains in its previous state, and remains usable.
2547 In addition, any package transaction may be @emph{rolled back}. So, if,
2548 for example, an upgrade installs a new version of a package that turns
2549 out to have a serious bug, users may roll back to the previous instance
2550 of their profile, which was known to work well. Similarly, the global
2551 system configuration on Guix is subject to
2552 transactional upgrades and roll-back
2553 (@pxref{Using the Configuration System}).
2555 All packages in the package store may be @emph{garbage-collected}.
2556 Guix can determine which packages are still referenced by user
2557 profiles, and remove those that are provably no longer referenced
2558 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2559 generations of their profile so that the packages they refer to can be
2562 @cindex reproducibility
2563 @cindex reproducible builds
2564 Guix takes a @dfn{purely functional} approach to package
2565 management, as described in the introduction (@pxref{Introduction}).
2566 Each @file{/gnu/store} package directory name contains a hash of all the
2567 inputs that were used to build that package---compiler, libraries, build
2568 scripts, etc. This direct correspondence allows users to make sure a
2569 given package installation matches the current state of their
2570 distribution. It also helps maximize @dfn{build reproducibility}:
2571 thanks to the isolated build environments that are used, a given build
2572 is likely to yield bit-identical files when performed on different
2573 machines (@pxref{Invoking guix-daemon, container}).
2576 This foundation allows Guix to support @dfn{transparent binary/source
2577 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2578 available from an external source---a @dfn{substitute}, Guix just
2579 downloads it and unpacks it;
2580 otherwise, it builds the package from source, locally
2581 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2582 reproducible, users do not have to trust servers that provide
2583 substitutes: they can force a local build and @emph{challenge} providers
2584 (@pxref{Invoking guix challenge}).
2586 Control over the build environment is a feature that is also useful for
2587 developers. The @command{guix environment} command allows developers of
2588 a package to quickly set up the right development environment for their
2589 package, without having to manually install the dependencies of the
2590 package into their profile (@pxref{Invoking guix environment}).
2592 @cindex replication, of software environments
2593 @cindex provenance tracking, of software artifacts
2594 All of Guix and its package definitions is version-controlled, and
2595 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2596 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2597 Guix instance on a different machine or at a later point in time, which in
2598 turn allows you to @emph{replicate complete software environments}, while
2599 retaining precise @dfn{provenance tracking} of the software.
2601 @node Invoking guix package
2602 @section Invoking @command{guix package}
2604 @cindex installing packages
2605 @cindex removing packages
2606 @cindex package installation
2607 @cindex package removal
2608 The @command{guix package} command is the tool that allows users to
2609 install, upgrade, and remove packages, as well as rolling back to
2610 previous configurations. It operates only on the user's own profile,
2611 and works with normal user privileges (@pxref{Features}). Its syntax
2615 guix package @var{options}
2618 @cindex transactions
2619 Primarily, @var{options} specifies the operations to be performed during
2620 the transaction. Upon completion, a new profile is created, but
2621 previous @dfn{generations} of the profile remain available, should the user
2624 For example, to remove @code{lua} and install @code{guile} and
2625 @code{guile-cairo} in a single transaction:
2628 guix package -r lua -i guile guile-cairo
2631 @cindex aliases, for @command{guix package}
2632 For your convenience, we also provide the following aliases:
2636 @command{guix search} is an alias for @command{guix package -s},
2638 @command{guix install} is an alias for @command{guix package -i},
2640 @command{guix remove} is an alias for @command{guix package -r},
2642 and @command{guix upgrade} is an alias for @command{guix package -u}.
2645 These aliases are less expressive than @command{guix package} and provide
2646 fewer options, so in some cases you'll probably want to use @command{guix
2649 @command{guix package} also supports a @dfn{declarative approach}
2650 whereby the user specifies the exact set of packages to be available and
2651 passes it @i{via} the @option{--manifest} option
2652 (@pxref{profile-manifest, @option{--manifest}}).
2655 For each user, a symlink to the user's default profile is automatically
2656 created in @file{$HOME/.guix-profile}. This symlink always points to the
2657 current generation of the user's default profile. Thus, users can add
2658 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2659 variable, and so on.
2660 @cindex search paths
2661 If you are not using Guix System, consider adding the
2662 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2663 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2664 shells get all the right environment variable definitions:
2667 GUIX_PROFILE="$HOME/.guix-profile" ; \
2668 source "$HOME/.guix-profile/etc/profile"
2671 In a multi-user setup, user profiles are stored in a place registered as
2672 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2673 to (@pxref{Invoking guix gc}). That directory is normally
2674 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2675 @var{localstatedir} is the value passed to @code{configure} as
2676 @code{--localstatedir}, and @var{user} is the user name. The
2677 @file{per-user} directory is created when @command{guix-daemon} is
2678 started, and the @var{user} sub-directory is created by @command{guix
2681 The @var{options} can be among the following:
2685 @item --install=@var{package} @dots{}
2686 @itemx -i @var{package} @dots{}
2687 Install the specified @var{package}s.
2689 Each @var{package} may specify either a simple package name, such as
2690 @code{guile}, or a package name followed by an at-sign and version number,
2691 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2692 case, the newest version prefixed by @code{1.8} is selected.)
2694 If no version number is specified, the
2695 newest available version will be selected. In addition, @var{package}
2696 may contain a colon, followed by the name of one of the outputs of the
2697 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2698 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2699 name (and optionally version) are searched for among the GNU
2700 distribution modules (@pxref{Package Modules}).
2702 @cindex propagated inputs
2703 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2704 that automatically get installed along with the required package
2705 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2706 @code{package} objects}, for information about propagated inputs in
2707 package definitions).
2709 @anchor{package-cmd-propagated-inputs}
2710 An example is the GNU MPC library: its C header files refer to those of
2711 the GNU MPFR library, which in turn refer to those of the GMP library.
2712 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2713 in the profile; removing MPC also removes MPFR and GMP---unless they had
2714 also been explicitly installed by the user.
2716 Besides, packages sometimes rely on the definition of environment
2717 variables for their search paths (see explanation of
2718 @code{--search-paths} below). Any missing or possibly incorrect
2719 environment variable definitions are reported here.
2721 @item --install-from-expression=@var{exp}
2723 Install the package @var{exp} evaluates to.
2725 @var{exp} must be a Scheme expression that evaluates to a
2726 @code{<package>} object. This option is notably useful to disambiguate
2727 between same-named variants of a package, with expressions such as
2728 @code{(@@ (gnu packages base) guile-final)}.
2730 Note that this option installs the first output of the specified
2731 package, which may be insufficient when needing a specific output of a
2732 multiple-output package.
2734 @item --install-from-file=@var{file}
2735 @itemx -f @var{file}
2736 Install the package that the code within @var{file} evaluates to.
2738 As an example, @var{file} might contain a definition like this
2739 (@pxref{Defining Packages}):
2742 @verbatiminclude package-hello.scm
2745 Developers may find it useful to include such a @file{guix.scm} file
2746 in the root of their project source tree that can be used to test
2747 development snapshots and create reproducible development environments
2748 (@pxref{Invoking guix environment}).
2750 @item --remove=@var{package} @dots{}
2751 @itemx -r @var{package} @dots{}
2752 Remove the specified @var{package}s.
2754 As for @code{--install}, each @var{package} may specify a version number
2755 and/or output name in addition to the package name. For instance,
2756 @code{-r glibc:debug} would remove the @code{debug} output of
2759 @item --upgrade[=@var{regexp} @dots{}]
2760 @itemx -u [@var{regexp} @dots{}]
2761 @cindex upgrading packages
2762 Upgrade all the installed packages. If one or more @var{regexp}s are
2763 specified, upgrade only installed packages whose name matches a
2764 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2766 Note that this upgrades package to the latest version of packages found
2767 in the distribution currently installed. To update your distribution,
2768 you should regularly run @command{guix pull} (@pxref{Invoking guix
2771 @item --do-not-upgrade[=@var{regexp} @dots{}]
2772 When used together with the @code{--upgrade} option, do @emph{not}
2773 upgrade any packages whose name matches a @var{regexp}. For example, to
2774 upgrade all packages in the current profile except those containing the
2775 substring ``emacs'':
2778 $ guix package --upgrade . --do-not-upgrade emacs
2781 @item @anchor{profile-manifest}--manifest=@var{file}
2782 @itemx -m @var{file}
2783 @cindex profile declaration
2784 @cindex profile manifest
2785 Create a new generation of the profile from the manifest object
2786 returned by the Scheme code in @var{file}.
2788 This allows you to @emph{declare} the profile's contents rather than
2789 constructing it through a sequence of @code{--install} and similar
2790 commands. The advantage is that @var{file} can be put under version
2791 control, copied to different machines to reproduce the same profile, and
2794 @c FIXME: Add reference to (guix profile) documentation when available.
2795 @var{file} must return a @dfn{manifest} object, which is roughly a list
2798 @findex packages->manifest
2800 (use-package-modules guile emacs)
2805 ;; Use a specific package output.
2806 (list guile-2.0 "debug")))
2809 @findex specifications->manifest
2810 In this example we have to know which modules define the @code{emacs}
2811 and @code{guile-2.0} variables to provide the right
2812 @code{use-package-modules} line, which can be cumbersome. We can
2813 instead provide regular package specifications and let
2814 @code{specifications->manifest} look up the corresponding package
2818 (specifications->manifest
2819 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2823 @cindex rolling back
2824 @cindex undoing transactions
2825 @cindex transactions, undoing
2826 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2827 the last transaction.
2829 When combined with options such as @code{--install}, roll back occurs
2830 before any other actions.
2832 When rolling back from the first generation that actually contains
2833 installed packages, the profile is made to point to the @dfn{zeroth
2834 generation}, which contains no files apart from its own metadata.
2836 After having rolled back, installing, removing, or upgrading packages
2837 overwrites previous future generations. Thus, the history of the
2838 generations in a profile is always linear.
2840 @item --switch-generation=@var{pattern}
2841 @itemx -S @var{pattern}
2843 Switch to a particular generation defined by @var{pattern}.
2845 @var{pattern} may be either a generation number or a number prefixed
2846 with ``+'' or ``-''. The latter means: move forward/backward by a
2847 specified number of generations. For example, if you want to return to
2848 the latest generation after @code{--roll-back}, use
2849 @code{--switch-generation=+1}.
2851 The difference between @code{--roll-back} and
2852 @code{--switch-generation=-1} is that @code{--switch-generation} will
2853 not make a zeroth generation, so if a specified generation does not
2854 exist, the current generation will not be changed.
2856 @item --search-paths[=@var{kind}]
2857 @cindex search paths
2858 Report environment variable definitions, in Bash syntax, that may be
2859 needed in order to use the set of installed packages. These environment
2860 variables are used to specify @dfn{search paths} for files used by some
2861 of the installed packages.
2863 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2864 environment variables to be defined so it can look for headers and
2865 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2866 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2867 library are installed in the profile, then @code{--search-paths} will
2868 suggest setting these variables to @code{@var{profile}/include} and
2869 @code{@var{profile}/lib}, respectively.
2871 The typical use case is to define these environment variables in the
2875 $ eval `guix package --search-paths`
2878 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2879 meaning that the returned environment variable definitions will either
2880 be exact settings, or prefixes or suffixes of the current value of these
2881 variables. When omitted, @var{kind} defaults to @code{exact}.
2883 This option can also be used to compute the @emph{combined} search paths
2884 of several profiles. Consider this example:
2887 $ guix package -p foo -i guile
2888 $ guix package -p bar -i guile-json
2889 $ guix package -p foo -p bar --search-paths
2892 The last command above reports about the @code{GUILE_LOAD_PATH}
2893 variable, even though, taken individually, neither @file{foo} nor
2894 @file{bar} would lead to that recommendation.
2897 @item --profile=@var{profile}
2898 @itemx -p @var{profile}
2899 Use @var{profile} instead of the user's default profile.
2901 @cindex collisions, in a profile
2902 @cindex colliding packages in profiles
2903 @cindex profile collisions
2904 @item --allow-collisions
2905 Allow colliding packages in the new profile. Use at your own risk!
2907 By default, @command{guix package} reports as an error @dfn{collisions}
2908 in the profile. Collisions happen when two or more different versions
2909 or variants of a given package end up in the profile.
2912 Use the bootstrap Guile to build the profile. This option is only
2913 useful to distribution developers.
2917 In addition to these actions, @command{guix package} supports the
2918 following options to query the current state of a profile, or the
2919 availability of packages:
2923 @item --search=@var{regexp}
2924 @itemx -s @var{regexp}
2925 @cindex searching for packages
2926 List the available packages whose name, synopsis, or description matches
2927 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2928 Print all the metadata of matching packages in
2929 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2930 GNU recutils manual}).
2932 This allows specific fields to be extracted using the @command{recsel}
2933 command, for instance:
2936 $ guix package -s malloc | recsel -p name,version,relevance
2950 Similarly, to show the name of all the packages available under the
2951 terms of the GNU@tie{}LGPL version 3:
2954 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2961 It is also possible to refine search results using several @code{-s} flags to
2962 @command{guix package}, or several arguments to @command{guix search}. For
2963 example, the following command returns a list of board games (this time using
2964 the @command{guix search} alias):
2967 $ guix search '\<board\>' game | recsel -p name
2972 If we were to omit @code{-s game}, we would also get software packages
2973 that deal with printed circuit boards; removing the angle brackets
2974 around @code{board} would further add packages that have to do with
2977 And now for a more elaborate example. The following command searches
2978 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2979 libraries, and prints the name and synopsis of the matching packages:
2982 $ guix search crypto library | \
2983 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2987 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2988 information on @dfn{selection expressions} for @code{recsel -e}.
2990 @item --show=@var{package}
2991 Show details about @var{package}, taken from the list of available packages, in
2992 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2996 $ guix package --show=python | recsel -p name,version
3004 You may also specify the full name of a package to only get details about a
3005 specific version of it:
3007 $ guix package --show=python@@3.4 | recsel -p name,version
3014 @item --list-installed[=@var{regexp}]
3015 @itemx -I [@var{regexp}]
3016 List the currently installed packages in the specified profile, with the
3017 most recently installed packages shown last. When @var{regexp} is
3018 specified, list only installed packages whose name matches @var{regexp}.
3020 For each installed package, print the following items, separated by
3021 tabs: the package name, its version string, the part of the package that
3022 is installed (for instance, @code{out} for the default output,
3023 @code{include} for its headers, etc.), and the path of this package in
3026 @item --list-available[=@var{regexp}]
3027 @itemx -A [@var{regexp}]
3028 List packages currently available in the distribution for this system
3029 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3030 installed packages whose name matches @var{regexp}.
3032 For each package, print the following items separated by tabs: its name,
3033 its version string, the parts of the package (@pxref{Packages with
3034 Multiple Outputs}), and the source location of its definition.
3036 @item --list-generations[=@var{pattern}]
3037 @itemx -l [@var{pattern}]
3039 Return a list of generations along with their creation dates; for each
3040 generation, show the installed packages, with the most recently
3041 installed packages shown last. Note that the zeroth generation is never
3044 For each installed package, print the following items, separated by
3045 tabs: the name of a package, its version string, the part of the package
3046 that is installed (@pxref{Packages with Multiple Outputs}), and the
3047 location of this package in the store.
3049 When @var{pattern} is used, the command returns only matching
3050 generations. Valid patterns include:
3053 @item @emph{Integers and comma-separated integers}. Both patterns denote
3054 generation numbers. For instance, @code{--list-generations=1} returns
3057 And @code{--list-generations=1,8,2} outputs three generations in the
3058 specified order. Neither spaces nor trailing commas are allowed.
3060 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3061 specified generations and everything in between. Note that the start of
3062 a range must be smaller than its end.
3064 It is also possible to omit the endpoint. For example,
3065 @code{--list-generations=2..}, returns all generations starting from the
3068 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3069 or months by passing an integer along with the first letter of the
3070 duration. For example, @code{--list-generations=20d} lists generations
3071 that are up to 20 days old.
3074 @item --delete-generations[=@var{pattern}]
3075 @itemx -d [@var{pattern}]
3076 When @var{pattern} is omitted, delete all generations except the current
3079 This command accepts the same patterns as @option{--list-generations}.
3080 When @var{pattern} is specified, delete the matching generations. When
3081 @var{pattern} specifies a duration, generations @emph{older} than the
3082 specified duration match. For instance, @code{--delete-generations=1m}
3083 deletes generations that are more than one month old.
3085 If the current generation matches, it is @emph{not} deleted. Also, the
3086 zeroth generation is never deleted.
3088 Note that deleting generations prevents rolling back to them.
3089 Consequently, this command must be used with care.
3093 Finally, since @command{guix package} may actually start build
3094 processes, it supports all the common build options (@pxref{Common Build
3095 Options}). It also supports package transformation options, such as
3096 @option{--with-source} (@pxref{Package Transformation Options}).
3097 However, note that package transformations are lost when upgrading; to
3098 preserve transformations across upgrades, you should define your own
3099 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3100 (@pxref{Defining Packages}).
3103 @section Substitutes
3106 @cindex pre-built binaries
3107 Guix supports transparent source/binary deployment, which means that it
3108 can either build things locally, or download pre-built items from a
3109 server, or both. We call these pre-built items @dfn{substitutes}---they
3110 are substitutes for local build results. In many cases, downloading a
3111 substitute is much faster than building things locally.
3113 Substitutes can be anything resulting from a derivation build
3114 (@pxref{Derivations}). Of course, in the common case, they are
3115 pre-built package binaries, but source tarballs, for instance, which
3116 also result from derivation builds, can be available as substitutes.
3119 * Official Substitute Server:: One particular source of substitutes.
3120 * Substitute Server Authorization:: How to enable or disable substitutes.
3121 * Substitute Authentication:: How Guix verifies substitutes.
3122 * Proxy Settings:: How to get substitutes via proxy.
3123 * Substitution Failure:: What happens when substitution fails.
3124 * On Trusting Binaries:: How can you trust that binary blob?
3127 @node Official Substitute Server
3128 @subsection Official Substitute Server
3132 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3133 that builds packages from Guix continuously for some
3134 architectures, and makes them available as substitutes. This is the
3135 default source of substitutes; it can be overridden by passing the
3136 @option{--substitute-urls} option either to @command{guix-daemon}
3137 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3138 or to client tools such as @command{guix package}
3139 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3142 Substitute URLs can be either HTTP or HTTPS.
3143 HTTPS is recommended because communications are encrypted; conversely,
3144 using HTTP makes all communications visible to an eavesdropper, who
3145 could use the information gathered to determine, for instance, whether
3146 your system has unpatched security vulnerabilities.
3148 Substitutes from the official build farm are enabled by default when
3149 using Guix System (@pxref{GNU Distribution}). However,
3150 they are disabled by default when using Guix on a foreign distribution,
3151 unless you have explicitly enabled them via one of the recommended
3152 installation steps (@pxref{Installation}). The following paragraphs
3153 describe how to enable or disable substitutes for the official build
3154 farm; the same procedure can also be used to enable substitutes for any
3155 other substitute server.
3157 @node Substitute Server Authorization
3158 @subsection Substitute Server Authorization
3161 @cindex substitutes, authorization thereof
3162 @cindex access control list (ACL), for substitutes
3163 @cindex ACL (access control list), for substitutes
3164 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3166 must add its public key to the access control list (ACL) of archive
3167 imports, using the @command{guix archive} command (@pxref{Invoking guix
3168 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3169 be compromised and to serve genuine substitutes.
3171 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3172 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3173 the installation prefix of Guix. If you installed Guix from source,
3174 make sure you checked the GPG signature of
3175 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3176 Then, you can run something like this:
3179 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3183 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3184 of an independent build farm also run by the project, reachable at
3185 @indicateurl{https://mirror.hydra.gnu.org}.
3188 Once this is in place, the output of a command like @code{guix build}
3189 should change from something like:
3192 $ guix build emacs --dry-run
3193 The following derivations would be built:
3194 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3195 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3196 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3197 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3205 $ guix build emacs --dry-run
3206 112.3 MB would be downloaded:
3207 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3208 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3209 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3210 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3215 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3216 will be downloaded, when possible, for future builds.
3218 @cindex substitutes, how to disable
3219 The substitute mechanism can be disabled globally by running
3220 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3221 guix-daemon}). It can also be disabled temporarily by passing the
3222 @code{--no-substitutes} option to @command{guix package}, @command{guix
3223 build}, and other command-line tools.
3225 @node Substitute Authentication
3226 @subsection Substitute Authentication
3228 @cindex digital signatures
3229 Guix detects and raises an error when attempting to use a substitute
3230 that has been tampered with. Likewise, it ignores substitutes that are
3231 not signed, or that are not signed by one of the keys listed in the ACL.
3233 There is one exception though: if an unauthorized server provides
3234 substitutes that are @emph{bit-for-bit identical} to those provided by
3235 an authorized server, then the unauthorized server becomes eligible for
3236 downloads. For example, assume we have chosen two substitute servers
3240 --substitute-urls="https://a.example.org https://b.example.org"
3244 @cindex reproducible builds
3245 If the ACL contains only the key for @code{b.example.org}, and if
3246 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3247 then Guix will download substitutes from @code{a.example.org} because it
3248 comes first in the list and can be considered a mirror of
3249 @code{b.example.org}. In practice, independent build machines usually
3250 produce the same binaries, thanks to bit-reproducible builds (see
3253 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3254 (in other words, the server is not authenticated), contrary to what
3255 HTTPS clients such as Web browsers usually do. This is because Guix
3256 authenticates substitute information itself, as explained above, which
3257 is what we care about (whereas X.509 certificates are about
3258 authenticating bindings between domain names and public keys.)
3260 @node Proxy Settings
3261 @subsection Proxy Settings
3264 Substitutes are downloaded over HTTP or HTTPS.
3265 The @code{http_proxy} environment
3266 variable can be set in the environment of @command{guix-daemon} and is
3267 honored for downloads of substitutes. Note that the value of
3268 @code{http_proxy} in the environment where @command{guix build},
3269 @command{guix package}, and other client commands are run has
3270 @emph{absolutely no effect}.
3272 @node Substitution Failure
3273 @subsection Substitution Failure
3275 Even when a substitute for a derivation is available, sometimes the
3276 substitution attempt will fail. This can happen for a variety of
3277 reasons: the substitute server might be offline, the substitute may
3278 recently have been deleted, the connection might have been interrupted,
3281 When substitutes are enabled and a substitute for a derivation is
3282 available, but the substitution attempt fails, Guix will attempt to
3283 build the derivation locally depending on whether or not
3284 @code{--fallback} was given (@pxref{fallback-option,, common build
3285 option @code{--fallback}}). Specifically, if @code{--fallback} was
3286 omitted, then no local build will be performed, and the derivation is
3287 considered to have failed. However, if @code{--fallback} was given,
3288 then Guix will attempt to build the derivation locally, and the success
3289 or failure of the derivation depends on the success or failure of the
3290 local build. Note that when substitutes are disabled or no substitute
3291 is available for the derivation in question, a local build will
3292 @emph{always} be performed, regardless of whether or not
3293 @code{--fallback} was given.
3295 To get an idea of how many substitutes are available right now, you can
3296 try running the @command{guix weather} command (@pxref{Invoking guix
3297 weather}). This command provides statistics on the substitutes provided
3300 @node On Trusting Binaries
3301 @subsection On Trusting Binaries
3303 @cindex trust, of pre-built binaries
3304 Today, each individual's control over their own computing is at the
3305 mercy of institutions, corporations, and groups with enough power and
3306 determination to subvert the computing infrastructure and exploit its
3307 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3308 convenient, we encourage users to also build on their own, or even run
3309 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3310 interesting target. One way to help is by publishing the software you
3311 build using @command{guix publish} so that others have one more choice
3312 of server to download substitutes from (@pxref{Invoking guix publish}).
3314 Guix has the foundations to maximize build reproducibility
3315 (@pxref{Features}). In most cases, independent builds of a given
3316 package or derivation should yield bit-identical results. Thus, through
3317 a diverse set of independent package builds, we can strengthen the
3318 integrity of our systems. The @command{guix challenge} command aims to
3319 help users assess substitute servers, and to assist developers in
3320 finding out about non-deterministic package builds (@pxref{Invoking guix
3321 challenge}). Similarly, the @option{--check} option of @command{guix
3322 build} allows users to check whether previously-installed substitutes
3323 are genuine by rebuilding them locally (@pxref{build-check,
3324 @command{guix build --check}}).
3326 In the future, we want Guix to have support to publish and retrieve
3327 binaries to/from other users, in a peer-to-peer fashion. If you would
3328 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3330 @node Packages with Multiple Outputs
3331 @section Packages with Multiple Outputs
3333 @cindex multiple-output packages
3334 @cindex package outputs
3337 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3338 source package leads to exactly one directory in the store. When running
3339 @command{guix install glibc}, one installs the default output of the
3340 GNU libc package; the default output is called @code{out}, but its name
3341 can be omitted as shown in this command. In this particular case, the
3342 default output of @code{glibc} contains all the C header files, shared
3343 libraries, static libraries, Info documentation, and other supporting
3346 Sometimes it is more appropriate to separate the various types of files
3347 produced from a single source package into separate outputs. For
3348 instance, the GLib C library (used by GTK+ and related packages)
3349 installs more than 20 MiB of reference documentation as HTML pages.
3350 To save space for users who do not need it, the documentation goes to a
3351 separate output, called @code{doc}. To install the main GLib output,
3352 which contains everything but the documentation, one would run:
3358 @cindex documentation
3359 The command to install its documentation is:
3362 guix install glib:doc
3365 Some packages install programs with different ``dependency footprints''.
3366 For instance, the WordNet package installs both command-line tools and
3367 graphical user interfaces (GUIs). The former depend solely on the C
3368 library, whereas the latter depend on Tcl/Tk and the underlying X
3369 libraries. In this case, we leave the command-line tools in the default
3370 output, whereas the GUIs are in a separate output. This allows users
3371 who do not need the GUIs to save space. The @command{guix size} command
3372 can help find out about such situations (@pxref{Invoking guix size}).
3373 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3375 There are several such multiple-output packages in the GNU distribution.
3376 Other conventional output names include @code{lib} for libraries and
3377 possibly header files, @code{bin} for stand-alone programs, and
3378 @code{debug} for debugging information (@pxref{Installing Debugging
3379 Files}). The outputs of a packages are listed in the third column of
3380 the output of @command{guix package --list-available} (@pxref{Invoking
3384 @node Invoking guix gc
3385 @section Invoking @command{guix gc}
3387 @cindex garbage collector
3389 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3390 The @command{guix gc} command allows users to explicitly run the garbage
3391 collector to reclaim space from the @file{/gnu/store} directory. It is
3392 the @emph{only} way to remove files from @file{/gnu/store}---removing
3393 files or directories manually may break it beyond repair!
3396 @cindex garbage collector roots
3397 The garbage collector has a set of known @dfn{roots}: any file under
3398 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3399 cannot be deleted; any other file is considered @dfn{dead} and may be
3400 deleted. The set of garbage collector roots (``GC roots'' for short)
3401 includes default user profiles; by default, the symlinks under
3402 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3403 added with @command{guix build --root}, for example (@pxref{Invoking
3404 guix build}). The @command{guix gc --list-roots} command lists them.
3406 Prior to running @code{guix gc --collect-garbage} to make space, it is
3407 often useful to remove old generations from user profiles; that way, old
3408 package builds referenced by those generations can be reclaimed. This
3409 is achieved by running @code{guix package --delete-generations}
3410 (@pxref{Invoking guix package}).
3412 Our recommendation is to run a garbage collection periodically, or when
3413 you are short on disk space. For instance, to guarantee that at least
3414 5@tie{}GB are available on your disk, simply run:
3420 It is perfectly safe to run as a non-interactive periodic job
3421 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3422 Running @command{guix gc} with no arguments will collect as
3423 much garbage as it can, but that is often inconvenient: you may find
3424 yourself having to rebuild or re-download software that is ``dead'' from
3425 the GC viewpoint but that is necessary to build other pieces of
3426 software---e.g., the compiler tool chain.
3428 The @command{guix gc} command has three modes of operation: it can be
3429 used to garbage-collect any dead files (the default), to delete specific
3430 files (the @code{--delete} option), to print garbage-collector
3431 information, or for more advanced queries. The garbage collection
3432 options are as follows:
3435 @item --collect-garbage[=@var{min}]
3436 @itemx -C [@var{min}]
3437 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3438 sub-directories. This is the default operation when no option is
3441 When @var{min} is given, stop once @var{min} bytes have been collected.
3442 @var{min} may be a number of bytes, or it may include a unit as a
3443 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3444 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3446 When @var{min} is omitted, collect all the garbage.
3448 @item --free-space=@var{free}
3449 @itemx -F @var{free}
3450 Collect garbage until @var{free} space is available under
3451 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3452 as @code{500MiB}, as described above.
3454 When @var{free} or more is already available in @file{/gnu/store}, do
3455 nothing and exit immediately.
3457 @item --delete-generations[=@var{duration}]
3458 @itemx -d [@var{duration}]
3459 Before starting the garbage collection process, delete all the generations
3460 older than @var{duration}, for all the user profiles; when run as root, this
3461 applies to all the profiles @emph{of all the users}.
3463 For example, this command deletes all the generations of all your profiles
3464 that are older than 2 months (except generations that are current), and then
3465 proceeds to free space until at least 10 GiB are available:
3468 guix gc -d 2m -F 10G
3473 Attempt to delete all the store files and directories specified as
3474 arguments. This fails if some of the files are not in the store, or if
3475 they are still live.
3477 @item --list-failures
3478 List store items corresponding to cached build failures.
3480 This prints nothing unless the daemon was started with
3481 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3482 @option{--cache-failures}}).
3485 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3488 @item --clear-failures
3489 Remove the specified store items from the failed-build cache.
3491 Again, this option only makes sense when the daemon is started with
3492 @option{--cache-failures}. Otherwise, it does nothing.
3495 Show the list of dead files and directories still present in the
3496 store---i.e., files and directories no longer reachable from any root.
3499 Show the list of live store files and directories.
3503 In addition, the references among existing store files can be queried:
3509 @cindex package dependencies
3510 List the references (respectively, the referrers) of store files given
3516 List the requisites of the store files passed as arguments. Requisites
3517 include the store files themselves, their references, and the references
3518 of these, recursively. In other words, the returned list is the
3519 @dfn{transitive closure} of the store files.
3521 @xref{Invoking guix size}, for a tool to profile the size of the closure
3522 of an element. @xref{Invoking guix graph}, for a tool to visualize
3523 the graph of references.
3527 Return the derivation(s) leading to the given store items
3528 (@pxref{Derivations}).
3530 For example, this command:
3533 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3537 returns the @file{.drv} file(s) leading to the @code{emacs} package
3538 installed in your profile.
3540 Note that there may be zero matching @file{.drv} files, for instance
3541 because these files have been garbage-collected. There can also be more
3542 than one matching @file{.drv} due to fixed-output derivations.
3545 Lastly, the following options allow you to check the integrity of the
3546 store and to control disk usage.
3550 @item --verify[=@var{options}]
3551 @cindex integrity, of the store
3552 @cindex integrity checking
3553 Verify the integrity of the store.
3555 By default, make sure that all the store items marked as valid in the
3556 database of the daemon actually exist in @file{/gnu/store}.
3558 When provided, @var{options} must be a comma-separated list containing one
3559 or more of @code{contents} and @code{repair}.
3561 When passing @option{--verify=contents}, the daemon computes the
3562 content hash of each store item and compares it against its hash in the
3563 database. Hash mismatches are reported as data corruptions. Because it
3564 traverses @emph{all the files in the store}, this command can take a
3565 long time, especially on systems with a slow disk drive.
3567 @cindex repairing the store
3568 @cindex corruption, recovering from
3569 Using @option{--verify=repair} or @option{--verify=contents,repair}
3570 causes the daemon to try to repair corrupt store items by fetching
3571 substitutes for them (@pxref{Substitutes}). Because repairing is not
3572 atomic, and thus potentially dangerous, it is available only to the
3573 system administrator. A lightweight alternative, when you know exactly
3574 which items in the store are corrupt, is @command{guix build --repair}
3575 (@pxref{Invoking guix build}).
3578 @cindex deduplication
3579 Optimize the store by hard-linking identical files---this is
3580 @dfn{deduplication}.
3582 The daemon performs deduplication after each successful build or archive
3583 import, unless it was started with @code{--disable-deduplication}
3584 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3585 this option is primarily useful when the daemon was running with
3586 @code{--disable-deduplication}.
3590 @node Invoking guix pull
3591 @section Invoking @command{guix pull}
3593 @cindex upgrading Guix
3594 @cindex updating Guix
3595 @cindex @command{guix pull}
3597 Packages are installed or upgraded to the latest version available in
3598 the distribution currently available on your local machine. To update
3599 that distribution, along with the Guix tools, you must run @command{guix
3600 pull}: the command downloads the latest Guix source code and package
3601 descriptions, and deploys it. Source code is downloaded from a
3602 @uref{https://git-scm.com, Git} repository, by default the official
3603 GNU@tie{}Guix repository, though this can be customized.
3605 On completion, @command{guix package} will use packages and package
3606 versions from this just-retrieved copy of Guix. Not only that, but all
3607 the Guix commands and Scheme modules will also be taken from that latest
3608 version. New @command{guix} sub-commands added by the update also
3611 Any user can update their Guix copy using @command{guix pull}, and the
3612 effect is limited to the user who run @command{guix pull}. For
3613 instance, when user @code{root} runs @command{guix pull}, this has no
3614 effect on the version of Guix that user @code{alice} sees, and vice
3617 The result of running @command{guix pull} is a @dfn{profile} available
3618 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3619 make sure to add it to the beginning of your search path so that you use
3620 the latest version, and similarly for the Info manual
3621 (@pxref{Documentation}):
3624 export PATH="$HOME/.config/guix/current/bin:$PATH"
3625 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3628 The @code{--list-generations} or @code{-l} option lists past generations
3629 produced by @command{guix pull}, along with details about their provenance:
3633 Generation 1 Jun 10 2018 00:18:18
3635 repository URL: https://git.savannah.gnu.org/git/guix.git
3636 branch: origin/master
3637 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3639 Generation 2 Jun 11 2018 11:02:49
3641 repository URL: https://git.savannah.gnu.org/git/guix.git
3642 branch: origin/master
3643 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3644 2 new packages: keepalived, libnfnetlink
3645 6 packages upgraded: emacs-nix-mode@@2.0.4,
3646 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3647 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3649 Generation 3 Jun 13 2018 23:31:07 (current)
3651 repository URL: https://git.savannah.gnu.org/git/guix.git
3652 branch: origin/master
3653 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3654 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3655 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3658 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3659 describe the current status of Guix.
3661 This @code{~/.config/guix/current} profile works like any other profile
3662 created by @command{guix package} (@pxref{Invoking guix package}). That
3663 is, you can list generations, roll back to the previous
3664 generation---i.e., the previous Guix---and so on:
3667 $ guix package -p ~/.config/guix/current --roll-back
3668 switched from generation 3 to 2
3669 $ guix package -p ~/.config/guix/current --delete-generations=1
3670 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3673 The @command{guix pull} command is usually invoked with no arguments,
3674 but it supports the following options:
3677 @item --url=@var{url}
3678 @itemx --commit=@var{commit}
3679 @itemx --branch=@var{branch}
3680 Download code for the @code{guix} channel from the specified @var{url}, at the
3681 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3682 string), or @var{branch}.
3684 @cindex @file{channels.scm}, configuration file
3685 @cindex configuration file for channels
3686 These options are provided for convenience, but you can also specify your
3687 configuration in the @file{~/.config/guix/channels.scm} file or using the
3688 @option{--channels} option (see below).
3690 @item --channels=@var{file}
3691 @itemx -C @var{file}
3692 Read the list of channels from @var{file} instead of
3693 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3694 evaluates to a list of channel objects. @xref{Channels}, for more
3699 Display the list of packages added or upgraded since the previous generation.
3701 This is the same information as displayed upon @command{guix pull} completion,
3702 but without ellipses; it is also similar to the output of @command{guix pull
3703 -l} for the last generation (see below).
3705 @item --list-generations[=@var{pattern}]
3706 @itemx -l [@var{pattern}]
3707 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3708 is provided, the subset of generations that match @var{pattern}.
3709 The syntax of @var{pattern} is the same as with @code{guix package
3710 --list-generations} (@pxref{Invoking guix package}).
3712 @xref{Invoking guix describe}, for a way to display information about the
3713 current generation only.
3715 @item --profile=@var{profile}
3716 @itemx -p @var{profile}
3717 Use @var{profile} instead of @file{~/.config/guix/current}.
3721 Show which channel commit(s) would be used and what would be built or
3722 substituted but do not actually do it.
3724 @item --system=@var{system}
3725 @itemx -s @var{system}
3726 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3727 the system type of the build host.
3730 Produce verbose output, writing build logs to the standard error output.
3733 Use the bootstrap Guile to build the latest Guix. This option is only
3734 useful to Guix developers.
3737 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3738 repository and branch to pull from, as well as @emph{additional} repositories
3739 containing package modules that should be deployed. @xref{Channels}, for more
3742 In addition, @command{guix pull} supports all the common build options
3743 (@pxref{Common Build Options}).
3749 @cindex @file{channels.scm}, configuration file
3750 @cindex configuration file for channels
3751 @cindex @command{guix pull}, configuration file
3752 @cindex configuration of @command{guix pull}
3753 Guix and its package collection are updated by running @command{guix pull}
3754 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3755 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3756 customized by defining @dfn{channels} in the
3757 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3758 of a Git repository to be deployed, and @command{guix pull} can be instructed
3759 to pull from one or more channels. In other words, channels can be used to
3760 @emph{customize} and to @emph{extend} Guix, as we will see below.
3762 @subsection Using a Custom Guix Channel
3764 The channel called @code{guix} specifies where Guix itself---its command-line
3765 tools as well as its package collection---should be downloaded. For instance,
3766 suppose you want to update from your own copy of the Guix repository at
3767 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3768 write in @code{~/.config/guix/channels.scm} this specification:
3771 ;; Tell 'guix pull' to use my own repo.
3774 (url "https://example.org/my-guix.git")
3775 (branch "super-hacks")))
3779 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3780 branch of the repository at @code{example.org}.
3782 @subsection Specifying Additional Channels
3784 @cindex extending the package collection (channels)
3785 @cindex personal packages (channels)
3786 @cindex channels, for personal packages
3787 You can also specify @emph{additional channels} to pull from. Let's say you
3788 have a bunch of custom package variants or personal packages that you think
3789 would make little sense to contribute to the Guix project, but would like to
3790 have these packages transparently available to you at the command line. You
3791 would first write modules containing those package definitions (@pxref{Package
3792 Modules}), maintain them in a Git repository, and then you and anyone else can
3793 use it as an additional channel to get packages from. Neat, no?
3795 @c What follows stems from discussions at
3796 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3797 @c earlier discussions on guix-devel@gnu.org.
3799 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3800 publish your personal channel to the world, we would like to share a few words
3805 Before publishing a channel, please consider contributing your package
3806 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3807 to free software of all sorts, and packages in Guix proper are readily
3808 available to all Guix users and benefit from the project's quality assurance
3812 When you maintain package definitions outside Guix, we, Guix developers,
3813 consider that @emph{the compatibility burden is on you}. Remember that
3814 package modules and package definitions are just Scheme code that uses various
3815 programming interfaces (APIs). We want to remain free to change these APIs to
3816 keep improving Guix, possibly in ways that break your channel. We never
3817 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3821 Corollary: if you're using an external channel and that channel breaks, please
3822 @emph{report the issue to the channel authors}, not to the Guix project.
3825 You've been warned! Having said this, we believe external channels are a
3826 practical way to exert your freedom to augment Guix' package collection and to
3827 share your improvements, which are basic tenets of
3828 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3829 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3832 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3833 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3836 @vindex %default-channels
3838 ;; Add my personal packages to those Guix provides.
3840 (name 'my-personal-packages)
3841 (url "https://example.org/personal-packages.git"))
3846 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3847 add a channel the list of channels that the variable @code{%default-channels}
3848 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3849 Manual}). With this file in place, @command{guix pull} builds not only Guix
3850 but also the package modules from your own repository. The result in
3851 @file{~/.config/guix/current} is the union of Guix with your own package
3855 $ guix pull --list-generations
3857 Generation 19 Aug 27 2018 16:20:48
3859 repository URL: https://git.savannah.gnu.org/git/guix.git
3861 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3862 my-personal-packages dd3df5e
3863 repository URL: https://example.org/personal-packages.git
3865 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3866 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3867 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3871 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3872 both Guix and packages from the @code{my-personal-packages} channel. Among
3873 the new and upgraded packages that are listed, some like @code{my-gimp} and
3874 @code{my-emacs-with-cool-features} might come from
3875 @code{my-personal-packages}, while others come from the Guix default channel.
3877 To create a channel, create a Git repository containing your own package
3878 modules and make it available. The repository can contain anything, but a
3879 useful channel will contain Guile modules that export packages. Once you
3880 start using a channel, Guix will behave as if the root directory of that
3881 channel's Git repository has been added to the Guile load path (@pxref{Load
3882 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3883 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3884 module, then the module will be available under the name @code{(my-packages
3885 my-tools)}, and you will be able to use it like any other module
3886 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3888 @cindex dependencies, channels
3889 @cindex meta-data, channels
3890 @subsection Declaring Channel Dependencies
3892 Channel authors may decide to augment a package collection provided by other
3893 channels. They can declare their channel to be dependent on other channels in
3894 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3895 the channel repository.
3897 The meta-data file should contain a simple S-expression like this:
3904 (name some-collection)
3905 (url "https://example.org/first-collection.git"))
3907 (name some-other-collection)
3908 (url "https://example.org/second-collection.git")
3909 (branch "testing"))))
3912 In the above example this channel is declared to depend on two other channels,
3913 which will both be fetched automatically. The modules provided by the channel
3914 will be compiled in an environment where the modules of all these declared
3915 channels are available.
3917 For the sake of reliability and maintainability, you should avoid dependencies
3918 on channels that you don't control, and you should aim to keep the number of
3919 dependencies to a minimum.
3921 @subsection Replicating Guix
3923 @cindex pinning, channels
3924 @cindex replicating Guix
3925 @cindex reproducibility, of Guix
3926 The @command{guix pull --list-generations} output above shows precisely which
3927 commits were used to build this instance of Guix. We can thus replicate it,
3928 say, on another machine, by providing a channel specification in
3929 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3932 ;; Deploy specific commits of my channels of interest.
3935 (url "https://git.savannah.gnu.org/git/guix.git")
3936 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3938 (name 'my-personal-packages)
3939 (url "https://example.org/personal-packages.git")
3940 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3943 The @command{guix describe --format=channels} command can even generate this
3944 list of channels directly (@pxref{Invoking guix describe}).
3946 At this point the two machines run the @emph{exact same Guix}, with access to
3947 the @emph{exact same packages}. The output of @command{guix build gimp} on
3948 one machine will be exactly the same, bit for bit, as the output of the same
3949 command on the other machine. It also means both machines have access to all
3950 the source code of Guix and, transitively, to all the source code of every
3953 This gives you super powers, allowing you to track the provenance of binary
3954 artifacts with very fine grain, and to reproduce software environments at
3955 will---some sort of ``meta reproducibility'' capabilities, if you will.
3956 @xref{Inferiors}, for another way to take advantage of these super powers.
3961 @c TODO: Remove this once we're more confident about API stability.
3963 The functionality described here is a ``technology preview'' as of version
3964 @value{VERSION}. As such, the interface is subject to change.
3968 @cindex composition of Guix revisions
3969 Sometimes you might need to mix packages from the revision of Guix you're
3970 currently running with packages available in a different revision of Guix.
3971 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3972 revisions in arbitrary ways.
3974 @cindex inferior packages
3975 Technically, an ``inferior'' is essentially a separate Guix process connected
3976 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3977 @code{(guix inferior)} module allows you to create inferiors and to
3978 communicate with them. It also provides a high-level interface to browse and
3979 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3981 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3982 to interact with a separate revision of Guix. For example, let's assume you
3983 want to install in your profile the current @code{guile} package, along with
3984 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3985 because the newer @code{guile-json} has an incompatible API and you want to
3986 run your code against the old API@. To do that, you could write a manifest for
3987 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3988 manifest, you would create an inferior for that old Guix revision you care
3989 about, and you would look up the @code{guile-json} package in the inferior:
3992 (use-modules (guix inferior) (guix channels)
3993 (srfi srfi-1)) ;for 'first'
3996 ;; This is the old revision from which we want to
3997 ;; extract guile-json.
4000 (url "https://git.savannah.gnu.org/git/guix.git")
4002 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4005 ;; An inferior representing the above revision.
4006 (inferior-for-channels channels))
4008 ;; Now create a manifest with the current "guile" package
4009 ;; and the old "guile-json" package.
4011 (list (first (lookup-inferior-packages inferior "guile-json"))
4012 (specification->package "guile")))
4015 On its first run, @command{guix package --manifest} might have to build the
4016 channel you specified before it can create the inferior; subsequent runs will
4017 be much faster because the Guix revision will be cached.
4019 The @code{(guix inferior)} module provides the following procedures to open an
4022 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4023 [#:cache-directory] [#:ttl]
4024 Return an inferior for @var{channels}, a list of channels. Use the cache at
4025 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4026 This procedure opens a new connection to the build daemon.
4028 As a side effect, this procedure may build or substitute binaries for
4029 @var{channels}, which can take time.
4032 @deffn {Scheme Procedure} open-inferior @var{directory} @
4033 [#:command "bin/guix"]
4034 Open the inferior Guix in @var{directory}, running
4035 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4036 the inferior could not be launched.
4039 @cindex inferior packages
4040 The procedures listed below allow you to obtain and manipulate inferior
4043 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4044 Return the list of packages known to @var{inferior}.
4047 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4049 Return the sorted list of inferior packages matching @var{name} in
4050 @var{inferior}, with highest version numbers first. If @var{version} is true,
4051 return only packages with a version number prefixed by @var{version}.
4054 @deffn {Scheme Procedure} inferior-package? @var{obj}
4055 Return true if @var{obj} is an inferior package.
4058 @deffn {Scheme Procedure} inferior-package-name @var{package}
4059 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4060 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4061 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4062 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4063 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4064 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4065 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4066 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4067 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4068 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4069 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4070 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4071 These procedures are the counterpart of package record accessors
4072 (@pxref{package Reference}). Most of them work by querying the inferior
4073 @var{package} comes from, so the inferior must still be live when you call
4077 Inferior packages can be used transparently like any other package or
4078 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4079 transparently handled by the @code{packages->manifest} procedure, which is
4080 commonly use in manifests (@pxref{Invoking guix package, the
4081 @option{--manifest} option of @command{guix package}}). Thus you can insert
4082 an inferior package pretty much anywhere you would insert a regular package:
4083 in manifests, in the @code{packages} field of your @code{operating-system}
4084 declaration, and so on.
4086 @node Invoking guix describe
4087 @section Invoking @command{guix describe}
4089 @cindex reproducibility
4090 @cindex replicating Guix
4091 Often you may want to answer questions like: ``Which revision of Guix am I
4092 using?'' or ``Which channels am I using?'' This is useful information in many
4093 situations: if you want to @emph{replicate} an environment on a different
4094 machine or user account, if you want to report a bug or to determine what
4095 change in the channels you are using caused it, or if you want to record your
4096 system state for reproducibility purposes. The @command{guix describe}
4097 command answers these questions.
4099 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4100 displays the channel(s) that it was built from, including their repository URL
4101 and commit IDs (@pxref{Channels}):
4105 Generation 10 Sep 03 2018 17:32:44 (current)
4107 repository URL: https://git.savannah.gnu.org/git/guix.git
4109 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4112 If you're familiar with the Git version control system, this is similar in
4113 spirit to @command{git describe}; the output is also similar to that of
4114 @command{guix pull --list-generations}, but limited to the current generation
4115 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4116 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4117 information is all it takes to describe the revision of Guix you're using, and
4118 also to replicate it.
4120 To make it easier to replicate Guix, @command{guix describe} can also be asked
4121 to return a list of channels instead of the human-readable description above:
4124 $ guix describe -f channels
4127 (url "https://git.savannah.gnu.org/git/guix.git")
4129 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4133 You can save this to a file and feed it to @command{guix pull -C} on some
4134 other machine or at a later point in time, which will instantiate @emph{this
4135 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4136 From there on, since you're able to deploy the same revision of Guix, you can
4137 just as well @emph{replicate a complete software environment}. We humbly
4138 think that this is @emph{awesome}, and we hope you'll like it too!
4140 The details of the options supported by @command{guix describe} are as
4144 @item --format=@var{format}
4145 @itemx -f @var{format}
4146 Produce output in the specified @var{format}, one of:
4150 produce human-readable output;
4152 produce a list of channel specifications that can be passed to @command{guix
4153 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4157 produce a list of channel specifications in JSON format;
4159 produce a list of channel specifications in Recutils format.
4162 @item --profile=@var{profile}
4163 @itemx -p @var{profile}
4164 Display information about @var{profile}.
4167 @node Invoking guix archive
4168 @section Invoking @command{guix archive}
4170 @cindex @command{guix archive}
4172 The @command{guix archive} command allows users to @dfn{export} files
4173 from the store into a single archive, and to later @dfn{import} them on
4174 a machine that runs Guix.
4175 In particular, it allows store files to be transferred from one machine
4176 to the store on another machine.
4179 If you're looking for a way to produce archives in a format suitable for
4180 tools other than Guix, @pxref{Invoking guix pack}.
4183 @cindex exporting store items
4184 To export store files as an archive to standard output, run:
4187 guix archive --export @var{options} @var{specifications}...
4190 @var{specifications} may be either store file names or package
4191 specifications, as for @command{guix package} (@pxref{Invoking guix
4192 package}). For instance, the following command creates an archive
4193 containing the @code{gui} output of the @code{git} package and the main
4194 output of @code{emacs}:
4197 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4200 If the specified packages are not built yet, @command{guix archive}
4201 automatically builds them. The build process may be controlled with the
4202 common build options (@pxref{Common Build Options}).
4204 To transfer the @code{emacs} package to a machine connected over SSH,
4208 guix archive --export -r emacs | ssh the-machine guix archive --import
4212 Similarly, a complete user profile may be transferred from one machine
4213 to another like this:
4216 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4217 ssh the-machine guix-archive --import
4221 However, note that, in both examples, all of @code{emacs} and the
4222 profile as well as all of their dependencies are transferred (due to
4223 @code{-r}), regardless of what is already available in the store on the
4224 target machine. The @code{--missing} option can help figure out which
4225 items are missing from the target store. The @command{guix copy}
4226 command simplifies and optimizes this whole process, so this is probably
4227 what you should use in this case (@pxref{Invoking guix copy}).
4229 @cindex nar, archive format
4230 @cindex normalized archive (nar)
4231 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4232 comparable in spirit to `tar', but with differences
4233 that make it more appropriate for our purposes. First, rather than
4234 recording all Unix metadata for each file, the nar format only mentions
4235 the file type (regular, directory, or symbolic link); Unix permissions
4236 and owner/group are dismissed. Second, the order in which directory
4237 entries are stored always follows the order of file names according to
4238 the C locale collation order. This makes archive production fully
4241 When exporting, the daemon digitally signs the contents of the archive,
4242 and that digital signature is appended. When importing, the daemon
4243 verifies the signature and rejects the import in case of an invalid
4244 signature or if the signing key is not authorized.
4245 @c FIXME: Add xref to daemon doc about signatures.
4247 The main options are:
4251 Export the specified store files or packages (see below.) Write the
4252 resulting archive to the standard output.
4254 Dependencies are @emph{not} included in the output, unless
4255 @code{--recursive} is passed.
4259 When combined with @code{--export}, this instructs @command{guix
4260 archive} to include dependencies of the given items in the archive.
4261 Thus, the resulting archive is self-contained: it contains the closure
4262 of the exported store items.
4265 Read an archive from the standard input, and import the files listed
4266 therein into the store. Abort if the archive has an invalid digital
4267 signature, or if it is signed by a public key not among the authorized
4268 keys (see @code{--authorize} below.)
4271 Read a list of store file names from the standard input, one per line,
4272 and write on the standard output the subset of these files missing from
4275 @item --generate-key[=@var{parameters}]
4276 @cindex signing, archives
4277 Generate a new key pair for the daemon. This is a prerequisite before
4278 archives can be exported with @code{--export}. Note that this operation
4279 usually takes time, because it needs to gather enough entropy to
4280 generate the key pair.
4282 The generated key pair is typically stored under @file{/etc/guix}, in
4283 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4284 key, which must be kept secret.) When @var{parameters} is omitted,
4285 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4286 versions before 1.6.0, it is a 4096-bit RSA key.
4287 Alternatively, @var{parameters} can specify
4288 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4289 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4290 Libgcrypt Reference Manual}).
4293 @cindex authorizing, archives
4294 Authorize imports signed by the public key passed on standard input.
4295 The public key must be in ``s-expression advanced format''---i.e., the
4296 same format as the @file{signing-key.pub} file.
4298 The list of authorized keys is kept in the human-editable file
4299 @file{/etc/guix/acl}. The file contains
4300 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4301 s-expressions''} and is structured as an access-control list in the
4302 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4305 @item --extract=@var{directory}
4306 @itemx -x @var{directory}
4307 Read a single-item archive as served by substitute servers
4308 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4309 low-level operation needed in only very narrow use cases; see below.
4311 For example, the following command extracts the substitute for Emacs
4312 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4316 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4317 | bunzip2 | guix archive -x /tmp/emacs
4320 Single-item archives are different from multiple-item archives produced
4321 by @command{guix archive --export}; they contain a single store item,
4322 and they do @emph{not} embed a signature. Thus this operation does
4323 @emph{no} signature verification and its output should be considered
4326 The primary purpose of this operation is to facilitate inspection of
4327 archive contents coming from possibly untrusted substitute servers.
4332 @c *********************************************************************
4334 @chapter Development
4336 @cindex software development
4337 If you are a software developer, Guix provides tools that you should find
4338 helpful---independently of the language you're developing in. This is what
4339 this chapter is about.
4341 The @command{guix environment} command provides a convenient way to set up
4342 @dfn{development environments} containing all the dependencies and tools
4343 necessary to work on the software package of your choice. The @command{guix
4344 pack} command allows you to create @dfn{application bundles} that can be
4345 easily distributed to users who do not run Guix.
4348 * Invoking guix environment:: Setting up development environments.
4349 * Invoking guix pack:: Creating software bundles.
4352 @node Invoking guix environment
4353 @section Invoking @command{guix environment}
4355 @cindex reproducible build environments
4356 @cindex development environments
4357 @cindex @command{guix environment}
4358 @cindex environment, package build environment
4359 The purpose of @command{guix environment} is to assist hackers in
4360 creating reproducible development environments without polluting their
4361 package profile. The @command{guix environment} tool takes one or more
4362 packages, builds all of their inputs, and creates a shell
4363 environment to use them.
4365 The general syntax is:
4368 guix environment @var{options} @var{package}@dots{}
4371 The following example spawns a new shell set up for the development of
4375 guix environment guile
4378 If the needed dependencies are not built yet, @command{guix environment}
4379 automatically builds them. The environment of the new shell is an augmented
4380 version of the environment that @command{guix environment} was run in.
4381 It contains the necessary search paths for building the given package
4382 added to the existing environment variables. To create a ``pure''
4383 environment, in which the original environment variables have been unset,
4384 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4385 environment variables such as @code{PATH} in their @file{~/.bashrc}
4386 file. As a consequence, when @code{guix environment} launches it, Bash
4387 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4388 environment variables. It is an error to define such environment
4389 variables in @file{.bashrc}; instead, they should be defined in
4390 @file{.bash_profile}, which is sourced only by log-in shells.
4391 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4392 details on Bash start-up files.}.
4394 @vindex GUIX_ENVIRONMENT
4395 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4396 variable in the shell it spawns; its value is the file name of the
4397 profile of this environment. This allows users to, say, define a
4398 specific prompt for development environments in their @file{.bashrc}
4399 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4402 if [ -n "$GUIX_ENVIRONMENT" ]
4404 export PS1="\u@@\h \w [dev]\$ "
4409 ...@: or to browse the profile:
4412 $ ls "$GUIX_ENVIRONMENT/bin"
4415 Additionally, more than one package may be specified, in which case the
4416 union of the inputs for the given packages are used. For example, the
4417 command below spawns a shell where all of the dependencies of both Guile
4418 and Emacs are available:
4421 guix environment guile emacs
4424 Sometimes an interactive shell session is not desired. An arbitrary
4425 command may be invoked by placing the @code{--} token to separate the
4426 command from the rest of the arguments:
4429 guix environment guile -- make -j4
4432 In other situations, it is more convenient to specify the list of
4433 packages needed in the environment. For example, the following command
4434 runs @command{python} from an environment containing Python@tie{}2.7 and
4438 guix environment --ad-hoc python2-numpy python-2.7 -- python
4441 Furthermore, one might want the dependencies of a package and also some
4442 additional packages that are not build-time or runtime dependencies, but
4443 are useful when developing nonetheless. Because of this, the
4444 @code{--ad-hoc} flag is positional. Packages appearing before
4445 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4446 added to the environment. Packages appearing after are interpreted as
4447 packages that will be added to the environment directly. For example,
4448 the following command creates a Guix development environment that
4449 additionally includes Git and strace:
4452 guix environment guix --ad-hoc git strace
4455 Sometimes it is desirable to isolate the environment as much as
4456 possible, for maximal purity and reproducibility. In particular, when
4457 using Guix on a host distro that is not Guix System, it is desirable to
4458 prevent access to @file{/usr/bin} and other system-wide resources from
4459 the development environment. For example, the following command spawns
4460 a Guile REPL in a ``container'' where only the store and the current
4461 working directory are mounted:
4464 guix environment --ad-hoc --container guile -- guile
4468 The @code{--container} option requires Linux-libre 3.19 or newer.
4471 The available options are summarized below.
4474 @item --root=@var{file}
4475 @itemx -r @var{file}
4476 @cindex persistent environment
4477 @cindex garbage collector root, for environments
4478 Make @var{file} a symlink to the profile for this environment, and
4479 register it as a garbage collector root.
4481 This is useful if you want to protect your environment from garbage
4482 collection, to make it ``persistent''.
4484 When this option is omitted, the environment is protected from garbage
4485 collection only for the duration of the @command{guix environment}
4486 session. This means that next time you recreate the same environment,
4487 you could have to rebuild or re-download packages. @xref{Invoking guix
4488 gc}, for more on GC roots.
4490 @item --expression=@var{expr}
4491 @itemx -e @var{expr}
4492 Create an environment for the package or list of packages that
4493 @var{expr} evaluates to.
4495 For example, running:
4498 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4501 starts a shell with the environment for this specific variant of the
4507 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4510 starts a shell with all the base system packages available.
4512 The above commands only use the default output of the given packages.
4513 To select other outputs, two element tuples can be specified:
4516 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4519 @item --load=@var{file}
4520 @itemx -l @var{file}
4521 Create an environment for the package or list of packages that the code
4522 within @var{file} evaluates to.
4524 As an example, @var{file} might contain a definition like this
4525 (@pxref{Defining Packages}):
4528 @verbatiminclude environment-gdb.scm
4531 @item --manifest=@var{file}
4532 @itemx -m @var{file}
4533 Create an environment for the packages contained in the manifest object
4534 returned by the Scheme code in @var{file}.
4536 This is similar to the same-named option in @command{guix package}
4537 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4541 Include all specified packages in the resulting environment, as if an
4542 @i{ad hoc} package were defined with them as inputs. This option is
4543 useful for quickly creating an environment without having to write a
4544 package expression to contain the desired inputs.
4546 For instance, the command:
4549 guix environment --ad-hoc guile guile-sdl -- guile
4552 runs @command{guile} in an environment where Guile and Guile-SDL are
4555 Note that this example implicitly asks for the default output of
4556 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4557 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4558 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4560 This option may be composed with the default behavior of @command{guix
4561 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4562 as packages whose dependencies will be added to the environment, the
4563 default behavior. Packages appearing after are interpreted as packages
4564 that will be added to the environment directly.
4567 Unset existing environment variables when building the new environment, except
4568 those specified with @option{--preserve} (see below.) This has the effect of
4569 creating an environment in which search paths only contain package inputs.
4571 @item --preserve=@var{regexp}
4572 @itemx -E @var{regexp}
4573 When used alongside @option{--pure}, preserve the environment variables
4574 matching @var{regexp}---in other words, put them on a ``white list'' of
4575 environment variables that must be preserved. This option can be repeated
4579 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4583 This example runs @command{mpirun} in a context where the only environment
4584 variables defined are @code{PATH}, environment variables whose name starts
4585 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4588 @item --search-paths
4589 Display the environment variable definitions that make up the
4592 @item --system=@var{system}
4593 @itemx -s @var{system}
4594 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4599 Run @var{command} within an isolated container. The current working
4600 directory outside the container is mapped inside the container.
4601 Additionally, unless overridden with @code{--user}, a dummy home
4602 directory is created that matches the current user's home directory, and
4603 @file{/etc/passwd} is configured accordingly.
4605 The spawned process runs as the current user outside the container. Inside
4606 the container, it has the same UID and GID as the current user, unless
4607 @option{--user} is passed (see below.)
4611 For containers, share the network namespace with the host system.
4612 Containers created without this flag only have access to the loopback
4615 @item --link-profile
4617 For containers, link the environment profile to
4618 @file{~/.guix-profile} within the container. This is equivalent to
4619 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4620 within the container. Linking will fail and abort the environment if
4621 the directory already exists, which will certainly be the case if
4622 @command{guix environment} was invoked in the user's home directory.
4624 Certain packages are configured to look in
4625 @code{~/.guix-profile} for configuration files and data;@footnote{For
4626 example, the @code{fontconfig} package inspects
4627 @file{~/.guix-profile/share/fonts} for additional fonts.}
4628 @code{--link-profile} allows these programs to behave as expected within
4631 @item --user=@var{user}
4632 @itemx -u @var{user}
4633 For containers, use the username @var{user} in place of the current
4634 user. The generated @file{/etc/passwd} entry within the container will
4635 contain the name @var{user}, the home directory will be
4636 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4637 the UID and GID inside the container are 1000. @var{user}
4638 need not exist on the system.
4640 Additionally, any shared or exposed path (see @code{--share} and
4641 @code{--expose} respectively) whose target is within the current user's
4642 home directory will be remapped relative to @file{/home/USER}; this
4643 includes the automatic mapping of the current working directory.
4646 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4648 guix environment --container --user=foo \
4649 --expose=$HOME/test \
4650 --expose=/tmp/target=$HOME/target
4653 While this will limit the leaking of user identity through home paths
4654 and each of the user fields, this is only one useful component of a
4655 broader privacy/anonymity solution---not one in and of itself.
4657 @item --expose=@var{source}[=@var{target}]
4658 For containers, expose the file system @var{source} from the host system
4659 as the read-only file system @var{target} within the container. If
4660 @var{target} is not specified, @var{source} is used as the target mount
4661 point in the container.
4663 The example below spawns a Guile REPL in a container in which the user's
4664 home directory is accessible read-only via the @file{/exchange}
4668 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4671 @item --share=@var{source}[=@var{target}]
4672 For containers, share the file system @var{source} from the host system
4673 as the writable file system @var{target} within the container. If
4674 @var{target} is not specified, @var{source} is used as the target mount
4675 point in the container.
4677 The example below spawns a Guile REPL in a container in which the user's
4678 home directory is accessible for both reading and writing via the
4679 @file{/exchange} directory:
4682 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4686 @command{guix environment}
4687 also supports all of the common build options that @command{guix
4688 build} supports (@pxref{Common Build Options}) as well as package
4689 transformation options (@pxref{Package Transformation Options}).
4691 @node Invoking guix pack
4692 @section Invoking @command{guix pack}
4694 Occasionally you want to pass software to people who are not (yet!)
4695 lucky enough to be using Guix. You'd tell them to run @command{guix
4696 package -i @var{something}}, but that's not possible in this case. This
4697 is where @command{guix pack} comes in.
4700 If you are looking for ways to exchange binaries among machines that
4701 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4702 publish}, and @ref{Invoking guix archive}.
4707 @cindex application bundle
4708 @cindex software bundle
4709 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4710 @dfn{software bundle}: it creates a tarball or some other archive
4711 containing the binaries of the software you're interested in, and all
4712 its dependencies. The resulting archive can be used on any machine that
4713 does not have Guix, and people can run the exact same binaries as those
4714 you have with Guix. The pack itself is created in a bit-reproducible
4715 fashion, so anyone can verify that it really contains the build results
4716 that you pretend to be shipping.
4718 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4719 their dependencies, you can run:
4722 $ guix pack guile emacs geiser
4724 /gnu/store/@dots{}-pack.tar.gz
4727 The result here is a tarball containing a @file{/gnu/store} directory
4728 with all the relevant packages. The resulting tarball contains a
4729 @dfn{profile} with the three packages of interest; the profile is the
4730 same as would be created by @command{guix package -i}. It is this
4731 mechanism that is used to create Guix's own standalone binary tarball
4732 (@pxref{Binary Installation}).
4734 Users of this pack would have to run
4735 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4736 find inconvenient. To work around it, you can create, say, a
4737 @file{/opt/gnu/bin} symlink to the profile:
4740 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4744 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4746 @cindex relocatable binaries, with @command{guix pack}
4747 What if the recipient of your pack does not have root privileges on
4748 their machine, and thus cannot unpack it in the root file system? In
4749 that case, you will want to use the @code{--relocatable} option (see
4750 below). This option produces @dfn{relocatable binaries}, meaning they
4751 they can be placed anywhere in the file system hierarchy: in the example
4752 above, users can unpack your tarball in their home directory and
4753 directly run @file{./opt/gnu/bin/guile}.
4755 @cindex Docker, build an image with guix pack
4756 Alternatively, you can produce a pack in the Docker image format using
4757 the following command:
4760 guix pack -f docker guile emacs geiser
4764 The result is a tarball that can be passed to the @command{docker load}
4766 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4767 documentation} for more information.
4769 @cindex Singularity, build an image with guix pack
4770 @cindex SquashFS, build an image with guix pack
4771 Yet another option is to produce a SquashFS image with the following
4775 guix pack -f squashfs guile emacs geiser
4779 The result is a SquashFS file system image that can either be mounted or
4780 directly be used as a file system container image with the
4781 @uref{https://singularity.lbl.gov, Singularity container execution
4782 environment}, using commands like @command{singularity shell} or
4783 @command{singularity exec}.
4785 Several command-line options allow you to customize your pack:
4788 @item --format=@var{format}
4789 @itemx -f @var{format}
4790 Produce a pack in the given @var{format}.
4792 The available formats are:
4796 This is the default format. It produces a tarball containing all the
4797 specified binaries and symlinks.
4800 This produces a tarball that follows the
4801 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4802 Docker Image Specification}.
4805 This produces a SquashFS image containing all the specified binaries and
4806 symlinks, as well as empty mount points for virtual file systems like
4810 @cindex relocatable binaries
4813 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4814 anywhere in the file system hierarchy and run from there.
4816 When this option is passed once, the resulting binaries require support for
4817 @dfn{user namespaces} in the kernel Linux; when passed
4818 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4819 PRoot support, can be thought of as the abbreviation of ``Really
4820 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4821 if user namespaces are unavailable, and essentially work anywhere---see below
4822 for the implications.
4824 For example, if you create a pack containing Bash with:
4827 guix pack -RR -S /mybin=bin bash
4831 ...@: you can copy that pack to a machine that lacks Guix, and from your
4832 home directory as a normal user, run:
4840 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4841 @file{/gnu/store} shows up and contains all the dependencies of
4842 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4843 altogether! That is probably the simplest way to deploy Guix-built
4844 software on a non-Guix machine.
4847 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4848 the kernel Linux, which allows unprivileged users to mount or change root.
4849 Old versions of Linux did not support it, and some GNU/Linux distributions
4852 To produce relocatable binaries that work even in the absence of user
4853 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4854 case, binaries will try user namespace support and fall back to PRoot if user
4855 namespaces are not supported.
4857 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4858 support for file system virtualization. It achieves that by using the
4859 @code{ptrace} system call on the running program. This approach has the
4860 advantage to work without requiring special kernel support, but it incurs
4861 run-time overhead every time a system call is made.
4864 @item --expression=@var{expr}
4865 @itemx -e @var{expr}
4866 Consider the package @var{expr} evaluates to.
4868 This has the same purpose as the same-named option in @command{guix
4869 build} (@pxref{Additional Build Options, @code{--expression} in
4870 @command{guix build}}).
4872 @item --manifest=@var{file}
4873 @itemx -m @var{file}
4874 Use the packages contained in the manifest object returned by the Scheme
4877 This has a similar purpose as the same-named option in @command{guix
4878 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4879 same manifest files. It allows you to define a collection of packages
4880 once and use it both for creating profiles and for creating archives
4881 for use on machines that do not have Guix installed. Note that you can
4882 specify @emph{either} a manifest file @emph{or} a list of packages,
4885 @item --system=@var{system}
4886 @itemx -s @var{system}
4887 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4888 the system type of the build host.
4890 @item --target=@var{triplet}
4891 @cindex cross-compilation
4892 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4893 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4894 configuration triplets,, autoconf, Autoconf}).
4896 @item --compression=@var{tool}
4897 @itemx -C @var{tool}
4898 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4899 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4901 @item --symlink=@var{spec}
4902 @itemx -S @var{spec}
4903 Add the symlinks specified by @var{spec} to the pack. This option can
4904 appear several times.
4906 @var{spec} has the form @code{@var{source}=@var{target}}, where
4907 @var{source} is the symlink that will be created and @var{target} is the
4910 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4911 symlink pointing to the @file{bin} sub-directory of the profile.
4913 @item --save-provenance
4914 Save provenance information for the packages passed on the command line.
4915 Provenance information includes the URL and commit of the channels in use
4918 Provenance information is saved in the
4919 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4920 usual package metadata---the name and version of each package, their
4921 propagated inputs, and so on. It is useful information to the recipient of
4922 the pack, who then knows how the pack was (supposedly) obtained.
4924 This option is not enabled by default because, like timestamps, provenance
4925 information contributes nothing to the build process. In other words, there
4926 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4927 Recording such ``silent'' metadata in the output thus potentially breaks the
4928 source-to-binary bitwise reproducibility property.
4930 @item --root=@var{file}
4931 @itemx -r @var{file}
4932 @cindex garbage collector root, for packs
4933 Make @var{file} a symlink to the resulting pack, and register it as a garbage
4936 @item --localstatedir
4937 @itemx --profile-name=@var{name}
4938 Include the ``local state directory'', @file{/var/guix}, in the resulting
4939 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4940 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4941 @file{~root/.guix-profile}.
4943 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4944 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4945 the pack means that the store is ``complete'' and manageable by Guix;
4946 not providing it pack means that the store is ``dead'': items cannot be
4947 added to it or removed from it after extraction of the pack.
4949 One use case for this is the Guix self-contained binary tarball
4950 (@pxref{Binary Installation}).
4953 Use the bootstrap binaries to build the pack. This option is only
4954 useful to Guix developers.
4957 In addition, @command{guix pack} supports all the common build options
4958 (@pxref{Common Build Options}) and all the package transformation
4959 options (@pxref{Package Transformation Options}).
4962 @c *********************************************************************
4963 @node Programming Interface
4964 @chapter Programming Interface
4966 GNU Guix provides several Scheme programming interfaces (APIs) to
4967 define, build, and query packages. The first interface allows users to
4968 write high-level package definitions. These definitions refer to
4969 familiar packaging concepts, such as the name and version of a package,
4970 its build system, and its dependencies. These definitions can then be
4971 turned into concrete build actions.
4973 Build actions are performed by the Guix daemon, on behalf of users. In a
4974 standard setup, the daemon has write access to the store---the
4975 @file{/gnu/store} directory---whereas users do not. The recommended
4976 setup also has the daemon perform builds in chroots, under a specific
4977 build users, to minimize interference with the rest of the system.
4980 Lower-level APIs are available to interact with the daemon and the
4981 store. To instruct the daemon to perform a build action, users actually
4982 provide it with a @dfn{derivation}. A derivation is a low-level
4983 representation of the build actions to be taken, and the environment in
4984 which they should occur---derivations are to package definitions what
4985 assembly is to C programs. The term ``derivation'' comes from the fact
4986 that build results @emph{derive} from them.
4988 This chapter describes all these APIs in turn, starting from high-level
4989 package definitions.
4992 * Package Modules:: Packages from the programmer's viewpoint.
4993 * Defining Packages:: Defining new packages.
4994 * Build Systems:: Specifying how packages are built.
4995 * The Store:: Manipulating the package store.
4996 * Derivations:: Low-level interface to package derivations.
4997 * The Store Monad:: Purely functional interface to the store.
4998 * G-Expressions:: Manipulating build expressions.
4999 * Invoking guix repl:: Fiddling with Guix interactively.
5002 @node Package Modules
5003 @section Package Modules
5005 From a programming viewpoint, the package definitions of the
5006 GNU distribution are provided by Guile modules in the @code{(gnu packages
5007 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5008 packages @dots{})} module name space are not necessarily ``GNU
5009 packages''. This module naming scheme follows the usual Guile module
5010 naming convention: @code{gnu} means that these modules are distributed
5011 as part of the GNU system, and @code{packages} identifies modules that
5012 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5013 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5014 module exports a variable named @code{emacs}, which is bound to a
5015 @code{<package>} object (@pxref{Defining Packages}).
5017 The @code{(gnu packages @dots{})} module name space is
5018 automatically scanned for packages by the command-line tools. For
5019 instance, when running @code{guix install emacs}, all the @code{(gnu
5020 packages @dots{})} modules are scanned until one that exports a package
5021 object whose name is @code{emacs} is found. This package search
5022 facility is implemented in the @code{(gnu packages)} module.
5024 @cindex customization, of packages
5025 @cindex package module search path
5026 Users can store package definitions in modules with different
5027 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5028 name and module name must match. For instance, the @code{(my-packages
5029 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5030 relative to the load path specified with @option{--load-path} or
5031 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5032 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5033 these package definitions visible to the user interfaces:
5037 By adding the directory containing your package modules to the search path
5038 with the @code{-L} flag of @command{guix package} and other commands
5039 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5040 environment variable described below.
5043 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5044 pulls from it. A channel is essentially a Git repository containing package
5045 modules. @xref{Channels}, for more information on how to define and use
5049 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5051 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5052 This is a colon-separated list of directories to search for additional
5053 package modules. Directories listed in this variable take precedence
5054 over the own modules of the distribution.
5057 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5058 each package is built based solely on other packages in the
5059 distribution. The root of this dependency graph is a small set of
5060 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5061 bootstrap)} module. For more information on bootstrapping,
5062 @pxref{Bootstrapping}.
5064 @node Defining Packages
5065 @section Defining Packages
5067 The high-level interface to package definitions is implemented in the
5068 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5069 example, the package definition, or @dfn{recipe}, for the GNU Hello
5070 package looks like this:
5073 (define-module (gnu packages hello)
5074 #:use-module (guix packages)
5075 #:use-module (guix download)
5076 #:use-module (guix build-system gnu)
5077 #:use-module (guix licenses)
5078 #:use-module (gnu packages gawk))
5080 (define-public hello
5086 (uri (string-append "mirror://gnu/hello/hello-" version
5090 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5091 (build-system gnu-build-system)
5092 (arguments '(#:configure-flags '("--enable-silent-rules")))
5093 (inputs `(("gawk" ,gawk)))
5094 (synopsis "Hello, GNU world: An example GNU package")
5095 (description "Guess what GNU Hello prints!")
5096 (home-page "https://www.gnu.org/software/hello/")
5101 Without being a Scheme expert, the reader may have guessed the meaning
5102 of the various fields here. This expression binds the variable
5103 @code{hello} to a @code{<package>} object, which is essentially a record
5104 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5105 This package object can be inspected using procedures found in the
5106 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5107 returns---surprise!---@code{"hello"}.
5109 With luck, you may be able to import part or all of the definition of
5110 the package you are interested in from another repository, using the
5111 @code{guix import} command (@pxref{Invoking guix import}).
5113 In the example above, @var{hello} is defined in a module of its own,
5114 @code{(gnu packages hello)}. Technically, this is not strictly
5115 necessary, but it is convenient to do so: all the packages defined in
5116 modules under @code{(gnu packages @dots{})} are automatically known to
5117 the command-line tools (@pxref{Package Modules}).
5119 There are a few points worth noting in the above package definition:
5123 The @code{source} field of the package is an @code{<origin>} object
5124 (@pxref{origin Reference}, for the complete reference).
5125 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5126 meaning that the source is a file to be downloaded over FTP or HTTP.
5128 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5129 the GNU mirrors defined in @code{(guix download)}.
5131 The @code{sha256} field specifies the expected SHA256 hash of the file
5132 being downloaded. It is mandatory, and allows Guix to check the
5133 integrity of the file. The @code{(base32 @dots{})} form introduces the
5134 base32 representation of the hash. You can obtain this information with
5135 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5136 hash} (@pxref{Invoking guix hash}).
5139 When needed, the @code{origin} form can also have a @code{patches} field
5140 listing patches to be applied, and a @code{snippet} field giving a
5141 Scheme expression to modify the source code.
5144 @cindex GNU Build System
5145 The @code{build-system} field specifies the procedure to build the
5146 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5147 represents the familiar GNU Build System, where packages may be
5148 configured, built, and installed with the usual @code{./configure &&
5149 make && make check && make install} command sequence.
5152 The @code{arguments} field specifies options for the build system
5153 (@pxref{Build Systems}). Here it is interpreted by
5154 @var{gnu-build-system} as a request run @file{configure} with the
5155 @code{--enable-silent-rules} flag.
5161 What about these quote (@code{'}) characters? They are Scheme syntax to
5162 introduce a literal list; @code{'} is synonymous with @code{quote}.
5163 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5164 for details. Here the value of the @code{arguments} field is a list of
5165 arguments passed to the build system down the road, as with @code{apply}
5166 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5169 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5170 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5171 @code{#:configure-flags} is a keyword used to pass a keyword argument
5172 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5176 The @code{inputs} field specifies inputs to the build process---i.e.,
5177 build-time or run-time dependencies of the package. Here, we define an
5178 input called @code{"gawk"} whose value is that of the @var{gawk}
5179 variable; @var{gawk} is itself bound to a @code{<package>} object.
5181 @cindex backquote (quasiquote)
5184 @cindex comma (unquote)
5188 @findex unquote-splicing
5189 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5190 us to introduce a literal list in the @code{inputs} field, while
5191 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5192 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5195 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5196 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5197 of ensuring that they are present (@pxref{Build Systems}).
5199 However, any other dependencies need to be specified in the
5200 @code{inputs} field. Any dependency not specified here will simply be
5201 unavailable to the build process, possibly leading to a build failure.
5204 @xref{package Reference}, for a full description of possible fields.
5206 Once a package definition is in place, the
5207 package may actually be built using the @code{guix build} command-line
5208 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5209 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5210 package definition using the @command{guix edit} command
5211 (@pxref{Invoking guix edit}).
5212 @xref{Packaging Guidelines}, for
5213 more information on how to test package definitions, and
5214 @ref{Invoking guix lint}, for information on how to check a definition
5215 for style conformance.
5216 @vindex GUIX_PACKAGE_PATH
5217 Lastly, @pxref{Channels}, for information
5218 on how to extend the distribution by adding your own package definitions
5221 Finally, updating the package definition to a new upstream version
5222 can be partly automated by the @command{guix refresh} command
5223 (@pxref{Invoking guix refresh}).
5225 Behind the scenes, a derivation corresponding to the @code{<package>}
5226 object is first computed by the @code{package-derivation} procedure.
5227 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5228 The build actions it prescribes may then be realized by using the
5229 @code{build-derivations} procedure (@pxref{The Store}).
5231 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5232 Return the @code{<derivation>} object of @var{package} for @var{system}
5233 (@pxref{Derivations}).
5235 @var{package} must be a valid @code{<package>} object, and @var{system}
5236 must be a string denoting the target system type---e.g.,
5237 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5238 must be a connection to the daemon, which operates on the store
5239 (@pxref{The Store}).
5243 @cindex cross-compilation
5244 Similarly, it is possible to compute a derivation that cross-builds a
5245 package for some other system:
5247 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5248 @var{package} @var{target} [@var{system}]
5249 Return the @code{<derivation>} object of @var{package} cross-built from
5250 @var{system} to @var{target}.
5252 @var{target} must be a valid GNU triplet denoting the target hardware
5253 and operating system, such as @code{"mips64el-linux-gnu"}
5254 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5257 @cindex package transformations
5258 @cindex input rewriting
5259 @cindex dependency tree rewriting
5260 Packages can be manipulated in arbitrary ways. An example of a useful
5261 transformation is @dfn{input rewriting}, whereby the dependency tree of
5262 a package is rewritten by replacing specific inputs by others:
5264 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5265 [@var{rewrite-name}]
5266 Return a procedure that, when passed a package, replaces its direct and
5267 indirect dependencies (but not its implicit inputs) according to
5268 @var{replacements}. @var{replacements} is a list of package pairs; the
5269 first element of each pair is the package to replace, and the second one
5272 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5273 the name of a package and returns its new name after rewrite.
5277 Consider this example:
5280 (define libressl-instead-of-openssl
5281 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5283 (package-input-rewriting `((,openssl . ,libressl))))
5285 (define git-with-libressl
5286 (libressl-instead-of-openssl git))
5290 Here we first define a rewriting procedure that replaces @var{openssl}
5291 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5292 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5293 This is exactly what the @option{--with-input} command-line option does
5294 (@pxref{Package Transformation Options, @option{--with-input}}).
5296 The following variant of @code{package-input-rewriting} can match packages to
5297 be replaced by name rather than by identity.
5299 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5300 Return a procedure that, given a package, applies the given @var{replacements} to
5301 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5302 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5303 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5304 replacement for that package.
5307 The example above could be rewritten this way:
5310 (define libressl-instead-of-openssl
5311 ;; Replace all the packages called "openssl" with LibreSSL.
5312 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5315 The key difference here is that, this time, packages are matched by spec and
5316 not by identity. In other words, any package in the graph that is called
5317 @code{openssl} will be replaced.
5319 A more generic procedure to rewrite a package dependency graph is
5320 @code{package-mapping}: it supports arbitrary changes to nodes in the
5323 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5324 Return a procedure that, given a package, applies @var{proc} to all the packages
5325 depended on and returns the resulting package. The procedure stops recursion
5326 when @var{cut?} returns true for a given package.
5330 * package Reference:: The package data type.
5331 * origin Reference:: The origin data type.
5335 @node package Reference
5336 @subsection @code{package} Reference
5338 This section summarizes all the options available in @code{package}
5339 declarations (@pxref{Defining Packages}).
5341 @deftp {Data Type} package
5342 This is the data type representing a package recipe.
5346 The name of the package, as a string.
5348 @item @code{version}
5349 The version of the package, as a string.
5352 An object telling how the source code for the package should be
5353 acquired. Most of the time, this is an @code{origin} object, which
5354 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5355 can also be any other ``file-like'' object such as a @code{local-file},
5356 which denotes a file from the local file system (@pxref{G-Expressions,
5357 @code{local-file}}).
5359 @item @code{build-system}
5360 The build system that should be used to build the package (@pxref{Build
5363 @item @code{arguments} (default: @code{'()})
5364 The arguments that should be passed to the build system. This is a
5365 list, typically containing sequential keyword-value pairs.
5367 @item @code{inputs} (default: @code{'()})
5368 @itemx @code{native-inputs} (default: @code{'()})
5369 @itemx @code{propagated-inputs} (default: @code{'()})
5370 @cindex inputs, of packages
5371 These fields list dependencies of the package. Each one is a list of
5372 tuples, where each tuple has a label for the input (a string) as its
5373 first element, a package, origin, or derivation as its second element,
5374 and optionally the name of the output thereof that should be used, which
5375 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5376 more on package outputs). For example, the list below specifies three
5380 `(("libffi" ,libffi)
5381 ("libunistring" ,libunistring)
5382 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5385 @cindex cross compilation, package dependencies
5386 The distinction between @code{native-inputs} and @code{inputs} is
5387 necessary when considering cross-compilation. When cross-compiling,
5388 dependencies listed in @code{inputs} are built for the @emph{target}
5389 architecture; conversely, dependencies listed in @code{native-inputs}
5390 are built for the architecture of the @emph{build} machine.
5392 @code{native-inputs} is typically used to list tools needed at
5393 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5394 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5395 this area (@pxref{Invoking guix lint}).
5397 @anchor{package-propagated-inputs}
5398 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5399 specified packages will be automatically installed alongside the package
5400 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5401 package}}, for information on how @command{guix package} deals with
5404 For example this is necessary when a C/C++ library needs headers of
5405 another library to compile, or when a pkg-config file refers to another
5406 one @i{via} its @code{Requires} field.
5408 Another example where @code{propagated-inputs} is useful is for languages
5409 that lack a facility to record the run-time search path akin to the
5410 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5411 more. To ensure that libraries written in those languages can find
5412 library code they depend on at run time, run-time dependencies must be
5413 listed in @code{propagated-inputs} rather than @code{inputs}.
5415 @item @code{outputs} (default: @code{'("out")})
5416 The list of output names of the package. @xref{Packages with Multiple
5417 Outputs}, for typical uses of additional outputs.
5419 @item @code{native-search-paths} (default: @code{'()})
5420 @itemx @code{search-paths} (default: @code{'()})
5421 A list of @code{search-path-specification} objects describing
5422 search-path environment variables honored by the package.
5424 @item @code{replacement} (default: @code{#f})
5425 This must be either @code{#f} or a package object that will be used as a
5426 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5429 @item @code{synopsis}
5430 A one-line description of the package.
5432 @item @code{description}
5433 A more elaborate description of the package.
5435 @item @code{license}
5436 @cindex license, of packages
5437 The license of the package; a value from @code{(guix licenses)},
5438 or a list of such values.
5440 @item @code{home-page}
5441 The URL to the home-page of the package, as a string.
5443 @item @code{supported-systems} (default: @var{%supported-systems})
5444 The list of systems supported by the package, as strings of the form
5445 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5447 @item @code{maintainers} (default: @code{'()})
5448 The list of maintainers of the package, as @code{maintainer} objects.
5450 @item @code{location} (default: source location of the @code{package} form)
5451 The source location of the package. It is useful to override this when
5452 inheriting from another package, in which case this field is not
5453 automatically corrected.
5457 @deffn {Scheme Syntax} this-package
5458 When used in the @emph{lexical scope} of a package field definition, this
5459 identifier resolves to the package being defined.
5461 The example below shows how to add a package as a native input of itself when
5469 ;; When cross-compiled, Guile, for example, depends on
5470 ;; a native version of itself. Add it here.
5471 (native-inputs (if (%current-target-system)
5472 `(("self" ,this-package))
5476 It is an error to refer to @code{this-package} outside a package definition.
5479 @node origin Reference
5480 @subsection @code{origin} Reference
5482 This section summarizes all the options available in @code{origin}
5483 declarations (@pxref{Defining Packages}).
5485 @deftp {Data Type} origin
5486 This is the data type representing a source code origin.
5490 An object containing the URI of the source. The object type depends on
5491 the @code{method} (see below). For example, when using the
5492 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5493 values are: a URL represented as a string, or a list thereof.
5496 A procedure that handles the URI.
5501 @item @var{url-fetch} from @code{(guix download)}
5502 download a file from the HTTP, HTTPS, or FTP URL specified in the
5506 @item @var{git-fetch} from @code{(guix git-download)}
5507 clone the Git version control repository, and check out the revision
5508 specified in the @code{uri} field as a @code{git-reference} object; a
5509 @code{git-reference} looks like this:
5513 (url "git://git.debian.org/git/pkg-shadow/shadow")
5514 (commit "v4.1.5.1"))
5519 A bytevector containing the SHA-256 hash of the source. Typically the
5520 @code{base32} form is used here to generate the bytevector from a
5523 You can obtain this information using @code{guix download}
5524 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5527 @item @code{file-name} (default: @code{#f})
5528 The file name under which the source code should be saved. When this is
5529 @code{#f}, a sensible default value will be used in most cases. In case
5530 the source is fetched from a URL, the file name from the URL will be
5531 used. For version control checkouts, it is recommended to provide the
5532 file name explicitly because the default is not very descriptive.
5534 @item @code{patches} (default: @code{'()})
5535 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5536 file-like objects}) pointing to patches to be applied to the source.
5538 This list of patches must be unconditional. In particular, it cannot
5539 depend on the value of @code{%current-system} or
5540 @code{%current-target-system}.
5542 @item @code{snippet} (default: @code{#f})
5543 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5544 in the source directory. This is a convenient way to modify the source,
5545 sometimes more convenient than a patch.
5547 @item @code{patch-flags} (default: @code{'("-p1")})
5548 A list of command-line flags that should be passed to the @code{patch}
5551 @item @code{patch-inputs} (default: @code{#f})
5552 Input packages or derivations to the patching process. When this is
5553 @code{#f}, the usual set of inputs necessary for patching are provided,
5554 such as GNU@tie{}Patch.
5556 @item @code{modules} (default: @code{'()})
5557 A list of Guile modules that should be loaded during the patching
5558 process and while running the code in the @code{snippet} field.
5560 @item @code{patch-guile} (default: @code{#f})
5561 The Guile package that should be used in the patching process. When
5562 this is @code{#f}, a sensible default is used.
5568 @section Build Systems
5570 @cindex build system
5571 Each package definition specifies a @dfn{build system} and arguments for
5572 that build system (@pxref{Defining Packages}). This @code{build-system}
5573 field represents the build procedure of the package, as well as implicit
5574 dependencies of that build procedure.
5576 Build systems are @code{<build-system>} objects. The interface to
5577 create and manipulate them is provided by the @code{(guix build-system)}
5578 module, and actual build systems are exported by specific modules.
5580 @cindex bag (low-level package representation)
5581 Under the hood, build systems first compile package objects to
5582 @dfn{bags}. A @dfn{bag} is like a package, but with less
5583 ornamentation---in other words, a bag is a lower-level representation of
5584 a package, which includes all the inputs of that package, including some
5585 that were implicitly added by the build system. This intermediate
5586 representation is then compiled to a derivation (@pxref{Derivations}).
5588 Build systems accept an optional list of @dfn{arguments}. In package
5589 definitions, these are passed @i{via} the @code{arguments} field
5590 (@pxref{Defining Packages}). They are typically keyword arguments
5591 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5592 Guile Reference Manual}). The value of these arguments is usually
5593 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5594 by the daemon (@pxref{Derivations}).
5596 The main build system is @var{gnu-build-system}, which implements the
5597 standard build procedure for GNU and many other packages. It
5598 is provided by the @code{(guix build-system gnu)} module.
5600 @defvr {Scheme Variable} gnu-build-system
5601 @var{gnu-build-system} represents the GNU Build System, and variants
5602 thereof (@pxref{Configuration, configuration and makefile conventions,,
5603 standards, GNU Coding Standards}).
5605 @cindex build phases
5606 In a nutshell, packages using it are configured, built, and installed with
5607 the usual @code{./configure && make && make check && make install}
5608 command sequence. In practice, a few additional steps are often needed.
5609 All these steps are split up in separate @dfn{phases},
5610 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5611 modules for more details about the build phases.}:
5615 Unpack the source tarball, and change the current directory to the
5616 extracted source tree. If the source is actually a directory, copy it
5617 to the build tree, and enter that directory.
5619 @item patch-source-shebangs
5620 Patch shebangs encountered in source files so they refer to the right
5621 store file names. For instance, this changes @code{#!/bin/sh} to
5622 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5625 Run the @file{configure} script with a number of default options, such
5626 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5627 by the @code{#:configure-flags} argument.
5630 Run @code{make} with the list of flags specified with
5631 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5632 (the default), build with @code{make -j}.
5635 Run @code{make check}, or some other target specified with
5636 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5637 @code{#:parallel-tests?} argument is true (the default), run @code{make
5641 Run @code{make install} with the flags listed in @code{#:make-flags}.
5643 @item patch-shebangs
5644 Patch shebangs on the installed executable files.
5647 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5648 is false), copying them to the @code{debug} output when available
5649 (@pxref{Installing Debugging Files}).
5652 @vindex %standard-phases
5653 The build-side module @code{(guix build gnu-build-system)} defines
5654 @var{%standard-phases} as the default list of build phases.
5655 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5656 procedure implements the actual phase.
5658 The list of phases used for a particular package can be changed with the
5659 @code{#:phases} parameter. For instance, passing:
5662 #:phases (modify-phases %standard-phases (delete 'configure))
5665 means that all the phases described above will be used, except the
5666 @code{configure} phase.
5668 In addition, this build system ensures that the ``standard'' environment
5669 for GNU packages is available. This includes tools such as GCC, libc,
5670 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5671 build-system gnu)} module for a complete list). We call these the
5672 @dfn{implicit inputs} of a package, because package definitions do not
5673 have to mention them.
5676 Other @code{<build-system>} objects are defined to support other
5677 conventions and tools used by free software packages. They inherit most
5678 of @var{gnu-build-system}, and differ mainly in the set of inputs
5679 implicitly added to the build process, and in the list of phases
5680 executed. Some of these build systems are listed below.
5682 @defvr {Scheme Variable} ant-build-system
5683 This variable is exported by @code{(guix build-system ant)}. It
5684 implements the build procedure for Java packages that can be built with
5685 @url{https://ant.apache.org/, Ant build tool}.
5687 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5688 provided by the @code{icedtea} package to the set of inputs. Different
5689 packages can be specified with the @code{#:ant} and @code{#:jdk}
5690 parameters, respectively.
5692 When the original package does not provide a suitable Ant build file,
5693 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5694 build file @file{build.xml} with tasks to build the specified jar
5695 archive. In this case the parameter @code{#:source-dir} can be used to
5696 specify the source sub-directory, defaulting to ``src''.
5698 The @code{#:main-class} parameter can be used with the minimal ant
5699 buildfile to specify the main class of the resulting jar. This makes the
5700 jar file executable. The @code{#:test-include} parameter can be used to
5701 specify the list of junit tests to run. It defaults to
5702 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5703 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5704 because abstract classes cannot be run as tests.
5706 The parameter @code{#:build-target} can be used to specify the Ant task
5707 that should be run during the @code{build} phase. By default the
5708 ``jar'' task will be run.
5712 @defvr {Scheme Variable} android-ndk-build-system
5713 @cindex Android distribution
5714 @cindex Android NDK build system
5715 This variable is exported by @code{(guix build-system android-ndk)}. It
5716 implements a build procedure for Android NDK (native development kit)
5717 packages using a Guix-specific build process.
5719 The build system assumes that packages install their public interface
5720 (header) files to the subdirectory "include" of the "out" output and
5721 their libraries to the subdirectory "lib" of the "out" output.
5723 It's also assumed that the union of all the dependencies of a package
5724 has no conflicting files.
5726 For the time being, cross-compilation is not supported - so right now
5727 the libraries and header files are assumed to be host tools.
5731 @defvr {Scheme Variable} asdf-build-system/source
5732 @defvrx {Scheme Variable} asdf-build-system/sbcl
5733 @defvrx {Scheme Variable} asdf-build-system/ecl
5735 These variables, exported by @code{(guix build-system asdf)}, implement
5736 build procedures for Common Lisp packages using
5737 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5738 definition facility for Common Lisp programs and libraries.
5740 The @code{asdf-build-system/source} system installs the packages in
5741 source form, and can be loaded using any common lisp implementation, via
5742 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5743 systems in the format which a particular implementation understands.
5744 These build systems can also be used to produce executable programs, or
5745 lisp images which contain a set of packages pre-loaded.
5747 The build system uses naming conventions. For binary packages, the
5748 package name should be prefixed with the lisp implementation, such as
5749 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5751 Additionally, the corresponding source package should be labeled using
5752 the same convention as python packages (see @ref{Python Modules}), using
5753 the @code{cl-} prefix.
5755 For binary packages, each system should be defined as a Guix package.
5756 If one package @code{origin} contains several systems, package variants
5757 can be created in order to build all the systems. Source packages,
5758 which use @code{asdf-build-system/source}, may contain several systems.
5760 In order to create executable programs and images, the build-side
5761 procedures @code{build-program} and @code{build-image} can be used.
5762 They should be called in a build phase after the @code{create-symlinks}
5763 phase, so that the system which was just built can be used within the
5764 resulting image. @code{build-program} requires a list of Common Lisp
5765 expressions to be passed as the @code{#:entry-program} argument.
5767 If the system is not defined within its own @code{.asd} file of the same
5768 name, then the @code{#:asd-file} parameter should be used to specify
5769 which file the system is defined in. Furthermore, if the package
5770 defines a system for its tests in a separate file, it will be loaded
5771 before the tests are run if it is specified by the
5772 @code{#:test-asd-file} parameter. If it is not set, the files
5773 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5774 and @code{test.asd} will be tried if they exist.
5776 If for some reason the package must be named in a different way than the
5777 naming conventions suggest, the @code{#:asd-system-name} parameter can
5778 be used to specify the name of the system.
5782 @defvr {Scheme Variable} cargo-build-system
5783 @cindex Rust programming language
5784 @cindex Cargo (Rust build system)
5785 This variable is exported by @code{(guix build-system cargo)}. It
5786 supports builds of packages using Cargo, the build tool of the
5787 @uref{https://www.rust-lang.org, Rust programming language}.
5789 In its @code{configure} phase, this build system replaces dependencies
5790 specified in the @file{Cargo.toml} file with inputs to the Guix package.
5791 The @code{install} phase installs the binaries, and it also installs the
5792 source code and @file{Cargo.toml} file.
5795 @cindex Clojure (programming language)
5796 @cindex simple Clojure build system
5797 @defvr {Scheme Variable} clojure-build-system
5798 This variable is exported by @code{(guix build-system clojure)}. It implements
5799 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5800 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5803 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5804 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5805 @code{#:zip} parameters, respectively.
5807 A list of source directories, test directories and jar names can be specified
5808 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5809 parameters, respectively. Compile directory and main class can be specified
5810 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5811 Other parameters are documented below.
5813 This build system is an extension of @var{ant-build-system}, but with the
5814 following phases changed:
5819 This phase calls @code{compile} in Clojure to compile source files and runs
5820 @command{jar} to create jars from both source files and compiled files
5821 according to the include list and exclude list specified in
5822 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5823 has priority over the include list. These lists consist of symbols
5824 representing Clojure libraries or the special keyword @code{#:all} representing
5825 all Clojure libraries found under the source directories. The parameter
5826 @code{#:omit-source?} decides if source should be included into the jars.
5829 This phase runs tests according to the include list and exclude list specified
5830 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5831 meanings are analogous to that of @code{#:aot-include} and
5832 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5833 stands for all Clojure libraries found under the test directories. The
5834 parameter @code{#:tests?} decides if tests should be run.
5837 This phase installs all jars built previously.
5840 Apart from the above, this build system also contains an additional phase:
5845 This phase installs all top-level files with base name matching
5846 @var{%doc-regex}. A different regex can be specified with the
5847 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5848 directories specified in @code{#:doc-dirs} are installed as well.
5852 @defvr {Scheme Variable} cmake-build-system
5853 This variable is exported by @code{(guix build-system cmake)}. It
5854 implements the build procedure for packages using the
5855 @url{https://www.cmake.org, CMake build tool}.
5857 It automatically adds the @code{cmake} package to the set of inputs.
5858 Which package is used can be specified with the @code{#:cmake}
5861 The @code{#:configure-flags} parameter is taken as a list of flags
5862 passed to the @command{cmake} command. The @code{#:build-type}
5863 parameter specifies in abstract terms the flags passed to the compiler;
5864 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5865 debugging information''), which roughly means that code is compiled with
5866 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5869 @defvr {Scheme Variable} dune-build-system
5870 This variable is exported by @code{(guix build-system dune)}. It
5871 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5872 tool for the OCaml programming language. It is implemented as an extension
5873 of the @code{ocaml-build-system} which is described below. As such, the
5874 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5877 It automatically adds the @code{dune} package to the set of inputs.
5878 Which package is used can be specified with the @code{#:dune}
5881 There is no @code{configure} phase because dune packages typically don't
5882 need to be configured. The @code{#:build-flags} parameter is taken as a
5883 list of flags passed to the @code{dune} command during the build.
5885 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5886 command instead of the more recent @code{dune} command while building
5887 a package. Its default value is @code{#f}.
5889 The @code{#:package} parameter can be passed to specify a package name, which
5890 is useful when a package contains multiple packages and you want to build
5891 only one of them. This is equivalent to passing the @code{-p} argument to
5895 @defvr {Scheme Variable} go-build-system
5896 This variable is exported by @code{(guix build-system go)}. It
5897 implements a build procedure for Go packages using the standard
5898 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5899 Go build mechanisms}.
5901 The user is expected to provide a value for the key @code{#:import-path}
5902 and, in some cases, @code{#:unpack-path}. The
5903 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5904 corresponds to the file system path expected by the package's build
5905 scripts and any referring packages, and provides a unique way to
5906 refer to a Go package. It is typically based on a combination of the
5907 package source code's remote URI and file system hierarchy structure. In
5908 some cases, you will need to unpack the package's source code to a
5909 different directory structure than the one indicated by the import path,
5910 and @code{#:unpack-path} should be used in such cases.
5912 Packages that provide Go libraries should install their source code into
5913 the built output. The key @code{#:install-source?}, which defaults to
5914 @code{#t}, controls whether or not the source code is installed. It can
5915 be set to @code{#f} for packages that only provide executable files.
5918 @defvr {Scheme Variable} glib-or-gtk-build-system
5919 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5920 is intended for use with packages making use of GLib or GTK+.
5922 This build system adds the following two phases to the ones defined by
5923 @var{gnu-build-system}:
5926 @item glib-or-gtk-wrap
5927 The phase @code{glib-or-gtk-wrap} ensures that programs in
5928 @file{bin/} are able to find GLib ``schemas'' and
5929 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5930 modules}. This is achieved by wrapping the programs in launch scripts
5931 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5932 environment variables.
5934 It is possible to exclude specific package outputs from that wrapping
5935 process by listing their names in the
5936 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5937 when an output is known not to contain any GLib or GTK+ binaries, and
5938 where wrapping would gratuitously add a dependency of that output on
5941 @item glib-or-gtk-compile-schemas
5942 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5943 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5944 GSettings schemas} of GLib are compiled. Compilation is performed by the
5945 @command{glib-compile-schemas} program. It is provided by the package
5946 @code{glib:bin} which is automatically imported by the build system.
5947 The @code{glib} package providing @command{glib-compile-schemas} can be
5948 specified with the @code{#:glib} parameter.
5951 Both phases are executed after the @code{install} phase.
5954 @defvr {Scheme Variable} guile-build-system
5955 This build system is for Guile packages that consist exclusively of Scheme
5956 code and that are so lean that they don't even have a makefile, let alone a
5957 @file{configure} script. It compiles Scheme code using @command{guild
5958 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5959 installs the @file{.scm} and @file{.go} files in the right place. It also
5960 installs documentation.
5962 This build system supports cross-compilation by using the @code{--target}
5963 option of @command{guild compile}.
5965 Packages built with @code{guile-build-system} must provide a Guile package in
5966 their @code{native-inputs} field.
5969 @defvr {Scheme Variable} minify-build-system
5970 This variable is exported by @code{(guix build-system minify)}. It
5971 implements a minification procedure for simple JavaScript packages.
5973 It adds @code{uglify-js} to the set of inputs and uses it to compress
5974 all JavaScript files in the @file{src} directory. A different minifier
5975 package can be specified with the @code{#:uglify-js} parameter, but it
5976 is expected that the package writes the minified code to the standard
5979 When the input JavaScript files are not all located in the @file{src}
5980 directory, the parameter @code{#:javascript-files} can be used to
5981 specify a list of file names to feed to the minifier.
5984 @defvr {Scheme Variable} ocaml-build-system
5985 This variable is exported by @code{(guix build-system ocaml)}. It implements
5986 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5987 of choosing the correct set of commands to run for each package. OCaml
5988 packages can expect many different commands to be run. This build system will
5991 When the package has a @file{setup.ml} file present at the top-level, it will
5992 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5993 @code{ocaml setup.ml -install}. The build system will assume that this file
5994 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5995 care of setting the prefix and enabling tests if they are not disabled. You
5996 can pass configure and build flags with the @code{#:configure-flags} and
5997 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5998 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5999 bypass this system in the build and install phases.
6001 When the package has a @file{configure} file, it is assumed that it is a
6002 hand-made configure script that requires a different argument format than
6003 in the @code{gnu-build-system}. You can add more flags with the
6004 @code{#:configure-flags} key.
6006 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6007 @code{#t}), it will be used and more flags can be passed to the build and
6008 install phases with the @code{#:make-flags} key.
6010 Finally, some packages do not have these files and use a somewhat standard
6011 location for its build system. In that case, the build system will run
6012 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6013 providing the path to the required findlib module. Additional flags can
6014 be passed via the @code{#:build-flags} key. Install is taken care of by
6015 @command{opam-installer}. In this case, the @code{opam} package must
6016 be added to the @code{native-inputs} field of the package definition.
6018 Note that most OCaml packages assume they will be installed in the same
6019 directory as OCaml, which is not what we want in guix. In particular, they
6020 will install @file{.so} files in their module's directory, which is usually
6021 fine because it is in the OCaml compiler directory. In guix though, these
6022 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6023 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6024 @file{.so} libraries should be installed.
6027 @defvr {Scheme Variable} python-build-system
6028 This variable is exported by @code{(guix build-system python)}. It
6029 implements the more or less standard build procedure used by Python
6030 packages, which consists in running @code{python setup.py build} and
6031 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6033 For packages that install stand-alone Python programs under @code{bin/},
6034 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6035 environment variable points to all the Python libraries they depend on.
6037 Which Python package is used to perform the build can be specified with
6038 the @code{#:python} parameter. This is a useful way to force a package
6039 to be built for a specific version of the Python interpreter, which
6040 might be necessary if the package is only compatible with a single
6041 interpreter version.
6043 By default guix calls @code{setup.py} under control of
6044 @code{setuptools}, much like @command{pip} does. Some packages are not
6045 compatible with setuptools (and pip), thus you can disable this by
6046 setting the @code{#:use-setuptools} parameter to @code{#f}.
6049 @defvr {Scheme Variable} perl-build-system
6050 This variable is exported by @code{(guix build-system perl)}. It
6051 implements the standard build procedure for Perl packages, which either
6052 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6053 followed by @code{Build} and @code{Build install}; or in running
6054 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6055 @code{make} and @code{make install}, depending on which of
6056 @code{Build.PL} or @code{Makefile.PL} is present in the package
6057 distribution. Preference is given to the former if both @code{Build.PL}
6058 and @code{Makefile.PL} exist in the package distribution. This
6059 preference can be reversed by specifying @code{#t} for the
6060 @code{#:make-maker?} parameter.
6062 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6063 passes flags specified by the @code{#:make-maker-flags} or
6064 @code{#:module-build-flags} parameter, respectively.
6066 Which Perl package is used can be specified with @code{#:perl}.
6069 @defvr {Scheme Variable} r-build-system
6070 This variable is exported by @code{(guix build-system r)}. It
6071 implements the build procedure used by @uref{https://r-project.org, R}
6072 packages, which essentially is little more than running @code{R CMD
6073 INSTALL --library=/gnu/store/@dots{}} in an environment where
6074 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6075 are run after installation using the R function
6076 @code{tools::testInstalledPackage}.
6079 @defvr {Scheme Variable} rakudo-build-system
6080 This variable is exported by @code{(guix build-system rakudo)}. It
6081 implements the build procedure used by @uref{https://rakudo.org/,
6082 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6083 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6084 installs the binaries, library files and the resources, as well as wrap
6085 the files under the @code{bin/} directory. Tests can be skipped by
6086 passing @code{#f} to the @code{tests?} parameter.
6088 Which rakudo package is used can be specified with @code{rakudo}.
6089 Which perl6-tap-harness package used for the tests can be specified with
6090 @code{#:prove6} or removed by passing @code{#f} to the
6091 @code{with-prove6?} parameter.
6092 Which perl6-zef package used for tests and installing can be specified
6093 with @code{#:zef} or removed by passing @code{#f} to the
6094 @code{with-zef?} parameter.
6097 @defvr {Scheme Variable} texlive-build-system
6098 This variable is exported by @code{(guix build-system texlive)}. It is
6099 used to build TeX packages in batch mode with a specified engine. The
6100 build system sets the @code{TEXINPUTS} variable to find all TeX source
6101 files in the inputs.
6103 By default it runs @code{luatex} on all files ending on @code{ins}. A
6104 different engine and format can be specified with the
6105 @code{#:tex-format} argument. Different build targets can be specified
6106 with the @code{#:build-targets} argument, which expects a list of file
6107 names. The build system adds only @code{texlive-bin} and
6108 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6109 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6110 and @code{#:texlive-latex-base}, respectively.
6112 The @code{#:tex-directory} parameter tells the build system where to
6113 install the built files under the texmf tree.
6116 @defvr {Scheme Variable} ruby-build-system
6117 This variable is exported by @code{(guix build-system ruby)}. It
6118 implements the RubyGems build procedure used by Ruby packages, which
6119 involves running @code{gem build} followed by @code{gem install}.
6121 The @code{source} field of a package that uses this build system
6122 typically references a gem archive, since this is the format that Ruby
6123 developers use when releasing their software. The build system unpacks
6124 the gem archive, potentially patches the source, runs the test suite,
6125 repackages the gem, and installs it. Additionally, directories and
6126 tarballs may be referenced to allow building unreleased gems from Git or
6127 a traditional source release tarball.
6129 Which Ruby package is used can be specified with the @code{#:ruby}
6130 parameter. A list of additional flags to be passed to the @command{gem}
6131 command can be specified with the @code{#:gem-flags} parameter.
6134 @defvr {Scheme Variable} waf-build-system
6135 This variable is exported by @code{(guix build-system waf)}. It
6136 implements a build procedure around the @code{waf} script. The common
6137 phases---@code{configure}, @code{build}, and @code{install}---are
6138 implemented by passing their names as arguments to the @code{waf}
6141 The @code{waf} script is executed by the Python interpreter. Which
6142 Python package is used to run the script can be specified with the
6143 @code{#:python} parameter.
6146 @defvr {Scheme Variable} scons-build-system
6147 This variable is exported by @code{(guix build-system scons)}. It
6148 implements the build procedure used by the SCons software construction
6149 tool. This build system runs @code{scons} to build the package,
6150 @code{scons test} to run tests, and then @code{scons install} to install
6153 Additional flags to be passed to @code{scons} can be specified with the
6154 @code{#:scons-flags} parameter. The version of Python used to run SCons
6155 can be specified by selecting the appropriate SCons package with the
6156 @code{#:scons} parameter.
6159 @defvr {Scheme Variable} haskell-build-system
6160 This variable is exported by @code{(guix build-system haskell)}. It
6161 implements the Cabal build procedure used by Haskell packages, which
6162 involves running @code{runhaskell Setup.hs configure
6163 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6164 Instead of installing the package by running @code{runhaskell Setup.hs
6165 install}, to avoid trying to register libraries in the read-only
6166 compiler store directory, the build system uses @code{runhaskell
6167 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6168 addition, the build system generates the package documentation by
6169 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6170 is passed. Optional Haddock parameters can be passed with the help of
6171 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6172 not found, the build system looks for @code{Setup.lhs} instead.
6174 Which Haskell compiler is used can be specified with the @code{#:haskell}
6175 parameter which defaults to @code{ghc}.
6178 @defvr {Scheme Variable} dub-build-system
6179 This variable is exported by @code{(guix build-system dub)}. It
6180 implements the Dub build procedure used by D packages, which
6181 involves running @code{dub build} and @code{dub run}.
6182 Installation is done by copying the files manually.
6184 Which D compiler is used can be specified with the @code{#:ldc}
6185 parameter which defaults to @code{ldc}.
6188 @defvr {Scheme Variable} emacs-build-system
6189 This variable is exported by @code{(guix build-system emacs)}. It
6190 implements an installation procedure similar to the packaging system
6191 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6193 It first creates the @code{@var{package}-autoloads.el} file, then it
6194 byte compiles all Emacs Lisp files. Differently from the Emacs
6195 packaging system, the Info documentation files are moved to the standard
6196 documentation directory and the @file{dir} file is deleted. Each
6197 package is installed in its own directory under
6198 @file{share/emacs/site-lisp/guix.d}.
6201 @defvr {Scheme Variable} font-build-system
6202 This variable is exported by @code{(guix build-system font)}. It
6203 implements an installation procedure for font packages where upstream
6204 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6205 need to be copied into place. It copies font files to standard
6206 locations in the output directory.
6209 @defvr {Scheme Variable} meson-build-system
6210 This variable is exported by @code{(guix build-system meson)}. It
6211 implements the build procedure for packages that use
6212 @url{https://mesonbuild.com, Meson} as their build system.
6214 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6215 of inputs, and they can be changed with the parameters @code{#:meson}
6216 and @code{#:ninja} if needed. The default Meson is
6217 @code{meson-for-build}, which is special because it doesn't clear the
6218 @code{RUNPATH} of binaries and libraries when they are installed.
6220 This build system is an extension of @var{gnu-build-system}, but with the
6221 following phases changed to some specific for Meson:
6226 The phase runs @code{meson} with the flags specified in
6227 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6228 @code{plain} unless something else is specified in @code{#:build-type}.
6231 The phase runs @code{ninja} to build the package in parallel by default, but
6232 this can be changed with @code{#:parallel-build?}.
6235 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6236 which is @code{"test"} by default.
6239 The phase runs @code{ninja install} and can not be changed.
6242 Apart from that, the build system also adds the following phases:
6247 This phase ensures that all binaries can find the libraries they need.
6248 It searches for required libraries in subdirectories of the package being
6249 built, and adds those to @code{RUNPATH} where needed. It also removes
6250 references to libraries left over from the build phase by
6251 @code{meson-for-build}, such as test dependencies, that aren't actually
6252 required for the program to run.
6254 @item glib-or-gtk-wrap
6255 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6256 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6258 @item glib-or-gtk-compile-schemas
6259 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6260 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6264 @defvr {Scheme Variable} linux-module-build-system
6265 @var{linux-module-build-system} allows building Linux kernel modules.
6267 @cindex build phases
6268 This build system is an extension of @var{gnu-build-system}, but with the
6269 following phases changed:
6274 This phase configures the environment so that the Linux kernel's Makefile
6275 can be used to build the external kernel module.
6278 This phase uses the Linux kernel's Makefile in order to build the external
6282 This phase uses the Linux kernel's Makefile in order to install the external
6286 It is possible and useful to specify the Linux kernel to use for building
6287 the module (in the "arguments" form of a package using the
6288 linux-module-build-system, use the key #:linux to specify it).
6291 Lastly, for packages that do not need anything as sophisticated, a
6292 ``trivial'' build system is provided. It is trivial in the sense that
6293 it provides basically no support: it does not pull any implicit inputs,
6294 and does not have a notion of build phases.
6296 @defvr {Scheme Variable} trivial-build-system
6297 This variable is exported by @code{(guix build-system trivial)}.
6299 This build system requires a @code{#:builder} argument. This argument
6300 must be a Scheme expression that builds the package output(s)---as
6301 with @code{build-expression->derivation} (@pxref{Derivations,
6302 @code{build-expression->derivation}}).
6312 Conceptually, the @dfn{store} is the place where derivations that have
6313 been built successfully are stored---by default, @file{/gnu/store}.
6314 Sub-directories in the store are referred to as @dfn{store items} or
6315 sometimes @dfn{store paths}. The store has an associated database that
6316 contains information such as the store paths referred to by each store
6317 path, and the list of @emph{valid} store items---results of successful
6318 builds. This database resides in @file{@var{localstatedir}/guix/db},
6319 where @var{localstatedir} is the state directory specified @i{via}
6320 @option{--localstatedir} at configure time, usually @file{/var}.
6322 The store is @emph{always} accessed by the daemon on behalf of its clients
6323 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6324 connect to the daemon over a Unix-domain socket, send requests to it,
6325 and read the result---these are remote procedure calls, or RPCs.
6328 Users must @emph{never} modify files under @file{/gnu/store} directly.
6329 This would lead to inconsistencies and break the immutability
6330 assumptions of Guix's functional model (@pxref{Introduction}).
6332 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6333 how to check the integrity of the store and attempt recovery from
6334 accidental modifications.
6337 The @code{(guix store)} module provides procedures to connect to the
6338 daemon, and to perform RPCs. These are described below. By default,
6339 @code{open-connection}, and thus all the @command{guix} commands,
6340 connect to the local daemon or to the URI specified by the
6341 @code{GUIX_DAEMON_SOCKET} environment variable.
6343 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6344 When set, the value of this variable should be a file name or a URI
6345 designating the daemon endpoint. When it is a file name, it denotes a
6346 Unix-domain socket to connect to. In addition to file names, the
6347 supported URI schemes are:
6352 These are for Unix-domain sockets.
6353 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6354 @file{/var/guix/daemon-socket/socket}.
6357 @cindex daemon, remote access
6358 @cindex remote access to the daemon
6359 @cindex daemon, cluster setup
6360 @cindex clusters, daemon setup
6361 These URIs denote connections over TCP/IP, without encryption nor
6362 authentication of the remote host. The URI must specify the host name
6363 and optionally a port number (by default port 44146 is used):
6366 guix://master.guix.example.org:1234
6369 This setup is suitable on local networks, such as clusters, where only
6370 trusted nodes may connect to the build daemon at
6371 @code{master.guix.example.org}.
6373 The @code{--listen} option of @command{guix-daemon} can be used to
6374 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6378 @cindex SSH access to build daemons
6379 These URIs allow you to connect to a remote daemon over
6380 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6381 A typical URL might look like this:
6384 ssh://charlie@@guix.example.org:22
6387 As for @command{guix copy}, the usual OpenSSH client configuration files
6388 are honored (@pxref{Invoking guix copy}).
6391 Additional URI schemes may be supported in the future.
6393 @c XXX: Remove this note when the protocol incurs fewer round trips
6394 @c and when (guix derivations) no longer relies on file system access.
6396 The ability to connect to remote build daemons is considered
6397 experimental as of @value{VERSION}. Please get in touch with us to
6398 share any problems or suggestions you may have (@pxref{Contributing}).
6402 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6403 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6404 @var{reserve-space?} is true, instruct it to reserve a little bit of
6405 extra space on the file system so that the garbage collector can still
6406 operate should the disk become full. Return a server object.
6408 @var{file} defaults to @var{%default-socket-path}, which is the normal
6409 location given the options that were passed to @command{configure}.
6412 @deffn {Scheme Procedure} close-connection @var{server}
6413 Close the connection to @var{server}.
6416 @defvr {Scheme Variable} current-build-output-port
6417 This variable is bound to a SRFI-39 parameter, which refers to the port
6418 where build and error logs sent by the daemon should be written.
6421 Procedures that make RPCs all take a server object as their first
6424 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6425 @cindex invalid store items
6426 Return @code{#t} when @var{path} designates a valid store item and
6427 @code{#f} otherwise (an invalid item may exist on disk but still be
6428 invalid, for instance because it is the result of an aborted or failed
6431 A @code{&store-protocol-error} condition is raised if @var{path} is not
6432 prefixed by the store directory (@file{/gnu/store}).
6435 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6436 Add @var{text} under file @var{name} in the store, and return its store
6437 path. @var{references} is the list of store paths referred to by the
6438 resulting store path.
6441 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6442 Build @var{derivations} (a list of @code{<derivation>} objects or
6443 derivation paths), and return when the worker is done building them.
6444 Return @code{#t} on success.
6447 Note that the @code{(guix monads)} module provides a monad as well as
6448 monadic versions of the above procedures, with the goal of making it
6449 more convenient to work with code that accesses the store (@pxref{The
6453 @i{This section is currently incomplete.}
6456 @section Derivations
6459 Low-level build actions and the environment in which they are performed
6460 are represented by @dfn{derivations}. A derivation contains the
6461 following pieces of information:
6465 The outputs of the derivation---derivations produce at least one file or
6466 directory in the store, but may produce more.
6469 @cindex build-time dependencies
6470 @cindex dependencies, build-time
6471 The inputs of the derivations---i.e., its build-time dependencies---which may
6472 be other derivations or plain files in the store (patches, build scripts,
6476 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6479 The file name of a build script in the store, along with the arguments
6483 A list of environment variables to be defined.
6487 @cindex derivation path
6488 Derivations allow clients of the daemon to communicate build actions to
6489 the store. They exist in two forms: as an in-memory representation,
6490 both on the client- and daemon-side, and as files in the store whose
6491 name end in @code{.drv}---these files are referred to as @dfn{derivation
6492 paths}. Derivations paths can be passed to the @code{build-derivations}
6493 procedure to perform the build actions they prescribe (@pxref{The
6496 @cindex fixed-output derivations
6497 Operations such as file downloads and version-control checkouts for
6498 which the expected content hash is known in advance are modeled as
6499 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6500 of a fixed-output derivation are independent of its inputs---e.g., a
6501 source code download produces the same result regardless of the download
6502 method and tools being used.
6505 @cindex run-time dependencies
6506 @cindex dependencies, run-time
6507 The outputs of derivations---i.e., the build results---have a set of
6508 @dfn{references}, as reported by the @code{references} RPC or the
6509 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6510 are the set of run-time dependencies of the build results. References are a
6511 subset of the inputs of the derivation; this subset is automatically computed
6512 by the build daemon by scanning all the files in the outputs.
6514 The @code{(guix derivations)} module provides a representation of
6515 derivations as Scheme objects, along with procedures to create and
6516 otherwise manipulate derivations. The lowest-level primitive to create
6517 a derivation is the @code{derivation} procedure:
6519 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6520 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6521 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6522 [#:system (%current-system)] [#:references-graphs #f] @
6523 [#:allowed-references #f] [#:disallowed-references #f] @
6524 [#:leaked-env-vars #f] [#:local-build? #f] @
6525 [#:substitutable? #t] [#:properties '()]
6526 Build a derivation with the given arguments, and return the resulting
6527 @code{<derivation>} object.
6529 When @var{hash} and @var{hash-algo} are given, a
6530 @dfn{fixed-output derivation} is created---i.e., one whose result is
6531 known in advance, such as a file download. If, in addition,
6532 @var{recursive?} is true, then that fixed output may be an executable
6533 file or a directory and @var{hash} must be the hash of an archive
6534 containing this output.
6536 When @var{references-graphs} is true, it must be a list of file
6537 name/store path pairs. In that case, the reference graph of each store
6538 path is exported in the build environment in the corresponding file, in
6539 a simple text format.
6541 When @var{allowed-references} is true, it must be a list of store items
6542 or outputs that the derivation's output may refer to. Likewise,
6543 @var{disallowed-references}, if true, must be a list of things the
6544 outputs may @emph{not} refer to.
6546 When @var{leaked-env-vars} is true, it must be a list of strings
6547 denoting environment variables that are allowed to ``leak'' from the
6548 daemon's environment to the build environment. This is only applicable
6549 to fixed-output derivations---i.e., when @var{hash} is true. The main
6550 use is to allow variables such as @code{http_proxy} to be passed to
6551 derivations that download files.
6553 When @var{local-build?} is true, declare that the derivation is not a
6554 good candidate for offloading and should rather be built locally
6555 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6556 where the costs of data transfers would outweigh the benefits.
6558 When @var{substitutable?} is false, declare that substitutes of the
6559 derivation's output should not be used (@pxref{Substitutes}). This is
6560 useful, for instance, when building packages that capture details of the
6561 host CPU instruction set.
6563 @var{properties} must be an association list describing ``properties'' of the
6564 derivation. It is kept as-is, uninterpreted, in the derivation.
6568 Here's an example with a shell script as its builder, assuming
6569 @var{store} is an open connection to the daemon, and @var{bash} points
6570 to a Bash executable in the store:
6573 (use-modules (guix utils)
6577 (let ((builder ; add the Bash script to the store
6578 (add-text-to-store store "my-builder.sh"
6579 "echo hello world > $out\n" '())))
6580 (derivation store "foo"
6581 bash `("-e" ,builder)
6582 #:inputs `((,bash) (,builder))
6583 #:env-vars '(("HOME" . "/homeless"))))
6584 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6587 As can be guessed, this primitive is cumbersome to use directly. A
6588 better approach is to write build scripts in Scheme, of course! The
6589 best course of action for that is to write the build code as a
6590 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6591 information, @pxref{G-Expressions}.
6593 Once upon a time, @code{gexp->derivation} did not exist and constructing
6594 derivations with build code written in Scheme was achieved with
6595 @code{build-expression->derivation}, documented below. This procedure
6596 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6598 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6599 @var{name} @var{exp} @
6600 [#:system (%current-system)] [#:inputs '()] @
6601 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6602 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6603 [#:references-graphs #f] [#:allowed-references #f] @
6604 [#:disallowed-references #f] @
6605 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6606 Return a derivation that executes Scheme expression @var{exp} as a
6607 builder for derivation @var{name}. @var{inputs} must be a list of
6608 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6609 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6610 modules from the current search path to be copied in the store,
6611 compiled, and made available in the load path during the execution of
6612 @var{exp}---e.g., @code{((guix build utils) (guix build
6613 gnu-build-system))}.
6615 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6616 to a list of output/path pairs, and where @code{%build-inputs} is bound
6617 to a list of string/output-path pairs made from @var{inputs}.
6618 Optionally, @var{env-vars} is a list of string pairs specifying the name
6619 and value of environment variables visible to the builder. The builder
6620 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6621 @var{exp} returns @code{#f}, the build is considered to have failed.
6623 @var{exp} is built using @var{guile-for-build} (a derivation). When
6624 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6625 @code{%guile-for-build} fluid is used instead.
6627 See the @code{derivation} procedure for the meaning of
6628 @var{references-graphs}, @var{allowed-references},
6629 @var{disallowed-references}, @var{local-build?}, and
6630 @var{substitutable?}.
6634 Here's an example of a single-output derivation that creates a directory
6635 containing one file:
6638 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6639 (mkdir out) ; create /gnu/store/@dots{}-goo
6640 (call-with-output-file (string-append out "/test")
6642 (display '(hello guix) p))))))
6643 (build-expression->derivation store "goo" builder))
6645 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6649 @node The Store Monad
6650 @section The Store Monad
6654 The procedures that operate on the store described in the previous
6655 sections all take an open connection to the build daemon as their first
6656 argument. Although the underlying model is functional, they either have
6657 side effects or depend on the current state of the store.
6659 The former is inconvenient: the connection to the build daemon has to be
6660 carried around in all those functions, making it impossible to compose
6661 functions that do not take that parameter with functions that do. The
6662 latter can be problematic: since store operations have side effects
6663 and/or depend on external state, they have to be properly sequenced.
6665 @cindex monadic values
6666 @cindex monadic functions
6667 This is where the @code{(guix monads)} module comes in. This module
6668 provides a framework for working with @dfn{monads}, and a particularly
6669 useful monad for our uses, the @dfn{store monad}. Monads are a
6670 construct that allows two things: associating ``context'' with values
6671 (in our case, the context is the store), and building sequences of
6672 computations (here computations include accesses to the store). Values
6673 in a monad---values that carry this additional context---are called
6674 @dfn{monadic values}; procedures that return such values are called
6675 @dfn{monadic procedures}.
6677 Consider this ``normal'' procedure:
6680 (define (sh-symlink store)
6681 ;; Return a derivation that symlinks the 'bash' executable.
6682 (let* ((drv (package-derivation store bash))
6683 (out (derivation->output-path drv))
6684 (sh (string-append out "/bin/bash")))
6685 (build-expression->derivation store "sh"
6686 `(symlink ,sh %output))))
6689 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6690 as a monadic function:
6693 (define (sh-symlink)
6694 ;; Same, but return a monadic value.
6695 (mlet %store-monad ((drv (package->derivation bash)))
6696 (gexp->derivation "sh"
6697 #~(symlink (string-append #$drv "/bin/bash")
6701 There are several things to note in the second version: the @code{store}
6702 parameter is now implicit and is ``threaded'' in the calls to the
6703 @code{package->derivation} and @code{gexp->derivation} monadic
6704 procedures, and the monadic value returned by @code{package->derivation}
6705 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6707 As it turns out, the call to @code{package->derivation} can even be
6708 omitted since it will take place implicitly, as we will see later
6709 (@pxref{G-Expressions}):
6712 (define (sh-symlink)
6713 (gexp->derivation "sh"
6714 #~(symlink (string-append #$bash "/bin/bash")
6719 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6720 @c for the funny quote.
6721 Calling the monadic @code{sh-symlink} has no effect. As someone once
6722 said, ``you exit a monad like you exit a building on fire: by running''.
6723 So, to exit the monad and get the desired effect, one must use
6724 @code{run-with-store}:
6727 (run-with-store (open-connection) (sh-symlink))
6728 @result{} /gnu/store/...-sh-symlink
6731 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6732 new ``meta-commands'' to make it easier to deal with monadic procedures:
6733 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6734 to ``run'' a single monadic value through the store:
6737 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6738 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6741 The latter enters a recursive REPL, where all the return values are
6742 automatically run through the store:
6745 scheme@@(guile-user)> ,enter-store-monad
6746 store-monad@@(guile-user) [1]> (package->derivation hello)
6747 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6748 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6749 $3 = "/gnu/store/@dots{}-foo"
6750 store-monad@@(guile-user) [1]> ,q
6751 scheme@@(guile-user)>
6755 Note that non-monadic values cannot be returned in the
6756 @code{store-monad} REPL.
6758 The main syntactic forms to deal with monads in general are provided by
6759 the @code{(guix monads)} module and are described below.
6761 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6762 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6766 @deffn {Scheme Syntax} return @var{val}
6767 Return a monadic value that encapsulates @var{val}.
6770 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6771 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6772 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6773 referred to as ``bind'', but that name denotes an unrelated procedure in
6774 Guile. Thus we use this somewhat cryptic symbol inherited from the
6775 Haskell language.}. There can be one @var{mproc} or several of them, as
6780 (with-monad %state-monad
6782 (lambda (x) (return (+ 1 x)))
6783 (lambda (x) (return (* 2 x)))))
6787 @result{} some-state
6791 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6793 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6795 Bind the variables @var{var} to the monadic values @var{mval} in
6796 @var{body}, which is a sequence of expressions. As with the bind
6797 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6798 value ``contained'' in @var{mval} and making @var{var} refer to that
6799 raw, non-monadic value within the scope of the @var{body}. The form
6800 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6801 @var{val}, as per @code{let}. The binding operations occur in sequence
6802 from left to right. The last expression of @var{body} must be a monadic
6803 expression, and its result will become the result of the @code{mlet} or
6804 @code{mlet*} when run in the @var{monad}.
6806 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6807 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6810 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6811 Bind @var{mexp} and the following monadic expressions in sequence,
6812 returning the result of the last expression. Every expression in the
6813 sequence must be a monadic expression.
6815 This is akin to @code{mlet}, except that the return values of the
6816 monadic expressions are ignored. In that sense, it is analogous to
6817 @code{begin}, but applied to monadic expressions.
6820 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6821 When @var{condition} is true, evaluate the sequence of monadic
6822 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6823 @var{condition} is false, return @code{*unspecified*} in the current
6824 monad. Every expression in the sequence must be a monadic expression.
6827 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6828 When @var{condition} is false, evaluate the sequence of monadic
6829 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6830 @var{condition} is true, return @code{*unspecified*} in the current
6831 monad. Every expression in the sequence must be a monadic expression.
6835 The @code{(guix monads)} module provides the @dfn{state monad}, which
6836 allows an additional value---the state---to be @emph{threaded} through
6837 monadic procedure calls.
6839 @defvr {Scheme Variable} %state-monad
6840 The state monad. Procedures in the state monad can access and change
6841 the state that is threaded.
6843 Consider the example below. The @code{square} procedure returns a value
6844 in the state monad. It returns the square of its argument, but also
6845 increments the current state value:
6849 (mlet %state-monad ((count (current-state)))
6850 (mbegin %state-monad
6851 (set-current-state (+ 1 count))
6854 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6859 When ``run'' through @var{%state-monad}, we obtain that additional state
6860 value, which is the number of @code{square} calls.
6863 @deffn {Monadic Procedure} current-state
6864 Return the current state as a monadic value.
6867 @deffn {Monadic Procedure} set-current-state @var{value}
6868 Set the current state to @var{value} and return the previous state as a
6872 @deffn {Monadic Procedure} state-push @var{value}
6873 Push @var{value} to the current state, which is assumed to be a list,
6874 and return the previous state as a monadic value.
6877 @deffn {Monadic Procedure} state-pop
6878 Pop a value from the current state and return it as a monadic value.
6879 The state is assumed to be a list.
6882 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6883 Run monadic value @var{mval} starting with @var{state} as the initial
6884 state. Return two values: the resulting value, and the resulting state.
6887 The main interface to the store monad, provided by the @code{(guix
6888 store)} module, is as follows.
6890 @defvr {Scheme Variable} %store-monad
6891 The store monad---an alias for @var{%state-monad}.
6893 Values in the store monad encapsulate accesses to the store. When its
6894 effect is needed, a value of the store monad must be ``evaluated'' by
6895 passing it to the @code{run-with-store} procedure (see below.)
6898 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6899 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6900 open store connection.
6903 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6904 Return as a monadic value the absolute file name in the store of the file
6905 containing @var{text}, a string. @var{references} is a list of store items that the
6906 resulting text file refers to; it defaults to the empty list.
6909 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6910 Return as a monadic value the absolute file name in the store of the file
6911 containing @var{data}, a bytevector. @var{references} is a list of store
6912 items that the resulting binary file refers to; it defaults to the empty list.
6915 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6916 [#:recursive? #t] [#:select? (const #t)]
6917 Return the name of @var{file} once interned in the store. Use
6918 @var{name} as its store name, or the basename of @var{file} if
6919 @var{name} is omitted.
6921 When @var{recursive?} is true, the contents of @var{file} are added
6922 recursively; if @var{file} designates a flat file and @var{recursive?}
6923 is true, its contents are added, and its permission bits are kept.
6925 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6926 @var{stat})} for each directory entry, where @var{file} is the entry's
6927 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6928 entries for which @var{select?} does not return true.
6930 The example below adds a file to the store, under two different names:
6933 (run-with-store (open-connection)
6934 (mlet %store-monad ((a (interned-file "README"))
6935 (b (interned-file "README" "LEGU-MIN")))
6936 (return (list a b))))
6938 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6943 The @code{(guix packages)} module exports the following package-related
6946 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6947 [#:system (%current-system)] [#:target #f] @
6950 value in the absolute file name of @var{file} within the @var{output}
6951 directory of @var{package}. When @var{file} is omitted, return the name
6952 of the @var{output} directory of @var{package}. When @var{target} is
6953 true, use it as a cross-compilation target triplet.
6956 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6957 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6958 @var{target} [@var{system}]
6959 Monadic version of @code{package-derivation} and
6960 @code{package-cross-derivation} (@pxref{Defining Packages}).
6965 @section G-Expressions
6967 @cindex G-expression
6968 @cindex build code quoting
6969 So we have ``derivations'', which represent a sequence of build actions
6970 to be performed to produce an item in the store (@pxref{Derivations}).
6971 These build actions are performed when asking the daemon to actually
6972 build the derivations; they are run by the daemon in a container
6973 (@pxref{Invoking guix-daemon}).
6975 @cindex strata of code
6976 It should come as no surprise that we like to write these build actions
6977 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6978 code@footnote{The term @dfn{stratum} in this context was coined by
6979 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6980 Kiselyov, who has written insightful
6981 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6982 on this topic}, refers to this kind of code generation as
6983 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6984 to the daemon, etc.---and the ``build code''---code that actually
6985 performs build actions, such as making directories, invoking
6986 @command{make}, etc.
6988 To describe a derivation and its build actions, one typically needs to
6989 embed build code inside host code. It boils down to manipulating build
6990 code as data, and the homoiconicity of Scheme---code has a direct
6991 representation as data---comes in handy for that. But we need more than
6992 the normal @code{quasiquote} mechanism in Scheme to construct build
6995 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6996 S-expressions adapted to build expressions. G-expressions, or
6997 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6998 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6999 @code{#$}, and @code{#$@@}), which are comparable to
7000 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7001 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7002 GNU Guile Reference Manual}). However, there are major differences:
7006 Gexps are meant to be written to a file and run or manipulated by other
7010 When a high-level object such as a package or derivation is unquoted
7011 inside a gexp, the result is as if its output file name had been
7015 Gexps carry information about the packages or derivations they refer to,
7016 and these dependencies are automatically added as inputs to the build
7017 processes that use them.
7020 @cindex lowering, of high-level objects in gexps
7021 This mechanism is not limited to package and derivation
7022 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7023 derivations or files in the store can be defined,
7024 such that these objects can also be inserted
7025 into gexps. For example, a useful type of high-level objects that can be
7026 inserted in a gexp is ``file-like objects'', which make it easy to
7027 add files to the store and to refer to them in
7028 derivations and such (see @code{local-file} and @code{plain-file}
7031 To illustrate the idea, here is an example of a gexp:
7038 (symlink (string-append #$coreutils "/bin/ls")
7042 This gexp can be passed to @code{gexp->derivation}; we obtain a
7043 derivation that builds a directory containing exactly one symlink to
7044 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7047 (gexp->derivation "the-thing" build-exp)
7050 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7051 substituted to the reference to the @var{coreutils} package in the
7052 actual build code, and @var{coreutils} is automatically made an input to
7053 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7054 output)}) is replaced by a string containing the directory name of the
7055 output of the derivation.
7057 @cindex cross compilation
7058 In a cross-compilation context, it is useful to distinguish between
7059 references to the @emph{native} build of a package---that can run on the
7060 host---versus references to cross builds of a package. To that end, the
7061 @code{#+} plays the same role as @code{#$}, but is a reference to a
7062 native package build:
7065 (gexp->derivation "vi"
7068 (system* (string-append #+coreutils "/bin/ln")
7070 (string-append #$emacs "/bin/emacs")
7071 (string-append #$output "/bin/vi")))
7072 #:target "mips64el-linux-gnu")
7076 In the example above, the native build of @var{coreutils} is used, so
7077 that @command{ln} can actually run on the host; but then the
7078 cross-compiled build of @var{emacs} is referenced.
7080 @cindex imported modules, for gexps
7081 @findex with-imported-modules
7082 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7083 able to use certain Guile modules from the ``host environment'' in the
7084 gexp, so those modules should be imported in the ``build environment''.
7085 The @code{with-imported-modules} form allows you to express that:
7088 (let ((build (with-imported-modules '((guix build utils))
7090 (use-modules (guix build utils))
7091 (mkdir-p (string-append #$output "/bin"))))))
7092 (gexp->derivation "empty-dir"
7095 (display "success!\n")
7100 In this example, the @code{(guix build utils)} module is automatically
7101 pulled into the isolated build environment of our gexp, such that
7102 @code{(use-modules (guix build utils))} works as expected.
7104 @cindex module closure
7105 @findex source-module-closure
7106 Usually you want the @emph{closure} of the module to be imported---i.e.,
7107 the module itself and all the modules it depends on---rather than just
7108 the module; failing to do that, attempts to use the module will fail
7109 because of missing dependent modules. The @code{source-module-closure}
7110 procedure computes the closure of a module by looking at its source file
7111 headers, which comes in handy in this case:
7114 (use-modules (guix modules)) ;for 'source-module-closure'
7116 (with-imported-modules (source-module-closure
7117 '((guix build utils)
7119 (gexp->derivation "something-with-vms"
7121 (use-modules (guix build utils)
7126 @cindex extensions, for gexps
7127 @findex with-extensions
7128 In the same vein, sometimes you want to import not just pure-Scheme
7129 modules, but also ``extensions'' such as Guile bindings to C libraries
7130 or other ``full-blown'' packages. Say you need the @code{guile-json}
7131 package available on the build side, here's how you would do it:
7134 (use-modules (gnu packages guile)) ;for 'guile-json'
7136 (with-extensions (list guile-json)
7137 (gexp->derivation "something-with-json"
7139 (use-modules (json))
7143 The syntactic form to construct gexps is summarized below.
7145 @deffn {Scheme Syntax} #~@var{exp}
7146 @deffnx {Scheme Syntax} (gexp @var{exp})
7147 Return a G-expression containing @var{exp}. @var{exp} may contain one
7148 or more of the following forms:
7152 @itemx (ungexp @var{obj})
7153 Introduce a reference to @var{obj}. @var{obj} may have one of the
7154 supported types, for example a package or a
7155 derivation, in which case the @code{ungexp} form is replaced by its
7156 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7158 If @var{obj} is a list, it is traversed and references to supported
7159 objects are substituted similarly.
7161 If @var{obj} is another gexp, its contents are inserted and its
7162 dependencies are added to those of the containing gexp.
7164 If @var{obj} is another kind of object, it is inserted as is.
7166 @item #$@var{obj}:@var{output}
7167 @itemx (ungexp @var{obj} @var{output})
7168 This is like the form above, but referring explicitly to the
7169 @var{output} of @var{obj}---this is useful when @var{obj} produces
7170 multiple outputs (@pxref{Packages with Multiple Outputs}).
7173 @itemx #+@var{obj}:output
7174 @itemx (ungexp-native @var{obj})
7175 @itemx (ungexp-native @var{obj} @var{output})
7176 Same as @code{ungexp}, but produces a reference to the @emph{native}
7177 build of @var{obj} when used in a cross compilation context.
7179 @item #$output[:@var{output}]
7180 @itemx (ungexp output [@var{output}])
7181 Insert a reference to derivation output @var{output}, or to the main
7182 output when @var{output} is omitted.
7184 This only makes sense for gexps passed to @code{gexp->derivation}.
7187 @itemx (ungexp-splicing @var{lst})
7188 Like the above, but splices the contents of @var{lst} inside the
7192 @itemx (ungexp-native-splicing @var{lst})
7193 Like the above, but refers to native builds of the objects listed in
7198 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7199 of the @code{gexp?} type (see below.)
7202 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7203 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7204 in their execution environment.
7206 Each item in @var{modules} can be the name of a module, such as
7207 @code{(guix build utils)}, or it can be a module name, followed by an
7208 arrow, followed by a file-like object:
7211 `((guix build utils)
7213 ((guix config) => ,(scheme-file "config.scm"
7214 #~(define-module @dots{}))))
7218 In the example above, the first two modules are taken from the search
7219 path, and the last one is created from the given file-like object.
7221 This form has @emph{lexical} scope: it has an effect on the gexps
7222 directly defined in @var{body}@dots{}, but not on those defined, say, in
7223 procedures called from @var{body}@dots{}.
7226 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7227 Mark the gexps defined in @var{body}@dots{} as requiring
7228 @var{extensions} in their build and execution environment.
7229 @var{extensions} is typically a list of package objects such as those
7230 defined in the @code{(gnu packages guile)} module.
7232 Concretely, the packages listed in @var{extensions} are added to the
7233 load path while compiling imported modules in @var{body}@dots{}; they
7234 are also added to the load path of the gexp returned by
7238 @deffn {Scheme Procedure} gexp? @var{obj}
7239 Return @code{#t} if @var{obj} is a G-expression.
7242 G-expressions are meant to be written to disk, either as code building
7243 some derivation, or as plain files in the store. The monadic procedures
7244 below allow you to do that (@pxref{The Store Monad}, for more
7245 information about monads.)
7247 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7248 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7249 [#:hash #f] [#:hash-algo #f] @
7250 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7251 [#:module-path @var{%load-path}] @
7252 [#:effective-version "2.2"] @
7253 [#:references-graphs #f] [#:allowed-references #f] @
7254 [#:disallowed-references #f] @
7255 [#:leaked-env-vars #f] @
7256 [#:script-name (string-append @var{name} "-builder")] @
7257 [#:deprecation-warnings #f] @
7258 [#:local-build? #f] [#:substitutable? #t] @
7259 [#:properties '()] [#:guile-for-build #f]
7260 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7261 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7262 stored in a file called @var{script-name}. When @var{target} is true,
7263 it is used as the cross-compilation target triplet for packages referred
7266 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7268 make @var{modules} available in the evaluation context of @var{exp};
7269 @var{modules} is a list of names of Guile modules searched in
7270 @var{module-path} to be copied in the store, compiled, and made available in
7271 the load path during the execution of @var{exp}---e.g., @code{((guix
7272 build utils) (guix build gnu-build-system))}.
7274 @var{effective-version} determines the string to use when adding extensions of
7275 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7277 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7280 When @var{references-graphs} is true, it must be a list of tuples of one of the
7284 (@var{file-name} @var{package})
7285 (@var{file-name} @var{package} @var{output})
7286 (@var{file-name} @var{derivation})
7287 (@var{file-name} @var{derivation} @var{output})
7288 (@var{file-name} @var{store-item})
7291 The right-hand-side of each element of @var{references-graphs} is automatically made
7292 an input of the build process of @var{exp}. In the build environment, each
7293 @var{file-name} contains the reference graph of the corresponding item, in a simple
7296 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7297 In the latter case, the list denotes store items that the result is allowed to
7298 refer to. Any reference to another store item will lead to a build error.
7299 Similarly for @var{disallowed-references}, which can list items that must not be
7300 referenced by the outputs.
7302 @var{deprecation-warnings} determines whether to show deprecation warnings while
7303 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7305 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7308 @cindex file-like objects
7309 The @code{local-file}, @code{plain-file}, @code{computed-file},
7310 @code{program-file}, and @code{scheme-file} procedures below return
7311 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7312 these objects lead to a file in the store. Consider this G-expression:
7315 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7316 #$(local-file "/tmp/my-nscd.conf"))
7319 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7320 to the store. Once expanded, for instance @i{via}
7321 @code{gexp->derivation}, the G-expression refers to that copy under
7322 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7323 does not have any effect on what the G-expression does.
7324 @code{plain-file} can be used similarly; it differs in that the file
7325 content is directly passed as a string.
7327 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7328 [#:recursive? #f] [#:select? (const #t)]
7329 Return an object representing local file @var{file} to add to the store; this
7330 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7331 up relative to the source file where this form appears. @var{file} will be added to
7332 the store under @var{name}--by default the base name of @var{file}.
7334 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7335 designates a flat file and @var{recursive?} is true, its contents are added, and its
7336 permission bits are kept.
7338 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7339 @var{stat})} for each directory entry, where @var{file} is the entry's
7340 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7341 entries for which @var{select?} does not return true.
7343 This is the declarative counterpart of the @code{interned-file} monadic
7344 procedure (@pxref{The Store Monad, @code{interned-file}}).
7347 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7348 Return an object representing a text file called @var{name} with the given
7349 @var{content} (a string or a bytevector) to be added to the store.
7351 This is the declarative counterpart of @code{text-file}.
7354 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7355 [#:options '(#:local-build? #t)]
7356 Return an object representing the store item @var{name}, a file or
7357 directory computed by @var{gexp}. @var{options}
7358 is a list of additional arguments to pass to @code{gexp->derivation}.
7360 This is the declarative counterpart of @code{gexp->derivation}.
7363 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7364 [#:guile (default-guile)] [#:module-path %load-path]
7365 Return an executable script @var{name} that runs @var{exp} using
7366 @var{guile}, with @var{exp}'s imported modules in its search path.
7367 Look up @var{exp}'s modules in @var{module-path}.
7369 The example below builds a script that simply invokes the @command{ls}
7373 (use-modules (guix gexp) (gnu packages base))
7375 (gexp->script "list-files"
7376 #~(execl #$(file-append coreutils "/bin/ls")
7380 When ``running'' it through the store (@pxref{The Store Monad,
7381 @code{run-with-store}}), we obtain a derivation that produces an
7382 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7385 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7387 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7391 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7392 [#:guile #f] [#:module-path %load-path]
7393 Return an object representing the executable store item @var{name} that
7394 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7395 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7397 This is the declarative counterpart of @code{gexp->script}.
7400 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7401 [#:set-load-path? #t] [#:module-path %load-path] @
7403 [#:guile (default-guile)]
7404 Return a derivation that builds a file @var{name} containing @var{exp}.
7405 When @var{splice?} is true, @var{exp} is considered to be a list of
7406 expressions that will be spliced in the resulting file.
7408 When @var{set-load-path?} is true, emit code in the resulting file to
7409 set @code{%load-path} and @code{%load-compiled-path} to honor
7410 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7413 The resulting file holds references to all the dependencies of @var{exp}
7414 or a subset thereof.
7417 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7418 Return an object representing the Scheme file @var{name} that contains
7421 This is the declarative counterpart of @code{gexp->file}.
7424 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7425 Return as a monadic value a derivation that builds a text file
7426 containing all of @var{text}. @var{text} may list, in addition to
7427 strings, objects of any type that can be used in a gexp: packages,
7428 derivations, local file objects, etc. The resulting store file holds
7429 references to all these.
7431 This variant should be preferred over @code{text-file} anytime the file
7432 to create will reference items from the store. This is typically the
7433 case when building a configuration file that embeds store file names,
7437 (define (profile.sh)
7438 ;; Return the name of a shell script in the store that
7439 ;; initializes the 'PATH' environment variable.
7440 (text-file* "profile.sh"
7441 "export PATH=" coreutils "/bin:"
7442 grep "/bin:" sed "/bin\n"))
7445 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7446 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7447 preventing them from being garbage-collected during its lifetime.
7450 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7451 Return an object representing store file @var{name} containing
7452 @var{text}. @var{text} is a sequence of strings and file-like objects,
7456 (mixed-text-file "profile"
7457 "export PATH=" coreutils "/bin:" grep "/bin")
7460 This is the declarative counterpart of @code{text-file*}.
7463 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7464 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7465 Each item in @var{files} must be a two-element list where the first element is the
7466 file name to use in the new directory, and the second element is a gexp
7467 denoting the target file. Here's an example:
7471 `(("hosts" ,(plain-file "hosts"
7472 "127.0.0.1 localhost"))
7473 ("bashrc" ,(plain-file "bashrc"
7474 "alias ls='ls --color=auto'"))))
7477 This yields an @code{etc} directory containing these two files.
7480 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7481 Return a directory that is the union of @var{things}, where @var{things} is a list of
7482 file-like objects denoting directories. For example:
7485 (directory-union "guile+emacs" (list guile emacs))
7488 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7491 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7492 Return a file-like object that expands to the concatenation of @var{obj}
7493 and @var{suffix}, where @var{obj} is a lowerable object and each
7494 @var{suffix} is a string.
7496 As an example, consider this gexp:
7499 (gexp->script "run-uname"
7500 #~(system* #$(file-append coreutils
7504 The same effect could be achieved with:
7507 (gexp->script "run-uname"
7508 #~(system* (string-append #$coreutils
7512 There is one difference though: in the @code{file-append} case, the
7513 resulting script contains the absolute file name as a string, whereas in
7514 the second case, the resulting script contains a @code{(string-append
7515 @dots{})} expression to construct the file name @emph{at run time}.
7519 Of course, in addition to gexps embedded in ``host'' code, there are
7520 also modules containing build tools. To make it clear that they are
7521 meant to be used in the build stratum, these modules are kept in the
7522 @code{(guix build @dots{})} name space.
7524 @cindex lowering, of high-level objects in gexps
7525 Internally, high-level objects are @dfn{lowered}, using their compiler,
7526 to either derivations or store items. For instance, lowering a package
7527 yields a derivation, and lowering a @code{plain-file} yields a store
7528 item. This is achieved using the @code{lower-object} monadic procedure.
7530 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7532 Return as a value in @var{%store-monad} the derivation or store item
7533 corresponding to @var{obj} for @var{system}, cross-compiling for
7534 @var{target} if @var{target} is true. @var{obj} must be an object that
7535 has an associated gexp compiler, such as a @code{<package>}.
7538 @node Invoking guix repl
7539 @section Invoking @command{guix repl}
7541 @cindex REPL, read-eval-print loop
7542 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7543 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7544 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7545 command, @command{guix repl} guarantees that all the Guix modules and all its
7546 dependencies are available in the search path. You can use it this way:
7550 scheme@@(guile-user)> ,use (gnu packages base)
7551 scheme@@(guile-user)> coreutils
7552 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7556 In addition, @command{guix repl} implements a simple machine-readable REPL
7557 protocol for use by @code{(guix inferior)}, a facility to interact with
7558 @dfn{inferiors}, separate processes running a potentially different revision
7561 The available options are as follows:
7564 @item --type=@var{type}
7565 @itemx -t @var{type}
7566 Start a REPL of the given @var{TYPE}, which can be one of the following:
7570 This is default, and it spawns a standard full-featured Guile REPL.
7572 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7573 that the @code{(guix inferior)} module speaks.
7576 @item --listen=@var{endpoint}
7577 By default, @command{guix repl} reads from standard input and writes to
7578 standard output. When this option is passed, it will instead listen for
7579 connections on @var{endpoint}. Here are examples of valid options:
7582 @item --listen=tcp:37146
7583 Accept connections on localhost on port 37146.
7585 @item --listen=unix:/tmp/socket
7586 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7590 @c *********************************************************************
7594 This section describes Guix command-line utilities. Some of them are
7595 primarily targeted at developers and users who write new package
7596 definitions, while others are more generally useful. They complement
7597 the Scheme programming interface of Guix in a convenient way.
7600 * Invoking guix build:: Building packages from the command line.
7601 * Invoking guix edit:: Editing package definitions.
7602 * Invoking guix download:: Downloading a file and printing its hash.
7603 * Invoking guix hash:: Computing the cryptographic hash of a file.
7604 * Invoking guix import:: Importing package definitions.
7605 * Invoking guix refresh:: Updating package definitions.
7606 * Invoking guix lint:: Finding errors in package definitions.
7607 * Invoking guix size:: Profiling disk usage.
7608 * Invoking guix graph:: Visualizing the graph of packages.
7609 * Invoking guix publish:: Sharing substitutes.
7610 * Invoking guix challenge:: Challenging substitute servers.
7611 * Invoking guix copy:: Copying to and from a remote store.
7612 * Invoking guix container:: Process isolation.
7613 * Invoking guix weather:: Assessing substitute availability.
7614 * Invoking guix processes:: Listing client processes.
7617 @node Invoking guix build
7618 @section Invoking @command{guix build}
7620 @cindex package building
7621 @cindex @command{guix build}
7622 The @command{guix build} command builds packages or derivations and
7623 their dependencies, and prints the resulting store paths. Note that it
7624 does not modify the user's profile---this is the job of the
7625 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7626 it is mainly useful for distribution developers.
7628 The general syntax is:
7631 guix build @var{options} @var{package-or-derivation}@dots{}
7634 As an example, the following command builds the latest versions of Emacs
7635 and of Guile, displays their build logs, and finally displays the
7636 resulting directories:
7639 guix build emacs guile
7642 Similarly, the following command builds all the available packages:
7645 guix build --quiet --keep-going \
7646 `guix package -A | cut -f1,2 --output-delimiter=@@`
7649 @var{package-or-derivation} may be either the name of a package found in
7650 the software distribution such as @code{coreutils} or
7651 @code{coreutils@@8.20}, or a derivation such as
7652 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7653 package with the corresponding name (and optionally version) is searched
7654 for among the GNU distribution modules (@pxref{Package Modules}).
7656 Alternatively, the @code{--expression} option may be used to specify a
7657 Scheme expression that evaluates to a package; this is useful when
7658 disambiguating among several same-named packages or package variants is
7661 There may be zero or more @var{options}. The available options are
7662 described in the subsections below.
7665 * Common Build Options:: Build options for most commands.
7666 * Package Transformation Options:: Creating variants of packages.
7667 * Additional Build Options:: Options specific to 'guix build'.
7668 * Debugging Build Failures:: Real life packaging experience.
7671 @node Common Build Options
7672 @subsection Common Build Options
7674 A number of options that control the build process are common to
7675 @command{guix build} and other commands that can spawn builds, such as
7676 @command{guix package} or @command{guix archive}. These are the
7681 @item --load-path=@var{directory}
7682 @itemx -L @var{directory}
7683 Add @var{directory} to the front of the package module search path
7684 (@pxref{Package Modules}).
7686 This allows users to define their own packages and make them visible to
7687 the command-line tools.
7691 Keep the build tree of failed builds. Thus, if a build fails, its build
7692 tree is kept under @file{/tmp}, in a directory whose name is shown at
7693 the end of the build log. This is useful when debugging build issues.
7694 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7697 This option has no effect when connecting to a remote daemon with a
7698 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7703 Keep going when some of the derivations fail to build; return only once
7704 all the builds have either completed or failed.
7706 The default behavior is to stop as soon as one of the specified
7707 derivations has failed.
7711 Do not build the derivations.
7713 @anchor{fallback-option}
7715 When substituting a pre-built binary fails, fall back to building
7716 packages locally (@pxref{Substitution Failure}).
7718 @item --substitute-urls=@var{urls}
7719 @anchor{client-substitute-urls}
7720 Consider @var{urls} the whitespace-separated list of substitute source
7721 URLs, overriding the default list of URLs of @command{guix-daemon}
7722 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7724 This means that substitutes may be downloaded from @var{urls}, provided
7725 they are signed by a key authorized by the system administrator
7726 (@pxref{Substitutes}).
7728 When @var{urls} is the empty string, substitutes are effectively
7731 @item --no-substitutes
7732 Do not use substitutes for build products. That is, always build things
7733 locally instead of allowing downloads of pre-built binaries
7734 (@pxref{Substitutes}).
7737 Do not ``graft'' packages. In practice, this means that package updates
7738 available as grafts are not applied. @xref{Security Updates}, for more
7739 information on grafts.
7741 @item --rounds=@var{n}
7742 Build each derivation @var{n} times in a row, and raise an error if
7743 consecutive build results are not bit-for-bit identical.
7745 This is a useful way to detect non-deterministic builds processes.
7746 Non-deterministic build processes are a problem because they make it
7747 practically impossible for users to @emph{verify} whether third-party
7748 binaries are genuine. @xref{Invoking guix challenge}, for more.
7750 Note that, currently, the differing build results are not kept around,
7751 so you will have to manually investigate in case of an error---e.g., by
7752 stashing one of the build results with @code{guix archive --export}
7753 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7756 @item --no-build-hook
7757 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7758 (@pxref{Daemon Offload Setup}). That is, always build things locally
7759 instead of offloading builds to remote machines.
7761 @item --max-silent-time=@var{seconds}
7762 When the build or substitution process remains silent for more than
7763 @var{seconds}, terminate it and report a build failure.
7765 By default, the daemon's setting is honored (@pxref{Invoking
7766 guix-daemon, @code{--max-silent-time}}).
7768 @item --timeout=@var{seconds}
7769 Likewise, when the build or substitution process lasts for more than
7770 @var{seconds}, terminate it and report a build failure.
7772 By default, the daemon's setting is honored (@pxref{Invoking
7773 guix-daemon, @code{--timeout}}).
7775 @c Note: This option is actually not part of %standard-build-options but
7776 @c most programs honor it.
7777 @cindex verbosity, of the command-line tools
7778 @cindex build logs, verbosity
7779 @item -v @var{level}
7780 @itemx --verbosity=@var{level}
7781 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7782 output is produced, 1 is for quiet output, and 2 shows all the build log
7783 output on standard error.
7785 @item --cores=@var{n}
7787 Allow the use of up to @var{n} CPU cores for the build. The special
7788 value @code{0} means to use as many CPU cores as available.
7790 @item --max-jobs=@var{n}
7792 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7793 guix-daemon, @code{--max-jobs}}, for details about this option and the
7794 equivalent @command{guix-daemon} option.
7796 @item --debug=@var{level}
7797 Produce debugging output coming from the build daemon. @var{level} must be an
7798 integer between 0 and 5; higher means more verbose output. Setting a level of
7799 4 or more may be helpful when debugging setup issues with the build daemon.
7803 Behind the scenes, @command{guix build} is essentially an interface to
7804 the @code{package-derivation} procedure of the @code{(guix packages)}
7805 module, and to the @code{build-derivations} procedure of the @code{(guix
7806 derivations)} module.
7808 In addition to options explicitly passed on the command line,
7809 @command{guix build} and other @command{guix} commands that support
7810 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7812 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7813 Users can define this variable to a list of command line options that
7814 will automatically be used by @command{guix build} and other
7815 @command{guix} commands that can perform builds, as in the example
7819 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7822 These options are parsed independently, and the result is appended to
7823 the parsed command-line options.
7827 @node Package Transformation Options
7828 @subsection Package Transformation Options
7830 @cindex package variants
7831 Another set of command-line options supported by @command{guix build}
7832 and also @command{guix package} are @dfn{package transformation
7833 options}. These are options that make it possible to define @dfn{package
7834 variants}---for instance, packages built from different source code.
7835 This is a convenient way to create customized packages on the fly
7836 without having to type in the definitions of package variants
7837 (@pxref{Defining Packages}).
7841 @item --with-source=@var{source}
7842 @itemx --with-source=@var{package}=@var{source}
7843 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7844 Use @var{source} as the source of @var{package}, and @var{version} as
7846 @var{source} must be a file name or a URL, as for @command{guix
7847 download} (@pxref{Invoking guix download}).
7849 When @var{package} is omitted,
7850 it is taken to be the package name specified on the
7851 command line that matches the base of @var{source}---e.g.,
7852 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7853 package is @code{guile}.
7855 Likewise, when @var{version} is omitted, the version string is inferred from
7856 @var{source}; in the previous example, it is @code{2.0.10}.
7858 This option allows users to try out versions of packages other than the
7859 one provided by the distribution. The example below downloads
7860 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7861 the @code{ed} package:
7864 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7867 As a developer, @code{--with-source} makes it easy to test release
7871 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7874 @dots{} or to build from a checkout in a pristine environment:
7877 $ git clone git://git.sv.gnu.org/guix.git
7878 $ guix build guix --with-source=guix@@1.0=./guix
7881 @item --with-input=@var{package}=@var{replacement}
7882 Replace dependency on @var{package} by a dependency on
7883 @var{replacement}. @var{package} must be a package name, and
7884 @var{replacement} must be a package specification such as @code{guile}
7885 or @code{guile@@1.8}.
7887 For instance, the following command builds Guix, but replaces its
7888 dependency on the current stable version of Guile with a dependency on
7889 the legacy version of Guile, @code{guile@@2.0}:
7892 guix build --with-input=guile=guile@@2.0 guix
7895 This is a recursive, deep replacement. So in this example, both
7896 @code{guix} and its dependency @code{guile-json} (which also depends on
7897 @code{guile}) get rebuilt against @code{guile@@2.0}.
7899 This is implemented using the @code{package-input-rewriting} Scheme
7900 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7902 @item --with-graft=@var{package}=@var{replacement}
7903 This is similar to @code{--with-input} but with an important difference:
7904 instead of rebuilding the whole dependency chain, @var{replacement} is
7905 built and then @dfn{grafted} onto the binaries that were initially
7906 referring to @var{package}. @xref{Security Updates}, for more
7907 information on grafts.
7909 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7910 and all its dependencies, replacing references to the version of GnuTLS
7911 they currently refer to:
7914 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7917 This has the advantage of being much faster than rebuilding everything.
7918 But there is a caveat: it works if and only if @var{package} and
7919 @var{replacement} are strictly compatible---for example, if they provide
7920 a library, the application binary interface (ABI) of those libraries
7921 must be compatible. If @var{replacement} is somehow incompatible with
7922 @var{package}, then the resulting package may be unusable. Use with
7925 @item --with-git-url=@var{package}=@var{url}
7926 @cindex Git, using the latest commit
7927 @cindex latest commit, building
7928 Build @var{package} from the latest commit of the @code{master} branch of the
7929 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7932 For example, the following command builds the NumPy Python library against the
7933 latest commit of the master branch of Python itself:
7936 guix build python-numpy \
7937 --with-git-url=python=https://github.com/python/cpython
7940 This option can also be combined with @code{--with-branch} or
7941 @code{--with-commit} (see below).
7943 @cindex continuous integration
7944 Obviously, since it uses the latest commit of the given branch, the result of
7945 such a command varies over time. Nevertheless it is a convenient way to
7946 rebuild entire software stacks against the latest commit of one or more
7947 packages. This is particularly useful in the context of continuous
7950 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7951 consecutive accesses to the same repository. You may want to clean it up once
7952 in a while to save disk space.
7954 @item --with-branch=@var{package}=@var{branch}
7955 Build @var{package} from the latest commit of @var{branch}. If the
7956 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7957 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7958 repository URL is taken from that @code{source}. Otherwise you have to use
7959 @code{--with-git-url} to specify the URL of the Git repository.
7961 For instance, the following command builds @code{guile-sqlite3} from the
7962 latest commit of its @code{master} branch, and then builds @code{guix} (which
7963 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7964 specific @code{guile-sqlite3} build:
7967 guix build --with-branch=guile-sqlite3=master cuirass
7970 @item --with-commit=@var{package}=@var{commit}
7971 This is similar to @code{--with-branch}, except that it builds from
7972 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7973 Git commit SHA1 identifier.
7976 @node Additional Build Options
7977 @subsection Additional Build Options
7979 The command-line options presented below are specific to @command{guix
7986 Build quietly, without displaying the build log; this is equivalent to
7987 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7988 (or similar) and can always be retrieved using the @option{--log-file} option.
7990 @item --file=@var{file}
7991 @itemx -f @var{file}
7992 Build the package, derivation, or other file-like object that the code within
7993 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7995 As an example, @var{file} might contain a package definition like this
7996 (@pxref{Defining Packages}):
7999 @verbatiminclude package-hello.scm
8002 @item --expression=@var{expr}
8003 @itemx -e @var{expr}
8004 Build the package or derivation @var{expr} evaluates to.
8006 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8007 guile-1.8)}, which unambiguously designates this specific variant of
8008 version 1.8 of Guile.
8010 Alternatively, @var{expr} may be a G-expression, in which case it is used
8011 as a build program passed to @code{gexp->derivation}
8012 (@pxref{G-Expressions}).
8014 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8015 (@pxref{The Store Monad}). The procedure must return a derivation as a
8016 monadic value, which is then passed through @code{run-with-store}.
8020 Build the source derivations of the packages, rather than the packages
8023 For instance, @code{guix build -S gcc} returns something like
8024 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8027 The returned source tarball is the result of applying any patches and
8028 code snippets specified in the package @code{origin} (@pxref{Defining
8032 Fetch and return the source of @var{package-or-derivation} and all their
8033 dependencies, recursively. This is a handy way to obtain a local copy
8034 of all the source code needed to build @var{packages}, allowing you to
8035 eventually build them even without network access. It is an extension
8036 of the @code{--source} option and can accept one of the following
8037 optional argument values:
8041 This value causes the @code{--sources} option to behave in the same way
8042 as the @code{--source} option.
8045 Build the source derivations of all packages, including any source that
8046 might be listed as @code{inputs}. This is the default value.
8049 $ guix build --sources tzdata
8050 The following derivations will be built:
8051 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8052 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8056 Build the source derivations of all packages, as well of all transitive
8057 inputs to the packages. This can be used e.g.@: to
8058 prefetch package source for later offline building.
8061 $ guix build --sources=transitive tzdata
8062 The following derivations will be built:
8063 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8064 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8065 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8066 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8067 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8068 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8074 @item --system=@var{system}
8075 @itemx -s @var{system}
8076 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8077 the system type of the build host. The @command{guix build} command allows
8078 you to repeat this option several times, in which case it builds for all the
8079 specified systems; other commands ignore extraneous @option{-s} options.
8082 The @code{--system} flag is for @emph{native} compilation and must not
8083 be confused with cross-compilation. See @code{--target} below for
8084 information on cross-compilation.
8087 An example use of this is on Linux-based systems, which can emulate
8088 different personalities. For instance, passing
8089 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8090 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8091 to build packages in a complete 32-bit environment.
8094 Building for an @code{armhf-linux} system is unconditionally enabled on
8095 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8096 allow for this functionality, notably the ThunderX.
8099 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8100 is enabled (@pxref{Virtualization Services,
8101 @code{qemu-binfmt-service-type}}), you can build for any system for
8102 which a QEMU @code{binfmt_misc} handler is installed.
8104 Builds for a system other than that of the machine you are using can
8105 also be offloaded to a remote machine of the right architecture.
8106 @xref{Daemon Offload Setup}, for more information on offloading.
8108 @item --target=@var{triplet}
8109 @cindex cross-compilation
8110 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8111 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8112 configuration triplets,, autoconf, Autoconf}).
8114 @anchor{build-check}
8116 @cindex determinism, checking
8117 @cindex reproducibility, checking
8118 Rebuild @var{package-or-derivation}, which are already available in the
8119 store, and raise an error if the build results are not bit-for-bit
8122 This mechanism allows you to check whether previously installed
8123 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8124 of a package is deterministic. @xref{Invoking guix challenge}, for more
8125 background information and tools.
8127 When used in conjunction with @option{--keep-failed}, the differing
8128 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8129 This makes it easy to look for differences between the two results.
8132 @cindex repairing store items
8133 @cindex corruption, recovering from
8134 Attempt to repair the specified store items, if they are corrupt, by
8135 re-downloading or rebuilding them.
8137 This operation is not atomic and thus restricted to @code{root}.
8141 Return the derivation paths, not the output paths, of the given
8144 @item --root=@var{file}
8145 @itemx -r @var{file}
8146 @cindex GC roots, adding
8147 @cindex garbage collector roots, adding
8148 Make @var{file} a symlink to the result, and register it as a garbage
8151 Consequently, the results of this @command{guix build} invocation are
8152 protected from garbage collection until @var{file} is removed. When
8153 that option is omitted, build results are eligible for garbage
8154 collection as soon as the build completes. @xref{Invoking guix gc}, for
8158 @cindex build logs, access
8159 Return the build log file names or URLs for the given
8160 @var{package-or-derivation}, or raise an error if build logs are
8163 This works regardless of how packages or derivations are specified. For
8164 instance, the following invocations are equivalent:
8167 guix build --log-file `guix build -d guile`
8168 guix build --log-file `guix build guile`
8169 guix build --log-file guile
8170 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8173 If a log is unavailable locally, and unless @code{--no-substitutes} is
8174 passed, the command looks for a corresponding log on one of the
8175 substitute servers (as specified with @code{--substitute-urls}.)
8177 So for instance, imagine you want to see the build log of GDB on MIPS,
8178 but you are actually on an @code{x86_64} machine:
8181 $ guix build --log-file gdb -s mips64el-linux
8182 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8185 You can freely access a huge library of build logs!
8188 @node Debugging Build Failures
8189 @subsection Debugging Build Failures
8191 @cindex build failures, debugging
8192 When defining a new package (@pxref{Defining Packages}), you will
8193 probably find yourself spending some time debugging and tweaking the
8194 build until it succeeds. To do that, you need to operate the build
8195 commands yourself in an environment as close as possible to the one the
8198 To that end, the first thing to do is to use the @option{--keep-failed}
8199 or @option{-K} option of @command{guix build}, which will keep the
8200 failed build tree in @file{/tmp} or whatever directory you specified as
8201 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8203 From there on, you can @command{cd} to the failed build tree and source
8204 the @file{environment-variables} file, which contains all the
8205 environment variable definitions that were in place when the build
8206 failed. So let's say you're debugging a build failure in package
8207 @code{foo}; a typical session would look like this:
8211 @dots{} @i{build fails}
8212 $ cd /tmp/guix-build-foo.drv-0
8213 $ source ./environment-variables
8217 Now, you can invoke commands as if you were the daemon (almost) and
8218 troubleshoot your build process.
8220 Sometimes it happens that, for example, a package's tests pass when you
8221 run them manually but they fail when the daemon runs them. This can
8222 happen because the daemon runs builds in containers where, unlike in our
8223 environment above, network access is missing, @file{/bin/sh} does not
8224 exist, etc. (@pxref{Build Environment Setup}).
8226 In such cases, you may need to run inspect the build process from within
8227 a container similar to the one the build daemon creates:
8232 $ cd /tmp/guix-build-foo.drv-0
8233 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8234 [env]# source ./environment-variables
8238 Here, @command{guix environment -C} creates a container and spawns a new
8239 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8240 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8241 the container, which would may find handy while debugging. The
8242 @option{--no-grafts} option makes sure we get the exact same
8243 environment, with ungrafted packages (@pxref{Security Updates}, for more
8246 To get closer to a container like that used by the build daemon, we can
8247 remove @file{/bin/sh}:
8253 (Don't worry, this is harmless: this is all happening in the throw-away
8254 container created by @command{guix environment}.)
8256 The @command{strace} command is probably not in the search path, but we
8260 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8263 In this way, not only you will have reproduced the environment variables
8264 the daemon uses, you will also be running the build process in a container
8265 similar to the one the daemon uses.
8268 @node Invoking guix edit
8269 @section Invoking @command{guix edit}
8271 @cindex @command{guix edit}
8272 @cindex package definition, editing
8273 So many packages, so many source files! The @command{guix edit} command
8274 facilitates the life of users and packagers by pointing their editor at
8275 the source file containing the definition of the specified packages.
8279 guix edit gcc@@4.9 vim
8283 launches the program specified in the @code{VISUAL} or in the
8284 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8287 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8288 have created your own packages on @code{GUIX_PACKAGE_PATH}
8289 (@pxref{Package Modules}), you will be able to edit the package
8290 recipes. In other cases, you will be able to examine the read-only recipes
8291 for packages currently in the store.
8294 @node Invoking guix download
8295 @section Invoking @command{guix download}
8297 @cindex @command{guix download}
8298 @cindex downloading package sources
8299 When writing a package definition, developers typically need to download
8300 a source tarball, compute its SHA256 hash, and write that
8301 hash in the package definition (@pxref{Defining Packages}). The
8302 @command{guix download} tool helps with this task: it downloads a file
8303 from the given URI, adds it to the store, and prints both its file name
8304 in the store and its SHA256 hash.
8306 The fact that the downloaded file is added to the store saves bandwidth:
8307 when the developer eventually tries to build the newly defined package
8308 with @command{guix build}, the source tarball will not have to be
8309 downloaded again because it is already in the store. It is also a
8310 convenient way to temporarily stash files, which may be deleted
8311 eventually (@pxref{Invoking guix gc}).
8313 The @command{guix download} command supports the same URIs as used in
8314 package definitions. In particular, it supports @code{mirror://} URIs.
8315 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8316 Guile bindings for GnuTLS are available in the user's environment; when
8317 they are not available, an error is raised. @xref{Guile Preparations,
8318 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8319 GnuTLS-Guile}, for more information.
8321 @command{guix download} verifies HTTPS server certificates by loading
8322 the certificates of X.509 authorities from the directory pointed to by
8323 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8324 Certificates}), unless @option{--no-check-certificate} is used.
8326 The following options are available:
8329 @item --format=@var{fmt}
8331 Write the hash in the format specified by @var{fmt}. For more
8332 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8334 @item --no-check-certificate
8335 Do not validate the X.509 certificates of HTTPS servers.
8337 When using this option, you have @emph{absolutely no guarantee} that you
8338 are communicating with the authentic server responsible for the given
8339 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8341 @item --output=@var{file}
8342 @itemx -o @var{file}
8343 Save the downloaded file to @var{file} instead of adding it to the
8347 @node Invoking guix hash
8348 @section Invoking @command{guix hash}
8350 @cindex @command{guix hash}
8351 The @command{guix hash} command computes the SHA256 hash of a file.
8352 It is primarily a convenience tool for anyone contributing to the
8353 distribution: it computes the cryptographic hash of a file, which can be
8354 used in the definition of a package (@pxref{Defining Packages}).
8356 The general syntax is:
8359 guix hash @var{option} @var{file}
8362 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8363 hash of data read from standard input. @command{guix hash} has the
8368 @item --format=@var{fmt}
8370 Write the hash in the format specified by @var{fmt}.
8372 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8373 (@code{hex} and @code{hexadecimal} can be used as well).
8375 If the @option{--format} option is not specified, @command{guix hash}
8376 will output the hash in @code{nix-base32}. This representation is used
8377 in the definitions of packages.
8381 Compute the hash on @var{file} recursively.
8383 In this case, the hash is computed on an archive containing @var{file},
8384 including its children if it is a directory. Some of the metadata of
8385 @var{file} is part of the archive; for instance, when @var{file} is a
8386 regular file, the hash is different depending on whether @var{file} is
8387 executable or not. Metadata such as time stamps has no impact on the
8388 hash (@pxref{Invoking guix archive}).
8389 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8394 When combined with @option{--recursive}, exclude version control system
8395 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8398 As an example, here is how you would compute the hash of a Git checkout,
8399 which is useful when using the @code{git-fetch} method (@pxref{origin
8403 $ git clone http://example.org/foo.git
8409 @node Invoking guix import
8410 @section Invoking @command{guix import}
8412 @cindex importing packages
8413 @cindex package import
8414 @cindex package conversion
8415 @cindex Invoking @command{guix import}
8416 The @command{guix import} command is useful for people who would like to
8417 add a package to the distribution with as little work as
8418 possible---a legitimate demand. The command knows of a few
8419 repositories from which it can ``import'' package metadata. The result
8420 is a package definition, or a template thereof, in the format we know
8421 (@pxref{Defining Packages}).
8423 The general syntax is:
8426 guix import @var{importer} @var{options}@dots{}
8429 @var{importer} specifies the source from which to import package
8430 metadata, and @var{options} specifies a package identifier and other
8431 options specific to @var{importer}. Currently, the available
8436 Import metadata for the given GNU package. This provides a template
8437 for the latest version of that GNU package, including the hash of its
8438 source tarball, and its canonical synopsis and description.
8440 Additional information such as the package dependencies and its
8441 license needs to be figured out manually.
8443 For example, the following command returns a package definition for
8447 guix import gnu hello
8450 Specific command-line options are:
8453 @item --key-download=@var{policy}
8454 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8455 keys when verifying the package signature. @xref{Invoking guix
8456 refresh, @code{--key-download}}.
8461 Import metadata from the @uref{https://pypi.python.org/, Python Package
8462 Index}. Information is taken from the JSON-formatted description
8463 available at @code{pypi.python.org} and usually includes all the relevant
8464 information, including package dependencies. For maximum efficiency, it
8465 is recommended to install the @command{unzip} utility, so that the
8466 importer can unzip Python wheels and gather data from them.
8468 The command below imports metadata for the @code{itsdangerous} Python
8472 guix import pypi itsdangerous
8478 Traverse the dependency graph of the given upstream package recursively
8479 and generate package expressions for all those packages that are not yet
8485 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8486 is taken from the JSON-formatted description available at
8487 @code{rubygems.org} and includes most relevant information, including
8488 runtime dependencies. There are some caveats, however. The metadata
8489 doesn't distinguish between synopses and descriptions, so the same string
8490 is used for both fields. Additionally, the details of non-Ruby
8491 dependencies required to build native extensions is unavailable and left
8492 as an exercise to the packager.
8494 The command below imports metadata for the @code{rails} Ruby package:
8497 guix import gem rails
8503 Traverse the dependency graph of the given upstream package recursively
8504 and generate package expressions for all those packages that are not yet
8510 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8511 Information is taken from the JSON-formatted metadata provided through
8512 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8513 relevant information, such as module dependencies. License information
8514 should be checked closely. If Perl is available in the store, then the
8515 @code{corelist} utility will be used to filter core modules out of the
8516 list of dependencies.
8518 The command command below imports metadata for the @code{Acme::Boolean}
8522 guix import cpan Acme::Boolean
8527 @cindex Bioconductor
8528 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8529 central repository for the @uref{https://r-project.org, GNU@tie{}R
8530 statistical and graphical environment}.
8532 Information is extracted from the @code{DESCRIPTION} file of the package.
8534 The command command below imports metadata for the @code{Cairo}
8538 guix import cran Cairo
8541 When @code{--recursive} is added, the importer will traverse the
8542 dependency graph of the given upstream package recursively and generate
8543 package expressions for all those packages that are not yet in Guix.
8545 When @code{--archive=bioconductor} is added, metadata is imported from
8546 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8547 packages for for the analysis and comprehension of high-throughput
8548 genomic data in bioinformatics.
8550 Information is extracted from the @code{DESCRIPTION} file of a package
8551 published on the web interface of the Bioconductor SVN repository.
8553 The command below imports metadata for the @code{GenomicRanges}
8557 guix import cran --archive=bioconductor GenomicRanges
8563 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8564 comprehensive TeX archive network for TeX packages that are part of the
8565 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8567 Information about the package is obtained through the XML API provided
8568 by CTAN, while the source code is downloaded from the SVN repository of
8569 the Tex Live project. This is done because the CTAN does not keep
8572 The command command below imports metadata for the @code{fontspec}
8576 guix import texlive fontspec
8579 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8580 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8581 tree in the TeX Live SVN repository, but from the specified sibling
8582 directory under the same root.
8584 The command below imports metadata for the @code{ifxetex} package from
8585 CTAN while fetching the sources from the directory
8586 @file{texmf/source/generic}:
8589 guix import texlive --archive=generic ifxetex
8593 @cindex JSON, import
8594 Import package metadata from a local JSON file. Consider the following
8595 example package definition in JSON format:
8601 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8602 "build-system": "gnu",
8603 "home-page": "https://www.gnu.org/software/hello/",
8604 "synopsis": "Hello, GNU world: An example GNU package",
8605 "description": "GNU Hello prints a greeting.",
8606 "license": "GPL-3.0+",
8607 "native-inputs": ["gcc@@6"]
8611 The field names are the same as for the @code{<package>} record
8612 (@xref{Defining Packages}). References to other packages are provided
8613 as JSON lists of quoted package specification strings such as
8614 @code{guile} or @code{guile@@2.0}.
8616 The importer also supports a more explicit source definition using the
8617 common fields for @code{<origin>} records:
8623 "method": "url-fetch",
8624 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8626 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8633 The command below reads metadata from the JSON file @code{hello.json}
8634 and outputs a package expression:
8637 guix import json hello.json
8641 Import metadata from a local copy of the source of the
8642 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8643 relies on the @command{nix-instantiate} command of
8644 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8645 typically written in a mixture of Nix-language and Bash code. This
8646 command only imports the high-level package structure that is written in
8647 the Nix language. It normally includes all the basic fields of a
8650 When importing a GNU package, the synopsis and descriptions are replaced
8651 by their canonical upstream variant.
8653 Usually, you will first need to do:
8656 export NIX_REMOTE=daemon
8660 so that @command{nix-instantiate} does not try to open the Nix database.
8662 As an example, the command below imports the package definition of
8663 LibreOffice (more precisely, it imports the definition of the package
8664 bound to the @code{libreoffice} top-level attribute):
8667 guix import nix ~/path/to/nixpkgs libreoffice
8672 Import metadata from the Haskell community's central package archive
8673 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8674 Cabal files and includes all the relevant information, including package
8677 Specific command-line options are:
8682 Read a Cabal file from standard input.
8683 @item --no-test-dependencies
8685 Do not include dependencies required only by the test suites.
8686 @item --cabal-environment=@var{alist}
8687 @itemx -e @var{alist}
8688 @var{alist} is a Scheme alist defining the environment in which the
8689 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8690 @code{arch}, @code{impl} and a string representing the name of a flag.
8691 The value associated with a flag has to be either the symbol
8692 @code{true} or @code{false}. The value associated with other keys
8693 has to conform to the Cabal file format definition. The default value
8694 associated with the keys @code{os}, @code{arch} and @code{impl} is
8695 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8698 Traverse the dependency graph of the given upstream package recursively
8699 and generate package expressions for all those packages that are not yet
8703 The command below imports metadata for the latest version of the
8704 @code{HTTP} Haskell package without including test dependencies and
8705 specifying the value of the flag @samp{network-uri} as @code{false}:
8708 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8711 A specific package version may optionally be specified by following the
8712 package name by an at-sign and a version number as in the following example:
8715 guix import hackage mtl@@2.1.3.1
8720 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8721 It takes a package name, looks up the package version included in a
8722 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8723 release and uses the @code{hackage} importer to retrieve its metadata.
8724 Note that it is up to you to select an LTS release compatible with the
8725 GHC compiler used by Guix.
8727 Specific command-line options are:
8730 @item --no-test-dependencies
8732 Do not include dependencies required only by the test suites.
8733 @item --lts-version=@var{version}
8734 @itemx -l @var{version}
8735 @var{version} is the desired LTS release version. If omitted the latest
8739 Traverse the dependency graph of the given upstream package recursively
8740 and generate package expressions for all those packages that are not yet
8744 The command below imports metadata for the @code{HTTP} Haskell package
8745 included in the LTS Stackage release version 7.18:
8748 guix import stackage --lts-version=7.18 HTTP
8753 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8754 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8756 Specific command-line options are:
8759 @item --archive=@var{repo}
8760 @itemx -a @var{repo}
8761 @var{repo} identifies the archive repository from which to retrieve the
8762 information. Currently the supported repositories and their identifiers
8766 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8767 identifier. This is the default.
8769 Packages from @code{elpa.gnu.org} are signed with one of the keys
8770 contained in the GnuPG keyring at
8771 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8772 @code{emacs} package (@pxref{Package Installation, ELPA package
8773 signatures,, emacs, The GNU Emacs Manual}).
8776 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8777 @code{melpa-stable} identifier.
8780 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8786 Traverse the dependency graph of the given upstream package recursively
8787 and generate package expressions for all those packages that are not yet
8793 Import metadata from the crates.io Rust package repository
8794 @uref{https://crates.io, crates.io}.
8799 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8800 repository used by the OCaml community.
8803 The structure of the @command{guix import} code is modular. It would be
8804 useful to have more importers for other package formats, and your help
8805 is welcome here (@pxref{Contributing}).
8807 @node Invoking guix refresh
8808 @section Invoking @command{guix refresh}
8810 @cindex @command {guix refresh}
8811 The primary audience of the @command{guix refresh} command is developers
8812 of the GNU software distribution. By default, it reports any packages
8813 provided by the distribution that are outdated compared to the latest
8814 upstream version, like this:
8818 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8819 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8822 Alternately, one can specify packages to consider, in which case a
8823 warning is emitted for packages that lack an updater:
8826 $ guix refresh coreutils guile guile-ssh
8827 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8828 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8831 @command{guix refresh} browses the upstream repository of each package and determines
8832 the highest version number of the releases therein. The command
8833 knows how to update specific types of packages: GNU packages, ELPA
8834 packages, etc.---see the documentation for @option{--type} below. There
8835 are many packages, though, for which it lacks a method to determine
8836 whether a new upstream release is available. However, the mechanism is
8837 extensible, so feel free to get in touch with us to add a new method!
8842 Consider the packages specified, and all the packages upon which they depend.
8845 $ guix refresh --recursive coreutils
8846 gnu/packages/acl.scm:35:2: warning: no updater for acl
8847 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8848 gnu/packages/xml.scm:68:2: warning: no updater for expat
8849 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8855 Sometimes the upstream name differs from the package name used in Guix,
8856 and @command{guix refresh} needs a little help. Most updaters honor the
8857 @code{upstream-name} property in package definitions, which can be used
8861 (define-public network-manager
8863 (name "network-manager")
8865 (properties '((upstream-name . "NetworkManager")))))
8868 When passed @code{--update}, it modifies distribution source files to
8869 update the version numbers and source tarball hashes of those package
8870 recipes (@pxref{Defining Packages}). This is achieved by downloading
8871 each package's latest source tarball and its associated OpenPGP
8872 signature, authenticating the downloaded tarball against its signature
8873 using @command{gpg}, and finally computing its hash. When the public
8874 key used to sign the tarball is missing from the user's keyring, an
8875 attempt is made to automatically retrieve it from a public key server;
8876 when this is successful, the key is added to the user's keyring; otherwise,
8877 @command{guix refresh} reports an error.
8879 The following options are supported:
8883 @item --expression=@var{expr}
8884 @itemx -e @var{expr}
8885 Consider the package @var{expr} evaluates to.
8887 This is useful to precisely refer to a package, as in this example:
8890 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8893 This command lists the dependents of the ``final'' libc (essentially all
8898 Update distribution source files (package recipes) in place. This is
8899 usually run from a checkout of the Guix source tree (@pxref{Running
8900 Guix Before It Is Installed}):
8903 $ ./pre-inst-env guix refresh -s non-core -u
8906 @xref{Defining Packages}, for more information on package definitions.
8908 @item --select=[@var{subset}]
8909 @itemx -s @var{subset}
8910 Select all the packages in @var{subset}, one of @code{core} or
8913 The @code{core} subset refers to all the packages at the core of the
8914 distribution---i.e., packages that are used to build ``everything
8915 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8916 changing one of these packages in the distribution entails a rebuild of
8917 all the others. Thus, such updates are an inconvenience to users in
8918 terms of build time or bandwidth used to achieve the upgrade.
8920 The @code{non-core} subset refers to the remaining packages. It is
8921 typically useful in cases where an update of the core packages would be
8924 @item --manifest=@var{file}
8925 @itemx -m @var{file}
8926 Select all the packages from the manifest in @var{file}. This is useful to
8927 check if any packages of the user manifest can be updated.
8929 @item --type=@var{updater}
8930 @itemx -t @var{updater}
8931 Select only packages handled by @var{updater} (may be a comma-separated
8932 list of updaters). Currently, @var{updater} may be one of:
8936 the updater for GNU packages;
8938 the updater for GNOME packages;
8940 the updater for KDE packages;
8942 the updater for X.org packages;
8944 the updater for packages hosted on kernel.org;
8946 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
8948 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8950 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8952 the updater for @uref{https://www.cpan.org/, CPAN} packages;
8954 the updater for @uref{https://pypi.python.org, PyPI} packages.
8956 the updater for @uref{https://rubygems.org, RubyGems} packages.
8958 the updater for @uref{https://github.com, GitHub} packages.
8960 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8962 the updater for @uref{https://www.stackage.org, Stackage} packages.
8964 the updater for @uref{https://crates.io, Crates} packages.
8966 the updater for @uref{https://launchpad.net, Launchpad} packages.
8969 For instance, the following command only checks for updates of Emacs
8970 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8973 $ guix refresh --type=elpa,cran
8974 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8975 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8980 In addition, @command{guix refresh} can be passed one or more package
8981 names, as in this example:
8984 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8988 The command above specifically updates the @code{emacs} and
8989 @code{idutils} packages. The @code{--select} option would have no
8990 effect in this case.
8992 When considering whether to upgrade a package, it is sometimes
8993 convenient to know which packages would be affected by the upgrade and
8994 should be checked for compatibility. For this the following option may
8995 be used when passing @command{guix refresh} one or more package names:
8999 @item --list-updaters
9001 List available updaters and exit (see @option{--type} above.)
9003 For each updater, display the fraction of packages it covers; at the
9004 end, display the fraction of packages covered by all these updaters.
9006 @item --list-dependent
9008 List top-level dependent packages that would need to be rebuilt as a
9009 result of upgrading one or more packages.
9011 @xref{Invoking guix graph, the @code{reverse-package} type of
9012 @command{guix graph}}, for information on how to visualize the list of
9013 dependents of a package.
9017 Be aware that the @code{--list-dependent} option only
9018 @emph{approximates} the rebuilds that would be required as a result of
9019 an upgrade. More rebuilds might be required under some circumstances.
9022 $ guix refresh --list-dependent flex
9023 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9024 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9027 The command above lists a set of packages that could be built to check
9028 for compatibility with an upgraded @code{flex} package.
9032 @item --list-transitive
9033 List all the packages which one or more packages depend upon.
9036 $ guix refresh --list-transitive flex
9037 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9038 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{}
9043 The command above lists a set of packages which, when changed, would cause
9044 @code{flex} to be rebuilt.
9046 The following options can be used to customize GnuPG operation:
9050 @item --gpg=@var{command}
9051 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9052 for in @code{$PATH}.
9054 @item --keyring=@var{file}
9055 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9056 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9057 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9058 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9059 information on a tool to manipulate keybox files).
9061 When this option is omitted, @command{guix refresh} uses
9062 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9063 signing keys. OpenPGP signatures are checked against keys from this keyring;
9064 missing keys are downloaded to this keyring as well (see
9065 @option{--key-download} below.)
9067 You can export keys from your default GPG keyring into a keybox file using
9068 commands like this one:
9071 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9074 Likewise, you can fetch keys to a specific keybox file like this:
9077 gpg --no-default-keyring --keyring mykeyring.kbx \
9078 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9081 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9082 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9084 @item --key-download=@var{policy}
9085 Handle missing OpenPGP keys according to @var{policy}, which may be one
9090 Always download missing OpenPGP keys from the key server, and add them
9091 to the user's GnuPG keyring.
9094 Never try to download missing OpenPGP keys. Instead just bail out.
9097 When a package signed with an unknown OpenPGP key is encountered, ask
9098 the user whether to download it or not. This is the default behavior.
9101 @item --key-server=@var{host}
9102 Use @var{host} as the OpenPGP key server when importing a public key.
9106 The @code{github} updater uses the
9107 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9108 releases. When used repeatedly e.g.@: when refreshing all packages,
9109 GitHub will eventually refuse to answer any further API requests. By
9110 default 60 API requests per hour are allowed, and a full refresh on all
9111 GitHub packages in Guix requires more than this. Authentication with
9112 GitHub through the use of an API token alleviates these limits. To use
9113 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9114 token procured from @uref{https://github.com/settings/tokens} or
9118 @node Invoking guix lint
9119 @section Invoking @command{guix lint}
9121 @cindex @command{guix lint}
9122 @cindex package, checking for errors
9123 The @command{guix lint} command is meant to help package developers avoid
9124 common errors and use a consistent style. It runs a number of checks on
9125 a given set of packages in order to find common mistakes in their
9126 definitions. Available @dfn{checkers} include (see
9127 @code{--list-checkers} for a complete list):
9132 Validate certain typographical and stylistic rules about package
9133 descriptions and synopses.
9135 @item inputs-should-be-native
9136 Identify inputs that should most likely be native inputs.
9142 @itemx source-file-name
9143 Probe @code{home-page} and @code{source} URLs and report those that are
9144 invalid. Suggest a @code{mirror://} URL when applicable. If the
9145 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9146 URL. Check that the source file name is meaningful, e.g.@: is not just a
9147 version number or ``git-checkout'', without a declared @code{file-name}
9148 (@pxref{origin Reference}).
9150 @item source-unstable-tarball
9151 Parse the @code{source} URL to determine if a tarball from GitHub is
9152 autogenerated or if it is a release tarball. Unfortunately GitHub's
9153 autogenerated tarballs are sometimes regenerated.
9156 @cindex security vulnerabilities
9157 @cindex CVE, Common Vulnerabilities and Exposures
9158 Report known vulnerabilities found in the Common Vulnerabilities and
9159 Exposures (CVE) databases of the current and past year
9160 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9163 To view information about a particular vulnerability, visit pages such as:
9167 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9169 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9173 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9174 @code{CVE-2015-7554}.
9176 Package developers can specify in package recipes the
9177 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9178 name and version of the package when they differ from the name or version
9179 that Guix uses, as in this example:
9185 ;; CPE calls this package "grub2".
9186 (properties '((cpe-name . "grub2")
9187 (cpe-version . "2.3")))
9190 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9191 Some entries in the CVE database do not specify which version of a
9192 package they apply to, and would thus ``stick around'' forever. Package
9193 developers who found CVE alerts and verified they can be ignored can
9194 declare them as in this example:
9200 ;; These CVEs no longer apply and can be safely ignored.
9201 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9204 "CVE-2011-5244")))))
9208 Warn about obvious source code formatting issues: trailing white space,
9209 use of tabulations, etc.
9212 The general syntax is:
9215 guix lint @var{options} @var{package}@dots{}
9218 If no package is given on the command line, then all packages are checked.
9219 The @var{options} may be zero or more of the following:
9222 @item --list-checkers
9224 List and describe all the available checkers that will be run on packages
9229 Only enable the checkers specified in a comma-separated list using the
9230 names returned by @code{--list-checkers}.
9234 @node Invoking guix size
9235 @section Invoking @command{guix size}
9238 @cindex package size
9240 @cindex @command{guix size}
9241 The @command{guix size} command helps package developers profile the
9242 disk usage of packages. It is easy to overlook the impact of an
9243 additional dependency added to a package, or the impact of using a
9244 single output for a package that could easily be split (@pxref{Packages
9245 with Multiple Outputs}). Such are the typical issues that
9246 @command{guix size} can highlight.
9248 The command can be passed one or more package specifications
9249 such as @code{gcc@@4.8}
9250 or @code{guile:debug}, or a file name in the store. Consider this
9254 $ guix size coreutils
9255 store item total self
9256 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9257 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9258 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9259 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9260 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9261 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9262 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9263 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9268 The store items listed here constitute the @dfn{transitive closure} of
9269 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9270 would be returned by:
9273 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9276 Here the output shows three columns next to store items. The first column,
9277 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9278 the store item---that is, its own size plus the size of all its
9279 dependencies. The next column, labeled ``self'', shows the size of the
9280 item itself. The last column shows the ratio of the size of the item
9281 itself to the space occupied by all the items listed here.
9283 In this example, we see that the closure of Coreutils weighs in at
9284 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9285 libraries. (That libc and GCC's libraries represent a large fraction of
9286 the closure is not a problem @i{per se} because they are always available
9287 on the system anyway.)
9289 When the package(s) passed to @command{guix size} are available in the
9290 store@footnote{More precisely, @command{guix size} looks for the
9291 @emph{ungrafted} variant of the given package(s), as returned by
9292 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9293 for information on grafts.}, @command{guix size} queries the daemon to determine its
9294 dependencies, and measures its size in the store, similar to @command{du
9295 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9298 When the given packages are @emph{not} in the store, @command{guix size}
9299 reports information based on the available substitutes
9300 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9301 store items that are not even on disk, only available remotely.
9303 You can also specify several package names:
9306 $ guix size coreutils grep sed bash
9307 store item total self
9308 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9309 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9310 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9311 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9317 In this example we see that the combination of the four packages takes
9318 102.3@tie{}MiB in total, which is much less than the sum of each closure
9319 since they have a lot of dependencies in common.
9321 The available options are:
9325 @item --substitute-urls=@var{urls}
9326 Use substitute information from @var{urls}.
9327 @xref{client-substitute-urls, the same option for @code{guix build}}.
9329 @item --sort=@var{key}
9330 Sort lines according to @var{key}, one of the following options:
9334 the size of each item (the default);
9336 the total size of the item's closure.
9339 @item --map-file=@var{file}
9340 Write a graphical map of disk usage in PNG format to @var{file}.
9342 For the example above, the map looks like this:
9344 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9345 produced by @command{guix size}}
9347 This option requires that
9348 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9349 installed and visible in Guile's module search path. When that is not
9350 the case, @command{guix size} fails as it tries to load it.
9352 @item --system=@var{system}
9353 @itemx -s @var{system}
9354 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9358 @node Invoking guix graph
9359 @section Invoking @command{guix graph}
9362 @cindex @command{guix graph}
9363 @cindex package dependencies
9364 Packages and their dependencies form a @dfn{graph}, specifically a
9365 directed acyclic graph (DAG). It can quickly become difficult to have a
9366 mental model of the package DAG, so the @command{guix graph} command
9367 provides a visual representation of the DAG. By default,
9368 @command{guix graph} emits a DAG representation in the input format of
9369 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9370 directly to the @command{dot} command of Graphviz. It can also emit an
9371 HTML page with embedded JavaScript code to display a ``chord diagram''
9372 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9373 emit Cypher queries to construct a graph in a graph database supporting
9374 the @uref{https://www.opencypher.org/, openCypher} query language.
9375 The general syntax is:
9378 guix graph @var{options} @var{package}@dots{}
9381 For example, the following command generates a PDF file representing the
9382 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9386 guix graph coreutils | dot -Tpdf > dag.pdf
9389 The output looks like this:
9391 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9393 Nice little graph, no?
9395 But there is more than one graph! The one above is concise: it is the
9396 graph of package objects, omitting implicit inputs such as GCC, libc,
9397 grep, etc. It is often useful to have such a concise graph, but
9398 sometimes one may want to see more details. @command{guix graph} supports
9399 several types of graphs, allowing you to choose the level of detail:
9403 This is the default type used in the example above. It shows the DAG of
9404 package objects, excluding implicit dependencies. It is concise, but
9405 filters out many details.
9407 @item reverse-package
9408 This shows the @emph{reverse} DAG of packages. For example:
9411 guix graph --type=reverse-package ocaml
9414 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9415 you are also interested in cases where OCaml is an implicit dependency, see
9416 @code{reverse-bag} below.)
9418 Note that for core packages this can yield huge graphs. If all you want
9419 is to know the number of packages that depend on a given package, use
9420 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9421 @option{--list-dependent}}).
9424 This is the package DAG, @emph{including} implicit inputs.
9426 For instance, the following command:
9429 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9432 ...@: yields this bigger graph:
9434 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9436 At the bottom of the graph, we see all the implicit inputs of
9437 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9439 Now, note that the dependencies of these implicit inputs---that is, the
9440 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9441 here, for conciseness.
9444 Similar to @code{bag-emerged}, but this time including all the bootstrap
9447 @item bag-with-origins
9448 Similar to @code{bag}, but also showing origins and their dependencies.
9451 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9452 it also takes implicit dependencies into account. For example:
9455 guix graph -t reverse-bag dune
9459 ...@: yields the graph of all packages that depend on Dune, directly or
9460 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9461 @i{via} @code{dune-build-system}, this shows a large number of packages,
9462 whereas @code{reverse-package} would show very few if any.
9465 This is the most detailed representation: It shows the DAG of
9466 derivations (@pxref{Derivations}) and plain store items. Compared to
9467 the above representation, many additional nodes are visible, including
9468 build scripts, patches, Guile modules, etc.
9470 For this type of graph, it is also possible to pass a @file{.drv} file
9471 name instead of a package name, as in:
9474 guix graph -t derivation `guix system build -d my-config.scm`
9478 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9479 For example, the following command shows the graph for the package
9480 module that defines the @code{guile} package:
9483 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9487 All the types above correspond to @emph{build-time dependencies}. The
9488 following graph type represents the @emph{run-time dependencies}:
9492 This is the graph of @dfn{references} of a package output, as returned
9493 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9495 If the given package output is not available in the store, @command{guix
9496 graph} attempts to obtain dependency information from substitutes.
9498 Here you can also pass a store file name instead of a package name. For
9499 example, the command below produces the reference graph of your profile
9500 (which can be big!):
9503 guix graph -t references `readlink -f ~/.guix-profile`
9507 This is the graph of the @dfn{referrers} of a store item, as returned by
9508 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9510 This relies exclusively on local information from your store. For
9511 instance, let us suppose that the current Inkscape is available in 10
9512 profiles on your machine; @command{guix graph -t referrers inkscape}
9513 will show a graph rooted at Inkscape and with those 10 profiles linked
9516 It can help determine what is preventing a store item from being garbage
9521 The available options are the following:
9524 @item --type=@var{type}
9525 @itemx -t @var{type}
9526 Produce a graph output of @var{type}, where @var{type} must be one of
9527 the values listed above.
9530 List the supported graph types.
9532 @item --backend=@var{backend}
9533 @itemx -b @var{backend}
9534 Produce a graph using the selected @var{backend}.
9536 @item --list-backends
9537 List the supported graph backends.
9539 Currently, the available backends are Graphviz and d3.js.
9541 @item --expression=@var{expr}
9542 @itemx -e @var{expr}
9543 Consider the package @var{expr} evaluates to.
9545 This is useful to precisely refer to a package, as in this example:
9548 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9551 @item --system=@var{system}
9552 @itemx -s @var{system}
9553 Display the graph for @var{system}---e.g., @code{i686-linux}.
9555 The package dependency graph is largely architecture-independent, but there
9556 are some architecture-dependent bits that this option allows you to visualize.
9561 @node Invoking guix publish
9562 @section Invoking @command{guix publish}
9564 @cindex @command{guix publish}
9565 The purpose of @command{guix publish} is to enable users to easily share
9566 their store with others, who can then use it as a substitute server
9567 (@pxref{Substitutes}).
9569 When @command{guix publish} runs, it spawns an HTTP server which allows
9570 anyone with network access to obtain substitutes from it. This means
9571 that any machine running Guix can also act as if it were a build farm,
9572 since the HTTP interface is compatible with Hydra, the software behind
9573 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9575 For security, each substitute is signed, allowing recipients to check
9576 their authenticity and integrity (@pxref{Substitutes}). Because
9577 @command{guix publish} uses the signing key of the system, which is only
9578 readable by the system administrator, it must be started as root; the
9579 @code{--user} option makes it drop root privileges early on.
9581 The signing key pair must be generated before @command{guix publish} is
9582 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9585 The general syntax is:
9588 guix publish @var{options}@dots{}
9591 Running @command{guix publish} without any additional arguments will
9592 spawn an HTTP server on port 8080:
9598 Once a publishing server has been authorized (@pxref{Invoking guix
9599 archive}), the daemon may download substitutes from it:
9602 guix-daemon --substitute-urls=http://example.org:8080
9605 By default, @command{guix publish} compresses archives on the fly as it
9606 serves them. This ``on-the-fly'' mode is convenient in that it requires
9607 no setup and is immediately available. However, when serving lots of
9608 clients, we recommend using the @option{--cache} option, which enables
9609 caching of the archives before they are sent to clients---see below for
9610 details. The @command{guix weather} command provides a handy way to
9611 check what a server provides (@pxref{Invoking guix weather}).
9613 As a bonus, @command{guix publish} also serves as a content-addressed
9614 mirror for source files referenced in @code{origin} records
9615 (@pxref{origin Reference}). For instance, assuming @command{guix
9616 publish} is running on @code{example.org}, the following URL returns the
9617 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9618 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9621 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9624 Obviously, these URLs only work for files that are in the store; in
9625 other cases, they return 404 (``Not Found'').
9627 @cindex build logs, publication
9628 Build logs are available from @code{/log} URLs like:
9631 http://example.org/log/gwspk@dots{}-guile-2.2.3
9635 When @command{guix-daemon} is configured to save compressed build logs,
9636 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9637 URLs return the compressed log as-is, with an appropriate
9638 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9639 running @command{guix-daemon} with @code{--log-compression=gzip} since
9640 Web browsers can automatically decompress it, which is not the case with
9643 The following options are available:
9646 @item --port=@var{port}
9647 @itemx -p @var{port}
9648 Listen for HTTP requests on @var{port}.
9650 @item --listen=@var{host}
9651 Listen on the network interface for @var{host}. The default is to
9652 accept connections from any interface.
9654 @item --user=@var{user}
9655 @itemx -u @var{user}
9656 Change privileges to @var{user} as soon as possible---i.e., once the
9657 server socket is open and the signing key has been read.
9659 @item --compression[=@var{level}]
9660 @itemx -C [@var{level}]
9661 Compress data using the given @var{level}. When @var{level} is zero,
9662 disable compression. The range 1 to 9 corresponds to different gzip
9663 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9666 Unless @option{--cache} is used, compression occurs on the fly and
9667 the compressed streams are not
9668 cached. Thus, to reduce load on the machine that runs @command{guix
9669 publish}, it may be a good idea to choose a low compression level, to
9670 run @command{guix publish} behind a caching proxy, or to use
9671 @option{--cache}. Using @option{--cache} has the advantage that it
9672 allows @command{guix publish} to add @code{Content-Length} HTTP header
9675 @item --cache=@var{directory}
9676 @itemx -c @var{directory}
9677 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9678 and only serve archives that are in cache.
9680 When this option is omitted, archives and meta-data are created
9681 on-the-fly. This can reduce the available bandwidth, especially when
9682 compression is enabled, since this may become CPU-bound. Another
9683 drawback of the default mode is that the length of archives is not known
9684 in advance, so @command{guix publish} does not add a
9685 @code{Content-Length} HTTP header to its responses, which in turn
9686 prevents clients from knowing the amount of data being downloaded.
9688 Conversely, when @option{--cache} is used, the first request for a store
9689 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9690 background process to @dfn{bake} the archive---computing its
9691 @code{.narinfo} and compressing the archive, if needed. Once the
9692 archive is cached in @var{directory}, subsequent requests succeed and
9693 are served directly from the cache, which guarantees that clients get
9694 the best possible bandwidth.
9696 The ``baking'' process is performed by worker threads. By default, one
9697 thread per CPU core is created, but this can be customized. See
9698 @option{--workers} below.
9700 When @option{--ttl} is used, cached entries are automatically deleted
9701 when they have expired.
9703 @item --workers=@var{N}
9704 When @option{--cache} is used, request the allocation of @var{N} worker
9705 threads to ``bake'' archives.
9707 @item --ttl=@var{ttl}
9708 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9709 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9710 days, @code{1m} means 1 month, and so on.
9712 This allows the user's Guix to keep substitute information in cache for
9713 @var{ttl}. However, note that @code{guix publish} does not itself
9714 guarantee that the store items it provides will indeed remain available
9715 for as long as @var{ttl}.
9717 Additionally, when @option{--cache} is used, cached entries that have
9718 not been accessed for @var{ttl} and that no longer have a corresponding
9719 item in the store, may be deleted.
9721 @item --nar-path=@var{path}
9722 Use @var{path} as the prefix for the URLs of ``nar'' files
9723 (@pxref{Invoking guix archive, normalized archives}).
9725 By default, nars are served at a URL such as
9726 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9727 change the @code{/nar} part to @var{path}.
9729 @item --public-key=@var{file}
9730 @itemx --private-key=@var{file}
9731 Use the specific @var{file}s as the public/private key pair used to sign
9732 the store items being published.
9734 The files must correspond to the same key pair (the private key is used
9735 for signing and the public key is merely advertised in the signature
9736 metadata). They must contain keys in the canonical s-expression format
9737 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9738 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9739 @file{/etc/guix/signing-key.sec} are used.
9741 @item --repl[=@var{port}]
9742 @itemx -r [@var{port}]
9743 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9744 Reference Manual}) on @var{port} (37146 by default). This is used
9745 primarily for debugging a running @command{guix publish} server.
9748 Enabling @command{guix publish} on Guix System is a one-liner: just
9749 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9750 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9751 @code{guix-publish-service-type}}).
9753 If you are instead running Guix on a ``foreign distro'', follow these
9758 If your host distro uses the systemd init system:
9761 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9762 /etc/systemd/system/
9763 # systemctl start guix-publish && systemctl enable guix-publish
9767 If your host distro uses the Upstart init system:
9770 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9771 # start guix-publish
9775 Otherwise, proceed similarly with your distro's init system.
9778 @node Invoking guix challenge
9779 @section Invoking @command{guix challenge}
9781 @cindex reproducible builds
9782 @cindex verifiable builds
9783 @cindex @command{guix challenge}
9785 Do the binaries provided by this server really correspond to the source
9786 code it claims to build? Is a package build process deterministic?
9787 These are the questions the @command{guix challenge} command attempts to
9790 The former is obviously an important question: Before using a substitute
9791 server (@pxref{Substitutes}), one had better @emph{verify} that it
9792 provides the right binaries, and thus @emph{challenge} it. The latter
9793 is what enables the former: If package builds are deterministic, then
9794 independent builds of the package should yield the exact same result,
9795 bit for bit; if a server provides a binary different from the one
9796 obtained locally, it may be either corrupt or malicious.
9798 We know that the hash that shows up in @file{/gnu/store} file names is
9799 the hash of all the inputs of the process that built the file or
9800 directory---compilers, libraries, build scripts,
9801 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9802 one store file name should map to exactly one build output.
9803 @command{guix challenge} checks whether there is, indeed, a single
9804 mapping by comparing the build outputs of several independent builds of
9805 any given store item.
9807 The command output looks like this:
9810 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9811 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9812 updating list of substitutes from 'https://guix.example.org'... 100.0%
9813 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9814 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9815 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9816 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9817 /gnu/store/@dots{}-git-2.5.0 contents differ:
9818 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9819 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9820 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9821 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9822 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9823 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9824 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9828 6,406 store items were analyzed:
9829 - 4,749 (74.1%) were identical
9830 - 525 (8.2%) differed
9831 - 1,132 (17.7%) were inconclusive
9835 In this example, @command{guix challenge} first scans the store to
9836 determine the set of locally-built derivations---as opposed to store
9837 items that were downloaded from a substitute server---and then queries
9838 all the substitute servers. It then reports those store items for which
9839 the servers obtained a result different from the local build.
9841 @cindex non-determinism, in package builds
9842 As an example, @code{guix.example.org} always gets a different answer.
9843 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9844 case of Git. This might indicate that the build process of Git is
9845 non-deterministic, meaning that its output varies as a function of
9846 various things that Guix does not fully control, in spite of building
9847 packages in isolated environments (@pxref{Features}). Most common
9848 sources of non-determinism include the addition of timestamps in build
9849 results, the inclusion of random numbers, and directory listings sorted
9850 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9853 To find out what is wrong with this Git binary, we can do something along
9854 these lines (@pxref{Invoking guix archive}):
9857 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9858 | guix archive -x /tmp/git
9859 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9862 This command shows the difference between the files resulting from the
9863 local build, and the files resulting from the build on
9864 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9865 diffutils, Comparing and Merging Files}). The @command{diff} command
9866 works great for text files. When binary files differ, a better option
9867 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9868 visualize differences for all kinds of files.
9870 Once you have done that work, you can tell whether the differences are due
9871 to a non-deterministic build process or to a malicious server. We try
9872 hard to remove sources of non-determinism in packages to make it easier
9873 to verify substitutes, but of course, this is a process that
9874 involves not just Guix, but a large part of the free software community.
9875 In the meantime, @command{guix challenge} is one tool to help address
9878 If you are writing packages for Guix, you are encouraged to check
9879 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9880 same build result as you did with:
9883 $ guix challenge @var{package}
9887 where @var{package} is a package specification such as
9888 @code{guile@@2.0} or @code{glibc:debug}.
9890 The general syntax is:
9893 guix challenge @var{options} [@var{packages}@dots{}]
9896 When a difference is found between the hash of a locally-built item and
9897 that of a server-provided substitute, or among substitutes provided by
9898 different servers, the command displays it as in the example above and
9899 its exit code is 2 (other non-zero exit codes denote other kinds of
9902 The one option that matters is:
9906 @item --substitute-urls=@var{urls}
9907 Consider @var{urls} the whitespace-separated list of substitute source
9912 Show details about matches (identical contents) in addition to
9913 information about mismatches.
9917 @node Invoking guix copy
9918 @section Invoking @command{guix copy}
9920 @cindex copy, of store items, over SSH
9921 @cindex SSH, copy of store items
9922 @cindex sharing store items across machines
9923 @cindex transferring store items across machines
9924 The @command{guix copy} command copies items from the store of one
9925 machine to that of another machine over a secure shell (SSH)
9926 connection@footnote{This command is available only when Guile-SSH was
9927 found. @xref{Requirements}, for details.}. For example, the following
9928 command copies the @code{coreutils} package, the user's profile, and all
9929 their dependencies over to @var{host}, logged in as @var{user}:
9932 guix copy --to=@var{user}@@@var{host} \
9933 coreutils `readlink -f ~/.guix-profile`
9936 If some of the items to be copied are already present on @var{host},
9937 they are not actually sent.
9939 The command below retrieves @code{libreoffice} and @code{gimp} from
9940 @var{host}, assuming they are available there:
9943 guix copy --from=@var{host} libreoffice gimp
9946 The SSH connection is established using the Guile-SSH client, which is
9947 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9948 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9950 The key used to sign items that are sent must be accepted by the remote
9951 machine. Likewise, the key used by the remote machine to sign items you
9952 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9953 own daemon. @xref{Invoking guix archive}, for more information about
9954 store item authentication.
9956 The general syntax is:
9959 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9962 You must always specify one of the following options:
9965 @item --to=@var{spec}
9966 @itemx --from=@var{spec}
9967 Specify the host to send to or receive from. @var{spec} must be an SSH
9968 spec such as @code{example.org}, @code{charlie@@example.org}, or
9969 @code{charlie@@example.org:2222}.
9972 The @var{items} can be either package names, such as @code{gimp}, or
9973 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9975 When specifying the name of a package to send, it is first built if
9976 needed, unless @option{--dry-run} was specified. Common build options
9977 are supported (@pxref{Common Build Options}).
9980 @node Invoking guix container
9981 @section Invoking @command{guix container}
9983 @cindex @command{guix container}
9985 As of version @value{VERSION}, this tool is experimental. The interface
9986 is subject to radical change in the future.
9989 The purpose of @command{guix container} is to manipulate processes
9990 running within an isolated environment, commonly known as a
9991 ``container'', typically created by the @command{guix environment}
9992 (@pxref{Invoking guix environment}) and @command{guix system container}
9993 (@pxref{Invoking guix system}) commands.
9995 The general syntax is:
9998 guix container @var{action} @var{options}@dots{}
10001 @var{action} specifies the operation to perform with a container, and
10002 @var{options} specifies the context-specific arguments for the action.
10004 The following actions are available:
10008 Execute a command within the context of a running container.
10013 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10016 @var{pid} specifies the process ID of the running container.
10017 @var{program} specifies an executable file name within the root file
10018 system of the container. @var{arguments} are the additional options that
10019 will be passed to @var{program}.
10021 The following command launches an interactive login shell inside a
10022 Guix system container, started by @command{guix system container}, and whose
10023 process ID is 9001:
10026 guix container exec 9001 /run/current-system/profile/bin/bash --login
10029 Note that the @var{pid} cannot be the parent process of a container. It
10030 must be PID 1 of the container or one of its child processes.
10034 @node Invoking guix weather
10035 @section Invoking @command{guix weather}
10037 Occasionally you're grumpy because substitutes are lacking and you end
10038 up building packages by yourself (@pxref{Substitutes}). The
10039 @command{guix weather} command reports on substitute availability on the
10040 specified servers so you can have an idea of whether you'll be grumpy
10041 today. It can sometimes be useful info as a user, but it is primarily
10042 useful to people running @command{guix publish} (@pxref{Invoking guix
10045 @cindex statistics, for substitutes
10046 @cindex availability of substitutes
10047 @cindex substitute availability
10048 @cindex weather, substitute availability
10049 Here's a sample run:
10052 $ guix weather --substitute-urls=https://guix.example.org
10053 computing 5,872 package derivations for x86_64-linux...
10054 looking for 6,128 store items on https://guix.example.org..
10055 updating list of substitutes from 'https://guix.example.org'... 100.0%
10056 https://guix.example.org
10057 43.4% substitutes available (2,658 out of 6,128)
10058 7,032.5 MiB of nars (compressed)
10059 19,824.2 MiB on disk (uncompressed)
10060 0.030 seconds per request (182.9 seconds in total)
10061 33.5 requests per second
10063 9.8% (342 out of 3,470) of the missing items are queued
10065 x86_64-linux: 518 (59.7%)
10066 i686-linux: 221 (25.5%)
10067 aarch64-linux: 128 (14.8%)
10068 build rate: 23.41 builds per hour
10069 x86_64-linux: 11.16 builds per hour
10070 i686-linux: 6.03 builds per hour
10071 aarch64-linux: 6.41 builds per hour
10074 @cindex continuous integration, statistics
10075 As you can see, it reports the fraction of all the packages for which
10076 substitutes are available on the server---regardless of whether
10077 substitutes are enabled, and regardless of whether this server's signing
10078 key is authorized. It also reports the size of the compressed archives
10079 (``nars'') provided by the server, the size the corresponding store
10080 items occupy in the store (assuming deduplication is turned off), and
10081 the server's throughput. The second part gives continuous integration
10082 (CI) statistics, if the server supports it. In addition, using the
10083 @option{--coverage} option, @command{guix weather} can list ``important''
10084 package substitutes missing on the server (see below).
10086 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10087 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10088 challenge}, it ignores signatures on those substitutes, which is
10089 innocuous since the command only gathers statistics and cannot install
10092 The general syntax is:
10095 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10098 When @var{packages} is omitted, @command{guix weather} checks the availability
10099 of substitutes for @emph{all} the packages, or for those specified with
10100 @option{--manifest}; otherwise it only considers the specified packages. It
10101 is also possible to query specific system types with @option{--system}. The
10102 available options are listed below.
10105 @item --substitute-urls=@var{urls}
10106 @var{urls} is the space-separated list of substitute server URLs to
10107 query. When this option is omitted, the default set of substitute
10108 servers is queried.
10110 @item --system=@var{system}
10111 @itemx -s @var{system}
10112 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10113 option can be repeated, in which case @command{guix weather} will query
10114 substitutes for several system types.
10116 @item --manifest=@var{file}
10117 Instead of querying substitutes for all the packages, only ask for those
10118 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10119 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10122 @item --coverage[=@var{count}]
10123 @itemx -c [@var{count}]
10124 Report on substitute coverage for packages: list packages with at least
10125 @var{count} dependents (zero by default) for which substitutes are
10126 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10127 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10128 @var{b} usually lacks substitutes as well. The result looks like this:
10131 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10132 computing 8,983 package derivations for x86_64-linux...
10133 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10134 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10135 @value{SUBSTITUTE-URL}
10136 64.7% substitutes available (6,047 out of 9,343)
10138 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10139 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10140 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10141 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10145 What this example shows is that @code{kcoreaddons} and presumably the 58
10146 packages that depend on it have no substitutes at @code{ci.guix.info};
10147 likewise for @code{qgpgme} and the 46 packages that depend on it.
10149 If you are a Guix developer, or if you are taking care of this build farm,
10150 you'll probably want to have a closer look at these packages: they may simply
10154 @node Invoking guix processes
10155 @section Invoking @command{guix processes}
10157 The @command{guix processes} command can be useful to developers and system
10158 administrators, especially on multi-user machines and on build farms: it lists
10159 the current sessions (connections to the daemon), as well as information about
10160 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10161 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10162 listed.}. Here's an example of the information it returns:
10165 $ sudo guix processes
10168 ClientCommand: guix environment --ad-hoc python
10172 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10176 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10177 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10178 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10179 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10180 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10181 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10182 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10185 In this example we see that @command{guix-daemon} has three clients:
10186 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10187 integration tool; their process identifier (PID) is given by the
10188 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10189 @command{guix-daemon} sub-process of this particular session.
10191 The @code{LockHeld} fields show which store items are currently locked by this
10192 session, which corresponds to store items being built or substituted (the
10193 @code{LockHeld} field is not displayed when @command{guix processes} is not
10194 running as root.) Last, by looking at the @code{ChildProcess} field, we
10195 understand that these three builds are being offloaded (@pxref{Daemon Offload
10198 The output is in Recutils format so we can use the handy @command{recsel}
10199 command to select sessions of interest (@pxref{Selection Expressions,,,
10200 recutils, GNU recutils manual}). As an example, the command shows the command
10201 line and PID of the client that triggered the build of a Perl package:
10204 $ sudo guix processes | \
10205 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10207 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10211 @node System Configuration
10212 @chapter System Configuration
10214 @cindex system configuration
10215 Guix System supports a consistent whole-system configuration
10216 mechanism. By that we mean that all aspects of the global system
10217 configuration---such as the available system services, timezone and
10218 locale settings, user accounts---are declared in a single place. Such
10219 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10221 One of the advantages of putting all the system configuration under the
10222 control of Guix is that it supports transactional system upgrades, and
10223 makes it possible to roll back to a previous system instantiation,
10224 should something go wrong with the new one (@pxref{Features}). Another
10225 advantage is that it makes it easy to replicate the exact same configuration
10226 across different machines, or at different points in time, without
10227 having to resort to additional administration tools layered on top of
10228 the own tools of the system.
10229 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10231 This section describes this mechanism. First we focus on the system
10232 administrator's viewpoint---explaining how the system is configured and
10233 instantiated. Then we show how this mechanism can be extended, for
10234 instance to support new system services.
10237 * Using the Configuration System:: Customizing your GNU system.
10238 * operating-system Reference:: Detail of operating-system declarations.
10239 * File Systems:: Configuring file system mounts.
10240 * Mapped Devices:: Block device extra processing.
10241 * User Accounts:: Specifying user accounts.
10242 * Keyboard Layout:: How the system interprets key strokes.
10243 * Locales:: Language and cultural convention settings.
10244 * Services:: Specifying system services.
10245 * Setuid Programs:: Programs running with root privileges.
10246 * X.509 Certificates:: Authenticating HTTPS servers.
10247 * Name Service Switch:: Configuring libc's name service switch.
10248 * Initial RAM Disk:: Linux-Libre bootstrapping.
10249 * Bootloader Configuration:: Configuring the boot loader.
10250 * Invoking guix system:: Instantiating a system configuration.
10251 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10252 * Defining Services:: Adding new service definitions.
10255 @node Using the Configuration System
10256 @section Using the Configuration System
10258 The operating system is configured by providing an
10259 @code{operating-system} declaration in a file that can then be passed to
10260 the @command{guix system} command (@pxref{Invoking guix system}). A
10261 simple setup, with the default system services, the default Linux-Libre
10262 kernel, initial RAM disk, and boot loader looks like this:
10264 @findex operating-system
10266 @include os-config-bare-bones.texi
10269 This example should be self-describing. Some of the fields defined
10270 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10271 Others, such as @code{packages} and @code{services}, can be omitted, in
10272 which case they get a default value.
10274 Below we discuss the effect of some of the most important fields
10275 (@pxref{operating-system Reference}, for details about all the available
10276 fields), and how to @dfn{instantiate} the operating system using
10277 @command{guix system}.
10279 @unnumberedsubsec Bootloader
10281 @cindex legacy boot, on Intel machines
10282 @cindex BIOS boot, on Intel machines
10285 The @code{bootloader} field describes the method that will be used to boot
10286 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10287 mode, as in the example above. However, more recent machines rely instead on
10288 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10289 the @code{bootloader} field should contain something along these lines:
10292 (bootloader-configuration
10293 (bootloader grub-efi-bootloader)
10294 (target "/boot/efi"))
10297 @xref{Bootloader Configuration}, for more information on the available
10298 configuration options.
10300 @unnumberedsubsec Globally-Visible Packages
10302 @vindex %base-packages
10303 The @code{packages} field lists packages that will be globally visible
10304 on the system, for all user accounts---i.e., in every user's @code{PATH}
10305 environment variable---in addition to the per-user profiles
10306 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10307 provides all the tools one would expect for basic user and administrator
10308 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10309 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10310 etc. The example above adds GNU@tie{}Screen to those,
10311 taken from the @code{(gnu packages screen)}
10312 module (@pxref{Package Modules}). The
10313 @code{(list package output)} syntax can be used to add a specific output
10317 (use-modules (gnu packages))
10318 (use-modules (gnu packages dns))
10322 (packages (cons (list bind "utils")
10326 @findex specification->package
10327 Referring to packages by variable name, like @code{bind} above, has
10328 the advantage of being unambiguous; it also allows typos and such to be
10329 diagnosed right away as ``unbound variables''. The downside is that one
10330 needs to know which module defines which package, and to augment the
10331 @code{use-package-modules} line accordingly. To avoid that, one can use
10332 the @code{specification->package} procedure of the @code{(gnu packages)}
10333 module, which returns the best package for a given name or name and
10337 (use-modules (gnu packages))
10341 (packages (append (map specification->package
10342 '("tcpdump" "htop" "gnupg@@2.0"))
10346 @unnumberedsubsec System Services
10349 @vindex %base-services
10350 The @code{services} field lists @dfn{system services} to be made
10351 available when the system starts (@pxref{Services}).
10352 The @code{operating-system} declaration above specifies that, in
10353 addition to the basic services, we want the OpenSSH secure shell
10354 daemon listening on port 2222 (@pxref{Networking Services,
10355 @code{openssh-service-type}}). Under the hood,
10356 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10357 right command-line options, possibly with supporting configuration files
10358 generated as needed (@pxref{Defining Services}).
10360 @cindex customization, of services
10361 @findex modify-services
10362 Occasionally, instead of using the base services as is, you will want to
10363 customize them. To do this, use @code{modify-services} (@pxref{Service
10364 Reference, @code{modify-services}}) to modify the list.
10366 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10367 (the console log-in) in the @var{%base-services} list (@pxref{Base
10368 Services, @code{%base-services}}). To do that, you can write the
10369 following in your operating system declaration:
10372 (define %my-services
10373 ;; My very own list of services.
10374 (modify-services %base-services
10375 (guix-service-type config =>
10376 (guix-configuration
10378 (use-substitutes? #f)
10379 (extra-options '("--gc-keep-derivations"))))
10380 (mingetty-service-type config =>
10381 (mingetty-configuration
10382 (inherit config)))))
10386 (services %my-services))
10389 This changes the configuration---i.e., the service parameters---of the
10390 @code{guix-service-type} instance, and that of all the
10391 @code{mingetty-service-type} instances in the @var{%base-services} list.
10392 Observe how this is accomplished: first, we arrange for the original
10393 configuration to be bound to the identifier @code{config} in the
10394 @var{body}, and then we write the @var{body} so that it evaluates to the
10395 desired configuration. In particular, notice how we use @code{inherit}
10396 to create a new configuration which has the same values as the old
10397 configuration, but with a few modifications.
10399 @cindex encrypted disk
10400 The configuration for a typical ``desktop'' usage, with an encrypted
10401 root partition, the X11 display
10402 server, GNOME and Xfce (users can choose which of these desktop
10403 environments to use at the log-in screen by pressing @kbd{F1}), network
10404 management, power management, and more, would look like this:
10407 @include os-config-desktop.texi
10410 A graphical system with a choice of lightweight window managers
10411 instead of full-blown desktop environments would look like this:
10414 @include os-config-lightweight-desktop.texi
10417 This example refers to the @file{/boot/efi} file system by its UUID,
10418 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10419 as returned by the @command{blkid} command.
10421 @xref{Desktop Services}, for the exact list of services provided by
10422 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10423 information about the @code{nss-certs} package that is used here.
10425 Again, @var{%desktop-services} is just a list of service objects. If
10426 you want to remove services from there, you can do so using the
10427 procedures for list filtering (@pxref{SRFI-1 Filtering and
10428 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10429 following expression returns a list that contains all the services in
10430 @var{%desktop-services} minus the Avahi service:
10433 (remove (lambda (service)
10434 (eq? (service-kind service) avahi-service-type))
10438 @unnumberedsubsec Instantiating the System
10440 Assuming the @code{operating-system} declaration
10441 is stored in the @file{my-system-config.scm}
10442 file, the @command{guix system reconfigure my-system-config.scm} command
10443 instantiates that configuration, and makes it the default GRUB boot
10444 entry (@pxref{Invoking guix system}).
10446 The normal way to change the system configuration is by updating this
10447 file and re-running @command{guix system reconfigure}. One should never
10448 have to touch files in @file{/etc} or to run commands that modify the
10449 system state such as @command{useradd} or @command{grub-install}. In
10450 fact, you must avoid that since that would not only void your warranty
10451 but also prevent you from rolling back to previous versions of your
10452 system, should you ever need to.
10454 @cindex roll-back, of the operating system
10455 Speaking of roll-back, each time you run @command{guix system
10456 reconfigure}, a new @dfn{generation} of the system is created---without
10457 modifying or deleting previous generations. Old system generations get
10458 an entry in the bootloader boot menu, allowing you to boot them in case
10459 something went wrong with the latest generation. Reassuring, no? The
10460 @command{guix system list-generations} command lists the system
10461 generations available on disk. It is also possible to roll back the
10462 system via the commands @command{guix system roll-back} and
10463 @command{guix system switch-generation}.
10465 Although the @command{guix system reconfigure} command will not modify
10466 previous generations, you must take care when the current generation is not
10467 the latest (e.g., after invoking @command{guix system roll-back}), since
10468 the operation might overwrite a later generation (@pxref{Invoking guix
10471 @unnumberedsubsec The Programming Interface
10473 At the Scheme level, the bulk of an @code{operating-system} declaration
10474 is instantiated with the following monadic procedure (@pxref{The Store
10477 @deffn {Monadic Procedure} operating-system-derivation os
10478 Return a derivation that builds @var{os}, an @code{operating-system}
10479 object (@pxref{Derivations}).
10481 The output of the derivation is a single directory that refers to all
10482 the packages, configuration files, and other supporting files needed to
10483 instantiate @var{os}.
10486 This procedure is provided by the @code{(gnu system)} module. Along
10487 with @code{(gnu services)} (@pxref{Services}), this module contains the
10488 guts of Guix System. Make sure to visit it!
10491 @node operating-system Reference
10492 @section @code{operating-system} Reference
10494 This section summarizes all the options available in
10495 @code{operating-system} declarations (@pxref{Using the Configuration
10498 @deftp {Data Type} operating-system
10499 This is the data type representing an operating system configuration.
10500 By that, we mean all the global system configuration, not per-user
10501 configuration (@pxref{Using the Configuration System}).
10504 @item @code{kernel} (default: @var{linux-libre})
10505 The package object of the operating system kernel to use@footnote{Currently
10506 only the Linux-libre kernel is supported. In the future, it will be
10507 possible to use the GNU@tie{}Hurd.}.
10509 @item @code{kernel-arguments} (default: @code{'("quiet")})
10510 List of strings or gexps representing additional arguments to pass on
10511 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10513 @item @code{bootloader}
10514 The system bootloader configuration object. @xref{Bootloader Configuration}.
10517 This is the label (a string) as it appears in the bootloader's menu entry.
10518 The default label includes the kernel name and version.
10520 @item @code{keyboard-layout} (default: @code{#f})
10521 This field specifies the keyboard layout to use in the console. It can be
10522 either @code{#f}, in which case the default keyboard layout is used (usually
10523 US English), or a @code{<keyboard-layout>} record.
10525 This keyboard layout is in effect as soon as the kernel has booted. For
10526 instance, it is the keyboard layout in effect when you type a passphrase if
10527 your root file system is on a @code{luks-device-mapping} mapped device
10528 (@pxref{Mapped Devices}).
10531 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10532 that used by the graphical display server. @xref{Bootloader Configuration},
10533 for information on how to specify the bootloader's keyboard layout. @xref{X
10534 Window}, for information on how to specify the keyboard layout used by the X
10538 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10540 @cindex initial RAM disk
10541 The list of Linux kernel modules that need to be available in the
10542 initial RAM disk. @xref{Initial RAM Disk}.
10544 @item @code{initrd} (default: @code{base-initrd})
10545 A procedure that returns an initial RAM disk for the Linux
10546 kernel. This field is provided to support low-level customization and
10547 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10549 @item @code{firmware} (default: @var{%base-firmware})
10551 List of firmware packages loadable by the operating system kernel.
10553 The default includes firmware needed for Atheros- and Broadcom-based
10554 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10555 respectively). @xref{Hardware Considerations}, for more info on
10556 supported hardware.
10558 @item @code{host-name}
10561 @item @code{hosts-file}
10563 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10564 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10565 Reference Manual}). The default is a file with entries for
10566 @code{localhost} and @var{host-name}.
10568 @item @code{mapped-devices} (default: @code{'()})
10569 A list of mapped devices. @xref{Mapped Devices}.
10571 @item @code{file-systems}
10572 A list of file systems. @xref{File Systems}.
10574 @item @code{swap-devices} (default: @code{'()})
10575 @cindex swap devices
10576 A list of strings identifying devices or files to be used for ``swap
10577 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10578 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10579 It is possible to specify a swap file in a file system on a mapped
10580 device, provided that the necessary device mapping and file system are
10581 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10583 @item @code{users} (default: @code{%base-user-accounts})
10584 @itemx @code{groups} (default: @var{%base-groups})
10585 List of user accounts and groups. @xref{User Accounts}.
10587 If the @code{users} list lacks a user account with UID@tie{}0, a
10588 ``root'' account with UID@tie{}0 is automatically added.
10590 @item @code{skeletons} (default: @code{(default-skeletons)})
10591 A list target file name/file-like object tuples (@pxref{G-Expressions,
10592 file-like objects}). These are the skeleton files that will be added to
10593 the home directory of newly-created user accounts.
10595 For instance, a valid value may look like this:
10598 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10599 (".guile" ,(plain-file "guile"
10600 "(use-modules (ice-9 readline))
10601 (activate-readline)")))
10604 @item @code{issue} (default: @var{%default-issue})
10605 A string denoting the contents of the @file{/etc/issue} file, which is
10606 displayed when users log in on a text console.
10608 @item @code{packages} (default: @var{%base-packages})
10609 The set of packages installed in the global profile, which is accessible
10610 at @file{/run/current-system/profile}.
10612 The default set includes core utilities and it is good practice to
10613 install non-core utilities in user profiles (@pxref{Invoking guix
10616 @item @code{timezone}
10617 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10619 You can run the @command{tzselect} command to find out which timezone
10620 string corresponds to your region. Choosing an invalid timezone name
10621 causes @command{guix system} to fail.
10623 @item @code{locale} (default: @code{"en_US.utf8"})
10624 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10625 Library Reference Manual}). @xref{Locales}, for more information.
10627 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10628 The list of locale definitions to be compiled and that may be used at
10629 run time. @xref{Locales}.
10631 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10632 The list of GNU@tie{}libc packages whose locale data and tools are used
10633 to build the locale definitions. @xref{Locales}, for compatibility
10634 considerations that justify this option.
10636 @item @code{name-service-switch} (default: @var{%default-nss})
10637 Configuration of the libc name service switch (NSS)---a
10638 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10641 @item @code{services} (default: @var{%base-services})
10642 A list of service objects denoting system services. @xref{Services}.
10644 @cindex essential services
10645 @item @code{essential-services} (default: ...)
10646 The list of ``essential services''---i.e., things like instances of
10647 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10648 Reference}), which are derived from the operating system definition itself.
10649 As a user you should @emph{never} need to touch this field.
10651 @item @code{pam-services} (default: @code{(base-pam-services)})
10653 @cindex pluggable authentication modules
10654 Linux @dfn{pluggable authentication module} (PAM) services.
10655 @c FIXME: Add xref to PAM services section.
10657 @item @code{setuid-programs} (default: @var{%setuid-programs})
10658 List of string-valued G-expressions denoting setuid programs.
10659 @xref{Setuid Programs}.
10661 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10662 @cindex sudoers file
10663 The contents of the @file{/etc/sudoers} file as a file-like object
10664 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10666 This file specifies which users can use the @command{sudo} command, what
10667 they are allowed to do, and what privileges they may gain. The default
10668 is that only @code{root} and members of the @code{wheel} group may use
10673 @deffn {Scheme Syntax} this-operating-system
10674 When used in the @emph{lexical scope} of an operating system field definition,
10675 this identifier resolves to the operating system being defined.
10677 The example below shows how to refer to the operating system being defined in
10678 the definition of the @code{label} field:
10681 (use-modules (gnu) (guix))
10685 (label (package-full-name
10686 (operating-system-kernel this-operating-system))))
10689 It is an error to refer to @code{this-operating-system} outside an operating
10696 @section File Systems
10698 The list of file systems to be mounted is specified in the
10699 @code{file-systems} field of the operating system declaration
10700 (@pxref{Using the Configuration System}). Each file system is declared
10701 using the @code{file-system} form, like this:
10705 (mount-point "/home")
10706 (device "/dev/sda3")
10710 As usual, some of the fields are mandatory---those shown in the example
10711 above---while others can be omitted. These are described below.
10713 @deftp {Data Type} file-system
10714 Objects of this type represent file systems to be mounted. They
10715 contain the following members:
10719 This is a string specifying the type of the file system---e.g.,
10722 @item @code{mount-point}
10723 This designates the place where the file system is to be mounted.
10725 @item @code{device}
10726 This names the ``source'' of the file system. It can be one of three
10727 things: a file system label, a file system UUID, or the name of a
10728 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10729 systems without having to hard-code their actual device
10730 name@footnote{Note that, while it is tempting to use
10731 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10732 result, this is not recommended: These special device nodes are created
10733 by the udev daemon and may be unavailable at the time the device is
10736 @findex file-system-label
10737 File system labels are created using the @code{file-system-label}
10738 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10739 plain strings. Here's an example of a file system referred to by its
10740 label, as shown by the @command{e2label} command:
10744 (mount-point "/home")
10746 (device (file-system-label "my-home")))
10750 UUIDs are converted from their string representation (as shown by the
10751 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10752 @code{uuid} form expects 16-byte UUIDs as defined in
10753 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10754 form of UUID used by the ext2 family of file systems and others, but it
10755 is different from ``UUIDs'' found in FAT file systems, for instance.},
10760 (mount-point "/home")
10762 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10765 When the source of a file system is a mapped device (@pxref{Mapped
10766 Devices}), its @code{device} field @emph{must} refer to the mapped
10767 device name---e.g., @file{"/dev/mapper/root-partition"}.
10768 This is required so that
10769 the system knows that mounting the file system depends on having the
10770 corresponding device mapping established.
10772 @item @code{flags} (default: @code{'()})
10773 This is a list of symbols denoting mount flags. Recognized flags
10774 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10775 access to special files), @code{no-suid} (ignore setuid and setgid
10776 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10777 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10778 Library Reference Manual}, for more information on these flags.
10780 @item @code{options} (default: @code{#f})
10781 This is either @code{#f}, or a string denoting mount options passed to the
10782 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10783 Reference Manual}, for details and run @command{man 8 mount} for options for
10784 various file systems.
10786 @item @code{mount?} (default: @code{#t})
10787 This value indicates whether to automatically mount the file system when
10788 the system is brought up. When set to @code{#f}, the file system gets
10789 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10790 is not automatically mounted.
10792 @item @code{needed-for-boot?} (default: @code{#f})
10793 This Boolean value indicates whether the file system is needed when
10794 booting. If that is true, then the file system is mounted when the
10795 initial RAM disk (initrd) is loaded. This is always the case, for
10796 instance, for the root file system.
10798 @item @code{check?} (default: @code{#t})
10799 This Boolean indicates whether the file system needs to be checked for
10800 errors before being mounted.
10802 @item @code{create-mount-point?} (default: @code{#f})
10803 When true, the mount point is created if it does not exist yet.
10805 @item @code{dependencies} (default: @code{'()})
10806 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10807 representing file systems that must be mounted or mapped devices that
10808 must be opened before (and unmounted or closed after) this one.
10810 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10811 a dependency of @file{/sys/fs/cgroup/cpu} and
10812 @file{/sys/fs/cgroup/memory}.
10814 Another example is a file system that depends on a mapped device, for
10815 example for an encrypted partition (@pxref{Mapped Devices}).
10819 The @code{(gnu system file-systems)} exports the following useful
10822 @defvr {Scheme Variable} %base-file-systems
10823 These are essential file systems that are required on normal systems,
10824 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10825 below.) Operating system declarations should always contain at least
10829 @defvr {Scheme Variable} %pseudo-terminal-file-system
10830 This is the file system to be mounted as @file{/dev/pts}. It supports
10831 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10832 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10833 Manual}). Pseudo-terminals are used by terminal emulators such as
10837 @defvr {Scheme Variable} %shared-memory-file-system
10838 This file system is mounted as @file{/dev/shm} and is used to support
10839 memory sharing across processes (@pxref{Memory-mapped I/O,
10840 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10843 @defvr {Scheme Variable} %immutable-store
10844 This file system performs a read-only ``bind mount'' of
10845 @file{/gnu/store}, making it read-only for all the users including
10846 @code{root}. This prevents against accidental modification by software
10847 running as @code{root} or by system administrators.
10849 The daemon itself is still able to write to the store: it remounts it
10850 read-write in its own ``name space.''
10853 @defvr {Scheme Variable} %binary-format-file-system
10854 The @code{binfmt_misc} file system, which allows handling of arbitrary
10855 executable file types to be delegated to user space. This requires the
10856 @code{binfmt.ko} kernel module to be loaded.
10859 @defvr {Scheme Variable} %fuse-control-file-system
10860 The @code{fusectl} file system, which allows unprivileged users to mount
10861 and unmount user-space FUSE file systems. This requires the
10862 @code{fuse.ko} kernel module to be loaded.
10865 @node Mapped Devices
10866 @section Mapped Devices
10868 @cindex device mapping
10869 @cindex mapped devices
10870 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10871 such as a hard disk partition, can be @dfn{mapped} into another device,
10872 usually in @code{/dev/mapper/},
10873 with additional processing over the data that flows through
10874 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10875 concept of a ``mapped device'' and that of a file system: both boil down
10876 to @emph{translating} input/output operations made on a file to
10877 operations on its backing store. Thus, the Hurd implements mapped
10878 devices, like file systems, using the generic @dfn{translator} mechanism
10879 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10880 typical example is encryption device mapping: all writes to the mapped
10881 device are encrypted, and all reads are deciphered, transparently.
10882 Guix extends this notion by considering any device or set of devices that
10883 are @dfn{transformed} in some way to create a new device; for instance,
10884 RAID devices are obtained by @dfn{assembling} several other devices, such
10885 as hard disks or partitions, into a new one that behaves as one partition.
10886 Other examples, not yet implemented, are LVM logical volumes.
10888 Mapped devices are declared using the @code{mapped-device} form,
10889 defined as follows; for examples, see below.
10891 @deftp {Data Type} mapped-device
10892 Objects of this type represent device mappings that will be made when
10893 the system boots up.
10897 This is either a string specifying the name of the block device to be mapped,
10898 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10899 need to be assembled for creating a new one.
10902 This string specifies the name of the resulting mapped device. For
10903 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10904 specifying @code{"my-partition"} leads to the creation of
10905 the @code{"/dev/mapper/my-partition"} device.
10906 For RAID devices of type @code{raid-device-mapping}, the full device name
10907 such as @code{"/dev/md0"} needs to be given.
10910 This must be a @code{mapped-device-kind} object, which specifies how
10911 @var{source} is mapped to @var{target}.
10915 @defvr {Scheme Variable} luks-device-mapping
10916 This defines LUKS block device encryption using the @command{cryptsetup}
10917 command from the package with the same name. It relies on the
10918 @code{dm-crypt} Linux kernel module.
10921 @defvr {Scheme Variable} raid-device-mapping
10922 This defines a RAID device, which is assembled using the @code{mdadm}
10923 command from the package with the same name. It requires a Linux kernel
10924 module for the appropriate RAID level to be loaded, such as @code{raid456}
10925 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10928 @cindex disk encryption
10930 The following example specifies a mapping from @file{/dev/sda3} to
10931 @file{/dev/mapper/home} using LUKS---the
10932 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10933 standard mechanism for disk encryption.
10934 The @file{/dev/mapper/home}
10935 device can then be used as the @code{device} of a @code{file-system}
10936 declaration (@pxref{File Systems}).
10940 (source "/dev/sda3")
10942 (type luks-device-mapping))
10945 Alternatively, to become independent of device numbering, one may obtain
10946 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10950 cryptsetup luksUUID /dev/sda3
10953 and use it as follows:
10957 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10959 (type luks-device-mapping))
10962 @cindex swap encryption
10963 It is also desirable to encrypt swap space, since swap space may contain
10964 sensitive data. One way to accomplish that is to use a swap file in a
10965 file system on a device mapped via LUKS encryption. In this way, the
10966 swap file is encrypted because the entire device is encrypted.
10967 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10969 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10970 may be declared as follows:
10974 (source (list "/dev/sda1" "/dev/sdb1"))
10975 (target "/dev/md0")
10976 (type raid-device-mapping))
10979 The @file{/dev/md0} device can then be used as the @code{device} of a
10980 @code{file-system} declaration (@pxref{File Systems}).
10981 Note that the RAID level need not be given; it is chosen during the
10982 initial creation and formatting of the RAID device and is determined
10983 automatically later.
10986 @node User Accounts
10987 @section User Accounts
10991 @cindex user accounts
10992 User accounts and groups are entirely managed through the
10993 @code{operating-system} declaration. They are specified with the
10994 @code{user-account} and @code{user-group} forms:
11000 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11001 "audio" ;sound card
11002 "video" ;video devices such as webcams
11003 "cdrom")) ;the good ol' CD-ROM
11004 (comment "Bob's sister")
11005 (home-directory "/home/alice"))
11008 When booting or upon completion of @command{guix system reconfigure},
11009 the system ensures that only the user accounts and groups specified in
11010 the @code{operating-system} declaration exist, and with the specified
11011 properties. Thus, account or group creations or modifications made by
11012 directly invoking commands such as @command{useradd} are lost upon
11013 reconfiguration or reboot. This ensures that the system remains exactly
11016 @deftp {Data Type} user-account
11017 Objects of this type represent user accounts. The following members may
11022 The name of the user account.
11026 This is the name (a string) or identifier (a number) of the user group
11027 this account belongs to.
11029 @item @code{supplementary-groups} (default: @code{'()})
11030 Optionally, this can be defined as a list of group names that this
11031 account belongs to.
11033 @item @code{uid} (default: @code{#f})
11034 This is the user ID for this account (a number), or @code{#f}. In the
11035 latter case, a number is automatically chosen by the system when the
11036 account is created.
11038 @item @code{comment} (default: @code{""})
11039 A comment about the account, such as the account owner's full name.
11041 @item @code{home-directory}
11042 This is the name of the home directory for the account.
11044 @item @code{create-home-directory?} (default: @code{#t})
11045 Indicates whether the home directory of this account should be created
11046 if it does not exist yet.
11048 @item @code{shell} (default: Bash)
11049 This is a G-expression denoting the file name of a program to be used as
11050 the shell (@pxref{G-Expressions}).
11052 @item @code{system?} (default: @code{#f})
11053 This Boolean value indicates whether the account is a ``system''
11054 account. System accounts are sometimes treated specially; for instance,
11055 graphical login managers do not list them.
11057 @anchor{user-account-password}
11058 @cindex password, for user accounts
11059 @item @code{password} (default: @code{#f})
11060 You would normally leave this field to @code{#f}, initialize user
11061 passwords as @code{root} with the @command{passwd} command, and then let
11062 users change it with @command{passwd}. Passwords set with
11063 @command{passwd} are of course preserved across reboot and
11066 If you @emph{do} want to set an initial password for an account, then
11067 this field must contain the encrypted password, as a string. You can use the
11068 @code{crypt} procedure for this purpose:
11075 ;; Specify a SHA-512-hashed initial password.
11076 (password (crypt "InitialPassword!" "$6$abc")))
11080 The hash of this initial password will be available in a file in
11081 @file{/gnu/store}, readable by all the users, so this method must be used with
11085 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11086 more information on password encryption, and @ref{Encryption,,, guile, GNU
11087 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11093 User group declarations are even simpler:
11096 (user-group (name "students"))
11099 @deftp {Data Type} user-group
11100 This type is for, well, user groups. There are just a few fields:
11104 The name of the group.
11106 @item @code{id} (default: @code{#f})
11107 The group identifier (a number). If @code{#f}, a new number is
11108 automatically allocated when the group is created.
11110 @item @code{system?} (default: @code{#f})
11111 This Boolean value indicates whether the group is a ``system'' group.
11112 System groups have low numerical IDs.
11114 @item @code{password} (default: @code{#f})
11115 What, user groups can have a password? Well, apparently yes. Unless
11116 @code{#f}, this field specifies the password of the group.
11121 For convenience, a variable lists all the basic user groups one may
11124 @defvr {Scheme Variable} %base-groups
11125 This is the list of basic user groups that users and/or packages expect
11126 to be present on the system. This includes groups such as ``root'',
11127 ``wheel'', and ``users'', as well as groups used to control access to
11128 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11131 @defvr {Scheme Variable} %base-user-accounts
11132 This is the list of basic system accounts that programs may expect to
11133 find on a GNU/Linux system, such as the ``nobody'' account.
11135 Note that the ``root'' account is not included here. It is a
11136 special-case and is automatically added whether or not it is specified.
11139 @node Keyboard Layout
11140 @section Keyboard Layout
11142 @cindex keyboard layout
11144 To specify what each key of your keyboard does, you need to tell the operating
11145 system what @dfn{keyboard layout} you want to use. The default, when nothing
11146 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11147 However, German speakers will usually prefer the German QWERTZ layout, French
11148 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11149 or bépo, and they might even want to further customize the effect of some of
11150 the keys. This section explains how to get that done.
11152 @cindex keyboard layout, definition
11153 There are three components that will want to know about your keyboard layout:
11157 The @emph{bootloader} may want to know what keyboard layout you want to use
11158 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11159 you want, for instance, to make sure that you can type the passphrase of your
11160 encrypted root partition using the right layout.
11163 The @emph{operating system kernel}, Linux, will need that so that the console
11164 is properly configured (@pxref{operating-system Reference,
11165 @code{keyboard-layout}}).
11168 The @emph{graphical display server}, usually Xorg, also has its own idea of
11169 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11172 Guix allows you to configure all three separately but, fortunately, it allows
11173 you to share the same keyboard layout for all three components.
11175 @cindex XKB, keyboard layouts
11176 Keyboard layouts are represented by records created by the
11177 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11178 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11179 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11180 optional variant name, an optional keyboard model name, and a possibly empty
11181 list of additional options. In most cases the layout name is all you care
11182 about. Here are a few example:
11185 ;; The German QWERTZ layout. Here we assume a standard
11186 ;; "pc105" keyboard model.
11187 (keyboard-layout "de")
11189 ;; The bépo variant of the French layout.
11190 (keyboard-layout "fr" "bepo")
11192 ;; The Catalan layout.
11193 (keyboard-layout "es" "cat")
11195 ;; The Latin American Spanish layout. In addition, the
11196 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11197 ;; and the "Menu" key is used as a "Compose" key to enter
11198 ;; accented letters.
11199 (keyboard-layout "latam"
11200 #:options '("ctrl:nocaps" "compose:menu"))
11202 ;; The Russian layout for a ThinkPad keyboard.
11203 (keyboard-layout "ru" #:model "thinkpad")
11205 ;; The "US international" layout, which is the US layout plus
11206 ;; dead keys to enter accented characters. This is for an
11207 ;; Apple MacBook keyboard.
11208 (keyboard-layout "us" "intl" #:model "macbook78")
11211 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11212 for a complete list of supported layouts, variants, and models.
11214 @cindex keyboard layout, configuration
11215 Let's say you want your system to use the Turkish keyboard layout throughout
11216 your system---bootloader, console, and Xorg. Here's what your system
11217 configuration would look like:
11219 @findex set-xorg-configuration
11221 ;; Using the Turkish layout for the bootloader, the console,
11226 (keyboard-layout (keyboard-layout "tr")) ;for the console
11227 (bootloader (bootloader-configuration
11228 (bootloader grub-efi-bootloader)
11229 (target "/boot/efi")
11230 (keyboard-layout keyboard-layout))) ;for GRUB
11231 (services (cons (set-xorg-configuration
11232 (xorg-configuration ;for Xorg
11233 (keyboard-layout keyboard-layout)))
11234 %desktop-services)))
11237 In the example above, for GRUB and for Xorg, we just refer to the
11238 @code{keyboard-layout} field defined above, but we could just as well refer to
11239 a different layout. The @code{set-xorg-configuration} procedure communicates
11240 the desired Xorg configuration to the graphical log-in manager, by default
11243 We've discussed how to specify the @emph{default} keyboard layout of your
11244 system when it starts, but you can also adjust it at run time:
11248 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11249 where you can select one or more keyboard layouts.
11252 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11253 allows you to change the current layout. For example, this is how you would
11254 change the layout to US Dvorak:
11257 setxkbmap us dvorak
11261 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11262 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11263 keyboard layout categorization described above. The command below loads the
11264 French bépo layout:
11275 A @dfn{locale} defines cultural conventions for a particular language
11276 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11277 Reference Manual}). Each locale has a name that typically has the form
11278 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11279 @code{fr_LU.utf8} designates the locale for the French language, with
11280 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11282 @cindex locale definition
11283 Usually, you will want to specify the default locale for the machine
11284 using the @code{locale} field of the @code{operating-system} declaration
11285 (@pxref{operating-system Reference, @code{locale}}).
11287 The selected locale is automatically added to the @dfn{locale
11288 definitions} known to the system if needed, with its codeset inferred
11289 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11290 @code{UTF-8} codeset. Additional locale definitions can be specified in
11291 the @code{locale-definitions} slot of @code{operating-system}---this is
11292 useful, for instance, if the codeset could not be inferred from the
11293 locale name. The default set of locale definitions includes some widely
11294 used locales, but not all the available locales, in order to save space.
11296 For instance, to add the North Frisian locale for Germany, the value of
11300 (cons (locale-definition
11301 (name "fy_DE.utf8") (source "fy_DE"))
11302 %default-locale-definitions)
11305 Likewise, to save space, one might want @code{locale-definitions} to
11306 list only the locales that are actually used, as in:
11309 (list (locale-definition
11310 (name "ja_JP.eucjp") (source "ja_JP")
11311 (charset "EUC-JP")))
11315 The compiled locale definitions are available at
11316 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11317 version, which is the default location where the GNU@tie{}libc provided
11318 by Guix looks for locale data. This can be overridden using the
11319 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11320 @code{LOCPATH} and locale packages}).
11322 The @code{locale-definition} form is provided by the @code{(gnu system
11323 locale)} module. Details are given below.
11325 @deftp {Data Type} locale-definition
11326 This is the data type of a locale definition.
11331 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11332 Reference Manual}, for more information on locale names.
11334 @item @code{source}
11335 The name of the source for that locale. This is typically the
11336 @code{@var{language}_@var{territory}} part of the locale name.
11338 @item @code{charset} (default: @code{"UTF-8"})
11339 The ``character set'' or ``code set'' for that locale,
11340 @uref{https://www.iana.org/assignments/character-sets, as defined by
11346 @defvr {Scheme Variable} %default-locale-definitions
11347 A list of commonly used UTF-8 locales, used as the default
11348 value of the @code{locale-definitions} field of @code{operating-system}
11351 @cindex locale name
11352 @cindex normalized codeset in locale names
11353 These locale definitions use the @dfn{normalized codeset} for the part
11354 that follows the dot in the name (@pxref{Using gettextized software,
11355 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11356 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11357 @code{uk_UA.UTF-8}.
11360 @subsection Locale Data Compatibility Considerations
11362 @cindex incompatibility, of locale data
11363 @code{operating-system} declarations provide a @code{locale-libcs} field
11364 to specify the GNU@tie{}libc packages that are used to compile locale
11365 declarations (@pxref{operating-system Reference}). ``Why would I
11366 care?'', you may ask. Well, it turns out that the binary format of
11367 locale data is occasionally incompatible from one libc version to
11370 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11371 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11372 For instance, a program linked against libc version 2.21 is unable to
11373 read locale data produced with libc 2.22; worse, that program
11374 @emph{aborts} instead of simply ignoring the incompatible locale
11375 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11376 the incompatible locale data, which is already an improvement.}.
11377 Similarly, a program linked against libc 2.22 can read most, but not
11378 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11379 data is incompatible); thus calls to @code{setlocale} may fail, but
11380 programs will not abort.
11382 The ``problem'' with Guix is that users have a lot of freedom: They can
11383 choose whether and when to upgrade software in their profiles, and might
11384 be using a libc version different from the one the system administrator
11385 used to build the system-wide locale data.
11387 Fortunately, unprivileged users can also install their own locale data
11388 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11389 @code{GUIX_LOCPATH} and locale packages}).
11391 Still, it is best if the system-wide locale data at
11392 @file{/run/current-system/locale} is built for all the libc versions
11393 actually in use on the system, so that all the programs can access
11394 it---this is especially crucial on a multi-user system. To do that, the
11395 administrator can specify several libc packages in the
11396 @code{locale-libcs} field of @code{operating-system}:
11399 (use-package-modules base)
11403 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11406 This example would lead to a system containing locale definitions for
11407 both libc 2.21 and the current version of libc in
11408 @file{/run/current-system/locale}.
11414 @cindex system services
11415 An important part of preparing an @code{operating-system} declaration is
11416 listing @dfn{system services} and their configuration (@pxref{Using the
11417 Configuration System}). System services are typically daemons launched
11418 when the system boots, or other actions needed at that time---e.g.,
11419 configuring network access.
11421 Guix has a broad definition of ``service'' (@pxref{Service
11422 Composition}), but many services are managed by the GNU@tie{}Shepherd
11423 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11424 command allows you to list the available services, show their status,
11425 start and stop them, or do other specific operations (@pxref{Jump
11426 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11432 The above command, run as @code{root}, lists the currently defined
11433 services. The @command{herd doc} command shows a synopsis of the given
11434 service and its associated actions:
11438 Run libc's name service cache daemon (nscd).
11440 # herd doc nscd action invalidate
11441 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11444 The @command{start}, @command{stop}, and @command{restart} sub-commands
11445 have the effect you would expect. For instance, the commands below stop
11446 the nscd service and restart the Xorg display server:
11450 Service nscd has been stopped.
11451 # herd restart xorg-server
11452 Service xorg-server has been stopped.
11453 Service xorg-server has been started.
11456 The following sections document the available services, starting with
11457 the core services, that may be used in an @code{operating-system}
11461 * Base Services:: Essential system services.
11462 * Scheduled Job Execution:: The mcron service.
11463 * Log Rotation:: The rottlog service.
11464 * Networking Services:: Network setup, SSH daemon, etc.
11465 * X Window:: Graphical display.
11466 * Printing Services:: Local and remote printer support.
11467 * Desktop Services:: D-Bus and desktop services.
11468 * Sound Services:: ALSA and Pulseaudio services.
11469 * Database Services:: SQL databases, key-value stores, etc.
11470 * Mail Services:: IMAP, POP3, SMTP, and all that.
11471 * Messaging Services:: Messaging services.
11472 * Telephony Services:: Telephony services.
11473 * Monitoring Services:: Monitoring services.
11474 * Kerberos Services:: Kerberos services.
11475 * LDAP Services:: LDAP services.
11476 * Web Services:: Web servers.
11477 * Certificate Services:: TLS certificates via Let's Encrypt.
11478 * DNS Services:: DNS daemons.
11479 * VPN Services:: VPN daemons.
11480 * Network File System:: NFS related services.
11481 * Continuous Integration:: The Cuirass service.
11482 * Power Management Services:: Extending battery life.
11483 * Audio Services:: The MPD.
11484 * Virtualization Services:: Virtualization services.
11485 * Version Control Services:: Providing remote access to Git repositories.
11486 * Game Services:: Game servers.
11487 * Miscellaneous Services:: Other services.
11490 @node Base Services
11491 @subsection Base Services
11493 The @code{(gnu services base)} module provides definitions for the basic
11494 services that one expects from the system. The services exported by
11495 this module are listed below.
11497 @defvr {Scheme Variable} %base-services
11498 This variable contains a list of basic services (@pxref{Service Types
11499 and Services}, for more information on service objects) one would
11500 expect from the system: a login service (mingetty) on each tty, syslogd,
11501 the libc name service cache daemon (nscd), the udev device manager, and
11504 This is the default value of the @code{services} field of
11505 @code{operating-system} declarations. Usually, when customizing a
11506 system, you will want to append services to @var{%base-services}, like
11510 (append (list (service avahi-service-type)
11511 (service openssh-service-type))
11516 @defvr {Scheme Variable} special-files-service-type
11517 This is the service that sets up ``special files'' such as
11518 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11520 The value associated with @code{special-files-service-type} services
11521 must be a list of tuples where the first element is the ``special file''
11522 and the second element is its target. By default it is:
11524 @cindex @file{/bin/sh}
11525 @cindex @file{sh}, in @file{/bin}
11527 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11530 @cindex @file{/usr/bin/env}
11531 @cindex @file{env}, in @file{/usr/bin}
11532 If you want to add, say, @code{/usr/bin/env} to your system, you can
11536 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11537 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11540 Since this is part of @code{%base-services}, you can use
11541 @code{modify-services} to customize the set of special files
11542 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11543 to add a special file is @i{via} the @code{extra-special-file} procedure
11547 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11548 Use @var{target} as the ``special file'' @var{file}.
11550 For example, adding the following lines to the @code{services} field of
11551 your operating system declaration leads to a @file{/usr/bin/env}
11555 (extra-special-file "/usr/bin/env"
11556 (file-append coreutils "/bin/env"))
11560 @deffn {Scheme Procedure} host-name-service @var{name}
11561 Return a service that sets the host name to @var{name}.
11564 @deffn {Scheme Procedure} login-service @var{config}
11565 Return a service to run login according to @var{config}, a
11566 @code{<login-configuration>} object, which specifies the message of the day,
11567 among other things.
11570 @deftp {Data Type} login-configuration
11571 This is the data type representing the configuration of login.
11576 @cindex message of the day
11577 A file-like object containing the ``message of the day''.
11579 @item @code{allow-empty-passwords?} (default: @code{#t})
11580 Allow empty passwords by default so that first-time users can log in when
11581 the 'root' account has just been created.
11586 @deffn {Scheme Procedure} mingetty-service @var{config}
11587 Return a service to run mingetty according to @var{config}, a
11588 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11592 @deftp {Data Type} mingetty-configuration
11593 This is the data type representing the configuration of Mingetty, which
11594 provides the default implementation of virtual console log-in.
11599 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11601 @item @code{auto-login} (default: @code{#f})
11602 When true, this field must be a string denoting the user name under
11603 which the system automatically logs in. When it is @code{#f}, a
11604 user name and password must be entered to log in.
11606 @item @code{login-program} (default: @code{#f})
11607 This must be either @code{#f}, in which case the default log-in program
11608 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11609 the name of the log-in program.
11611 @item @code{login-pause?} (default: @code{#f})
11612 When set to @code{#t} in conjunction with @var{auto-login}, the user
11613 will have to press a key before the log-in shell is launched.
11615 @item @code{mingetty} (default: @var{mingetty})
11616 The Mingetty package to use.
11621 @deffn {Scheme Procedure} agetty-service @var{config}
11622 Return a service to run agetty according to @var{config}, an
11623 @code{<agetty-configuration>} object, which specifies the tty to run,
11624 among other things.
11627 @deftp {Data Type} agetty-configuration
11628 This is the data type representing the configuration of agetty, which
11629 implements virtual and serial console log-in. See the @code{agetty(8)}
11630 man page for more information.
11635 The name of the console this agetty runs on, as a string---e.g.,
11636 @code{"ttyS0"}. This argument is optional, it will default to
11637 a reasonable default serial port used by the kernel Linux.
11639 For this, if there is a value for an option @code{agetty.tty} in the kernel
11640 command line, agetty will extract the device name of the serial port
11641 from it and use that.
11643 If not and if there is a value for an option @code{console} with a tty in
11644 the Linux command line, agetty will extract the device name of the
11645 serial port from it and use that.
11647 In both cases, agetty will leave the other serial device settings
11648 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11651 @item @code{baud-rate} (default: @code{#f})
11652 A string containing a comma-separated list of one or more baud rates, in
11655 @item @code{term} (default: @code{#f})
11656 A string containing the value used for the @code{TERM} environment
11659 @item @code{eight-bits?} (default: @code{#f})
11660 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11663 @item @code{auto-login} (default: @code{#f})
11664 When passed a login name, as a string, the specified user will be logged
11665 in automatically without prompting for their login name or password.
11667 @item @code{no-reset?} (default: @code{#f})
11668 When @code{#t}, don't reset terminal cflags (control modes).
11670 @item @code{host} (default: @code{#f})
11671 This accepts a string containing the "login_host", which will be written
11672 into the @file{/var/run/utmpx} file.
11674 @item @code{remote?} (default: @code{#f})
11675 When set to @code{#t} in conjunction with @var{host}, this will add an
11676 @code{-r} fakehost option to the command line of the login program
11677 specified in @var{login-program}.
11679 @item @code{flow-control?} (default: @code{#f})
11680 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11682 @item @code{no-issue?} (default: @code{#f})
11683 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11684 not be displayed before presenting the login prompt.
11686 @item @code{init-string} (default: @code{#f})
11687 This accepts a string that will be sent to the tty or modem before
11688 sending anything else. It can be used to initialize a modem.
11690 @item @code{no-clear?} (default: @code{#f})
11691 When set to @code{#t}, agetty will not clear the screen before showing
11694 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11695 This must be either a gexp denoting the name of a log-in program, or
11696 unset, in which case the default value is the @command{login} from the
11699 @item @code{local-line} (default: @code{#f})
11700 Control the CLOCAL line flag. This accepts one of three symbols as
11701 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11702 the default value chosen by agetty is @code{'auto}.
11704 @item @code{extract-baud?} (default: @code{#f})
11705 When set to @code{#t}, instruct agetty to try to extract the baud rate
11706 from the status messages produced by certain types of modems.
11708 @item @code{skip-login?} (default: @code{#f})
11709 When set to @code{#t}, do not prompt the user for a login name. This
11710 can be used with @var{login-program} field to use non-standard login
11713 @item @code{no-newline?} (default: @code{#f})
11714 When set to @code{#t}, do not print a newline before printing the
11715 @file{/etc/issue} file.
11717 @c Is this dangerous only when used with login-program, or always?
11718 @item @code{login-options} (default: @code{#f})
11719 This option accepts a string containing options that are passed to the
11720 login program. When used with the @var{login-program}, be aware that a
11721 malicious user could try to enter a login name containing embedded
11722 options that could be parsed by the login program.
11724 @item @code{login-pause} (default: @code{#f})
11725 When set to @code{#t}, wait for any key before showing the login prompt.
11726 This can be used in conjunction with @var{auto-login} to save memory by
11727 lazily spawning shells.
11729 @item @code{chroot} (default: @code{#f})
11730 Change root to the specified directory. This option accepts a directory
11733 @item @code{hangup?} (default: @code{#f})
11734 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11735 specified terminal.
11737 @item @code{keep-baud?} (default: @code{#f})
11738 When set to @code{#t}, try to keep the existing baud rate. The baud
11739 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11742 @item @code{timeout} (default: @code{#f})
11743 When set to an integer value, terminate if no user name could be read
11744 within @var{timeout} seconds.
11746 @item @code{detect-case?} (default: @code{#f})
11747 When set to @code{#t}, turn on support for detecting an uppercase-only
11748 terminal. This setting will detect a login name containing only
11749 uppercase letters as indicating an uppercase-only terminal and turn on
11750 some upper-to-lower case conversions. Note that this will not support
11751 Unicode characters.
11753 @item @code{wait-cr?} (default: @code{#f})
11754 When set to @code{#t}, wait for the user or modem to send a
11755 carriage-return or linefeed character before displaying
11756 @file{/etc/issue} or login prompt. This is typically used with the
11757 @var{init-string} option.
11759 @item @code{no-hints?} (default: @code{#f})
11760 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11763 @item @code{no-hostname?} (default: @code{#f})
11764 By default, the hostname is printed. When this option is set to
11765 @code{#t}, no hostname will be shown at all.
11767 @item @code{long-hostname?} (default: @code{#f})
11768 By default, the hostname is only printed until the first dot. When this
11769 option is set to @code{#t}, the fully qualified hostname by
11770 @code{gethostname} or @code{getaddrinfo} is shown.
11772 @item @code{erase-characters} (default: @code{#f})
11773 This option accepts a string of additional characters that should be
11774 interpreted as backspace when the user types their login name.
11776 @item @code{kill-characters} (default: @code{#f})
11777 This option accepts a string that should be interpreted to mean "ignore
11778 all previous characters" (also called a "kill" character) when the user
11779 types their login name.
11781 @item @code{chdir} (default: @code{#f})
11782 This option accepts, as a string, a directory path that will be changed
11785 @item @code{delay} (default: @code{#f})
11786 This options accepts, as an integer, the number of seconds to sleep
11787 before opening the tty and displaying the login prompt.
11789 @item @code{nice} (default: @code{#f})
11790 This option accepts, as an integer, the nice value with which to run the
11791 @command{login} program.
11793 @item @code{extra-options} (default: @code{'()})
11794 This option provides an "escape hatch" for the user to provide arbitrary
11795 command-line arguments to @command{agetty} as a list of strings.
11800 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11801 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11802 according to @var{config}, a @code{<kmscon-configuration>} object, which
11803 specifies the tty to run, among other things.
11806 @deftp {Data Type} kmscon-configuration
11807 This is the data type representing the configuration of Kmscon, which
11808 implements virtual console log-in.
11812 @item @code{virtual-terminal}
11813 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11815 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11816 A gexp denoting the name of the log-in program. The default log-in program is
11817 @command{login} from the Shadow tool suite.
11819 @item @code{login-arguments} (default: @code{'("-p")})
11820 A list of arguments to pass to @command{login}.
11822 @item @code{auto-login} (default: @code{#f})
11823 When passed a login name, as a string, the specified user will be logged
11824 in automatically without prompting for their login name or password.
11826 @item @code{hardware-acceleration?} (default: #f)
11827 Whether to use hardware acceleration.
11829 @item @code{kmscon} (default: @var{kmscon})
11830 The Kmscon package to use.
11835 @cindex name service cache daemon
11837 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11838 [#:name-services '()]
11839 Return a service that runs the libc name service cache daemon (nscd) with the
11840 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11841 Service Switch}, for an example.
11843 For convenience, the Shepherd service for nscd provides the following actions:
11847 @cindex cache invalidation, nscd
11848 @cindex nscd, cache invalidation
11849 This invalidate the given cache. For instance, running:
11852 herd invalidate nscd hosts
11856 invalidates the host name lookup cache of nscd.
11859 Running @command{herd statistics nscd} displays information about nscd usage
11865 @defvr {Scheme Variable} %nscd-default-configuration
11866 This is the default @code{<nscd-configuration>} value (see below) used
11867 by @code{nscd-service}. It uses the caches defined by
11868 @var{%nscd-default-caches}; see below.
11871 @deftp {Data Type} nscd-configuration
11872 This is the data type representing the name service cache daemon (nscd)
11877 @item @code{name-services} (default: @code{'()})
11878 List of packages denoting @dfn{name services} that must be visible to
11879 the nscd---e.g., @code{(list @var{nss-mdns})}.
11881 @item @code{glibc} (default: @var{glibc})
11882 Package object denoting the GNU C Library providing the @command{nscd}
11885 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11886 Name of the nscd log file. This is where debugging output goes when
11887 @code{debug-level} is strictly positive.
11889 @item @code{debug-level} (default: @code{0})
11890 Integer denoting the debugging levels. Higher numbers mean that more
11891 debugging output is logged.
11893 @item @code{caches} (default: @var{%nscd-default-caches})
11894 List of @code{<nscd-cache>} objects denoting things to be cached; see
11900 @deftp {Data Type} nscd-cache
11901 Data type representing a cache database of nscd and its parameters.
11905 @item @code{database}
11906 This is a symbol representing the name of the database to be cached.
11907 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11908 @code{services}, which designate the corresponding NSS database
11909 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11911 @item @code{positive-time-to-live}
11912 @itemx @code{negative-time-to-live} (default: @code{20})
11913 A number representing the number of seconds during which a positive or
11914 negative lookup result remains in cache.
11916 @item @code{check-files?} (default: @code{#t})
11917 Whether to check for updates of the files corresponding to
11920 For instance, when @var{database} is @code{hosts}, setting this flag
11921 instructs nscd to check for updates in @file{/etc/hosts} and to take
11924 @item @code{persistent?} (default: @code{#t})
11925 Whether the cache should be stored persistently on disk.
11927 @item @code{shared?} (default: @code{#t})
11928 Whether the cache should be shared among users.
11930 @item @code{max-database-size} (default: 32@tie{}MiB)
11931 Maximum size in bytes of the database cache.
11933 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11934 @c settings, so leave them out.
11939 @defvr {Scheme Variable} %nscd-default-caches
11940 List of @code{<nscd-cache>} objects used by default by
11941 @code{nscd-configuration} (see above).
11943 It enables persistent and aggressive caching of service and host name
11944 lookups. The latter provides better host name lookup performance,
11945 resilience in the face of unreliable name servers, and also better
11946 privacy---often the result of host name lookups is in local cache, so
11947 external name servers do not even need to be queried.
11950 @anchor{syslog-configuration-type}
11953 @deftp {Data Type} syslog-configuration
11954 This data type represents the configuration of the syslog daemon.
11957 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11958 The syslog daemon to use.
11960 @item @code{config-file} (default: @code{%default-syslog.conf})
11961 The syslog configuration file to use.
11966 @anchor{syslog-service}
11968 @deffn {Scheme Procedure} syslog-service @var{config}
11969 Return a service that runs a syslog daemon according to @var{config}.
11971 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11972 information on the configuration file syntax.
11975 @defvr {Scheme Variable} guix-service-type
11976 This is the type of the service that runs the build daemon,
11977 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11978 @code{guix-configuration} record as described below.
11981 @anchor{guix-configuration-type}
11982 @deftp {Data Type} guix-configuration
11983 This data type represents the configuration of the Guix build daemon.
11984 @xref{Invoking guix-daemon}, for more information.
11987 @item @code{guix} (default: @var{guix})
11988 The Guix package to use.
11990 @item @code{build-group} (default: @code{"guixbuild"})
11991 Name of the group for build user accounts.
11993 @item @code{build-accounts} (default: @code{10})
11994 Number of build user accounts to create.
11996 @item @code{authorize-key?} (default: @code{#t})
11997 @cindex substitutes, authorization thereof
11998 Whether to authorize the substitute keys listed in
11999 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12000 (@pxref{Substitutes}).
12002 @vindex %default-authorized-guix-keys
12003 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
12004 The list of authorized key files for archive imports, as a list of
12005 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12006 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12008 @item @code{use-substitutes?} (default: @code{#t})
12009 Whether to use substitutes.
12011 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
12012 The list of URLs where to look for substitutes by default.
12014 @item @code{max-silent-time} (default: @code{0})
12015 @itemx @code{timeout} (default: @code{0})
12016 The number of seconds of silence and the number of seconds of activity,
12017 respectively, after which a build process times out. A value of zero
12018 disables the timeout.
12020 @item @code{log-compression} (default: @code{'bzip2})
12021 The type of compression used for build logs---one of @code{gzip},
12022 @code{bzip2}, or @code{none}.
12024 @item @code{extra-options} (default: @code{'()})
12025 List of extra command-line options for @command{guix-daemon}.
12027 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12028 File where @command{guix-daemon}'s standard output and standard error
12031 @item @code{http-proxy} (default: @code{#f})
12032 The HTTP proxy used for downloading fixed-output derivations and
12035 @item @code{tmpdir} (default: @code{#f})
12036 A directory path where the @command{guix-daemon} will perform builds.
12041 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12042 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12043 udev rules can be provided as a list of files through the @var{rules}
12044 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12045 @code{(gnu services base)} simplify the creation of such rule files.
12048 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12049 Return a udev-rule file named @var{file-name} containing the rules
12050 defined by the @var{contents} literal.
12052 In the following example, a rule for a USB device is defined to be
12053 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12054 upon detecting a USB device with a given product identifier.
12057 (define %example-udev-rule
12059 "90-usb-thing.rules"
12060 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12061 "ATTR@{product@}==\"Example\", "
12062 "RUN+=\"/path/to/script\"")))
12065 The @command{herd rules udev} command, as root, returns the name of the
12066 directory containing all the active udev rules.
12069 Here we show how the default @var{udev-service} can be extended with it.
12075 (modify-services %desktop-services
12076 (udev-service-type config =>
12077 (udev-configuration (inherit config)
12078 (rules (append (udev-configuration-rules config)
12079 (list %example-udev-rule))))))))
12082 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12083 Return a udev file named @var{file-name} containing the rules defined
12084 within @var{file}, a file-like object.
12086 The following example showcases how we can use an existing rule file.
12089 (use-modules (guix download) ;for url-fetch
12090 (guix packages) ;for origin
12093 (define %android-udev-rules
12095 "51-android-udev.rules"
12096 (let ((version "20170910"))
12099 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12100 "android-udev-rules/" version "/51-android.rules"))
12102 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12106 Additionally, Guix package definitions can be included in @var{rules} in
12107 order to extend the udev rules with the definitions found under their
12108 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12109 @var{file->udev-rule} example, we could have used the
12110 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12111 packages android)} module.
12113 The following example shows how to use the @var{android-udev-rules}
12114 package so that the Android tool @command{adb} can detect devices
12115 without root privileges. It also details how to create the
12116 @code{adbusers} group, which is required for the proper functioning of
12117 the rules defined within the @var{android-udev-rules} package. To
12118 create such a group, we must define it both as part of the
12119 @var{supplementary-groups} of our @var{user-account} declaration, as
12120 well as in the @var{groups} field of the @var{operating-system} record.
12123 (use-modules (gnu packages android) ;for android-udev-rules
12124 (gnu system shadow) ;for user-group
12129 (users (cons (user-acount
12131 (supplementary-groups
12132 '("adbusers" ;for adb
12133 "wheel" "netdev" "audio" "video"))
12136 (groups (cons (user-group (system? #t) (name "adbusers"))
12142 (modify-services %desktop-services
12145 (udev-configuration (inherit config)
12146 (rules (cons android-udev-rules
12147 (udev-configuration-rules config))))))))
12150 @defvr {Scheme Variable} urandom-seed-service-type
12151 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12152 when rebooting. It also tries to seed @file{/dev/urandom} from
12153 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12157 @defvr {Scheme Variable} %random-seed-file
12158 This is the name of the file where some random bytes are saved by
12159 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12160 It defaults to @file{/var/lib/random-seed}.
12165 @defvr {Scheme Variable} gpm-service-type
12166 This is the type of the service that runs GPM, the @dfn{general-purpose
12167 mouse daemon}, which provides mouse support to the Linux console. GPM
12168 allows users to use the mouse in the console, notably to select, copy,
12171 The value for services of this type must be a @code{gpm-configuration}
12172 (see below). This service is not part of @var{%base-services}.
12175 @deftp {Data Type} gpm-configuration
12176 Data type representing the configuration of GPM.
12179 @item @code{options} (default: @code{%default-gpm-options})
12180 Command-line options passed to @command{gpm}. The default set of
12181 options instruct @command{gpm} to listen to mouse events on
12182 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12185 @item @code{gpm} (default: @code{gpm})
12186 The GPM package to use.
12191 @anchor{guix-publish-service-type}
12192 @deffn {Scheme Variable} guix-publish-service-type
12193 This is the service type for @command{guix publish} (@pxref{Invoking
12194 guix publish}). Its value must be a @code{guix-configuration}
12195 object, as described below.
12197 This assumes that @file{/etc/guix} already contains a signing key pair as
12198 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12199 archive}). If that is not the case, the service will fail to start.
12202 @deftp {Data Type} guix-publish-configuration
12203 Data type representing the configuration of the @code{guix publish}
12207 @item @code{guix} (default: @code{guix})
12208 The Guix package to use.
12210 @item @code{port} (default: @code{80})
12211 The TCP port to listen for connections.
12213 @item @code{host} (default: @code{"localhost"})
12214 The host (and thus, network interface) to listen to. Use
12215 @code{"0.0.0.0"} to listen on all the network interfaces.
12217 @item @code{compression-level} (default: @code{3})
12218 The gzip compression level at which substitutes are compressed. Use
12219 @code{0} to disable compression altogether, and @code{9} to get the best
12220 compression ratio at the expense of increased CPU usage.
12222 @item @code{nar-path} (default: @code{"nar"})
12223 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12224 publish, @code{--nar-path}}, for details.
12226 @item @code{cache} (default: @code{#f})
12227 When it is @code{#f}, disable caching and instead generate archives on
12228 demand. Otherwise, this should be the name of a directory---e.g.,
12229 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12230 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12231 @option{--cache}}, for more information on the tradeoffs involved.
12233 @item @code{workers} (default: @code{#f})
12234 When it is an integer, this is the number of worker threads used for
12235 caching; when @code{#f}, the number of processors is used.
12236 @xref{Invoking guix publish, @option{--workers}}, for more information.
12238 @item @code{ttl} (default: @code{#f})
12239 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12240 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12241 for more information.
12245 @anchor{rngd-service}
12246 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12247 [#:device "/dev/hwrng"]
12248 Return a service that runs the @command{rngd} program from @var{rng-tools}
12249 to add @var{device} to the kernel's entropy pool. The service will fail if
12250 @var{device} does not exist.
12253 @anchor{pam-limits-service}
12254 @cindex session limits
12259 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12261 Return a service that installs a configuration file for the
12262 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12263 @code{pam_limits} module}. The procedure optionally takes a list of
12264 @code{pam-limits-entry} values, which can be used to specify
12265 @code{ulimit} limits and nice priority limits to user sessions.
12267 The following limits definition sets two hard and soft limits for all
12268 login sessions of users in the @code{realtime} group:
12271 (pam-limits-service
12273 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12274 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12277 The first entry increases the maximum realtime priority for
12278 non-privileged processes; the second entry lifts any restriction of the
12279 maximum address space that can be locked in memory. These settings are
12280 commonly used for real-time audio systems.
12283 @node Scheduled Job Execution
12284 @subsection Scheduled Job Execution
12288 @cindex scheduling jobs
12289 The @code{(gnu services mcron)} module provides an interface to
12290 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12291 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12292 Unix @command{cron} daemon; the main difference is that it is
12293 implemented in Guile Scheme, which provides a lot of flexibility when
12294 specifying the scheduling of jobs and their actions.
12296 The example below defines an operating system that runs the
12297 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12298 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12299 well as the @command{mkid} command on behalf of an unprivileged user
12300 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12301 gexps to introduce job definitions that are passed to mcron
12302 (@pxref{G-Expressions}).
12305 (use-modules (guix) (gnu) (gnu services mcron))
12306 (use-package-modules base idutils)
12308 (define updatedb-job
12309 ;; Run 'updatedb' at 3AM every day. Here we write the
12310 ;; job's action as a Scheme procedure.
12311 #~(job '(next-hour '(3))
12313 (execl (string-append #$findutils "/bin/updatedb")
12315 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12317 (define garbage-collector-job
12318 ;; Collect garbage 5 minutes after midnight every day.
12319 ;; The job's action is a shell command.
12320 #~(job "5 0 * * *" ;Vixie cron syntax
12323 (define idutils-job
12324 ;; Update the index database as user "charlie" at 12:15PM
12325 ;; and 19:15PM. This runs from the user's home directory.
12326 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12327 (string-append #$idutils "/bin/mkid src")
12332 (services (cons (service mcron-service-type
12333 (mcron-configuration
12334 (jobs (list garbage-collector-job
12340 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12341 for more information on mcron job specifications. Below is the
12342 reference of the mcron service.
12344 On a running system, you can use the @code{schedule} action of the service to
12345 visualize the mcron jobs that will be executed next:
12348 # herd schedule mcron
12352 The example above lists the next five tasks that will be executed, but you can
12353 also specify the number of tasks to display:
12356 # herd schedule mcron 10
12359 @defvr {Scheme Variable} mcron-service-type
12360 This is the type of the @code{mcron} service, whose value is an
12361 @code{mcron-configuration} object.
12363 This service type can be the target of a service extension that provides
12364 it additional job specifications (@pxref{Service Composition}). In
12365 other words, it is possible to define services that provide additional
12369 @deftp {Data Type} mcron-configuration
12370 Data type representing the configuration of mcron.
12373 @item @code{mcron} (default: @var{mcron})
12374 The mcron package to use.
12377 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12378 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12379 specifications,, mcron, GNU@tie{}mcron}).
12385 @subsection Log Rotation
12388 @cindex log rotation
12390 Log files such as those found in @file{/var/log} tend to grow endlessly,
12391 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12392 their contents in separate files, possibly compressed. The @code{(gnu
12393 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12394 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12396 The example below defines an operating system that provides log rotation
12397 with the default settings, for commonly encountered log files.
12400 (use-modules (guix) (gnu))
12401 (use-service-modules admin mcron)
12402 (use-package-modules base idutils)
12406 (services (cons (service rottlog-service-type)
12410 @defvr {Scheme Variable} rottlog-service-type
12411 This is the type of the Rottlog service, whose value is a
12412 @code{rottlog-configuration} object.
12414 Other services can extend this one with new @code{log-rotation} objects
12415 (see below), thereby augmenting the set of files to be rotated.
12417 This service type can define mcron jobs (@pxref{Scheduled Job
12418 Execution}) to run the rottlog service.
12421 @deftp {Data Type} rottlog-configuration
12422 Data type representing the configuration of rottlog.
12425 @item @code{rottlog} (default: @code{rottlog})
12426 The Rottlog package to use.
12428 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12429 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12430 rottlog, GNU Rot[t]log Manual}).
12432 @item @code{rotations} (default: @code{%default-rotations})
12433 A list of @code{log-rotation} objects as defined below.
12436 This is a list of gexps where each gexp corresponds to an mcron job
12437 specification (@pxref{Scheduled Job Execution}).
12441 @deftp {Data Type} log-rotation
12442 Data type representing the rotation of a group of log files.
12444 Taking an example from the Rottlog manual (@pxref{Period Related File
12445 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12451 (files '("/var/log/apache/*"))
12452 (options '("storedir apache-archives"
12458 The list of fields is as follows:
12461 @item @code{frequency} (default: @code{'weekly})
12462 The log rotation frequency, a symbol.
12465 The list of files or file glob patterns to rotate.
12467 @item @code{options} (default: @code{'()})
12468 The list of rottlog options for this rotation (@pxref{Configuration
12469 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12471 @item @code{post-rotate} (default: @code{#f})
12472 Either @code{#f} or a gexp to execute once the rotation has completed.
12476 @defvr {Scheme Variable} %default-rotations
12477 Specifies weekly rotation of @var{%rotated-files} and
12478 a couple of other files.
12481 @defvr {Scheme Variable} %rotated-files
12482 The list of syslog-controlled files to be rotated. By default it is:
12483 @code{'("/var/log/messages" "/var/log/secure")}.
12486 @node Networking Services
12487 @subsection Networking Services
12489 The @code{(gnu services networking)} module provides services to configure
12490 the network interface.
12492 @cindex DHCP, networking service
12493 @defvr {Scheme Variable} dhcp-client-service-type
12494 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12495 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12496 is the DHCP client package to use, @code{isc-dhcp} by default.
12499 @deffn {Scheme Procedure} dhcpd-service-type
12500 This type defines a service that runs a DHCP daemon. To create a
12501 service of this type, you must supply a @code{<dhcpd-configuration>}.
12505 (service dhcpd-service-type
12506 (dhcpd-configuration
12507 (config-file (local-file "my-dhcpd.conf"))
12508 (interfaces '("enp0s25"))))
12512 @deftp {Data Type} dhcpd-configuration
12514 @item @code{package} (default: @code{isc-dhcp})
12515 The package that provides the DHCP daemon. This package is expected to
12516 provide the daemon at @file{sbin/dhcpd} relative to its output
12517 directory. The default package is the
12518 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12519 @item @code{config-file} (default: @code{#f})
12520 The configuration file to use. This is required. It will be passed to
12521 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12522 object (@pxref{G-Expressions, file-like objects}). See @code{man
12523 dhcpd.conf} for details on the configuration file syntax.
12524 @item @code{version} (default: @code{"4"})
12525 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12526 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12527 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12529 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12530 The run directory to use. At service activation time, this directory
12531 will be created if it does not exist.
12532 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12533 The PID file to use. This corresponds to the @code{-pf} option of
12534 @code{dhcpd}. See @code{man dhcpd} for details.
12535 @item @code{interfaces} (default: @code{'()})
12536 The names of the network interfaces on which dhcpd should listen for
12537 broadcasts. If this list is not empty, then its elements (which must be
12538 strings) will be appended to the @code{dhcpd} invocation when starting
12539 the daemon. It may not be necessary to explicitly specify any
12540 interfaces here; see @code{man dhcpd} for details.
12544 @defvr {Scheme Variable} static-networking-service-type
12545 This is the type for statically-configured network interfaces.
12546 @c TODO Document <static-networking> data structures.
12549 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12550 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12551 [#:requirement @code{'(udev)}]
12552 Return a service that starts @var{interface} with address @var{ip}. If
12553 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12554 it must be a string specifying the default network gateway. @var{requirement}
12555 can be used to declare a dependency on another service before configuring the
12558 This procedure can be called several times, one for each network
12559 interface of interest. Behind the scenes what it does is extend
12560 @code{static-networking-service-type} with additional network interfaces
12566 (static-networking-service "eno1" "192.168.1.82"
12567 #:gateway "192.168.1.2"
12568 #:name-servers '("192.168.1.2"))
12575 @cindex network management
12576 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12577 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12578 management daemon that aims to simplify wired and wireless networking.
12580 This service adds the @var{wicd} package to the global profile, providing
12581 several commands to interact with the daemon and configure networking:
12582 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12583 and @command{wicd-curses} user interfaces.
12586 @cindex ModemManager
12588 @defvr {Scheme Variable} modem-manager-service-type
12589 This is the service type for the
12590 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12591 service. The value for this service type is a
12592 @code{modem-manager-configuration} record.
12594 This service is part of @code{%desktop-services} (@pxref{Desktop
12598 @deftp {Data Type} modem-manager-configuration
12599 Data type representing the configuration of ModemManager.
12602 @item @code{modem-manager} (default: @code{modem-manager})
12603 The ModemManager package to use.
12608 @cindex NetworkManager
12610 @defvr {Scheme Variable} network-manager-service-type
12611 This is the service type for the
12612 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12613 service. The value for this service type is a
12614 @code{network-manager-configuration} record.
12616 This service is part of @code{%desktop-services} (@pxref{Desktop
12620 @deftp {Data Type} network-manager-configuration
12621 Data type representing the configuration of NetworkManager.
12624 @item @code{network-manager} (default: @code{network-manager})
12625 The NetworkManager package to use.
12627 @item @code{dns} (default: @code{"default"})
12628 Processing mode for DNS, which affects how NetworkManager uses the
12629 @code{resolv.conf} configuration file.
12633 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12634 provided by currently active connections.
12637 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12638 using a "split DNS" configuration if you are connected to a VPN, and
12639 then update @code{resolv.conf} to point to the local nameserver.
12642 NetworkManager will not modify @code{resolv.conf}.
12645 @item @code{vpn-plugins} (default: @code{'()})
12646 This is the list of available plugins for virtual private networks
12647 (VPNs). An example of this is the @code{network-manager-openvpn}
12648 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12654 @deffn {Scheme Variable} connman-service-type
12655 This is the service type to run @url{https://01.org/connman,Connman},
12656 a network connection manager.
12658 Its value must be an
12659 @code{connman-configuration} record as in this example:
12662 (service connman-service-type
12663 (connman-configuration
12664 (disable-vpn? #t)))
12667 See below for details about @code{connman-configuration}.
12670 @deftp {Data Type} connman-configuration
12671 Data Type representing the configuration of connman.
12674 @item @code{connman} (default: @var{connman})
12675 The connman package to use.
12677 @item @code{disable-vpn?} (default: @code{#f})
12678 When true, disable connman's vpn plugin.
12682 @cindex WPA Supplicant
12683 @defvr {Scheme Variable} wpa-supplicant-service-type
12684 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12685 supplicant}, an authentication daemon required to authenticate against
12686 encrypted WiFi or ethernet networks.
12689 @deftp {Data Type} wpa-supplicant-configuration
12690 Data type representing the configuration of WPA Supplicant.
12692 It takes the following parameters:
12695 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12696 The WPA Supplicant package to use.
12698 @item @code{dbus?} (default: @code{#t})
12699 Whether to listen for requests on D-Bus.
12701 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12702 Where to store the PID file.
12704 @item @code{interface} (default: @code{#f})
12705 If this is set, it must specify the name of a network interface that
12706 WPA supplicant will control.
12708 @item @code{config-file} (default: @code{#f})
12709 Optional configuration file to use.
12711 @item @code{extra-options} (default: @code{'()})
12712 List of additional command-line arguments to pass to the daemon.
12717 @defvr {Scheme Variable} iptables-service-type
12718 This is the service type to set up an iptables configuration. iptables is a
12719 packet filtering framework supported by the Linux kernel. This service
12720 supports configuring iptables for both IPv4 and IPv6. A simple example
12721 configuration rejecting all incoming connections except those to the ssh port
12725 (service iptables-service-type
12726 (iptables-configuration
12727 (ipv4-rules (plain-file "iptables.rules" "*filter
12731 -A INPUT -p tcp --dport 22 -j ACCEPT
12732 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12735 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12739 -A INPUT -p tcp --dport 22 -j ACCEPT
12740 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12746 @deftp {Data Type} iptables-configuration
12747 The data type representing the configuration of iptables.
12750 @item @code{iptables} (default: @code{iptables})
12751 The iptables package that provides @code{iptables-restore} and
12752 @code{ip6tables-restore}.
12753 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12754 The iptables rules to use. It will be passed to @code{iptables-restore}.
12755 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12757 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12758 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12759 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12764 @cindex NTP (Network Time Protocol), service
12765 @cindex real time clock
12766 @defvr {Scheme Variable} ntp-service-type
12767 This is the type of the service running the @uref{http://www.ntp.org,
12768 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12769 system clock synchronized with that of the specified NTP servers.
12771 The value of this service is an @code{ntpd-configuration} object, as described
12775 @deftp {Data Type} ntp-configuration
12776 This is the data type for the NTP service configuration.
12779 @item @code{servers} (default: @code{%ntp-servers})
12780 This is the list of servers (host names) with which @command{ntpd} will be
12783 @item @code{allow-large-adjustment?} (default: @code{#f})
12784 This determines whether @command{ntpd} is allowed to make an initial
12785 adjustment of more than 1,000 seconds.
12787 @item @code{ntp} (default: @code{ntp})
12788 The NTP package to use.
12792 @defvr {Scheme Variable} %ntp-servers
12793 List of host names used as the default NTP servers. These are servers of the
12794 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12798 @deffn {Scheme Procedure} openntpd-service-type
12799 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12800 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12801 clock synchronized with that of the given servers.
12805 openntpd-service-type
12806 (openntpd-configuration
12807 (listen-on '("127.0.0.1" "::1"))
12808 (sensor '("udcf0 correction 70000"))
12809 (constraint-from '("www.gnu.org"))
12810 (constraints-from '("https://www.google.com/"))
12811 (allow-large-adjustment? #t)))
12816 @deftp {Data Type} openntpd-configuration
12818 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12819 The openntpd executable to use.
12820 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12821 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12822 @item @code{query-from} (default: @code{'()})
12823 A list of local IP address the ntpd daemon should use for outgoing queries.
12824 @item @code{sensor} (default: @code{'()})
12825 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12826 will listen to each sensor that actually exists and ignore non-existent ones.
12827 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12829 @item @code{server} (default: @var{%ntp-servers})
12830 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12831 @item @code{servers} (default: @code{'()})
12832 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12833 @item @code{constraint-from} (default: @code{'()})
12834 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12835 This time information is not used for precision but acts as an authenticated
12836 constraint, thereby reducing the impact of unauthenticated NTP
12837 man-in-the-middle attacks.
12838 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12840 @item @code{constraints-from} (default: @code{'()})
12841 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12842 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12843 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12844 @item @code{allow-large-adjustment?} (default: @code{#f})
12845 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12851 @deffn {Scheme variable} inetd-service-type
12852 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12853 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12854 connections on internet sockets, and lazily starts the specified server
12855 program when a connection is made on one of these sockets.
12857 The value of this service is an @code{inetd-configuration} object. The
12858 following example configures the @command{inetd} daemon to provide the
12859 built-in @command{echo} service, as well as an smtp service which
12860 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12861 gateway @code{hostname}:
12866 (inetd-configuration
12870 (socket-type 'stream)
12877 (socket-type 'stream)
12881 (program (file-append openssh "/bin/ssh"))
12883 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12884 "-W" "smtp-server:25" "user@@hostname")))))
12887 See below for more details about @code{inetd-configuration}.
12890 @deftp {Data Type} inetd-configuration
12891 Data type representing the configuration of @command{inetd}.
12894 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12895 The @command{inetd} executable to use.
12897 @item @code{entries} (default: @code{'()})
12898 A list of @command{inetd} service entries. Each entry should be created
12899 by the @code{inetd-entry} constructor.
12903 @deftp {Data Type} inetd-entry
12904 Data type representing an entry in the @command{inetd} configuration.
12905 Each entry corresponds to a socket where @command{inetd} will listen for
12909 @item @code{node} (default: @code{#f})
12910 Optional string, a comma-separated list of local addresses
12911 @command{inetd} should use when listening for this service.
12912 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12913 description of all options.
12915 A string, the name must correspond to an entry in @code{/etc/services}.
12916 @item @code{socket-type}
12917 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12919 @item @code{protocol}
12920 A string, must correspond to an entry in @code{/etc/protocols}.
12921 @item @code{wait?} (default: @code{#t})
12922 Whether @command{inetd} should wait for the server to exit before
12923 listening to new service requests.
12925 A string containing the user (and, optionally, group) name of the user
12926 as whom the server should run. The group name can be specified in a
12927 suffix, separated by a colon or period, i.e.@: @code{"user"},
12928 @code{"user:group"} or @code{"user.group"}.
12929 @item @code{program} (default: @code{"internal"})
12930 The server program which will serve the requests, or @code{"internal"}
12931 if @command{inetd} should use a built-in service.
12932 @item @code{arguments} (default: @code{'()})
12933 A list strings or file-like objects, which are the server program's
12934 arguments, starting with the zeroth argument, i.e.@: the name of the
12935 program itself. For @command{inetd}'s internal services, this entry
12936 must be @code{'()} or @code{'("internal")}.
12939 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12940 detailed discussion of each configuration field.
12944 @defvr {Scheme Variable} tor-service-type
12945 This is the type for a service that runs the @uref{https://torproject.org,
12946 Tor} anonymous networking daemon. The service is configured using a
12947 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12948 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12952 @deftp {Data Type} tor-configuration
12954 @item @code{tor} (default: @code{tor})
12955 The package that provides the Tor daemon. This package is expected to provide
12956 the daemon at @file{bin/tor} relative to its output directory. The default
12957 package is the @uref{https://www.torproject.org, Tor Project's}
12960 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12961 The configuration file to use. It will be appended to a default configuration
12962 file, and the final configuration file will be passed to @code{tor} via its
12963 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12964 file-like objects}). See @code{man tor} for details on the configuration file
12967 @item @code{hidden-services} (default: @code{'()})
12968 The list of @code{<hidden-service>} records to use. For any hidden service
12969 you include in this list, appropriate configuration to enable the hidden
12970 service will be automatically added to the default configuration file. You
12971 may conveniently create @code{<hidden-service>} records using the
12972 @code{tor-hidden-service} procedure described below.
12974 @item @code{socks-socket-type} (default: @code{'tcp})
12975 The default socket type that Tor should use for its SOCKS socket. This must
12976 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12977 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12978 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12979 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12982 If you want to customize the SOCKS socket in more detail, leave
12983 @code{socks-socket-type} at its default value of @code{'tcp} and use
12984 @code{config-file} to override the default by providing your own
12985 @code{SocksPort} option.
12989 @cindex hidden service
12990 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12991 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12992 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12995 '((22 "127.0.0.1:22")
12996 (80 "127.0.0.1:8080"))
12999 In this example, port 22 of the hidden service is mapped to local port 22, and
13000 port 80 is mapped to local port 8080.
13002 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13003 the @file{hostname} file contains the @code{.onion} host name for the hidden
13006 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13007 project's documentation} for more information.
13010 The @code{(gnu services rsync)} module provides the following services:
13012 You might want an rsync daemon if you have files that you want available
13013 so anyone (or just yourself) can download existing files or upload new
13016 @deffn {Scheme Variable} rsync-service-type
13017 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13018 The value for this service type is a
13019 @command{rsync-configuration} record as in this example:
13022 (service rsync-service-type)
13025 See below for details about @code{rsync-configuration}.
13028 @deftp {Data Type} rsync-configuration
13029 Data type representing the configuration for @code{rsync-service}.
13032 @item @code{package} (default: @var{rsync})
13033 @code{rsync} package to use.
13035 @item @code{port-number} (default: @code{873})
13036 TCP port on which @command{rsync} listens for incoming connections. If port
13037 is less than @code{1024} @command{rsync} needs to be started as the
13038 @code{root} user and group.
13040 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13041 Name of the file where @command{rsync} writes its PID.
13043 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13044 Name of the file where @command{rsync} writes its lock file.
13046 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13047 Name of the file where @command{rsync} writes its log file.
13049 @item @code{use-chroot?} (default: @var{#t})
13050 Whether to use chroot for @command{rsync} shared directory.
13052 @item @code{share-path} (default: @file{/srv/rsync})
13053 Location of the @command{rsync} shared directory.
13055 @item @code{share-comment} (default: @code{"Rsync share"})
13056 Comment of the @command{rsync} shared directory.
13058 @item @code{read-only?} (default: @var{#f})
13059 Read-write permissions to shared directory.
13061 @item @code{timeout} (default: @code{300})
13062 I/O timeout in seconds.
13064 @item @code{user} (default: @var{"root"})
13065 Owner of the @code{rsync} process.
13067 @item @code{group} (default: @var{"root"})
13068 Group of the @code{rsync} process.
13070 @item @code{uid} (default: @var{"rsyncd"})
13071 User name or user ID that file transfers to and from that module should take
13072 place as when the daemon was run as @code{root}.
13074 @item @code{gid} (default: @var{"rsyncd"})
13075 Group name or group ID that will be used when accessing the module.
13080 Furthermore, @code{(gnu services ssh)} provides the following services.
13084 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13085 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13086 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13087 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13088 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13089 [#:public-key-authentication? #t] [#:initialize? #t]
13090 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13091 @var{host-key} must designate a file containing the host key, and readable
13094 When @var{daemonic?} is true, @command{lshd} will detach from the
13095 controlling terminal and log its output to syslogd, unless one sets
13096 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13097 depend on existence of syslogd service. When @var{pid-file?} is true,
13098 @command{lshd} writes its PID to the file called @var{pid-file}.
13100 When @var{initialize?} is true, automatically create the seed and host key
13101 upon service activation if they do not exist yet. This may take long and
13102 require interaction.
13104 When @var{initialize?} is false, it is up to the user to initialize the
13105 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13106 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13107 basics,,, lsh, LSH Manual}).
13109 When @var{interfaces} is empty, lshd listens for connections on all the
13110 network interfaces; otherwise, @var{interfaces} must be a list of host names
13113 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13114 passwords, and @var{root-login?} specifies whether to accept log-ins as
13117 The other options should be self-descriptive.
13122 @deffn {Scheme Variable} openssh-service-type
13123 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13124 shell daemon, @command{sshd}. Its value must be an
13125 @code{openssh-configuration} record as in this example:
13128 (service openssh-service-type
13129 (openssh-configuration
13130 (x11-forwarding? #t)
13131 (permit-root-login 'without-password)
13133 `(("alice" ,(local-file "alice.pub"))
13134 ("bob" ,(local-file "bob.pub"))))))
13137 See below for details about @code{openssh-configuration}.
13139 This service can be extended with extra authorized keys, as in this
13143 (service-extension openssh-service-type
13144 (const `(("charlie"
13145 ,(local-file "charlie.pub")))))
13149 @deftp {Data Type} openssh-configuration
13150 This is the configuration record for OpenSSH's @command{sshd}.
13153 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13154 Name of the file where @command{sshd} writes its PID.
13156 @item @code{port-number} (default: @code{22})
13157 TCP port on which @command{sshd} listens for incoming connections.
13159 @item @code{permit-root-login} (default: @code{#f})
13160 This field determines whether and when to allow logins as root. If
13161 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13162 If it's the symbol @code{'without-password}, then root logins are
13163 permitted but not with password-based authentication.
13165 @item @code{allow-empty-passwords?} (default: @code{#f})
13166 When true, users with empty passwords may log in. When false, they may
13169 @item @code{password-authentication?} (default: @code{#t})
13170 When true, users may log in with their password. When false, they have
13171 other authentication methods.
13173 @item @code{public-key-authentication?} (default: @code{#t})
13174 When true, users may log in using public key authentication. When
13175 false, users have to use other authentication method.
13177 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13178 This is used only by protocol version 2.
13180 @item @code{x11-forwarding?} (default: @code{#f})
13181 When true, forwarding of X11 graphical client connections is
13182 enabled---in other words, @command{ssh} options @option{-X} and
13183 @option{-Y} will work.
13185 @item @code{allow-agent-forwarding?} (default: @code{#t})
13186 Whether to allow agent forwarding.
13188 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13189 Whether to allow TCP forwarding.
13191 @item @code{gateway-ports?} (default: @code{#f})
13192 Whether to allow gateway ports.
13194 @item @code{challenge-response-authentication?} (default: @code{#f})
13195 Specifies whether challenge response authentication is allowed (e.g.@: via
13198 @item @code{use-pam?} (default: @code{#t})
13199 Enables the Pluggable Authentication Module interface. If set to
13200 @code{#t}, this will enable PAM authentication using
13201 @code{challenge-response-authentication?} and
13202 @code{password-authentication?}, in addition to PAM account and session
13203 module processing for all authentication types.
13205 Because PAM challenge response authentication usually serves an
13206 equivalent role to password authentication, you should disable either
13207 @code{challenge-response-authentication?} or
13208 @code{password-authentication?}.
13210 @item @code{print-last-log?} (default: @code{#t})
13211 Specifies whether @command{sshd} should print the date and time of the
13212 last user login when a user logs in interactively.
13214 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13215 Configures external subsystems (e.g.@: file transfer daemon).
13217 This is a list of two-element lists, each of which containing the
13218 subsystem name and a command (with optional arguments) to execute upon
13221 The command @command{internal-sftp} implements an in-process SFTP
13222 server. Alternately, one can specify the @command{sftp-server} command:
13224 (service openssh-service-type
13225 (openssh-configuration
13227 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13230 @item @code{accepted-environment} (default: @code{'()})
13231 List of strings describing which environment variables may be exported.
13233 Each string gets on its own line. See the @code{AcceptEnv} option in
13234 @code{man sshd_config}.
13236 This example allows ssh-clients to export the @code{COLORTERM} variable.
13237 It is set by terminal emulators, which support colors. You can use it in
13238 your shell's ressource file to enable colors for the prompt and commands
13239 if this variable is set.
13242 (service openssh-service-type
13243 (openssh-configuration
13244 (accepted-environment '("COLORTERM"))))
13247 @item @code{authorized-keys} (default: @code{'()})
13248 @cindex authorized keys, SSH
13249 @cindex SSH authorized keys
13250 This is the list of authorized keys. Each element of the list is a user
13251 name followed by one or more file-like objects that represent SSH public
13255 (openssh-configuration
13257 `(("rekado" ,(local-file "rekado.pub"))
13258 ("chris" ,(local-file "chris.pub"))
13259 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13263 registers the specified public keys for user accounts @code{rekado},
13264 @code{chris}, and @code{root}.
13266 Additional authorized keys can be specified @i{via}
13267 @code{service-extension}.
13269 Note that this does @emph{not} interfere with the use of
13270 @file{~/.ssh/authorized_keys}.
13272 @item @code{log-level} (default: @code{'info})
13273 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13274 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13275 page for @file{sshd_config} for the full list of level names.
13277 @item @code{extra-content} (default: @code{""})
13278 This field can be used to append arbitrary text to the configuration file. It
13279 is especially useful for elaborate configurations that cannot be expressed
13280 otherwise. This configuration, for example, would generally disable root
13281 logins, but permit them from one specific IP address:
13284 (openssh-configuration
13286 Match Address 192.168.0.1
13287 PermitRootLogin yes"))
13293 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13294 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13295 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13298 For example, to specify a Dropbear service listening on port 1234, add
13299 this call to the operating system's @code{services} field:
13302 (dropbear-service (dropbear-configuration
13303 (port-number 1234)))
13307 @deftp {Data Type} dropbear-configuration
13308 This data type represents the configuration of a Dropbear SSH daemon.
13311 @item @code{dropbear} (default: @var{dropbear})
13312 The Dropbear package to use.
13314 @item @code{port-number} (default: 22)
13315 The TCP port where the daemon waits for incoming connections.
13317 @item @code{syslog-output?} (default: @code{#t})
13318 Whether to enable syslog output.
13320 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13321 File name of the daemon's PID file.
13323 @item @code{root-login?} (default: @code{#f})
13324 Whether to allow @code{root} logins.
13326 @item @code{allow-empty-passwords?} (default: @code{#f})
13327 Whether to allow empty passwords.
13329 @item @code{password-authentication?} (default: @code{#t})
13330 Whether to enable password-based authentication.
13334 @defvr {Scheme Variable} %facebook-host-aliases
13335 This variable contains a string for use in @file{/etc/hosts}
13336 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13337 line contains a entry that maps a known server name of the Facebook
13338 on-line service---e.g., @code{www.facebook.com}---to the local
13339 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13341 This variable is typically used in the @code{hosts-file} field of an
13342 @code{operating-system} declaration (@pxref{operating-system Reference,
13343 @file{/etc/hosts}}):
13346 (use-modules (gnu) (guix))
13349 (host-name "mymachine")
13352 ;; Create a /etc/hosts file with aliases for "localhost"
13353 ;; and "mymachine", as well as for Facebook servers.
13354 (plain-file "hosts"
13355 (string-append (local-host-aliases host-name)
13356 %facebook-host-aliases))))
13359 This mechanism can prevent programs running locally, such as Web
13360 browsers, from accessing Facebook.
13363 The @code{(gnu services avahi)} provides the following definition.
13365 @defvr {Scheme Variable} avahi-service-type
13366 This is the service that runs @command{avahi-daemon}, a system-wide
13367 mDNS/DNS-SD responder that allows for service discovery and
13368 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13369 Its value must be a @code{zero-configuration} record---see below.
13371 This service extends the name service cache daemon (nscd) so that it can
13372 resolve @code{.local} host names using
13373 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13374 Service Switch}, for information on host name resolution.
13376 Additionally, add the @var{avahi} package to the system profile so that
13377 commands such as @command{avahi-browse} are directly usable.
13380 @deftp {Data Type} avahi-configuration
13381 Data type representation the configuration for Avahi.
13385 @item @code{host-name} (default: @code{#f})
13386 If different from @code{#f}, use that as the host name to
13387 publish for this machine; otherwise, use the machine's actual host name.
13389 @item @code{publish?} (default: @code{#t})
13390 When true, allow host names and services to be published (broadcast) over the
13393 @item @code{publish-workstation?} (default: @code{#t})
13394 When true, @command{avahi-daemon} publishes the machine's host name and IP
13395 address via mDNS on the local network. To view the host names published on
13396 your local network, you can run:
13399 avahi-browse _workstation._tcp
13402 @item @code{wide-area?} (default: @code{#f})
13403 When true, DNS-SD over unicast DNS is enabled.
13405 @item @code{ipv4?} (default: @code{#t})
13406 @itemx @code{ipv6?} (default: @code{#t})
13407 These fields determine whether to use IPv4/IPv6 sockets.
13409 @item @code{domains-to-browse} (default: @code{'()})
13410 This is a list of domains to browse.
13414 @deffn {Scheme Variable} openvswitch-service-type
13415 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13416 service, whose value should be an @code{openvswitch-configuration}
13420 @deftp {Data Type} openvswitch-configuration
13421 Data type representing the configuration of Open vSwitch, a multilayer
13422 virtual switch which is designed to enable massive network automation
13423 through programmatic extension.
13426 @item @code{package} (default: @var{openvswitch})
13427 Package object of the Open vSwitch.
13433 @subsection X Window
13436 @cindex X Window System
13437 @cindex login manager
13438 Support for the X Window graphical display system---specifically
13439 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13440 there is no @code{xorg-service} procedure. Instead, the X server is
13441 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13444 @cindex GNOME, login manager
13445 GDM of course allows users to log in into window managers and desktop
13446 environments other than GNOME; for those using GNOME, GDM is required for
13447 features such as automatic screen locking.
13449 @cindex window manager
13450 To use X11, you must install at least one @dfn{window manager}---for
13451 example the @code{windowmaker} or @code{openbox} packages---preferably
13452 by adding it to the @code{packages} field of your operating system
13453 definition (@pxref{operating-system Reference, system-wide packages}).
13455 @defvr {Scheme Variable} gdm-service-type
13456 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13457 Desktop Manager} (GDM), a program that manages graphical display servers and
13458 handles graphical user logins. Its value must be a @code{gdm-configuration}
13461 @cindex session types (X11)
13462 @cindex X11 session types
13463 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13464 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13465 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13466 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13467 set of packages automatically makes them available at the log-in screen.
13469 In addition, @file{~/.xsession} files are honored. When available,
13470 @file{~/.xsession} must be an executable that starts a window manager
13471 and/or other X clients.
13474 @deftp {Data Type} gdm-configuration
13476 @item @code{auto-login?} (default: @code{#f})
13477 @itemx @code{default-user} (default: @code{#f})
13478 When @code{auto-login?} is false, GDM presents a log-in screen.
13480 When @code{auto-login?} is true, GDM logs in directly as
13481 @code{default-user}.
13483 @item @code{gnome-shell-assets} (default: ...)
13484 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13486 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13487 Configuration of the Xorg graphical server.
13489 @item @code{xsession} (default: @code{(xinitrc)})
13490 Script to run before starting a X session.
13492 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13493 File name of the @code{dbus-daemon} executable.
13495 @item @code{gdm} (default: @code{gdm})
13496 The GDM package to use.
13500 @defvr {Scheme Variable} slim-service-type
13501 This is the type for the SLiM graphical login manager for X11.
13503 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13504 allows users to choose a session from the log-in screen using @kbd{F1}. It
13505 also honors @file{~/.xsession} files.
13507 Unlike GDM, SLiM does not spawn the user session on a different VT after
13508 logging in, which means that you can only start one graphical session. If you
13509 want to be able to run multiple graphical sessions at the same time you have
13510 to add multiple SLiM services to your system services. The following example
13511 shows how to replace the default GDM service with two SLiM services on tty7
13515 (use-modules (gnu services)
13516 (gnu services desktop)
13517 (gnu services xorg)
13518 (srfi srfi-1)) ;for 'remove'
13522 (services (cons* (service slim-service-type (slim-configuration
13525 (service slim-service-type (slim-configuration
13528 (remove (lambda (service)
13529 (eq? (service-kind service) gdm-service-type))
13530 %desktop-services))))
13535 @deftp {Data Type} slim-configuration
13536 Data type representing the configuration of @code{slim-service-type}.
13539 @item @code{allow-empty-passwords?} (default: @code{#t})
13540 Whether to allow logins with empty passwords.
13542 @item @code{auto-login?} (default: @code{#f})
13543 @itemx @code{default-user} (default: @code{""})
13544 When @code{auto-login?} is false, SLiM presents a log-in screen.
13546 When @code{auto-login?} is true, SLiM logs in directly as
13547 @code{default-user}.
13549 @item @code{theme} (default: @code{%default-slim-theme})
13550 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13551 The graphical theme to use and its name.
13553 @item @code{auto-login-session} (default: @code{#f})
13554 If true, this must be the name of the executable to start as the default
13555 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13557 If false, a session described by one of the available @file{.desktop}
13558 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13562 You must install at least one window manager in the system profile or in
13563 your user profile. Failing to do that, if @code{auto-login-session} is
13564 false, you will be unable to log in.
13567 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13568 Configuration of the Xorg graphical server.
13570 @item @code{display} (default @code{":0"})
13571 The display on which to start the Xorg graphical server.
13573 @item @code{vt} (default @code{"vt7"})
13574 The VT on which to start the Xorg graphical server.
13576 @item @code{xauth} (default: @code{xauth})
13577 The XAuth package to use.
13579 @item @code{shepherd} (default: @code{shepherd})
13580 The Shepherd package used when invoking @command{halt} and
13583 @item @code{sessreg} (default: @code{sessreg})
13584 The sessreg package used in order to register the session.
13586 @item @code{slim} (default: @code{slim})
13587 The SLiM package to use.
13591 @defvr {Scheme Variable} %default-theme
13592 @defvrx {Scheme Variable} %default-theme-name
13593 The default SLiM theme and its name.
13597 @deftp {Data Type} sddm-configuration
13598 This is the data type representing the sddm service configuration.
13601 @item @code{display-server} (default: "x11")
13602 Select display server to use for the greeter. Valid values are "x11"
13605 @item @code{numlock} (default: "on")
13606 Valid values are "on", "off" or "none".
13608 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13609 Command to run when halting.
13611 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13612 Command to run when rebooting.
13614 @item @code{theme} (default "maldives")
13615 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13617 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13618 Directory to look for themes.
13620 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13621 Directory to look for faces.
13623 @item @code{default-path} (default "/run/current-system/profile/bin")
13624 Default PATH to use.
13626 @item @code{minimum-uid} (default 1000)
13627 Minimum UID to display in SDDM.
13629 @item @code{maximum-uid} (default 2000)
13630 Maximum UID to display in SDDM
13632 @item @code{remember-last-user?} (default #t)
13633 Remember last user.
13635 @item @code{remember-last-session?} (default #t)
13636 Remember last session.
13638 @item @code{hide-users} (default "")
13639 Usernames to hide from SDDM greeter.
13641 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13642 Users with shells listed will be hidden from the SDDM greeter.
13644 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13645 Script to run before starting a wayland session.
13647 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13648 Directory to look for desktop files starting wayland sessions.
13650 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13651 Configuration of the Xorg graphical server.
13653 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13656 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13659 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13660 Script to run after starting xorg-server.
13662 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13663 Script to run before stopping xorg-server.
13665 @item @code{xsession-command} (default: @code{xinitrc})
13666 Script to run before starting a X session.
13668 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13669 Directory to look for desktop files starting X sessions.
13671 @item @code{minimum-vt} (default: 7)
13674 @item @code{auto-login-user} (default "")
13675 User to use for auto-login.
13677 @item @code{auto-login-session} (default "")
13678 Desktop file to use for auto-login.
13680 @item @code{relogin?} (default #f)
13681 Relogin after logout.
13686 @cindex login manager
13688 @deffn {Scheme Procedure} sddm-service config
13689 Return a service that spawns the SDDM graphical login manager for config of
13690 type @code{<sddm-configuration>}.
13693 (sddm-service (sddm-configuration
13694 (auto-login-user "Alice")
13695 (auto-login-session "xfce.desktop")))
13699 @cindex Xorg, configuration
13700 @deftp {Data Type} xorg-configuration
13701 This data type represents the configuration of the Xorg graphical display
13702 server. Note that there is not Xorg service; instead, the X server is started
13703 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13704 of these display managers aggregates an @code{xorg-configuration} record.
13707 @item @code{modules} (default: @code{%default-xorg-modules})
13708 This is a list of @dfn{module packages} loaded by the Xorg
13709 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13711 @item @code{fonts} (default: @code{%default-xorg-fonts})
13712 This is a list of font directories to add to the server's @dfn{font path}.
13714 @item @code{drivers} (default: @code{'()})
13715 This must be either the empty list, in which case Xorg chooses a graphics
13716 driver automatically, or a list of driver names that will be tried in this
13717 order---e.g., @code{("modesetting" "vesa")}.
13719 @item @code{resolutions} (default: @code{'()})
13720 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13721 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13724 @cindex keyboard layout, for Xorg
13725 @cindex keymap, for Xorg
13726 @item @code{keyboard-layout} (default: @code{#f})
13727 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13728 English (``qwerty'') for a 105-key PC keyboard.
13730 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13731 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13732 information on how to specify the keyboard layout.
13734 @item @code{extra-config} (default: @code{'()})
13735 This is a list of strings or objects appended to the configuration file. It
13736 is used to pass extra text to be added verbatim to the configuration file.
13738 @item @code{server} (default: @code{xorg-server})
13739 This is the package providing the Xorg server.
13741 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13742 This is the list of command-line arguments to pass to the X server. The
13743 default is @code{-nolisten tcp}.
13747 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13748 [@var{login-manager-service-type}]
13749 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13750 @var{config}, an @code{<xorg-configuration>} record.
13752 Since the Xorg configuration is embedded in the log-in manager's
13753 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13754 shorthand to set the Xorg configuration.
13757 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13758 Return a @code{startx} script in which the modules, fonts, etc. specified
13759 in @var{config}, are available. The result should be used in place of
13762 Usually the X server is started by a login manager.
13766 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13767 Add @var{package}, a package for a screen locker or screen saver whose
13768 command is @var{program}, to the set of setuid programs and add a PAM entry
13769 for it. For example:
13772 (screen-locker-service xlockmore "xlock")
13775 makes the good ol' XlockMore usable.
13779 @node Printing Services
13780 @subsection Printing Services
13782 @cindex printer support with CUPS
13783 The @code{(gnu services cups)} module provides a Guix service definition
13784 for the CUPS printing service. To add printer support to a Guix
13785 system, add a @code{cups-service} to the operating system definition:
13787 @deffn {Scheme Variable} cups-service-type
13788 The service type for the CUPS print server. Its value should be a valid
13789 CUPS configuration (see below). To use the default settings, simply
13792 (service cups-service-type)
13796 The CUPS configuration controls the basic things about your CUPS
13797 installation: what interfaces it listens on, what to do if a print job
13798 fails, how much logging to do, and so on. To actually add a printer,
13799 you have to visit the @url{http://localhost:631} URL, or use a tool such
13800 as GNOME's printer configuration services. By default, configuring a
13801 CUPS service will generate a self-signed certificate if needed, for
13802 secure connections to the print server.
13804 Suppose you want to enable the Web interface of CUPS and also add
13805 support for Epson printers @i{via} the @code{escpr} package and for HP
13806 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13807 like this (you need to use the @code{(gnu packages cups)} module):
13810 (service cups-service-type
13811 (cups-configuration
13812 (web-interface? #t)
13814 (list cups-filters escpr hplip-minimal))))
13817 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13818 package then it is suggested that you install the @code{hplip} package,
13819 either in your OS configuration file or as your user.
13821 The available configuration parameters follow. Each parameter
13822 definition is preceded by its type; for example, @samp{string-list foo}
13823 indicates that the @code{foo} parameter should be specified as a list of
13824 strings. There is also a way to specify the configuration as a string,
13825 if you have an old @code{cupsd.conf} file that you want to port over
13826 from some other system; see the end for more details.
13828 @c The following documentation was initially generated by
13829 @c (generate-documentation) in (gnu services cups). Manually maintained
13830 @c documentation is better, so we shouldn't hesitate to edit below as
13831 @c needed. However if the change you want to make to this documentation
13832 @c can be done in an automated way, it's probably easier to change
13833 @c (generate-documentation) than to make it below and have to deal with
13834 @c the churn as CUPS updates.
13837 Available @code{cups-configuration} fields are:
13839 @deftypevr {@code{cups-configuration} parameter} package cups
13843 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13844 Drivers and other extensions to the CUPS package.
13847 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13848 Configuration of where to write logs, what directories to use for print
13849 spools, and related privileged configuration parameters.
13851 Available @code{files-configuration} fields are:
13853 @deftypevr {@code{files-configuration} parameter} log-location access-log
13854 Defines the access log filename. Specifying a blank filename disables
13855 access log generation. The value @code{stderr} causes log entries to be
13856 sent to the standard error file when the scheduler is running in the
13857 foreground, or to the system log daemon when run in the background. The
13858 value @code{syslog} causes log entries to be sent to the system log
13859 daemon. The server name may be included in filenames using the string
13860 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13862 Defaults to @samp{"/var/log/cups/access_log"}.
13865 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13866 Where CUPS should cache data.
13868 Defaults to @samp{"/var/cache/cups"}.
13871 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13872 Specifies the permissions for all configuration files that the scheduler
13875 Note that the permissions for the printers.conf file are currently
13876 masked to only allow access from the scheduler user (typically root).
13877 This is done because printer device URIs sometimes contain sensitive
13878 authentication information that should not be generally known on the
13879 system. There is no way to disable this security feature.
13881 Defaults to @samp{"0640"}.
13884 @deftypevr {@code{files-configuration} parameter} log-location error-log
13885 Defines the error log filename. Specifying a blank filename disables
13886 error log generation. The value @code{stderr} causes log entries to be
13887 sent to the standard error file when the scheduler is running in the
13888 foreground, or to the system log daemon when run in the background. The
13889 value @code{syslog} causes log entries to be sent to the system log
13890 daemon. The server name may be included in filenames using the string
13891 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13893 Defaults to @samp{"/var/log/cups/error_log"}.
13896 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13897 Specifies which errors are fatal, causing the scheduler to exit. The
13902 No errors are fatal.
13905 All of the errors below are fatal.
13908 Browsing initialization errors are fatal, for example failed connections
13909 to the DNS-SD daemon.
13912 Configuration file syntax errors are fatal.
13915 Listen or Port errors are fatal, except for IPv6 failures on the
13916 loopback or @code{any} addresses.
13919 Log file creation or write errors are fatal.
13922 Bad startup file permissions are fatal, for example shared TLS
13923 certificate and key files with world-read permissions.
13926 Defaults to @samp{"all -browse"}.
13929 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13930 Specifies whether the file pseudo-device can be used for new printer
13931 queues. The URI @uref{file:///dev/null} is always allowed.
13933 Defaults to @samp{#f}.
13936 @deftypevr {@code{files-configuration} parameter} string group
13937 Specifies the group name or ID that will be used when executing external
13940 Defaults to @samp{"lp"}.
13943 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13944 Specifies the permissions for all log files that the scheduler writes.
13946 Defaults to @samp{"0644"}.
13949 @deftypevr {@code{files-configuration} parameter} log-location page-log
13950 Defines the page log filename. Specifying a blank filename disables
13951 page log generation. The value @code{stderr} causes log entries to be
13952 sent to the standard error file when the scheduler is running in the
13953 foreground, or to the system log daemon when run in the background. The
13954 value @code{syslog} causes log entries to be sent to the system log
13955 daemon. The server name may be included in filenames using the string
13956 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13958 Defaults to @samp{"/var/log/cups/page_log"}.
13961 @deftypevr {@code{files-configuration} parameter} string remote-root
13962 Specifies the username that is associated with unauthenticated accesses
13963 by clients claiming to be the root user. The default is @code{remroot}.
13965 Defaults to @samp{"remroot"}.
13968 @deftypevr {@code{files-configuration} parameter} file-name request-root
13969 Specifies the directory that contains print jobs and other HTTP request
13972 Defaults to @samp{"/var/spool/cups"}.
13975 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13976 Specifies the level of security sandboxing that is applied to print
13977 filters, backends, and other child processes of the scheduler; either
13978 @code{relaxed} or @code{strict}. This directive is currently only
13979 used/supported on macOS.
13981 Defaults to @samp{strict}.
13984 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13985 Specifies the location of TLS certificates and private keys. CUPS will
13986 look for public and private keys in this directory: a @code{.crt} files
13987 for PEM-encoded certificates and corresponding @code{.key} files for
13988 PEM-encoded private keys.
13990 Defaults to @samp{"/etc/cups/ssl"}.
13993 @deftypevr {@code{files-configuration} parameter} file-name server-root
13994 Specifies the directory containing the server configuration files.
13996 Defaults to @samp{"/etc/cups"}.
13999 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14000 Specifies whether the scheduler calls fsync(2) after writing
14001 configuration or state files.
14003 Defaults to @samp{#f}.
14006 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14007 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14010 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14011 Specifies the directory where temporary files are stored.
14013 Defaults to @samp{"/var/spool/cups/tmp"}.
14016 @deftypevr {@code{files-configuration} parameter} string user
14017 Specifies the user name or ID that is used when running external
14020 Defaults to @samp{"lp"}.
14024 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14025 Specifies the logging level for the AccessLog file. The @code{config}
14026 level logs when printers and classes are added, deleted, or modified and
14027 when configuration files are accessed or updated. The @code{actions}
14028 level logs when print jobs are submitted, held, released, modified, or
14029 canceled, and any of the conditions for @code{config}. The @code{all}
14030 level logs all requests.
14032 Defaults to @samp{actions}.
14035 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14036 Specifies whether to purge job history data automatically when it is no
14037 longer required for quotas.
14039 Defaults to @samp{#f}.
14042 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14043 Specifies which protocols to use for local printer sharing.
14045 Defaults to @samp{dnssd}.
14048 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14049 Specifies whether the CUPS web interface is advertised.
14051 Defaults to @samp{#f}.
14054 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14055 Specifies whether shared printers are advertised.
14057 Defaults to @samp{#f}.
14060 @deftypevr {@code{cups-configuration} parameter} string classification
14061 Specifies the security classification of the server. Any valid banner
14062 name can be used, including "classified", "confidential", "secret",
14063 "topsecret", and "unclassified", or the banner can be omitted to disable
14064 secure printing functions.
14066 Defaults to @samp{""}.
14069 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14070 Specifies whether users may override the classification (cover page) of
14071 individual print jobs using the @code{job-sheets} option.
14073 Defaults to @samp{#f}.
14076 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14077 Specifies the default type of authentication to use.
14079 Defaults to @samp{Basic}.
14082 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14083 Specifies whether encryption will be used for authenticated requests.
14085 Defaults to @samp{Required}.
14088 @deftypevr {@code{cups-configuration} parameter} string default-language
14089 Specifies the default language to use for text and web content.
14091 Defaults to @samp{"en"}.
14094 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14095 Specifies the default paper size for new print queues. @samp{"Auto"}
14096 uses a locale-specific default, while @samp{"None"} specifies there is
14097 no default paper size. Specific size names are typically
14098 @samp{"Letter"} or @samp{"A4"}.
14100 Defaults to @samp{"Auto"}.
14103 @deftypevr {@code{cups-configuration} parameter} string default-policy
14104 Specifies the default access policy to use.
14106 Defaults to @samp{"default"}.
14109 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14110 Specifies whether local printers are shared by default.
14112 Defaults to @samp{#t}.
14115 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14116 Specifies the delay for updating of configuration and state files, in
14117 seconds. A value of 0 causes the update to happen as soon as possible,
14118 typically within a few milliseconds.
14120 Defaults to @samp{30}.
14123 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14124 Specifies what to do when an error occurs. Possible values are
14125 @code{abort-job}, which will discard the failed print job;
14126 @code{retry-job}, which will retry the job at a later time;
14127 @code{retry-this-job}, which retries the failed job immediately; and
14128 @code{stop-printer}, which stops the printer.
14130 Defaults to @samp{stop-printer}.
14133 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14134 Specifies the maximum cost of filters that are run concurrently, which
14135 can be used to minimize disk, memory, and CPU resource problems. A
14136 limit of 0 disables filter limiting. An average print to a
14137 non-PostScript printer needs a filter limit of about 200. A PostScript
14138 printer needs about half that (100). Setting the limit below these
14139 thresholds will effectively limit the scheduler to printing a single job
14142 Defaults to @samp{0}.
14145 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14146 Specifies the scheduling priority of filters that are run to print a
14147 job. The nice value ranges from 0, the highest priority, to 19, the
14150 Defaults to @samp{0}.
14153 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14154 Specifies whether to do reverse lookups on connecting clients. The
14155 @code{double} setting causes @code{cupsd} to verify that the hostname
14156 resolved from the address matches one of the addresses returned for that
14157 hostname. Double lookups also prevent clients with unregistered
14158 addresses from connecting to your server. Only set this option to
14159 @code{#t} or @code{double} if absolutely required.
14161 Defaults to @samp{#f}.
14164 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14165 Specifies the number of seconds to wait before killing the filters and
14166 backend associated with a canceled or held job.
14168 Defaults to @samp{30}.
14171 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14172 Specifies the interval between retries of jobs in seconds. This is
14173 typically used for fax queues but can also be used with normal print
14174 queues whose error policy is @code{retry-job} or
14175 @code{retry-current-job}.
14177 Defaults to @samp{30}.
14180 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14181 Specifies the number of retries that are done for jobs. This is
14182 typically used for fax queues but can also be used with normal print
14183 queues whose error policy is @code{retry-job} or
14184 @code{retry-current-job}.
14186 Defaults to @samp{5}.
14189 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14190 Specifies whether to support HTTP keep-alive connections.
14192 Defaults to @samp{#t}.
14195 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14196 Specifies how long an idle client connection remains open, in seconds.
14198 Defaults to @samp{30}.
14201 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14202 Specifies the maximum size of print files, IPP requests, and HTML form
14203 data. A limit of 0 disables the limit check.
14205 Defaults to @samp{0}.
14208 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14209 Listens on the specified interfaces for connections. Valid values are
14210 of the form @var{address}:@var{port}, where @var{address} is either an
14211 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14212 indicate all addresses. Values can also be file names of local UNIX
14213 domain sockets. The Listen directive is similar to the Port directive
14214 but allows you to restrict access to specific interfaces or networks.
14217 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14218 Specifies the number of pending connections that will be allowed. This
14219 normally only affects very busy servers that have reached the MaxClients
14220 limit, but can also be triggered by large numbers of simultaneous
14221 connections. When the limit is reached, the operating system will
14222 refuse additional connections until the scheduler can accept the pending
14225 Defaults to @samp{128}.
14228 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14229 Specifies a set of additional access controls.
14231 Available @code{location-access-controls} fields are:
14233 @deftypevr {@code{location-access-controls} parameter} file-name path
14234 Specifies the URI path to which the access control applies.
14237 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14238 Access controls for all access to this path, in the same format as the
14239 @code{access-controls} of @code{operation-access-control}.
14241 Defaults to @samp{()}.
14244 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14245 Access controls for method-specific access to this path.
14247 Defaults to @samp{()}.
14249 Available @code{method-access-controls} fields are:
14251 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14252 If @code{#t}, apply access controls to all methods except the listed
14253 methods. Otherwise apply to only the listed methods.
14255 Defaults to @samp{#f}.
14258 @deftypevr {@code{method-access-controls} parameter} method-list methods
14259 Methods to which this access control applies.
14261 Defaults to @samp{()}.
14264 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14265 Access control directives, as a list of strings. Each string should be
14266 one directive, such as "Order allow,deny".
14268 Defaults to @samp{()}.
14273 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14274 Specifies the number of debugging messages that are retained for logging
14275 if an error occurs in a print job. Debug messages are logged regardless
14276 of the LogLevel setting.
14278 Defaults to @samp{100}.
14281 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14282 Specifies the level of logging for the ErrorLog file. The value
14283 @code{none} stops all logging while @code{debug2} logs everything.
14285 Defaults to @samp{info}.
14288 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14289 Specifies the format of the date and time in the log files. The value
14290 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14292 Defaults to @samp{standard}.
14295 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14296 Specifies the maximum number of simultaneous clients that are allowed by
14299 Defaults to @samp{100}.
14302 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14303 Specifies the maximum number of simultaneous clients that are allowed
14304 from a single address.
14306 Defaults to @samp{100}.
14309 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14310 Specifies the maximum number of copies that a user can print of each
14313 Defaults to @samp{9999}.
14316 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14317 Specifies the maximum time a job may remain in the @code{indefinite}
14318 hold state before it is canceled. A value of 0 disables cancellation of
14321 Defaults to @samp{0}.
14324 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14325 Specifies the maximum number of simultaneous jobs that are allowed. Set
14326 to 0 to allow an unlimited number of jobs.
14328 Defaults to @samp{500}.
14331 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14332 Specifies the maximum number of simultaneous jobs that are allowed per
14333 printer. A value of 0 allows up to MaxJobs jobs per printer.
14335 Defaults to @samp{0}.
14338 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14339 Specifies the maximum number of simultaneous jobs that are allowed per
14340 user. A value of 0 allows up to MaxJobs jobs per user.
14342 Defaults to @samp{0}.
14345 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14346 Specifies the maximum time a job may take to print before it is
14347 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14349 Defaults to @samp{10800}.
14352 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14353 Specifies the maximum size of the log files before they are rotated, in
14354 bytes. The value 0 disables log rotation.
14356 Defaults to @samp{1048576}.
14359 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14360 Specifies the maximum amount of time to allow between files in a
14361 multiple file print job, in seconds.
14363 Defaults to @samp{300}.
14366 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14367 Specifies the format of PageLog lines. Sequences beginning with percent
14368 (@samp{%}) characters are replaced with the corresponding information,
14369 while all other characters are copied literally. The following percent
14370 sequences are recognized:
14374 insert a single percent character
14377 insert the value of the specified IPP attribute
14380 insert the number of copies for the current page
14383 insert the current page number
14386 insert the current date and time in common log format
14392 insert the printer name
14395 insert the username
14398 A value of the empty string disables page logging. The string @code{%p
14399 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14400 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14403 Defaults to @samp{""}.
14406 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14407 Passes the specified environment variable(s) to child processes; a list
14410 Defaults to @samp{()}.
14413 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14414 Specifies named access control policies.
14416 Available @code{policy-configuration} fields are:
14418 @deftypevr {@code{policy-configuration} parameter} string name
14419 Name of the policy.
14422 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14423 Specifies an access list for a job's private values. @code{@@ACL} maps
14424 to the printer's requesting-user-name-allowed or
14425 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14426 owner. @code{@@SYSTEM} maps to the groups listed for the
14427 @code{system-group} field of the @code{files-config} configuration,
14428 which is reified into the @code{cups-files.conf(5)} file. Other
14429 possible elements of the access list include specific user names, and
14430 @code{@@@var{group}} to indicate members of a specific group. The
14431 access list may also be simply @code{all} or @code{default}.
14433 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14436 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14437 Specifies the list of job values to make private, or @code{all},
14438 @code{default}, or @code{none}.
14440 Defaults to @samp{"job-name job-originating-host-name
14441 job-originating-user-name phone"}.
14444 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14445 Specifies an access list for a subscription's private values.
14446 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14447 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14448 owner. @code{@@SYSTEM} maps to the groups listed for the
14449 @code{system-group} field of the @code{files-config} configuration,
14450 which is reified into the @code{cups-files.conf(5)} file. Other
14451 possible elements of the access list include specific user names, and
14452 @code{@@@var{group}} to indicate members of a specific group. The
14453 access list may also be simply @code{all} or @code{default}.
14455 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14458 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14459 Specifies the list of job values to make private, or @code{all},
14460 @code{default}, or @code{none}.
14462 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14463 notify-subscriber-user-name notify-user-data"}.
14466 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14467 Access control by IPP operation.
14469 Defaults to @samp{()}.
14473 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14474 Specifies whether job files (documents) are preserved after a job is
14475 printed. If a numeric value is specified, job files are preserved for
14476 the indicated number of seconds after printing. Otherwise a boolean
14477 value applies indefinitely.
14479 Defaults to @samp{86400}.
14482 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14483 Specifies whether the job history is preserved after a job is printed.
14484 If a numeric value is specified, the job history is preserved for the
14485 indicated number of seconds after printing. If @code{#t}, the job
14486 history is preserved until the MaxJobs limit is reached.
14488 Defaults to @samp{#t}.
14491 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14492 Specifies the amount of time to wait for job completion before
14493 restarting the scheduler.
14495 Defaults to @samp{30}.
14498 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14499 Specifies the maximum amount of memory to use when converting documents
14500 into bitmaps for a printer.
14502 Defaults to @samp{"128m"}.
14505 @deftypevr {@code{cups-configuration} parameter} string server-admin
14506 Specifies the email address of the server administrator.
14508 Defaults to @samp{"root@@localhost.localdomain"}.
14511 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14512 The ServerAlias directive is used for HTTP Host header validation when
14513 clients connect to the scheduler from external interfaces. Using the
14514 special name @code{*} can expose your system to known browser-based DNS
14515 rebinding attacks, even when accessing sites through a firewall. If the
14516 auto-discovery of alternate names does not work, we recommend listing
14517 each alternate name with a ServerAlias directive instead of using
14520 Defaults to @samp{*}.
14523 @deftypevr {@code{cups-configuration} parameter} string server-name
14524 Specifies the fully-qualified host name of the server.
14526 Defaults to @samp{"localhost"}.
14529 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14530 Specifies what information is included in the Server header of HTTP
14531 responses. @code{None} disables the Server header. @code{ProductOnly}
14532 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14533 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14534 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14535 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14536 2.0.0 (@var{uname}) IPP/2.0}.
14538 Defaults to @samp{Minimal}.
14541 @deftypevr {@code{cups-configuration} parameter} string set-env
14542 Set the specified environment variable to be passed to child processes.
14544 Defaults to @samp{"variable value"}.
14547 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14548 Listens on the specified interfaces for encrypted connections. Valid
14549 values are of the form @var{address}:@var{port}, where @var{address} is
14550 either an IPv6 address enclosed in brackets, an IPv4 address, or
14551 @code{*} to indicate all addresses.
14553 Defaults to @samp{()}.
14556 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14557 Sets encryption options. By default, CUPS only supports encryption
14558 using TLS v1.0 or higher using known secure cipher suites. The
14559 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14560 required for some older clients that do not implement newer ones. The
14561 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14562 older clients that do not support TLS v1.0.
14564 Defaults to @samp{()}.
14567 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14568 Specifies whether the scheduler requires clients to strictly adhere to
14569 the IPP specifications.
14571 Defaults to @samp{#f}.
14574 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14575 Specifies the HTTP request timeout, in seconds.
14577 Defaults to @samp{300}.
14581 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14582 Specifies whether the web interface is enabled.
14584 Defaults to @samp{#f}.
14587 At this point you're probably thinking ``oh dear, Guix manual, I like
14588 you but you can stop already with the configuration options''. Indeed.
14589 However, one more point: it could be that you have an existing
14590 @code{cupsd.conf} that you want to use. In that case, you can pass an
14591 @code{opaque-cups-configuration} as the configuration of a
14592 @code{cups-service-type}.
14594 Available @code{opaque-cups-configuration} fields are:
14596 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14600 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14601 The contents of the @code{cupsd.conf}, as a string.
14604 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14605 The contents of the @code{cups-files.conf} file, as a string.
14608 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14609 strings of the same name, you could instantiate a CUPS service like
14613 (service cups-service-type
14614 (opaque-cups-configuration
14615 (cupsd.conf cupsd.conf)
14616 (cups-files.conf cups-files.conf)))
14620 @node Desktop Services
14621 @subsection Desktop Services
14623 The @code{(gnu services desktop)} module provides services that are
14624 usually useful in the context of a ``desktop'' setup---that is, on a
14625 machine running a graphical display server, possibly with graphical user
14626 interfaces, etc. It also defines services that provide specific desktop
14627 environments like GNOME, Xfce or MATE.
14629 To simplify things, the module defines a variable containing the set of
14630 services that users typically expect on a machine with a graphical
14631 environment and networking:
14633 @defvr {Scheme Variable} %desktop-services
14634 This is a list of services that builds upon @var{%base-services} and
14635 adds or adjusts services for a typical ``desktop'' setup.
14637 In particular, it adds a graphical login manager (@pxref{X Window,
14638 @code{gdm-service-type}}), screen lockers, a network management tool
14639 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
14640 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
14641 energy and color management services, the @code{elogind} login and seat
14642 manager, the Polkit privilege service, the GeoClue location service, the
14643 AccountsService daemon that allows authorized users change system passwords,
14644 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
14645 name service switch service configured to be able to use @code{nss-mdns}
14646 (@pxref{Name Service Switch, mDNS}).
14649 The @var{%desktop-services} variable can be used as the @code{services}
14650 field of an @code{operating-system} declaration (@pxref{operating-system
14651 Reference, @code{services}}).
14653 Additionally, the @code{gnome-desktop-service-type},
14654 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14655 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14656 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14657 services like the backlight adjustment helpers and the power management
14658 utilities are added to the system, extending @code{polkit} and @code{dbus}
14659 appropriately, allowing GNOME to operate with elevated privileges on a
14660 limited number of special-purpose system interfaces. Additionally,
14661 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14662 metapackage to the system profile. Likewise, adding the Xfce service
14663 not only adds the @code{xfce} metapackage to the system profile, but it
14664 also gives the Thunar file manager the ability to open a ``root-mode''
14665 file management window, if the user authenticates using the
14666 administrator's password via the standard polkit graphical interface.
14667 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14668 appropriately, allowing MATE to operate with elevated privileges on a
14669 limited number of special-purpose system interfaces. Additionally,
14670 adding a service of type @code{mate-desktop-service-type} adds the MATE
14671 metapackage to the system profile. ``Adding Enlightenment'' means that
14672 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14673 are set as setuid, allowing Enlightenment's screen locker and other
14674 functionality to work as expetected.
14676 The desktop environments in Guix use the Xorg display server by
14677 default. If you'd like to use the newer display server protocol
14678 called Wayland, you need to use the @code{sddm-service} instead of
14679 GDM as the graphical login manager. You should then
14680 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14681 also try starting GNOME on Wayland manually from a TTY with the
14682 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14683 gnome-session``. Currently only GNOME has support for Wayland.
14685 @defvr {Scheme Variable} gnome-desktop-service-type
14686 This is the type of the service that adds the @uref{https://www.gnome.org,
14687 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14688 object (see below.)
14690 This service adds the @code{gnome} package to the system profile, and extends
14691 polkit with the actions from @code{gnome-settings-daemon}.
14694 @deftp {Data Type} gnome-desktop-configuration
14695 Configuration record for the GNOME desktop environment.
14698 @item @code{gnome} (default: @code{gnome})
14699 The GNOME package to use.
14703 @defvr {Scheme Variable} xfce-desktop-service-type
14704 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14705 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14708 This service adds the @code{xfce} package to the system profile, and
14709 extends polkit with the ability for @code{thunar} to manipulate the file
14710 system as root from within a user session, after the user has authenticated
14711 with the administrator's password.
14714 @deftp {Data Type} xfce-desktop-configuration
14715 Configuration record for the Xfce desktop environment.
14718 @item @code{xfce} (default: @code{xfce})
14719 The Xfce package to use.
14723 @deffn {Scheme Variable} mate-desktop-service-type
14724 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14725 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14726 object (see below.)
14728 This service adds the @code{mate} package to the system
14729 profile, and extends polkit with the actions from
14730 @code{mate-settings-daemon}.
14733 @deftp {Data Type} mate-desktop-configuration
14734 Configuration record for the MATE desktop environment.
14737 @item @code{mate} (default: @code{mate})
14738 The MATE package to use.
14742 @deffn {Scheme Variable} enlightenment-desktop-service-type
14743 Return a service that adds the @code{enlightenment} package to the system
14744 profile, and extends dbus with actions from @code{efl}.
14747 @deftp {Data Type} enlightenment-desktop-service-configuration
14749 @item @code{enlightenment} (default: @code{enlightenment})
14750 The enlightenment package to use.
14754 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14755 the default @code{%desktop-services} variable doesn't include any of
14756 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14757 @code{%desktop-services} in the @code{services} field of your
14758 @code{operating-system}:
14761 (use-modules (gnu))
14762 (use-service-modules desktop)
14765 ;; cons* adds items to the list given as its last argument.
14766 (services (cons* (service gnome-desktop-service-type)
14767 (service xfce-desktop-service)
14768 %desktop-services))
14772 These desktop environments will then be available as options in the
14773 graphical login window.
14775 The actual service definitions included in @code{%desktop-services} and
14776 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14777 are described below.
14779 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14780 Return a service that runs the ``system bus'', using @var{dbus}, with
14781 support for @var{services}.
14783 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14784 facility. Its system bus is used to allow system services to communicate
14785 and to be notified of system-wide events.
14787 @var{services} must be a list of packages that provide an
14788 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14789 and policy files. For example, to allow avahi-daemon to use the system bus,
14790 @var{services} must be equal to @code{(list avahi)}.
14793 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14794 Return a service that runs the @code{elogind} login and
14795 seat management daemon. @uref{https://github.com/elogind/elogind,
14796 Elogind} exposes a D-Bus interface that can be used to know which users
14797 are logged in, know what kind of sessions they have open, suspend the
14798 system, inhibit system suspend, reboot the system, and other tasks.
14800 Elogind handles most system-level power events for a computer, for
14801 example suspending the system when a lid is closed, or shutting it down
14802 when the power button is pressed.
14804 The @var{config} keyword argument specifies the configuration for
14805 elogind, and should be the result of an @code{(elogind-configuration
14806 (@var{parameter} @var{value})...)} invocation. Available parameters and
14807 their default values are:
14810 @item kill-user-processes?
14812 @item kill-only-users
14814 @item kill-exclude-users
14816 @item inhibit-delay-max-seconds
14818 @item handle-power-key
14820 @item handle-suspend-key
14822 @item handle-hibernate-key
14824 @item handle-lid-switch
14826 @item handle-lid-switch-docked
14828 @item power-key-ignore-inhibited?
14830 @item suspend-key-ignore-inhibited?
14832 @item hibernate-key-ignore-inhibited?
14834 @item lid-switch-ignore-inhibited?
14836 @item holdoff-timeout-seconds
14840 @item idle-action-seconds
14842 @item runtime-directory-size-percent
14844 @item runtime-directory-size
14848 @item suspend-state
14849 @code{("mem" "standby" "freeze")}
14852 @item hibernate-state
14854 @item hibernate-mode
14855 @code{("platform" "shutdown")}
14856 @item hybrid-sleep-state
14858 @item hybrid-sleep-mode
14859 @code{("suspend" "platform" "shutdown")}
14863 @deffn {Scheme Procedure} accountsservice-service @
14864 [#:accountsservice @var{accountsservice}]
14865 Return a service that runs AccountsService, a system service that can
14866 list available accounts, change their passwords, and so on.
14867 AccountsService integrates with PolicyKit to enable unprivileged users
14868 to acquire the capability to modify their system configuration.
14869 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14870 accountsservice web site} for more information.
14872 The @var{accountsservice} keyword argument is the @code{accountsservice}
14873 package to expose as a service.
14876 @deffn {Scheme Procedure} polkit-service @
14877 [#:polkit @var{polkit}]
14878 Return a service that runs the
14879 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14880 management service}, which allows system administrators to grant access to
14881 privileged operations in a structured way. By querying the Polkit service, a
14882 privileged system component can know when it should grant additional
14883 capabilities to ordinary users. For example, an ordinary user can be granted
14884 the capability to suspend the system if the user is logged in locally.
14887 @defvr {Scheme Variable} upower-service-type
14888 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
14889 system-wide monitor for power consumption and battery levels, with the given
14890 configuration settings.
14892 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14893 notably used by GNOME.
14896 @deftp {Data Type} upower-configuration
14897 Data type representation the configuration for UPower.
14901 @item @code{upower} (default: @var{upower})
14902 Package to use for @code{upower}.
14904 @item @code{watts-up-pro?} (default: @code{#f})
14905 Enable the Watts Up Pro device.
14907 @item @code{poll-batteries?} (default: @code{#t})
14908 Enable polling the kernel for battery level changes.
14910 @item @code{ignore-lid?} (default: @code{#f})
14911 Ignore the lid state, this can be useful if it's incorrect on a device.
14913 @item @code{use-percentage-for-policy?} (default: @code{#f})
14914 Whether battery percentage based policy should be used. The default is to use
14915 the time left, change to @code{#t} to use the percentage.
14917 @item @code{percentage-low} (default: @code{10})
14918 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14919 at which the battery is considered low.
14921 @item @code{percentage-critical} (default: @code{3})
14922 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14923 at which the battery is considered critical.
14925 @item @code{percentage-action} (default: @code{2})
14926 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14927 at which action will be taken.
14929 @item @code{time-low} (default: @code{1200})
14930 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14931 seconds at which the battery is considered low.
14933 @item @code{time-critical} (default: @code{300})
14934 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14935 seconds at which the battery is considered critical.
14937 @item @code{time-action} (default: @code{120})
14938 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14939 seconds at which action will be taken.
14941 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14942 The action taken when @code{percentage-action} or @code{time-action} is
14943 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14945 Possible values are:
14955 @code{'hybrid-sleep}.
14961 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14962 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
14963 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14964 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14965 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14968 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14969 Return a service that runs @command{colord}, a system service with a D-Bus
14970 interface to manage the color profiles of input and output devices such as
14971 screens and scanners. It is notably used by the GNOME Color Manager graphical
14972 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
14973 site} for more information.
14976 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14977 Return a configuration allowing an application to access GeoClue
14978 location data. @var{name} is the Desktop ID of the application, without
14979 the @code{.desktop} part. If @var{allowed?} is true, the application
14980 will have access to location information by default. The boolean
14981 @var{system?} value indicates whether an application is a system component
14982 or not. Finally @var{users} is a list of UIDs of all users for which
14983 this application is allowed location info access. An empty users list
14984 means that all users are allowed.
14987 @defvr {Scheme Variable} %standard-geoclue-applications
14988 The standard list of well-known GeoClue application configurations,
14989 granting authority to the GNOME date-and-time utility to ask for the
14990 current location in order to set the time zone, and allowing the
14991 IceCat and Epiphany web browsers to request location information.
14992 IceCat and Epiphany both query the user before allowing a web page to
14993 know the user's location.
14996 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14997 [#:whitelist '()] @
14998 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14999 [#:submit-data? #f]
15000 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15001 [#:submission-nick "geoclue"] @
15002 [#:applications %standard-geoclue-applications]
15003 Return a service that runs the GeoClue location service. This service
15004 provides a D-Bus interface to allow applications to request access to a
15005 user's physical location, and optionally to add information to online
15006 location databases. See
15007 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15008 web site} for more information.
15011 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15012 [@w{#:auto-enable? #f}]
15013 Return a service that runs the @command{bluetoothd} daemon, which
15014 manages all the Bluetooth devices and provides a number of D-Bus
15015 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15016 powered automatically at boot, which can be useful when using a
15017 bluetooth keyboard or mouse.
15019 Users need to be in the @code{lp} group to access the D-Bus service.
15022 @node Sound Services
15023 @subsection Sound Services
15025 @cindex sound support
15027 @cindex PulseAudio, sound support
15029 The @code{(gnu services sound)} module provides a service to configure the
15030 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15031 preferred ALSA output driver.
15033 @deffn {Scheme Variable} alsa-service-type
15034 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15035 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15036 configuration file. The value for this type is a @command{alsa-configuration}
15037 record as in this example:
15040 (service alsa-service-type)
15043 See below for details about @code{alsa-configuration}.
15046 @deftp {Data Type} alsa-configuration
15047 Data type representing the configuration for @code{alsa-service}.
15050 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15051 @code{alsa-plugins} package to use.
15053 @item @code{pulseaudio?} (default: @var{#t})
15054 Whether ALSA applications should transparently be made to use the
15055 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15057 Using PulseAudio allows you to run several sound-producing applications
15058 at the same time and to individual control them @i{via}
15059 @command{pavucontrol}, among other things.
15061 @item @code{extra-options} (default: @var{""})
15062 String to append to the @file{/etc/asound.conf} file.
15067 Individual users who want to override the system configuration of ALSA can do
15068 it with the @file{~/.asoundrc} file:
15071 # In guix, we have to specify the absolute path for plugins.
15073 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15076 # Routing ALSA to jack:
15077 # <http://jackaudio.org/faq/routing_alsa.html>.
15081 0 system:playback_1
15082 1 system:playback_2
15099 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15103 @node Database Services
15104 @subsection Database Services
15108 The @code{(gnu services databases)} module provides the following services.
15110 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15111 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15112 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15113 Return a service that runs @var{postgresql}, the PostgreSQL database
15116 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15117 creates a database cluster with @var{locale} as the default
15118 locale, stored in @var{data-directory}. It then listens on @var{port}.
15120 @cindex postgresql extension-packages
15121 Additional extensions are loaded from packages listed in
15122 @var{extension-packages}. Extensions are available at runtime. For instance,
15123 to create a geographic database using the @code{postgis} extension, a user can
15124 configure the postgresql-service as in this example:
15128 (use-package-modules databases geo)
15132 ;; postgresql is required to run `psql' but postgis is not required for
15133 ;; proper operation.
15134 (packages (cons* postgresql %base-packages))
15137 (postgresql-service #:extension-packages (list postgis))
15141 Then the extension becomes visible and you can initialise an empty geographic
15142 database in this way:
15146 > create database postgistest;
15147 > \connect postgistest;
15148 > create extension postgis;
15149 > create extension postgis_topology;
15152 There is no need to add this field for contrib extensions such as hstore or
15153 dblink as they are already loadable by postgresql. This field is only
15154 required to add extensions provided by other packages.
15157 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15158 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15161 The optional @var{config} argument specifies the configuration for
15162 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15165 @deftp {Data Type} mysql-configuration
15166 Data type representing the configuration of @var{mysql-service}.
15169 @item @code{mysql} (default: @var{mariadb})
15170 Package object of the MySQL database server, can be either @var{mariadb}
15173 For MySQL, a temporary root password will be displayed at activation time.
15174 For MariaDB, the root password is empty.
15176 @item @code{port} (default: @code{3306})
15177 TCP port on which the database server listens for incoming connections.
15181 @defvr {Scheme Variable} memcached-service-type
15182 This is the service type for the @uref{https://memcached.org/,
15183 Memcached} service, which provides a distributed in memory cache. The
15184 value for the service type is a @code{memcached-configuration} object.
15188 (service memcached-service-type)
15191 @deftp {Data Type} memcached-configuration
15192 Data type representing the configuration of memcached.
15195 @item @code{memcached} (default: @code{memcached})
15196 The Memcached package to use.
15198 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15199 Network interfaces on which to listen.
15201 @item @code{tcp-port} (default: @code{11211})
15202 Port on which to accept connections on,
15204 @item @code{udp-port} (default: @code{11211})
15205 Port on which to accept UDP connections on, a value of 0 will disable
15206 listening on a UDP socket.
15208 @item @code{additional-options} (default: @code{'()})
15209 Additional command line options to pass to @code{memcached}.
15213 @defvr {Scheme Variable} mongodb-service-type
15214 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15215 The value for the service type is a @code{mongodb-configuration} object.
15219 (service mongodb-service-type)
15222 @deftp {Data Type} mongodb-configuration
15223 Data type representing the configuration of mongodb.
15226 @item @code{mongodb} (default: @code{mongodb})
15227 The MongoDB package to use.
15229 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15230 The configuration file for MongoDB.
15232 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15233 This value is used to create the directory, so that it exists and is
15234 owned by the mongodb user. It should match the data-directory which
15235 MongoDB is configured to use through the configuration file.
15239 @defvr {Scheme Variable} redis-service-type
15240 This is the service type for the @uref{https://redis.io/, Redis}
15241 key/value store, whose value is a @code{redis-configuration} object.
15244 @deftp {Data Type} redis-configuration
15245 Data type representing the configuration of redis.
15248 @item @code{redis} (default: @code{redis})
15249 The Redis package to use.
15251 @item @code{bind} (default: @code{"127.0.0.1"})
15252 Network interface on which to listen.
15254 @item @code{port} (default: @code{6379})
15255 Port on which to accept connections on, a value of 0 will disable
15256 listening on a TCP socket.
15258 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15259 Directory in which to store the database and related files.
15263 @node Mail Services
15264 @subsection Mail Services
15268 The @code{(gnu services mail)} module provides Guix service definitions
15269 for email services: IMAP, POP3, and LMTP servers, as well as mail
15270 transport agents (MTAs). Lots of acronyms! These services are detailed
15271 in the subsections below.
15273 @subsubheading Dovecot Service
15275 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15276 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15279 By default, Dovecot does not need much configuration; the default
15280 configuration object created by @code{(dovecot-configuration)} will
15281 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15282 certificate will be generated for TLS-protected connections, though
15283 Dovecot will also listen on cleartext ports by default. There are a
15284 number of options, though, which mail administrators might need to change,
15285 and as is the case with other services, Guix allows the system
15286 administrator to specify these parameters via a uniform Scheme interface.
15288 For example, to specify that mail is located at @code{maildir~/.mail},
15289 one would instantiate the Dovecot service like this:
15292 (dovecot-service #:config
15293 (dovecot-configuration
15294 (mail-location "maildir:~/.mail")))
15297 The available configuration parameters follow. Each parameter
15298 definition is preceded by its type; for example, @samp{string-list foo}
15299 indicates that the @code{foo} parameter should be specified as a list of
15300 strings. There is also a way to specify the configuration as a string,
15301 if you have an old @code{dovecot.conf} file that you want to port over
15302 from some other system; see the end for more details.
15304 @c The following documentation was initially generated by
15305 @c (generate-documentation) in (gnu services mail). Manually maintained
15306 @c documentation is better, so we shouldn't hesitate to edit below as
15307 @c needed. However if the change you want to make to this documentation
15308 @c can be done in an automated way, it's probably easier to change
15309 @c (generate-documentation) than to make it below and have to deal with
15310 @c the churn as dovecot updates.
15312 Available @code{dovecot-configuration} fields are:
15314 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15315 The dovecot package.
15318 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15319 A list of IPs or hosts where to listen for connections. @samp{*}
15320 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15321 interfaces. If you want to specify non-default ports or anything more
15322 complex, customize the address and port fields of the
15323 @samp{inet-listener} of the specific services you are interested in.
15326 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15327 List of protocols we want to serve. Available protocols include
15328 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15330 Available @code{protocol-configuration} fields are:
15332 @deftypevr {@code{protocol-configuration} parameter} string name
15333 The name of the protocol.
15336 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15337 UNIX socket path to the master authentication server to find users.
15338 This is used by imap (for shared users) and lda.
15339 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15342 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15343 Space separated list of plugins to load.
15346 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15347 Maximum number of IMAP connections allowed for a user from each IP
15348 address. NOTE: The username is compared case-sensitively.
15349 Defaults to @samp{10}.
15354 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15355 List of services to enable. Available services include @samp{imap},
15356 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15359 Available @code{service-configuration} fields are:
15361 @deftypevr {@code{service-configuration} parameter} string kind
15362 The service kind. Valid values include @code{director},
15363 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15364 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15365 @code{tcpwrap}, @code{quota-warning}, or anything else.
15368 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15369 Listeners for the service. A listener is either a
15370 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15371 an @code{inet-listener-configuration}.
15372 Defaults to @samp{()}.
15374 Available @code{unix-listener-configuration} fields are:
15376 @deftypevr {@code{unix-listener-configuration} parameter} string path
15377 Path to the file, relative to @code{base-dir} field. This is also used as
15381 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15382 The access mode for the socket.
15383 Defaults to @samp{"0600"}.
15386 @deftypevr {@code{unix-listener-configuration} parameter} string user
15387 The user to own the socket.
15388 Defaults to @samp{""}.
15391 @deftypevr {@code{unix-listener-configuration} parameter} string group
15392 The group to own the socket.
15393 Defaults to @samp{""}.
15397 Available @code{fifo-listener-configuration} fields are:
15399 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15400 Path to the file, relative to @code{base-dir} field. This is also used as
15404 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15405 The access mode for the socket.
15406 Defaults to @samp{"0600"}.
15409 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15410 The user to own the socket.
15411 Defaults to @samp{""}.
15414 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15415 The group to own the socket.
15416 Defaults to @samp{""}.
15420 Available @code{inet-listener-configuration} fields are:
15422 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15423 The protocol to listen for.
15426 @deftypevr {@code{inet-listener-configuration} parameter} string address
15427 The address on which to listen, or empty for all addresses.
15428 Defaults to @samp{""}.
15431 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15432 The port on which to listen.
15435 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15436 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15438 Defaults to @samp{#t}.
15443 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15444 Maximum number of simultaneous client connections per process. Once
15445 this number of connections is received, the next incoming connection
15446 will prompt Dovecot to spawn another process. If set to 0,
15447 @code{default-client-limit} is used instead.
15449 Defaults to @samp{0}.
15453 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15454 Number of connections to handle before starting a new process.
15455 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15456 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15457 Defaults to @samp{1}.
15461 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15462 Maximum number of processes that can exist for this service. If set to
15463 0, @code{default-process-limit} is used instead.
15465 Defaults to @samp{0}.
15469 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15470 Number of processes to always keep waiting for more connections.
15471 Defaults to @samp{0}.
15474 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15475 If you set @samp{service-count 0}, you probably need to grow
15477 Defaults to @samp{256000000}.
15482 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15483 Dict configuration, as created by the @code{dict-configuration}
15486 Available @code{dict-configuration} fields are:
15488 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15489 A list of key-value pairs that this dict should hold.
15490 Defaults to @samp{()}.
15495 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15496 A list of passdb configurations, each one created by the
15497 @code{passdb-configuration} constructor.
15499 Available @code{passdb-configuration} fields are:
15501 @deftypevr {@code{passdb-configuration} parameter} string driver
15502 The driver that the passdb should use. Valid values include
15503 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15505 Defaults to @samp{"pam"}.
15508 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15509 Space separated list of arguments to the passdb driver.
15510 Defaults to @samp{""}.
15515 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15516 List of userdb configurations, each one created by the
15517 @code{userdb-configuration} constructor.
15519 Available @code{userdb-configuration} fields are:
15521 @deftypevr {@code{userdb-configuration} parameter} string driver
15522 The driver that the userdb should use. Valid values include
15523 @samp{passwd} and @samp{static}.
15524 Defaults to @samp{"passwd"}.
15527 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15528 Space separated list of arguments to the userdb driver.
15529 Defaults to @samp{""}.
15532 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15533 Override fields from passwd.
15534 Defaults to @samp{()}.
15539 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15540 Plug-in configuration, created by the @code{plugin-configuration}
15544 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15545 List of namespaces. Each item in the list is created by the
15546 @code{namespace-configuration} constructor.
15548 Available @code{namespace-configuration} fields are:
15550 @deftypevr {@code{namespace-configuration} parameter} string name
15551 Name for this namespace.
15554 @deftypevr {@code{namespace-configuration} parameter} string type
15555 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15556 Defaults to @samp{"private"}.
15559 @deftypevr {@code{namespace-configuration} parameter} string separator
15560 Hierarchy separator to use. You should use the same separator for
15561 all namespaces or some clients get confused. @samp{/} is usually a good
15562 one. The default however depends on the underlying mail storage
15564 Defaults to @samp{""}.
15567 @deftypevr {@code{namespace-configuration} parameter} string prefix
15568 Prefix required to access this namespace. This needs to be
15569 different for all namespaces. For example @samp{Public/}.
15570 Defaults to @samp{""}.
15573 @deftypevr {@code{namespace-configuration} parameter} string location
15574 Physical location of the mailbox. This is in the same format as
15575 mail_location, which is also the default for it.
15576 Defaults to @samp{""}.
15579 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15580 There can be only one INBOX, and this setting defines which
15582 Defaults to @samp{#f}.
15585 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15586 If namespace is hidden, it's not advertised to clients via NAMESPACE
15587 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15588 useful when converting from another server with different namespaces
15589 which you want to deprecate but still keep working. For example you can
15590 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15592 Defaults to @samp{#f}.
15595 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15596 Show the mailboxes under this namespace with the LIST command. This
15597 makes the namespace visible for clients that do not support the NAMESPACE
15598 extension. The special @code{children} value lists child mailboxes, but
15599 hides the namespace prefix.
15600 Defaults to @samp{#t}.
15603 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15604 Namespace handles its own subscriptions. If set to @code{#f}, the
15605 parent namespace handles them. The empty prefix should always have this
15607 Defaults to @samp{#t}.
15610 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15611 List of predefined mailboxes in this namespace.
15612 Defaults to @samp{()}.
15614 Available @code{mailbox-configuration} fields are:
15616 @deftypevr {@code{mailbox-configuration} parameter} string name
15617 Name for this mailbox.
15620 @deftypevr {@code{mailbox-configuration} parameter} string auto
15621 @samp{create} will automatically create this mailbox.
15622 @samp{subscribe} will both create and subscribe to the mailbox.
15623 Defaults to @samp{"no"}.
15626 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15627 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15628 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15629 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15630 Defaults to @samp{()}.
15637 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15638 Base directory where to store runtime data.
15639 Defaults to @samp{"/var/run/dovecot/"}.
15642 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15643 Greeting message for clients.
15644 Defaults to @samp{"Dovecot ready."}.
15647 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15648 List of trusted network ranges. Connections from these IPs are
15649 allowed to override their IP addresses and ports (for logging and for
15650 authentication checks). @samp{disable-plaintext-auth} is also ignored
15651 for these networks. Typically you would specify your IMAP proxy servers
15653 Defaults to @samp{()}.
15656 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15657 List of login access check sockets (e.g.@: tcpwrap).
15658 Defaults to @samp{()}.
15661 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15662 Show more verbose process titles (in ps). Currently shows user name
15663 and IP address. Useful for seeing who is actually using the IMAP
15664 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15666 Defaults to @samp{#f}.
15669 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15670 Should all processes be killed when Dovecot master process shuts down.
15671 Setting this to @code{#f} means that Dovecot can be upgraded without
15672 forcing existing client connections to close (although that could also
15673 be a problem if the upgrade is e.g.@: due to a security fix).
15674 Defaults to @samp{#t}.
15677 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15678 If non-zero, run mail commands via this many connections to doveadm
15679 server, instead of running them directly in the same process.
15680 Defaults to @samp{0}.
15683 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15684 UNIX socket or host:port used for connecting to doveadm server.
15685 Defaults to @samp{"doveadm-server"}.
15688 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15689 List of environment variables that are preserved on Dovecot startup
15690 and passed down to all of its child processes. You can also give
15691 key=value pairs to always set specific settings.
15694 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15695 Disable LOGIN command and all other plaintext authentications unless
15696 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15697 matches the local IP (i.e.@: you're connecting from the same computer),
15698 the connection is considered secure and plaintext authentication is
15699 allowed. See also ssl=required setting.
15700 Defaults to @samp{#t}.
15703 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15704 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15705 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15706 for caching to be used.
15707 Defaults to @samp{0}.
15710 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15711 Time to live for cached data. After TTL expires the cached record
15712 is no longer used, *except* if the main database lookup returns internal
15713 failure. We also try to handle password changes automatically: If
15714 user's previous authentication was successful, but this one wasn't, the
15715 cache isn't used. For now this works only with plaintext
15717 Defaults to @samp{"1 hour"}.
15720 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15721 TTL for negative hits (user not found, password mismatch).
15722 0 disables caching them completely.
15723 Defaults to @samp{"1 hour"}.
15726 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15727 List of realms for SASL authentication mechanisms that need them.
15728 You can leave it empty if you don't want to support multiple realms.
15729 Many clients simply use the first one listed here, so keep the default
15731 Defaults to @samp{()}.
15734 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15735 Default realm/domain to use if none was specified. This is used for
15736 both SASL realms and appending @@domain to username in plaintext
15738 Defaults to @samp{""}.
15741 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15742 List of allowed characters in username. If the user-given username
15743 contains a character not listed in here, the login automatically fails.
15744 This is just an extra check to make sure user can't exploit any
15745 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15746 you want to allow all characters, set this value to empty.
15747 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15750 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15751 Username character translations before it's looked up from
15752 databases. The value contains series of from -> to characters. For
15753 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15754 translated to @samp{@@}.
15755 Defaults to @samp{""}.
15758 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15759 Username formatting before it's looked up from databases. You can
15760 use the standard variables here, e.g.@: %Lu would lowercase the username,
15761 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15762 change the @samp{@@} into @samp{-AT-}. This translation is done after
15763 @samp{auth-username-translation} changes.
15764 Defaults to @samp{"%Lu"}.
15767 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15768 If you want to allow master users to log in by specifying the master
15769 username within the normal username string (i.e.@: not using SASL
15770 mechanism's support for it), you can specify the separator character
15771 here. The format is then <username><separator><master username>.
15772 UW-IMAP uses @samp{*} as the separator, so that could be a good
15774 Defaults to @samp{""}.
15777 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15778 Username to use for users logging in with ANONYMOUS SASL
15780 Defaults to @samp{"anonymous"}.
15783 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15784 Maximum number of dovecot-auth worker processes. They're used to
15785 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15786 They're automatically created and destroyed as needed.
15787 Defaults to @samp{30}.
15790 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15791 Host name to use in GSSAPI principal names. The default is to use
15792 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15793 allow all keytab entries.
15794 Defaults to @samp{""}.
15797 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15798 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15799 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15800 need to change the auth service to run as root to be able to read this
15802 Defaults to @samp{""}.
15805 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15806 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15807 and @samp{ntlm-auth} helper.
15808 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15809 Defaults to @samp{#f}.
15812 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15813 Path for Samba's @samp{ntlm-auth} helper binary.
15814 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15817 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15818 Time to delay before replying to failed authentications.
15819 Defaults to @samp{"2 secs"}.
15822 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15823 Require a valid SSL client certificate or the authentication
15825 Defaults to @samp{#f}.
15828 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15829 Take the username from client's SSL certificate, using
15830 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15832 Defaults to @samp{#f}.
15835 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15836 List of wanted authentication mechanisms. Supported mechanisms are:
15837 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15838 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15839 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15840 @samp{disable-plaintext-auth} setting.
15843 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15844 List of IPs or hostnames to all director servers, including ourself.
15845 Ports can be specified as ip:port. The default port is the same as what
15846 director service's @samp{inet-listener} is using.
15847 Defaults to @samp{()}.
15850 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15851 List of IPs or hostnames to all backend mail servers. Ranges are
15852 allowed too, like 10.0.0.10-10.0.0.30.
15853 Defaults to @samp{()}.
15856 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15857 How long to redirect users to a specific server after it no longer
15858 has any connections.
15859 Defaults to @samp{"15 min"}.
15862 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15863 How the username is translated before being hashed. Useful values
15864 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15865 are shared within domain.
15866 Defaults to @samp{"%Lu"}.
15869 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15870 Log file to use for error messages. @samp{syslog} logs to syslog,
15871 @samp{/dev/stderr} logs to stderr.
15872 Defaults to @samp{"syslog"}.
15875 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15876 Log file to use for informational messages. Defaults to
15878 Defaults to @samp{""}.
15881 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15882 Log file to use for debug messages. Defaults to
15883 @samp{info-log-path}.
15884 Defaults to @samp{""}.
15887 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15888 Syslog facility to use if you're logging to syslog. Usually if you
15889 don't want to use @samp{mail}, you'll use local0..local7. Also other
15890 standard facilities are supported.
15891 Defaults to @samp{"mail"}.
15894 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15895 Log unsuccessful authentication attempts and the reasons why they
15897 Defaults to @samp{#f}.
15900 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
15901 In case of password mismatches, log the attempted password. Valid
15902 values are no, plain and sha1. sha1 can be useful for detecting brute
15903 force password attempts vs. user simply trying the same password over
15904 and over again. You can also truncate the value to n chars by appending
15905 ":n" (e.g.@: sha1:6).
15906 Defaults to @samp{"no"}.
15909 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15910 Even more verbose logging for debugging purposes. Shows for example
15912 Defaults to @samp{#f}.
15915 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15916 In case of password mismatches, log the passwords and used scheme so
15917 the problem can be debugged. Enabling this also enables
15919 Defaults to @samp{#f}.
15922 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15923 Enable mail process debugging. This can help you figure out why
15924 Dovecot isn't finding your mails.
15925 Defaults to @samp{#f}.
15928 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15929 Show protocol level SSL errors.
15930 Defaults to @samp{#f}.
15933 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15934 Prefix for each line written to log file. % codes are in
15935 strftime(3) format.
15936 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15939 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15940 List of elements we want to log. The elements which have a
15941 non-empty variable value are joined together to form a comma-separated
15945 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15946 Login log format. %s contains @samp{login-log-format-elements}
15947 string, %$ contains the data we want to log.
15948 Defaults to @samp{"%$: %s"}.
15951 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15952 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15953 of possible variables you can use.
15954 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15957 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15958 Format to use for logging mail deliveries. You can use variables:
15961 Delivery status message (e.g.@: @samp{saved to INBOX})
15973 Defaults to @samp{"msgid=%m: %$"}.
15976 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15977 Location for users' mailboxes. The default is empty, which means
15978 that Dovecot tries to find the mailboxes automatically. This won't work
15979 if the user doesn't yet have any mail, so you should explicitly tell
15980 Dovecot the full location.
15982 If you're using mbox, giving a path to the INBOX
15983 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15984 where the other mailboxes are kept. This is called the "root mail
15985 directory", and it must be the first path given in the
15986 @samp{mail-location} setting.
15988 There are a few special variables you can use, eg.:
15994 user part in user@@domain, same as %u if there's no domain
15996 domain part in user@@domain, empty if there's no domain
16001 See doc/wiki/Variables.txt for full list. Some examples:
16003 @item maildir:~/Maildir
16004 @item mbox:~/mail:INBOX=/var/mail/%u
16005 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16007 Defaults to @samp{""}.
16010 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16011 System user and group used to access mails. If you use multiple,
16012 userdb can override these by returning uid or gid fields. You can use
16013 either numbers or names. <doc/wiki/UserIds.txt>.
16014 Defaults to @samp{""}.
16017 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16019 Defaults to @samp{""}.
16022 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16023 Group to enable temporarily for privileged operations. Currently
16024 this is used only with INBOX when either its initial creation or
16025 dotlocking fails. Typically this is set to "mail" to give access to
16027 Defaults to @samp{""}.
16030 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16031 Grant access to these supplementary groups for mail processes.
16032 Typically these are used to set up access to shared mailboxes. Note
16033 that it may be dangerous to set these if users can create
16034 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16035 could allow a user to delete others' mailboxes, or ln -s
16036 /secret/shared/box ~/mail/mybox would allow reading it).
16037 Defaults to @samp{""}.
16040 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16041 Allow full file system access to clients. There's no access checks
16042 other than what the operating system does for the active UID/GID. It
16043 works with both maildir and mboxes, allowing you to prefix mailboxes
16044 names with e.g.@: /path/ or ~user/.
16045 Defaults to @samp{#f}.
16048 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16049 Don't use mmap() at all. This is required if you store indexes to
16050 shared file systems (NFS or clustered file system).
16051 Defaults to @samp{#f}.
16054 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16055 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16056 supports @samp{O_EXCL} since version 3, so this should be safe to use
16057 nowadays by default.
16058 Defaults to @samp{#t}.
16061 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16062 When to use fsync() or fdatasync() calls:
16065 Whenever necessary to avoid losing important data
16067 Useful with e.g.@: NFS when write()s are delayed
16069 Never use it (best performance, but crashes can lose data).
16071 Defaults to @samp{"optimized"}.
16074 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16075 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16076 NFS caches whenever needed. If you're using only a single mail server
16078 Defaults to @samp{#f}.
16081 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16082 Mail index files also exist in NFS. Setting this to yes requires
16083 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16084 Defaults to @samp{#f}.
16087 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16088 Locking method for index files. Alternatives are fcntl, flock and
16089 dotlock. Dotlocking uses some tricks which may create more disk I/O
16090 than other locking methods. NFS users: flock doesn't work, remember to
16091 change @samp{mmap-disable}.
16092 Defaults to @samp{"fcntl"}.
16095 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16096 Directory in which LDA/LMTP temporarily stores incoming mails >128
16098 Defaults to @samp{"/tmp"}.
16101 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16102 Valid UID range for users. This is mostly to make sure that users can't
16103 log in as daemons or other system users. Note that denying root logins is
16104 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16106 Defaults to @samp{500}.
16109 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16111 Defaults to @samp{0}.
16114 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16115 Valid GID range for users. Users having non-valid GID as primary group ID
16116 aren't allowed to log in. If user belongs to supplementary groups with
16117 non-valid GIDs, those groups are not set.
16118 Defaults to @samp{1}.
16121 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16123 Defaults to @samp{0}.
16126 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16127 Maximum allowed length for mail keyword name. It's only forced when
16128 trying to create new keywords.
16129 Defaults to @samp{50}.
16132 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16133 List of directories under which chrooting is allowed for mail
16134 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16135 too). This setting doesn't affect @samp{login-chroot}
16136 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16137 "/./" in home dirs are ignored. WARNING: Never add directories here
16138 which local users can modify, that may lead to root exploit. Usually
16139 this should be done only if you don't allow shell access for users.
16140 <doc/wiki/Chrooting.txt>.
16141 Defaults to @samp{()}.
16144 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16145 Default chroot directory for mail processes. This can be overridden
16146 for specific users in user database by giving /./ in user's home
16147 directory (e.g.@: /home/./user chroots into /home). Note that usually
16148 there is no real need to do chrooting, Dovecot doesn't allow users to
16149 access files outside their mail directory anyway. If your home
16150 directories are prefixed with the chroot directory, append "/."@: to
16151 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16152 Defaults to @samp{""}.
16155 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16156 UNIX socket path to master authentication server to find users.
16157 This is used by imap (for shared users) and lda.
16158 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16161 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16162 Directory where to look up mail plugins.
16163 Defaults to @samp{"/usr/lib/dovecot"}.
16166 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16167 List of plugins to load for all services. Plugins specific to IMAP,
16168 LDA, etc.@: are added to this list in their own .conf files.
16169 Defaults to @samp{()}.
16172 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16173 The minimum number of mails in a mailbox before updates are done to
16174 cache file. This allows optimizing Dovecot's behavior to do less disk
16175 writes at the cost of more disk reads.
16176 Defaults to @samp{0}.
16179 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16180 When IDLE command is running, mailbox is checked once in a while to
16181 see if there are any new mails or other changes. This setting defines
16182 the minimum time to wait between those checks. Dovecot can also use
16183 dnotify, inotify and kqueue to find out immediately when changes
16185 Defaults to @samp{"30 secs"}.
16188 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16189 Save mails with CR+LF instead of plain LF. This makes sending those
16190 mails take less CPU, especially with sendfile() syscall with Linux and
16191 FreeBSD. But it also creates a bit more disk I/O which may just make it
16192 slower. Also note that if other software reads the mboxes/maildirs,
16193 they may handle the extra CRs wrong and cause problems.
16194 Defaults to @samp{#f}.
16197 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16198 By default LIST command returns all entries in maildir beginning
16199 with a dot. Enabling this option makes Dovecot return only entries
16200 which are directories. This is done by stat()ing each entry, so it
16201 causes more disk I/O.
16202 (For systems setting struct @samp{dirent->d_type} this check is free
16203 and it's done always regardless of this setting).
16204 Defaults to @samp{#f}.
16207 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16208 When copying a message, do it with hard links whenever possible.
16209 This makes the performance much better, and it's unlikely to have any
16211 Defaults to @samp{#t}.
16214 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16215 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16216 directory only when its mtime changes unexpectedly or when we can't find
16217 the mail otherwise.
16218 Defaults to @samp{#f}.
16221 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16222 Which locking methods to use for locking mbox. There are four
16227 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16228 solution. If you want to use /var/mail/ like directory, the users will
16229 need write access to that directory.
16231 Same as dotlock, but if it fails because of permissions or because there
16232 isn't enough disk space, just skip it.
16234 Use this if possible. Works with NFS too if lockd is used.
16236 May not exist in all systems. Doesn't work with NFS.
16238 May not exist in all systems. Doesn't work with NFS.
16241 You can use multiple locking methods; if you do the order they're declared
16242 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16243 locking methods as well. Some operating systems don't allow using some of
16244 them simultaneously.
16247 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16251 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16252 Maximum time to wait for lock (all of them) before aborting.
16253 Defaults to @samp{"5 mins"}.
16256 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16257 If dotlock exists but the mailbox isn't modified in any way,
16258 override the lock file after this much time.
16259 Defaults to @samp{"2 mins"}.
16262 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16263 When mbox changes unexpectedly we have to fully read it to find out
16264 what changed. If the mbox is large this can take a long time. Since
16265 the change is usually just a newly appended mail, it'd be faster to
16266 simply read the new mails. If this setting is enabled, Dovecot does
16267 this but still safely fallbacks to re-reading the whole mbox file
16268 whenever something in mbox isn't how it's expected to be. The only real
16269 downside to this setting is that if some other MUA changes message
16270 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16271 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16272 Defaults to @samp{#t}.
16275 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16276 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16277 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16278 @samp{mbox-dirty-syncs} is ignored.
16279 Defaults to @samp{#f}.
16282 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16283 Delay writing mbox headers until doing a full write sync (EXPUNGE
16284 and CHECK commands and when closing the mailbox). This is especially
16285 useful for POP3 where clients often delete all mails. The downside is
16286 that our changes aren't immediately visible to other MUAs.
16287 Defaults to @samp{#t}.
16290 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16291 If mbox size is smaller than this (e.g.@: 100k), don't write index
16292 files. If an index file already exists it's still read, just not
16294 Defaults to @samp{0}.
16297 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16298 Maximum dbox file size until it's rotated.
16299 Defaults to @samp{10000000}.
16302 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16303 Maximum dbox file age until it's rotated. Typically in days. Day
16304 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16306 Defaults to @samp{"1d"}.
16309 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16310 When creating new mdbox files, immediately preallocate their size to
16311 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16312 with some file systems (ext4, xfs).
16313 Defaults to @samp{#f}.
16316 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16317 sdbox and mdbox support saving mail attachments to external files,
16318 which also allows single instance storage for them. Other backends
16319 don't support this for now.
16321 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16323 Directory root where to store mail attachments. Disabled, if empty.
16324 Defaults to @samp{""}.
16327 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16328 Attachments smaller than this aren't saved externally. It's also
16329 possible to write a plugin to disable saving specific attachments
16331 Defaults to @samp{128000}.
16334 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16335 File system backend to use for saving attachments:
16338 No SiS done by Dovecot (but this might help FS's own deduplication)
16340 SiS with immediate byte-by-byte comparison during saving
16341 @item sis-queue posix
16342 SiS with delayed comparison and deduplication.
16344 Defaults to @samp{"sis posix"}.
16347 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16348 Hash format to use in attachment filenames. You can add any text and
16349 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16350 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16351 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16352 Defaults to @samp{"%@{sha1@}"}.
16355 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16357 Defaults to @samp{100}.
16360 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16362 Defaults to @samp{1000}.
16365 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16366 Default VSZ (virtual memory size) limit for service processes.
16367 This is mainly intended to catch and kill processes that leak memory
16368 before they eat up everything.
16369 Defaults to @samp{256000000}.
16372 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16373 Login user is internally used by login processes. This is the most
16374 untrusted user in Dovecot system. It shouldn't have access to anything
16376 Defaults to @samp{"dovenull"}.
16379 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16380 Internal user is used by unprivileged processes. It should be
16381 separate from login user, so that login processes can't disturb other
16383 Defaults to @samp{"dovecot"}.
16386 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16387 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16388 Defaults to @samp{"required"}.
16391 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16392 PEM encoded X.509 SSL/TLS certificate (public key).
16393 Defaults to @samp{"</etc/dovecot/default.pem"}.
16396 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16397 PEM encoded SSL/TLS private key. The key is opened before
16398 dropping root privileges, so keep the key file unreadable by anyone but
16400 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16403 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16404 If key file is password protected, give the password here.
16405 Alternatively give it when starting dovecot with -p parameter. Since
16406 this file is often world-readable, you may want to place this setting
16407 instead to a different.
16408 Defaults to @samp{""}.
16411 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16412 PEM encoded trusted certificate authority. Set this only if you
16413 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16414 contain the CA certificate(s) followed by the matching
16415 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16416 Defaults to @samp{""}.
16419 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16420 Require that CRL check succeeds for client certificates.
16421 Defaults to @samp{#t}.
16424 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16425 Request client to send a certificate. If you also want to require
16426 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16427 Defaults to @samp{#f}.
16430 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16431 Which field from certificate to use for username. commonName and
16432 x500UniqueIdentifier are the usual choices. You'll also need to set
16433 @samp{auth-ssl-username-from-cert? #t}.
16434 Defaults to @samp{"commonName"}.
16437 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16438 Minimum SSL protocol version to accept.
16439 Defaults to @samp{"TLSv1"}.
16442 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16443 SSL ciphers to use.
16444 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16447 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16448 SSL crypto device to use, for valid values run "openssl engine".
16449 Defaults to @samp{""}.
16452 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16453 Address to use when sending rejection mails.
16454 %d expands to recipient domain.
16455 Defaults to @samp{"postmaster@@%d"}.
16458 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16459 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16460 and in LMTP replies. Default is the system's real hostname@@domain.
16461 Defaults to @samp{""}.
16464 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16465 If user is over quota, return with temporary failure instead of
16467 Defaults to @samp{#f}.
16470 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16471 Binary to use for sending mails.
16472 Defaults to @samp{"/usr/sbin/sendmail"}.
16475 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16476 If non-empty, send mails via this SMTP host[:port] instead of
16478 Defaults to @samp{""}.
16481 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16482 Subject: header to use for rejection mails. You can use the same
16483 variables as for @samp{rejection-reason} below.
16484 Defaults to @samp{"Rejected: %s"}.
16487 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16488 Human readable error message for rejection mails. You can use
16501 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16504 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16505 Delimiter character between local-part and detail in email
16507 Defaults to @samp{"+"}.
16510 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16511 Header where the original recipient address (SMTP's RCPT TO:
16512 address) is taken from if not available elsewhere. With dovecot-lda -a
16513 parameter overrides this. A commonly used header for this is
16515 Defaults to @samp{""}.
16518 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16519 Should saving a mail to a nonexistent mailbox automatically create
16521 Defaults to @samp{#f}.
16524 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16525 Should automatically created mailboxes be also automatically
16527 Defaults to @samp{#f}.
16530 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16531 Maximum IMAP command line length. Some clients generate very long
16532 command lines with huge mailboxes, so you may need to raise this if you
16533 get "Too long argument" or "IMAP command line too large" errors
16535 Defaults to @samp{64000}.
16538 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16539 IMAP logout format string:
16542 total number of bytes read from client
16544 total number of bytes sent to client.
16546 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16547 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@}"}.
16550 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16551 Override the IMAP CAPABILITY response. If the value begins with '+',
16552 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16553 Defaults to @samp{""}.
16556 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16557 How long to wait between "OK Still here" notifications when client
16559 Defaults to @samp{"2 mins"}.
16562 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16563 ID field names and values to send to clients. Using * as the value
16564 makes Dovecot use the default value. The following fields have default
16565 values currently: name, version, os, os-version, support-url,
16567 Defaults to @samp{""}.
16570 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16571 ID fields sent by client to log. * means everything.
16572 Defaults to @samp{""}.
16575 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16576 Workarounds for various client bugs:
16579 @item delay-newmail
16580 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16581 CHECK commands. Some clients ignore them otherwise, for example OSX
16582 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16583 may show user "Message no longer in server" errors. Note that OE6
16584 still breaks even with this workaround if synchronization is set to
16587 @item tb-extra-mailbox-sep
16588 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16589 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16590 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16592 @item tb-lsub-flags
16593 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16594 This makes Thunderbird realize they aren't selectable and show them
16595 greyed out, instead of only later giving "not selectable" popup error.
16597 Defaults to @samp{()}.
16600 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16601 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16602 Defaults to @samp{""}.
16606 Whew! Lots of configuration options. The nice thing about it though is
16607 that Guix has a complete interface to Dovecot's configuration
16608 language. This allows not only a nice way to declare configurations,
16609 but also offers reflective capabilities as well: users can write code to
16610 inspect and transform configurations from within Scheme.
16612 However, it could be that you just want to get a @code{dovecot.conf} up
16613 and running. In that case, you can pass an
16614 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16615 @code{dovecot-service}. As its name indicates, an opaque configuration
16616 does not have easy reflective capabilities.
16618 Available @code{opaque-dovecot-configuration} fields are:
16620 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16621 The dovecot package.
16624 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16625 The contents of the @code{dovecot.conf}, as a string.
16628 For example, if your @code{dovecot.conf} is just the empty string, you
16629 could instantiate a dovecot service like this:
16632 (dovecot-service #:config
16633 (opaque-dovecot-configuration
16637 @subsubheading OpenSMTPD Service
16639 @deffn {Scheme Variable} opensmtpd-service-type
16640 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16641 service, whose value should be an @code{opensmtpd-configuration} object
16642 as in this example:
16645 (service opensmtpd-service-type
16646 (opensmtpd-configuration
16647 (config-file (local-file "./my-smtpd.conf"))))
16651 @deftp {Data Type} opensmtpd-configuration
16652 Data type representing the configuration of opensmtpd.
16655 @item @code{package} (default: @var{opensmtpd})
16656 Package object of the OpenSMTPD SMTP server.
16658 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16659 File-like object of the OpenSMTPD configuration file to use. By default
16660 it listens on the loopback network interface, and allows for mail from
16661 users and daemons on the local machine, as well as permitting email to
16662 remote servers. Run @command{man smtpd.conf} for more information.
16667 @subsubheading Exim Service
16669 @cindex mail transfer agent (MTA)
16670 @cindex MTA (mail transfer agent)
16673 @deffn {Scheme Variable} exim-service-type
16674 This is the type of the @uref{https://exim.org, Exim} mail transfer
16675 agent (MTA), whose value should be an @code{exim-configuration} object
16676 as in this example:
16679 (service exim-service-type
16680 (exim-configuration
16681 (config-file (local-file "./my-exim.conf"))))
16685 In order to use an @code{exim-service-type} service you must also have a
16686 @code{mail-aliases-service-type} service present in your
16687 @code{operating-system} (even if it has no aliases).
16689 @deftp {Data Type} exim-configuration
16690 Data type representing the configuration of exim.
16693 @item @code{package} (default: @var{exim})
16694 Package object of the Exim server.
16696 @item @code{config-file} (default: @code{#f})
16697 File-like object of the Exim configuration file to use. If its value is
16698 @code{#f} then use the default configuration file from the package
16699 provided in @code{package}. The resulting configuration file is loaded
16700 after setting the @code{exim_user} and @code{exim_group} configuration
16706 @subsubheading Mail Aliases Service
16708 @cindex email aliases
16709 @cindex aliases, for email addresses
16711 @deffn {Scheme Variable} mail-aliases-service-type
16712 This is the type of the service which provides @code{/etc/aliases},
16713 specifying how to deliver mail to users on this system.
16716 (service mail-aliases-service-type
16717 '(("postmaster" "bob")
16718 ("bob" "bob@@example.com" "bob@@example2.com")))
16722 The configuration for a @code{mail-aliases-service-type} service is an
16723 association list denoting how to deliver mail that comes to this
16724 system. Each entry is of the form @code{(alias addresses ...)}, with
16725 @code{alias} specifying the local alias and @code{addresses} specifying
16726 where to deliver this user's mail.
16728 The aliases aren't required to exist as users on the local system. In
16729 the above example, there doesn't need to be a @code{postmaster} entry in
16730 the @code{operating-system}'s @code{user-accounts} in order to deliver
16731 the @code{postmaster} mail to @code{bob} (which subsequently would
16732 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16734 @subsubheading GNU Mailutils IMAP4 Daemon
16735 @cindex GNU Mailutils IMAP4 Daemon
16737 @deffn {Scheme Variable} imap4d-service-type
16738 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16739 mailutils, GNU Mailutils Manual}), whose value should be an
16740 @code{imap4d-configuration} object as in this example:
16743 (service imap4d-service-type
16744 (imap4d-configuration
16745 (config-file (local-file "imap4d.conf"))))
16749 @deftp {Data Type} imap4d-configuration
16750 Data type representing the configuration of @command{imap4d}.
16753 @item @code{package} (default: @code{mailutils})
16754 The package that provides @command{imap4d}.
16756 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16757 File-like object of the configuration file to use, by default it will listen
16758 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16759 Mailutils Manual}, for details.
16764 @node Messaging Services
16765 @subsection Messaging Services
16770 The @code{(gnu services messaging)} module provides Guix service
16771 definitions for messaging services: currently only Prosody is supported.
16773 @subsubheading Prosody Service
16775 @deffn {Scheme Variable} prosody-service-type
16776 This is the type for the @uref{https://prosody.im, Prosody XMPP
16777 communication server}. Its value must be a @code{prosody-configuration}
16778 record as in this example:
16781 (service prosody-service-type
16782 (prosody-configuration
16783 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16786 (int-component-configuration
16787 (hostname "conference.example.net")
16789 (mod-muc (mod-muc-configuration)))))
16792 (virtualhost-configuration
16793 (domain "example.net"))))))
16796 See below for details about @code{prosody-configuration}.
16800 By default, Prosody does not need much configuration. Only one
16801 @code{virtualhosts} field is needed: it specifies the domain you wish
16804 You can perform various sanity checks on the generated configuration
16805 with the @code{prosodyctl check} command.
16807 Prosodyctl will also help you to import certificates from the
16808 @code{letsencrypt} directory so that the @code{prosody} user can access
16809 them. See @url{https://prosody.im/doc/letsencrypt}.
16812 prosodyctl --root cert import /etc/letsencrypt/live
16815 The available configuration parameters follow. Each parameter
16816 definition is preceded by its type; for example, @samp{string-list foo}
16817 indicates that the @code{foo} parameter should be specified as a list of
16818 strings. Types starting with @code{maybe-} denote parameters that won't
16819 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16821 There is also a way to specify the configuration as a string, if you
16822 have an old @code{prosody.cfg.lua} file that you want to port over from
16823 some other system; see the end for more details.
16825 The @code{file-object} type designates either a file-like object
16826 (@pxref{G-Expressions, file-like objects}) or a file name.
16828 @c The following documentation was initially generated by
16829 @c (generate-documentation) in (gnu services messaging). Manually maintained
16830 @c documentation is better, so we shouldn't hesitate to edit below as
16831 @c needed. However if the change you want to make to this documentation
16832 @c can be done in an automated way, it's probably easier to change
16833 @c (generate-documentation) than to make it below and have to deal with
16834 @c the churn as Prosody updates.
16836 Available @code{prosody-configuration} fields are:
16838 @deftypevr {@code{prosody-configuration} parameter} package prosody
16839 The Prosody package.
16842 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16843 Location of the Prosody data storage directory. See
16844 @url{https://prosody.im/doc/configure}.
16845 Defaults to @samp{"/var/lib/prosody"}.
16848 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16849 Additional plugin directories. They are searched in all the specified
16850 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16851 Defaults to @samp{()}.
16854 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16855 Every virtual host and component needs a certificate so that clients and
16856 servers can securely verify its identity. Prosody will automatically load
16857 certificates/keys from the directory specified here.
16858 Defaults to @samp{"/etc/prosody/certs"}.
16861 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16862 This is a list of accounts that are admins for the server. Note that you
16863 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16864 @url{https://prosody.im/doc/creating_accounts}.
16865 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16866 Defaults to @samp{()}.
16869 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16870 Enable use of libevent for better performance under high load. See
16871 @url{https://prosody.im/doc/libevent}.
16872 Defaults to @samp{#f}.
16875 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16876 This is the list of modules Prosody will load on startup. It looks for
16877 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16878 Documentation on modules can be found at:
16879 @url{https://prosody.im/doc/modules}.
16880 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16883 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16884 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16885 should you want to disable them then add them to this list.
16886 Defaults to @samp{()}.
16889 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16890 Path to a text file where the shared groups are defined. If this path is
16891 empty then @samp{mod_groups} does nothing. See
16892 @url{https://prosody.im/doc/modules/mod_groups}.
16893 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16896 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16897 Disable account creation by default, for security. See
16898 @url{https://prosody.im/doc/creating_accounts}.
16899 Defaults to @samp{#f}.
16902 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16903 These are the SSL/TLS-related settings. Most of them are disabled so to
16904 use Prosody's defaults. If you do not completely understand these options, do
16905 not add them to your config, it is easy to lower the security of your server
16906 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16908 Available @code{ssl-configuration} fields are:
16910 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16911 This determines what handshake to use.
16914 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16915 Path to your private key file.
16918 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16919 Path to your certificate file.
16922 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16923 Path to directory containing root certificates that you wish Prosody to
16924 trust when verifying the certificates of remote servers.
16925 Defaults to @samp{"/etc/ssl/certs"}.
16928 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16929 Path to a file containing root certificates that you wish Prosody to trust.
16930 Similar to @code{capath} but with all certificates concatenated together.
16933 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16934 A list of verification options (these mostly map to OpenSSL's
16935 @code{set_verify()} flags).
16938 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16939 A list of general options relating to SSL/TLS. These map to OpenSSL's
16940 @code{set_options()}. For a full list of options available in LuaSec, see the
16944 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16945 How long a chain of certificate authorities to check when looking for a
16946 trusted root certificate.
16949 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16950 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16951 clients, and in what order.
16954 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16955 A path to a file containing parameters for Diffie-Hellman key exchange. You
16956 can create such a file with:
16957 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16960 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16961 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16962 @samp{"secp384r1"}.
16965 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16966 A list of "extra" verification options.
16969 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16970 Password for encrypted private keys.
16975 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16976 Whether to force all client-to-server connections to be encrypted or not.
16977 See @url{https://prosody.im/doc/modules/mod_tls}.
16978 Defaults to @samp{#f}.
16981 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16982 Set of mechanisms that will never be offered. See
16983 @url{https://prosody.im/doc/modules/mod_saslauth}.
16984 Defaults to @samp{("DIGEST-MD5")}.
16987 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16988 Whether to force all server-to-server connections to be encrypted or not.
16989 See @url{https://prosody.im/doc/modules/mod_tls}.
16990 Defaults to @samp{#f}.
16993 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16994 Whether to require encryption and certificate authentication. This
16995 provides ideal security, but requires servers you communicate with to support
16996 encryption AND present valid, trusted certificates. See
16997 @url{https://prosody.im/doc/s2s#security}.
16998 Defaults to @samp{#f}.
17001 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17002 Many servers don't support encryption or have invalid or self-signed
17003 certificates. You can list domains here that will not be required to
17004 authenticate using certificates. They will be authenticated using DNS. See
17005 @url{https://prosody.im/doc/s2s#security}.
17006 Defaults to @samp{()}.
17009 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
17010 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
17011 valid certificates for some domains by specifying a list here. See
17012 @url{https://prosody.im/doc/s2s#security}.
17013 Defaults to @samp{()}.
17016 @deftypevr {@code{prosody-configuration} parameter} string authentication
17017 Select the authentication backend to use. The default provider stores
17018 passwords in plaintext and uses Prosody's configured data storage to store the
17019 authentication data. If you do not trust your server please see
17020 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17021 about using the hashed backend. See also
17022 @url{https://prosody.im/doc/authentication}
17023 Defaults to @samp{"internal_plain"}.
17026 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17027 Set logging options. Advanced logging configuration is not yet supported
17028 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17029 Defaults to @samp{"*syslog"}.
17032 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17033 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17034 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17037 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17038 Maximum allowed size of the HTTP body (in bytes).
17041 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17042 Some modules expose their own URL in various ways. This URL is built
17043 from the protocol, host and port used. If Prosody sits behind a proxy, the
17044 public URL will be @code{http-external-url} instead. See
17045 @url{https://prosody.im/doc/http#external_url}.
17048 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17049 A host in Prosody is a domain on which user accounts can be created. For
17050 example if you want your users to have addresses like
17051 @samp{"john.smith@@example.com"} then you need to add a host
17052 @samp{"example.com"}. All options in this list will apply only to this host.
17054 Note: the name "virtual" host is used in configuration to avoid confusion with
17055 the actual physical host that Prosody is installed on. A single Prosody
17056 instance can serve many domains, each one defined as a VirtualHost entry in
17057 Prosody's configuration. Conversely a server that hosts a single domain would
17058 have just one VirtualHost entry.
17060 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17062 Available @code{virtualhost-configuration} fields are:
17064 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:
17065 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17066 Domain you wish Prosody to serve.
17071 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17072 Components are extra services on a server which are available to clients,
17073 usually on a subdomain of the main server (such as
17074 @samp{"mycomponent.example.com"}). Example components might be chatroom
17075 servers, user directories, or gateways to other protocols.
17077 Internal components are implemented with Prosody-specific plugins. To add an
17078 internal component, you simply fill the hostname field, and the plugin you wish
17079 to use for the component.
17081 See @url{https://prosody.im/doc/components}.
17082 Defaults to @samp{()}.
17084 Available @code{int-component-configuration} fields are:
17086 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:
17087 @deftypevr {@code{int-component-configuration} parameter} string hostname
17088 Hostname of the component.
17091 @deftypevr {@code{int-component-configuration} parameter} string plugin
17092 Plugin you wish to use for the component.
17095 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17096 Multi-user chat (MUC) is Prosody's module for allowing you to create
17097 hosted chatrooms/conferences for XMPP users.
17099 General information on setting up and using multi-user chatrooms can be found
17100 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17101 which you should read if you are new to XMPP chatrooms.
17103 See also @url{https://prosody.im/doc/modules/mod_muc}.
17105 Available @code{mod-muc-configuration} fields are:
17107 @deftypevr {@code{mod-muc-configuration} parameter} string name
17108 The name to return in service discovery responses.
17109 Defaults to @samp{"Prosody Chatrooms"}.
17112 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17113 If @samp{#t}, this will only allow admins to create new chatrooms.
17114 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17115 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17116 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17117 restricts to service administrators only.
17118 Defaults to @samp{#f}.
17121 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17122 Maximum number of history messages that will be sent to the member that has
17123 just joined the room.
17124 Defaults to @samp{20}.
17131 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17132 External components use XEP-0114, which most standalone components
17133 support. To add an external component, you simply fill the hostname field. See
17134 @url{https://prosody.im/doc/components}.
17135 Defaults to @samp{()}.
17137 Available @code{ext-component-configuration} fields are:
17139 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:
17140 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17141 Password which the component will use to log in.
17144 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17145 Hostname of the component.
17150 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17151 Port(s) Prosody listens on for component connections.
17152 Defaults to @samp{(5347)}.
17155 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17156 Interface Prosody listens on for component connections.
17157 Defaults to @samp{"127.0.0.1"}.
17160 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17161 Raw content that will be added to the configuration file.
17164 It could be that you just want to get a @code{prosody.cfg.lua}
17165 up and running. In that case, you can pass an
17166 @code{opaque-prosody-configuration} record as the value of
17167 @code{prosody-service-type}. As its name indicates, an opaque configuration
17168 does not have easy reflective capabilities.
17169 Available @code{opaque-prosody-configuration} fields are:
17171 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17172 The prosody package.
17175 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17176 The contents of the @code{prosody.cfg.lua} to use.
17179 For example, if your @code{prosody.cfg.lua} is just the empty
17180 string, you could instantiate a prosody service like this:
17183 (service prosody-service-type
17184 (opaque-prosody-configuration
17185 (prosody.cfg.lua "")))
17188 @c end of Prosody auto-generated documentation
17190 @subsubheading BitlBee Service
17192 @cindex IRC (Internet Relay Chat)
17193 @cindex IRC gateway
17194 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17195 interface to a variety of messaging protocols such as XMPP.
17197 @defvr {Scheme Variable} bitlbee-service-type
17198 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17199 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17202 To have BitlBee listen on port 6667 on localhost, add this line to your
17206 (service bitlbee-service-type)
17210 @deftp {Data Type} bitlbee-configuration
17211 This is the configuration for BitlBee, with the following fields:
17214 @item @code{interface} (default: @code{"127.0.0.1"})
17215 @itemx @code{port} (default: @code{6667})
17216 Listen on the network interface corresponding to the IP address
17217 specified in @var{interface}, on @var{port}.
17219 When @var{interface} is @code{127.0.0.1}, only local clients can
17220 connect; when it is @code{0.0.0.0}, connections can come from any
17221 networking interface.
17223 @item @code{package} (default: @code{bitlbee})
17224 The BitlBee package to use.
17226 @item @code{plugins} (default: @code{'()})
17227 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17229 @item @code{extra-settings} (default: @code{""})
17230 Configuration snippet added as-is to the BitlBee configuration file.
17234 @subsubheading Quassel Service
17236 @cindex IRC (Internet Relay Chat)
17237 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17238 meaning that one or more clients can attach to and detach from the
17241 @defvr {Scheme Variable} quassel-service-type
17242 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17243 IRC backend daemon. Its value is a @code{quassel-configuration}
17247 @deftp {Data Type} quassel-configuration
17248 This is the configuration for Quassel, with the following fields:
17251 @item @code{quassel} (default: @code{quassel})
17252 The Quassel package to use.
17254 @item @code{interface} (default: @code{"::,0.0.0.0"})
17255 @item @code{port} (default: @code{4242})
17256 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17257 interfaces specified in the comma delimited @var{interface}, on
17260 @item @code{loglevel} (default: @code{"Info"})
17261 The level of logging desired. Accepted values are Debug, Info, Warning
17266 @node Telephony Services
17267 @subsection Telephony Services
17269 @cindex Murmur (VoIP server)
17270 @cindex VoIP server
17271 This section describes how to set up and run a Murmur server. Murmur is
17272 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17275 @deftp {Data Type} murmur-configuration
17276 The service type for the Murmur server. An example configuration can
17280 (service murmur-service-type
17281 (murmur-configuration
17283 "Welcome to this Mumble server running on Guix!")
17284 (cert-required? #t) ;disallow text password logins
17285 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17286 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17289 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17290 password with the command that is printed during the activation phase.
17292 It is recommended to register a normal Mumble user account
17293 and grant it admin or moderator rights.
17294 You can use the @code{mumble} client to
17295 login as new normal user, register yourself, and log out.
17296 For the next step login with the name @code{SuperUser} use
17297 the @code{SuperUser} password that you set previously,
17298 and grant your newly registered mumble user administrator or moderator
17299 rights and create some channels.
17301 Available @code{murmur-configuration} fields are:
17304 @item @code{package} (default: @code{mumble})
17305 Package that contains @code{bin/murmurd}.
17307 @item @code{user} (default: @code{"murmur"})
17308 User who will run the Murmur server.
17310 @item @code{group} (default: @code{"murmur"})
17311 Group of the user who will run the murmur server.
17313 @item @code{port} (default: @code{64738})
17314 Port on which the server will listen.
17316 @item @code{welcome-text} (default: @code{""})
17317 Welcome text sent to clients when they connect.
17319 @item @code{server-password} (default: @code{""})
17320 Password the clients have to enter in order to connect.
17322 @item @code{max-users} (default: @code{100})
17323 Maximum of users that can be connected to the server at once.
17325 @item @code{max-user-bandwidth} (default: @code{#f})
17326 Maximum voice traffic a user can send per second.
17328 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17329 File name of the sqlite database.
17330 The service's user will become the owner of the directory.
17332 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17333 File name of the log file.
17334 The service's user will become the owner of the directory.
17336 @item @code{autoban-attempts} (default: @code{10})
17337 Maximum number of logins a user can make in @code{autoban-timeframe}
17338 without getting auto banned for @code{autoban-time}.
17340 @item @code{autoban-timeframe} (default: @code{120})
17341 Timeframe for autoban in seconds.
17343 @item @code{autoban-time} (default: @code{300})
17344 Amount of time in seconds for which a client gets banned
17345 when violating the autoban limits.
17347 @item @code{opus-threshold} (default: @code{100})
17348 Percentage of clients that need to support opus
17349 before switching over to opus audio codec.
17351 @item @code{channel-nesting-limit} (default: @code{10})
17352 How deep channels can be nested at maximum.
17354 @item @code{channelname-regex} (default: @code{#f})
17355 A string in form of a Qt regular expression that channel names must conform to.
17357 @item @code{username-regex} (default: @code{#f})
17358 A string in form of a Qt regular expression that user names must conform to.
17360 @item @code{text-message-length} (default: @code{5000})
17361 Maximum size in bytes that a user can send in one text chat message.
17363 @item @code{image-message-length} (default: @code{(* 128 1024)})
17364 Maximum size in bytes that a user can send in one image message.
17366 @item @code{cert-required?} (default: @code{#f})
17367 If it is set to @code{#t} clients that use weak password authentication
17368 will not be accepted. Users must have completed the certificate wizard to join.
17370 @item @code{remember-channel?} (default: @code{#f})
17371 Should murmur remember the last channel each user was in when they disconnected
17372 and put them into the remembered channel when they rejoin.
17374 @item @code{allow-html?} (default: @code{#f})
17375 Should html be allowed in text messages, user comments, and channel descriptions.
17377 @item @code{allow-ping?} (default: @code{#f})
17378 Setting to true exposes the current user count, the maximum user count, and
17379 the server's maximum bandwidth per client to unauthenticated users. In the
17380 Mumble client, this information is shown in the Connect dialog.
17382 Disabling this setting will prevent public listing of the server.
17384 @item @code{bonjour?} (default: @code{#f})
17385 Should the server advertise itself in the local network through the bonjour protocol.
17387 @item @code{send-version?} (default: @code{#f})
17388 Should the murmur server version be exposed in ping requests.
17390 @item @code{log-days} (default: @code{31})
17391 Murmur also stores logs in the database, which are accessible via RPC.
17392 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17393 or -1 to disable logging to the database.
17395 @item @code{obfuscate-ips?} (default: @code{#t})
17396 Should logged ips be obfuscated to protect the privacy of users.
17398 @item @code{ssl-cert} (default: @code{#f})
17399 File name of the SSL/TLS certificate used for encrypted connections.
17402 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17404 @item @code{ssl-key} (default: @code{#f})
17405 Filepath to the ssl private key used for encrypted connections.
17407 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17410 @item @code{ssl-dh-params} (default: @code{#f})
17411 File name of a PEM-encoded file with Diffie-Hellman parameters
17412 for the SSL/TLS encryption. Alternatively you set it to
17413 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17414 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17416 @item @code{ssl-ciphers} (default: @code{#f})
17417 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17420 This option is specified using
17421 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17422 OpenSSL cipher list notation}.
17424 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17425 before setting it here, to get a feel for which cipher suites you will get.
17426 After setting this option, it is recommend that you inspect your Murmur log
17427 to ensure that Murmur is using the cipher suites that you expected it to.
17429 Note: Changing this option may impact the backwards compatibility of your
17430 Murmur server, and can remove the ability for older Mumble clients to be able
17433 @item @code{public-registration} (default: @code{#f})
17434 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17436 You can optionally register your server in the public server list that the
17437 @code{mumble} client shows on startup.
17438 You cannot register your server if you have set a @code{server-password},
17439 or set @code{allow-ping} to @code{#f}.
17441 It might take a few hours until it shows up in the public list.
17443 @item @code{file} (default: @code{#f})
17444 Optional alternative override for this configuration.
17448 @deftp {Data Type} murmur-public-registration-configuration
17449 Configuration for public registration of a murmur service.
17453 This is a display name for your server. Not to be confused with the hostname.
17455 @item @code{password}
17456 A password to identify your registration.
17457 Subsequent updates will need the same password. Don't lose your password.
17460 This should be a @code{http://} or @code{https://} link to your web
17463 @item @code{hostname} (default: @code{#f})
17464 By default your server will be listed by its IP address.
17465 If it is set your server will be linked by this host name instead.
17471 @node Monitoring Services
17472 @subsection Monitoring Services
17474 @subsubheading Tailon Service
17476 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17477 viewing and searching log files.
17479 The following example will configure the service with default values.
17480 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17483 (service tailon-service-type)
17486 The following example customises more of the Tailon configuration,
17487 adding @command{sed} to the list of allowed commands.
17490 (service tailon-service-type
17491 (tailon-configuration
17493 (tailon-configuration-file
17494 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17498 @deftp {Data Type} tailon-configuration
17499 Data type representing the configuration of Tailon.
17500 This type has the following parameters:
17503 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17504 The configuration file to use for Tailon. This can be set to a
17505 @dfn{tailon-configuration-file} record value, or any gexp
17506 (@pxref{G-Expressions}).
17508 For example, to instead use a local file, the @code{local-file} function
17512 (service tailon-service-type
17513 (tailon-configuration
17514 (config-file (local-file "./my-tailon.conf"))))
17517 @item @code{package} (default: @code{tailon})
17518 The tailon package to use.
17523 @deftp {Data Type} tailon-configuration-file
17524 Data type representing the configuration options for Tailon.
17525 This type has the following parameters:
17528 @item @code{files} (default: @code{(list "/var/log")})
17529 List of files to display. The list can include strings for a single file
17530 or directory, or a list, where the first item is the name of a
17531 subsection, and the remaining items are the files or directories in that
17534 @item @code{bind} (default: @code{"localhost:8080"})
17535 Address and port to which Tailon should bind on.
17537 @item @code{relative-root} (default: @code{#f})
17538 URL path to use for Tailon, set to @code{#f} to not use a path.
17540 @item @code{allow-transfers?} (default: @code{#t})
17541 Allow downloading the log files in the web interface.
17543 @item @code{follow-names?} (default: @code{#t})
17544 Allow tailing of not-yet existent files.
17546 @item @code{tail-lines} (default: @code{200})
17547 Number of lines to read initially from each file.
17549 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17550 Commands to allow running. By default, @code{sed} is disabled.
17552 @item @code{debug?} (default: @code{#f})
17553 Set @code{debug?} to @code{#t} to show debug messages.
17555 @item @code{wrap-lines} (default: @code{#t})
17556 Initial line wrapping state in the web interface. Set to @code{#t} to
17557 initially wrap lines (the default), or to @code{#f} to initially not
17560 @item @code{http-auth} (default: @code{#f})
17561 HTTP authentication type to use. Set to @code{#f} to disable
17562 authentication (the default). Supported values are @code{"digest"} or
17565 @item @code{users} (default: @code{#f})
17566 If HTTP authentication is enabled (see @code{http-auth}), access will be
17567 restricted to the credentials provided here. To configure users, use a
17568 list of pairs, where the first element of the pair is the username, and
17569 the 2nd element of the pair is the password.
17572 (tailon-configuration-file
17573 (http-auth "basic")
17574 (users '(("user1" . "password1")
17575 ("user2" . "password2"))))
17582 @subsubheading Darkstat Service
17584 Darkstat is a packet sniffer that captures network traffic, calculates
17585 statistics about usage, and serves reports over HTTP.
17587 @defvar {Scheme Variable} darkstat-service-type
17588 This is the service type for the
17589 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17590 service, its value must be a @code{darkstat-configuration} record as in
17594 (service darkstat-service-type
17595 (darkstat-configuration
17596 (interface "eno1")))
17600 @deftp {Data Type} darkstat-configuration
17601 Data type representing the configuration of @command{darkstat}.
17604 @item @code{package} (default: @code{darkstat})
17605 The darkstat package to use.
17607 @item @code{interface}
17608 Capture traffic on the specified network interface.
17610 @item @code{port} (default: @code{"667"})
17611 Bind the web interface to the specified port.
17613 @item @code{bind-address} (default: @code{"127.0.0.1"})
17614 Bind the web interface to the specified address.
17616 @item @code{base} (default: @code{"/"})
17617 Specify the path of the base URL. This can be useful if
17618 @command{darkstat} is accessed via a reverse proxy.
17623 @subsubheading Prometheus Node Exporter Service
17625 @cindex prometheus-node-exporter
17626 The Prometheus ``node exporter'' makes hardware and operating system statistics
17627 provided by the Linux kernel available for the Prometheus monitoring system.
17628 This service should be deployed on all physical nodes and virtual machines,
17629 where monitoring these statistics is desirable.
17631 @defvar {Scheme variable} prometheus-node-exporter-service-type
17632 This is the service type for the
17633 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17634 service, its value must be a @code{prometheus-node-exporter-configuration}
17635 record as in this example:
17638 (service prometheus-node-exporter-service-type
17639 (prometheus-node-exporter-configuration
17640 (web-listen-address ":9100")))
17644 @deftp {Data Type} prometheus-node-exporter-configuration
17645 Data type representing the configuration of @command{node_exporter}.
17648 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17649 The prometheus-node-exporter package to use.
17651 @item @code{web-listen-address} (default: @code{":9100"})
17652 Bind the web interface to the specified address.
17657 @subsubheading Zabbix server
17658 @cindex zabbix zabbix-server
17659 Zabbix provides monitoring metrics, among others network utilization, CPU load
17660 and disk space consumption:
17663 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17664 @item Auto-discovery of servers and network devices and interfaces.
17665 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17666 @item Distributed monitoring with centralized web administration.
17667 @item Native high performance agents.
17668 @item SLA, and ITIL KPI metrics on reporting.
17669 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17670 @item Remote command execution through Zabbix proxies.
17673 @c %start of fragment
17675 Available @code{zabbix-server-configuration} fields are:
17677 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17678 The zabbix-server package.
17682 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17683 User who will run the Zabbix server.
17685 Defaults to @samp{"zabbix"}.
17689 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17690 Group who will run the Zabbix server.
17692 Defaults to @samp{"zabbix"}.
17696 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17697 Database host name.
17699 Defaults to @samp{"127.0.0.1"}.
17703 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17706 Defaults to @samp{"zabbix"}.
17710 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17713 Defaults to @samp{"zabbix"}.
17717 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17718 Database password. Please, use @code{include-files} with
17719 @code{DBPassword=SECRET} inside a specified file instead.
17721 Defaults to @samp{""}.
17725 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17728 Defaults to @samp{5432}.
17732 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17733 Specifies where log messages are written to:
17737 @code{system} - syslog.
17740 @code{file} - file specified with @code{log-file} parameter.
17743 @code{console} - standard output.
17747 Defaults to @samp{""}.
17751 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17752 Log file name for @code{log-type} @code{file} parameter.
17754 Defaults to @samp{"/var/log/zabbix/server.log"}.
17758 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17761 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17765 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17766 The location of certificate authority (CA) files for SSL server
17767 certificate verification.
17769 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17773 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17774 Location of SSL client certificates.
17776 Defaults to @samp{"/etc/ssl/certs"}.
17780 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17781 Extra options will be appended to Zabbix server configuration file.
17783 Defaults to @samp{""}.
17787 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17788 You may include individual files or all files in a directory in the
17789 configuration file.
17791 Defaults to @samp{()}.
17795 @c %end of fragment
17797 @subsubheading Zabbix agent
17798 @cindex zabbix zabbix-agent
17800 Zabbix agent gathers information for Zabbix server.
17802 @c %start of fragment
17804 Available @code{zabbix-agent-configuration} fields are:
17806 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17807 The zabbix-agent package.
17811 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17812 User who will run the Zabbix agent.
17814 Defaults to @samp{"zabbix"}.
17818 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17819 Group who will run the Zabbix agent.
17821 Defaults to @samp{"zabbix"}.
17825 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17826 Unique, case sensitive hostname which is required for active checks and
17827 must match hostname as configured on the server.
17829 Defaults to @samp{"Zabbix server"}.
17833 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17834 Specifies where log messages are written to:
17838 @code{system} - syslog.
17841 @code{file} - file specified with @code{log-file} parameter.
17844 @code{console} - standard output.
17848 Defaults to @samp{""}.
17852 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17853 Log file name for @code{log-type} @code{file} parameter.
17855 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17859 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17862 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17866 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17867 List of IP addresses, optionally in CIDR notation, or hostnames of
17868 Zabbix servers and Zabbix proxies. Incoming connections will be
17869 accepted only from the hosts listed here.
17871 Defaults to @samp{("127.0.0.1")}.
17875 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17876 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17877 proxies for active checks. If port is not specified, default port is
17878 used. If this parameter is not specified, active checks are disabled.
17880 Defaults to @samp{("127.0.0.1")}.
17884 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17885 Extra options will be appended to Zabbix server configuration file.
17887 Defaults to @samp{""}.
17891 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17892 You may include individual files or all files in a directory in the
17893 configuration file.
17895 Defaults to @samp{()}.
17899 @c %end of fragment
17901 @subsubheading Zabbix front-end
17902 @cindex zabbix zabbix-front-end
17904 This service provides a WEB interface to Zabbix server.
17906 @c %start of fragment
17908 Available @code{zabbix-front-end-configuration} fields are:
17910 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17911 NGINX configuration.
17915 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17916 Database host name.
17918 Defaults to @samp{"localhost"}.
17922 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17925 Defaults to @samp{5432}.
17929 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17932 Defaults to @samp{"zabbix"}.
17936 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17939 Defaults to @samp{"zabbix"}.
17943 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17944 Database password. Please, use @code{db-secret-file} instead.
17946 Defaults to @samp{""}.
17950 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17951 Secret file which will be appended to @file{zabbix.conf.php} file. This
17952 file contains credentials for use by Zabbix front-end. You are expected
17953 to create it manually.
17955 Defaults to @samp{""}.
17959 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17960 Zabbix server hostname.
17962 Defaults to @samp{"localhost"}.
17966 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17967 Zabbix server port.
17969 Defaults to @samp{10051}.
17974 @c %end of fragment
17976 @node Kerberos Services
17977 @subsection Kerberos Services
17980 The @code{(gnu services kerberos)} module provides services relating to
17981 the authentication protocol @dfn{Kerberos}.
17983 @subsubheading Krb5 Service
17985 Programs using a Kerberos client library normally
17986 expect a configuration file in @file{/etc/krb5.conf}.
17987 This service generates such a file from a definition provided in the
17988 operating system declaration.
17989 It does not cause any daemon to be started.
17991 No ``keytab'' files are provided by this service---you must explicitly create them.
17992 This service is known to work with the MIT client library, @code{mit-krb5}.
17993 Other implementations have not been tested.
17995 @defvr {Scheme Variable} krb5-service-type
17996 A service type for Kerberos 5 clients.
18000 Here is an example of its use:
18002 (service krb5-service-type
18003 (krb5-configuration
18004 (default-realm "EXAMPLE.COM")
18005 (allow-weak-crypto? #t)
18008 (name "EXAMPLE.COM")
18009 (admin-server "groucho.example.com")
18010 (kdc "karl.example.com"))
18013 (admin-server "kerb-admin.argrx.edu")
18014 (kdc "keys.argrx.edu"))))))
18018 This example provides a Kerberos@tie{}5 client configuration which:
18020 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18021 of which have distinct administration servers and key distribution centers;
18022 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18023 specified by clients;
18024 @item Accepts services which only support encryption types known to be weak.
18027 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18028 Only the most commonly used ones are described here.
18029 For a full list, and more detailed explanation of each, see the MIT
18030 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18034 @deftp {Data Type} krb5-realm
18035 @cindex realm, kerberos
18038 This field is a string identifying the name of the realm.
18039 A common convention is to use the fully qualified DNS name of your organization,
18040 converted to upper case.
18042 @item @code{admin-server}
18043 This field is a string identifying the host where the administration server is
18047 This field is a string identifying the key distribution center
18052 @deftp {Data Type} krb5-configuration
18055 @item @code{allow-weak-crypto?} (default: @code{#f})
18056 If this flag is @code{#t} then services which only offer encryption algorithms
18057 known to be weak will be accepted.
18059 @item @code{default-realm} (default: @code{#f})
18060 This field should be a string identifying the default Kerberos
18061 realm for the client.
18062 You should set this field to the name of your Kerberos realm.
18063 If this value is @code{#f}
18064 then a realm must be specified with every Kerberos principal when invoking programs
18065 such as @command{kinit}.
18067 @item @code{realms}
18068 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18070 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18076 @subsubheading PAM krb5 Service
18079 The @code{pam-krb5} service allows for login authentication and password
18080 management via Kerberos.
18081 You will need this service if you want PAM enabled applications to authenticate
18082 users using Kerberos.
18084 @defvr {Scheme Variable} pam-krb5-service-type
18085 A service type for the Kerberos 5 PAM module.
18088 @deftp {Data Type} pam-krb5-configuration
18089 Data type representing the configuration of the Kerberos 5 PAM module.
18090 This type has the following parameters:
18092 @item @code{pam-krb5} (default: @code{pam-krb5})
18093 The pam-krb5 package to use.
18095 @item @code{minimum-uid} (default: @code{1000})
18096 The smallest user ID for which Kerberos authentications should be attempted.
18097 Local accounts with lower values will silently fail to authenticate.
18102 @node LDAP Services
18103 @subsection LDAP Services
18105 @cindex nslcd, LDAP service
18107 The @code{(gnu services authentication)} module provides the
18108 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18109 server. In addition to configuring the service itself, you may want to add
18110 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18111 Switch} for detailed information.
18113 Here is a simple operating system declaration with a default configuration of
18114 the @code{nslcd-service-type} and a Name Service Switch configuration that
18115 consults the @code{ldap} name service last:
18118 (use-service-modules authentication)
18119 (use-modules (gnu system nss))
18125 (service nslcd-service-type)
18126 (service dhcp-client-service-type)
18128 (name-service-switch
18129 (let ((services (list (name-service (name "db"))
18130 (name-service (name "files"))
18131 (name-service (name "ldap")))))
18132 (name-service-switch
18133 (inherit %mdns-host-lookup-nss)
18134 (password services)
18137 (netgroup services)
18138 (gshadow services)))))
18141 @c %start of generated documentation for nslcd-configuration
18143 Available @code{nslcd-configuration} fields are:
18145 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18146 The @code{nss-pam-ldapd} package to use.
18150 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18151 The number of threads to start that can handle requests and perform LDAP
18152 queries. Each thread opens a separate connection to the LDAP server.
18153 The default is to start 5 threads.
18155 Defaults to @samp{disabled}.
18159 @deftypevr {@code{nslcd-configuration} parameter} string uid
18160 This specifies the user id with which the daemon should be run.
18162 Defaults to @samp{"nslcd"}.
18166 @deftypevr {@code{nslcd-configuration} parameter} string gid
18167 This specifies the group id with which the daemon should be run.
18169 Defaults to @samp{"nslcd"}.
18173 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18174 This option controls the way logging is done via a list containing
18175 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18176 or "syslog", or an absolute file name. The LEVEL argument is optional
18177 and specifies the log level. The log level may be one of the following
18178 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18179 messages with the specified log level or higher are logged.
18181 Defaults to @samp{("/var/log/nslcd" info)}.
18185 @deftypevr {@code{nslcd-configuration} parameter} list uri
18186 The list of LDAP server URIs. Normally, only the first server will be
18187 used with the following servers as fall-back.
18189 Defaults to @samp{("ldap://localhost:389/")}.
18193 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18194 The version of the LDAP protocol to use. The default is to use the
18195 maximum version supported by the LDAP library.
18197 Defaults to @samp{disabled}.
18201 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18202 Specifies the distinguished name with which to bind to the directory
18203 server for lookups. The default is to bind anonymously.
18205 Defaults to @samp{disabled}.
18209 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18210 Specifies the credentials with which to bind. This option is only
18211 applicable when used with binddn.
18213 Defaults to @samp{disabled}.
18217 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18218 Specifies the distinguished name to use when the root user tries to
18219 modify a user's password using the PAM module.
18221 Defaults to @samp{disabled}.
18225 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18226 Specifies the credentials with which to bind if the root user tries to
18227 change a user's password. This option is only applicable when used with
18230 Defaults to @samp{disabled}.
18234 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18235 Specifies the SASL mechanism to be used when performing SASL
18238 Defaults to @samp{disabled}.
18242 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18243 Specifies the SASL realm to be used when performing SASL authentication.
18245 Defaults to @samp{disabled}.
18249 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18250 Specifies the authentication identity to be used when performing SASL
18253 Defaults to @samp{disabled}.
18257 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18258 Specifies the authorization identity to be used when performing SASL
18261 Defaults to @samp{disabled}.
18265 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18266 Determines whether the LDAP server host name should be canonicalised. If
18267 this is enabled the LDAP library will do a reverse host name lookup. By
18268 default, it is left up to the LDAP library whether this check is
18271 Defaults to @samp{disabled}.
18275 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18276 Set the name for the GSS-API Kerberos credentials cache.
18278 Defaults to @samp{disabled}.
18282 @deftypevr {@code{nslcd-configuration} parameter} string base
18283 The directory search base.
18285 Defaults to @samp{"dc=example,dc=com"}.
18289 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18290 Specifies the search scope (subtree, onelevel, base or children). The
18291 default scope is subtree; base scope is almost never useful for name
18292 service lookups; children scope is not supported on all servers.
18294 Defaults to @samp{(subtree)}.
18298 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18299 Specifies the policy for dereferencing aliases. The default policy is
18300 to never dereference aliases.
18302 Defaults to @samp{disabled}.
18306 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18307 Specifies whether automatic referral chasing should be enabled. The
18308 default behaviour is to chase referrals.
18310 Defaults to @samp{disabled}.
18314 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18315 This option allows for custom attributes to be looked up instead of the
18316 default RFC 2307 attributes. It is a list of maps, each consisting of
18317 the name of a map, the RFC 2307 attribute to match and the query
18318 expression for the attribute as it is available in the directory.
18320 Defaults to @samp{()}.
18324 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18325 A list of filters consisting of the name of a map to which the filter
18326 applies and an LDAP search filter expression.
18328 Defaults to @samp{()}.
18332 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18333 Specifies the time limit in seconds to use when connecting to the
18334 directory server. The default value is 10 seconds.
18336 Defaults to @samp{disabled}.
18340 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18341 Specifies the time limit (in seconds) to wait for a response from the
18342 LDAP server. A value of zero, which is the default, is to wait
18343 indefinitely for searches to be completed.
18345 Defaults to @samp{disabled}.
18349 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18350 Specifies the period if inactivity (in seconds) after which the con‐
18351 nection to the LDAP server will be closed. The default is not to time
18354 Defaults to @samp{disabled}.
18358 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18359 Specifies the number of seconds to sleep when connecting to all LDAP
18360 servers fails. By default one second is waited between the first
18361 failure and the first retry.
18363 Defaults to @samp{disabled}.
18367 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18368 Specifies the time after which the LDAP server is considered to be
18369 permanently unavailable. Once this time is reached retries will be done
18370 only once per this time period. The default value is 10 seconds.
18372 Defaults to @samp{disabled}.
18376 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18377 Specifies whether to use SSL/TLS or not (the default is not to). If
18378 'start-tls is specified then StartTLS is used rather than raw LDAP over
18381 Defaults to @samp{disabled}.
18385 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18386 Specifies what checks to perform on a server-supplied certificate. The
18387 meaning of the values is described in the ldap.conf(5) manual page.
18389 Defaults to @samp{disabled}.
18393 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18394 Specifies the directory containing X.509 certificates for peer authen‐
18395 tication. This parameter is ignored when using GnuTLS.
18397 Defaults to @samp{disabled}.
18401 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18402 Specifies the path to the X.509 certificate for peer authentication.
18404 Defaults to @samp{disabled}.
18408 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18409 Specifies the path to an entropy source. This parameter is ignored when
18412 Defaults to @samp{disabled}.
18416 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18417 Specifies the ciphers to use for TLS as a string.
18419 Defaults to @samp{disabled}.
18423 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18424 Specifies the path to the file containing the local certificate for
18425 client TLS authentication.
18427 Defaults to @samp{disabled}.
18431 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18432 Specifies the path to the file containing the private key for client TLS
18435 Defaults to @samp{disabled}.
18439 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18440 Set this to a number greater than 0 to request paged results from the
18441 LDAP server in accordance with RFC2696. The default (0) is to not
18442 request paged results.
18444 Defaults to @samp{disabled}.
18448 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18449 This option prevents group membership lookups through LDAP for the
18450 specified users. Alternatively, the value 'all-local may be used. With
18451 that value nslcd builds a full list of non-LDAP users on startup.
18453 Defaults to @samp{disabled}.
18457 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18458 This option ensures that LDAP users with a numeric user id lower than
18459 the specified value are ignored.
18461 Defaults to @samp{disabled}.
18465 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18466 This option specifies an offset that is added to all LDAP numeric user
18467 ids. This can be used to avoid user id collisions with local users.
18469 Defaults to @samp{disabled}.
18473 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18474 This option specifies an offset that is added to all LDAP numeric group
18475 ids. This can be used to avoid user id collisions with local groups.
18477 Defaults to @samp{disabled}.
18481 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18482 If this option is set, the member attribute of a group may point to
18483 another group. Members of nested groups are also returned in the higher
18484 level group and parent groups are returned when finding groups for a
18485 specific user. The default is not to perform extra searches for nested
18488 Defaults to @samp{disabled}.
18492 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18493 If this option is set, the group member list is not retrieved when
18494 looking up groups. Lookups for finding which groups a user belongs to
18495 will remain functional so the user will likely still get the correct
18496 groups assigned on login.
18498 Defaults to @samp{disabled}.
18502 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18503 If this option is set, functions which cause all user/group entries to
18504 be loaded from the directory will not succeed in doing so. This can
18505 dramatically reduce LDAP server load in situations where there are a
18506 great number of users and/or groups. This option is not recommended for
18507 most configurations.
18509 Defaults to @samp{disabled}.
18513 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18514 This option can be used to specify how user and group names are verified
18515 within the system. This pattern is used to check all user and group
18516 names that are requested and returned from LDAP.
18518 Defaults to @samp{disabled}.
18522 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18523 This specifies whether or not to perform searches using case-insensitive
18524 matching. Enabling this could open up the system to authorization
18525 bypass vulnerabilities and introduce nscd cache poisoning
18526 vulnerabilities which allow denial of service.
18528 Defaults to @samp{disabled}.
18532 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18533 This option specifies whether password policy controls are requested and
18534 handled from the LDAP server when performing user authentication.
18536 Defaults to @samp{disabled}.
18540 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18541 By default nslcd performs an LDAP search with the user's credentials
18542 after BIND (authentication) to ensure that the BIND operation was
18543 successful. The default search is a simple check to see if the user's
18544 DN exists. A search filter can be specified that will be used instead.
18545 It should return at least one entry.
18547 Defaults to @samp{disabled}.
18551 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18552 This option allows flexible fine tuning of the authorisation check that
18553 should be performed. The search filter specified is executed and if any
18554 entries match, access is granted, otherwise access is denied.
18556 Defaults to @samp{disabled}.
18560 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18561 If this option is set password modification using pam_ldap will be
18562 denied and the specified message will be presented to the user instead.
18563 The message can be used to direct the user to an alternative means of
18564 changing their password.
18566 Defaults to @samp{disabled}.
18570 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18571 List of pam service names for which LDAP authentication should suffice.
18573 Defaults to @samp{()}.
18577 @c %end of generated documentation for nslcd-configuration
18581 @subsection Web Services
18586 The @code{(gnu services web)} module provides the Apache HTTP Server,
18587 the nginx web server, and also a fastcgi wrapper daemon.
18589 @subsubheading Apache HTTP Server
18591 @deffn {Scheme Variable} httpd-service-type
18592 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18593 (@dfn{httpd}). The value for this service type is a
18594 @code{httpd-configuration} record.
18596 A simple example configuration is given below.
18599 (service httpd-service-type
18600 (httpd-configuration
18603 (server-name "www.example.com")
18604 (document-root "/srv/http/www.example.com")))))
18607 Other services can also extend the @code{httpd-service-type} to add to
18611 (simple-service 'my-extra-server httpd-service-type
18615 (list (string-append
18616 "ServerName "www.example.com
18617 DocumentRoot \"/srv/http/www.example.com\"")))))
18621 The details for the @code{httpd-configuration}, @code{httpd-module},
18622 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18625 @deffn {Data Type} httpd-configuration
18626 This data type represents the configuration for the httpd service.
18629 @item @code{package} (default: @code{httpd})
18630 The httpd package to use.
18632 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18633 The pid file used by the shepherd-service.
18635 @item @code{config} (default: @code{(httpd-config-file)})
18636 The configuration file to use with the httpd service. The default value
18637 is a @code{httpd-config-file} record, but this can also be a different
18638 G-expression that generates a file, for example a @code{plain-file}. A
18639 file outside of the store can also be specified through a string.
18644 @deffn {Data Type} httpd-module
18645 This data type represents a module for the httpd service.
18649 The name of the module.
18652 The file for the module. This can be relative to the httpd package being
18653 used, the absolute location of a file, or a G-expression for a file
18654 within the store, for example @code{(file-append mod-wsgi
18655 "/modules/mod_wsgi.so")}.
18660 @defvr {Scheme Variable} %default-httpd-modules
18661 A default list of @code{httpd-module} objects.
18664 @deffn {Data Type} httpd-config-file
18665 This data type represents a configuration file for the httpd service.
18668 @item @code{modules} (default: @code{%default-httpd-modules})
18669 The modules to load. Additional modules can be added here, or loaded by
18670 additional configuration.
18672 For example, in order to handle requests for PHP files, you can use Apache’s
18673 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18676 (service httpd-service-type
18677 (httpd-configuration
18682 (name "proxy_module")
18683 (file "modules/mod_proxy.so"))
18685 (name "proxy_fcgi_module")
18686 (file "modules/mod_proxy_fcgi.so"))
18687 %default-httpd-modules))
18688 (extra-config (list "\
18689 <FilesMatch \\.php$>
18690 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18691 </FilesMatch>"))))))
18692 (service php-fpm-service-type
18693 (php-fpm-configuration
18694 (socket "/var/run/php-fpm.sock")
18695 (socket-group "httpd")))
18698 @item @code{server-root} (default: @code{httpd})
18699 The @code{ServerRoot} in the configuration file, defaults to the httpd
18700 package. Directives including @code{Include} and @code{LoadModule} are
18701 taken as relative to the server root.
18703 @item @code{server-name} (default: @code{#f})
18704 The @code{ServerName} in the configuration file, used to specify the
18705 request scheme, hostname and port that the server uses to identify
18708 This doesn't need to be set in the server config, and can be specifyed
18709 in virtual hosts. The default is @code{#f} to not specify a
18712 @item @code{document-root} (default: @code{"/srv/http"})
18713 The @code{DocumentRoot} from which files will be served.
18715 @item @code{listen} (default: @code{'("80")})
18716 The list of values for the @code{Listen} directives in the config
18717 file. The value should be a list of strings, when each string can
18718 specify the port number to listen on, and optionally the IP address and
18721 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18722 The @code{PidFile} to use. This should match the @code{pid-file} set in
18723 the @code{httpd-configuration} so that the Shepherd service is
18724 configured correctly.
18726 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18727 The @code{ErrorLog} to which the server will log errors.
18729 @item @code{user} (default: @code{"httpd"})
18730 The @code{User} which the server will answer requests as.
18732 @item @code{group} (default: @code{"httpd"})
18733 The @code{Group} which the server will answer requests as.
18735 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18736 A flat list of strings and G-expressions which will be added to the end
18737 of the configuration file.
18739 Any values which the service is extended with will be appended to this
18745 @deffn {Data Type} httpd-virtualhost
18746 This data type represents a virtualhost configuration block for the httpd service.
18748 These should be added to the extra-config for the httpd-service.
18751 (simple-service 'my-extra-server httpd-service-type
18755 (list (string-append
18756 "ServerName "www.example.com
18757 DocumentRoot \"/srv/http/www.example.com\"")))))
18761 @item @code{addresses-and-ports}
18762 The addresses and ports for the @code{VirtualHost} directive.
18764 @item @code{contents}
18765 The contents of the @code{VirtualHost} directive, this should be a list
18766 of strings and G-expressions.
18771 @subsubheading NGINX
18773 @deffn {Scheme Variable} nginx-service-type
18774 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18775 value for this service type is a @code{<nginx-configuration>} record.
18777 A simple example configuration is given below.
18780 (service nginx-service-type
18781 (nginx-configuration
18783 (list (nginx-server-configuration
18784 (server-name '("www.example.com"))
18785 (root "/srv/http/www.example.com"))))))
18788 In addition to adding server blocks to the service configuration
18789 directly, this service can be extended by other services to add server
18790 blocks, as in this example:
18793 (simple-service 'my-extra-server nginx-service-type
18794 (list (nginx-server-configuration
18795 (root "/srv/http/extra-website")
18796 (try-files (list "$uri" "$uri/index.html")))))
18800 At startup, @command{nginx} has not yet read its configuration file, so
18801 it uses a default file to log error messages. If it fails to load its
18802 configuration file, that is where error messages are logged. After the
18803 configuration file is loaded, the default error log file changes as per
18804 configuration. In our case, startup error messages can be found in
18805 @file{/var/run/nginx/logs/error.log}, and after configuration in
18806 @file{/var/log/nginx/error.log}. The second location can be changed
18807 with the @var{log-directory} configuration option.
18809 @deffn {Data Type} nginx-configuration
18810 This data type represents the configuration for NGinx. Some
18811 configuration can be done through this and the other provided record
18812 types, or alternatively, a config file can be provided.
18815 @item @code{nginx} (default: @code{nginx})
18816 The nginx package to use.
18818 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18819 The directory to which NGinx will write log files.
18821 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18822 The directory in which NGinx will create a pid file, and write temporary
18825 @item @code{server-blocks} (default: @code{'()})
18826 A list of @dfn{server blocks} to create in the generated configuration
18827 file, the elements should be of type
18828 @code{<nginx-server-configuration>}.
18830 The following example would setup NGinx to serve @code{www.example.com}
18831 from the @code{/srv/http/www.example.com} directory, without using
18834 (service nginx-service-type
18835 (nginx-configuration
18837 (list (nginx-server-configuration
18838 (server-name '("www.example.com"))
18839 (root "/srv/http/www.example.com"))))))
18842 @item @code{upstream-blocks} (default: @code{'()})
18843 A list of @dfn{upstream blocks} to create in the generated configuration
18844 file, the elements should be of type
18845 @code{<nginx-upstream-configuration>}.
18847 Configuring upstreams through the @code{upstream-blocks} can be useful
18848 when combined with @code{locations} in the
18849 @code{<nginx-server-configuration>} records. The following example
18850 creates a server configuration with one location configuration, that
18851 will proxy requests to a upstream configuration, which will handle
18852 requests with two servers.
18857 (nginx-configuration
18859 (list (nginx-server-configuration
18860 (server-name '("www.example.com"))
18861 (root "/srv/http/www.example.com")
18864 (nginx-location-configuration
18866 (body '("proxy_pass http://server-proxy;"))))))))
18868 (list (nginx-upstream-configuration
18869 (name "server-proxy")
18870 (servers (list "server1.example.com"
18871 "server2.example.com")))))))
18874 @item @code{file} (default: @code{#f})
18875 If a configuration @var{file} is provided, this will be used, rather than
18876 generating a configuration file from the provided @code{log-directory},
18877 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18878 proper operation, these arguments should match what is in @var{file} to ensure
18879 that the directories are created when the service is activated.
18881 This can be useful if you have an existing configuration file, or it's
18882 not possible to do what is required through the other parts of the
18883 nginx-configuration record.
18885 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18886 Bucket size for the server names hash tables, defaults to @code{#f} to
18887 use the size of the processors cache line.
18889 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18890 Maximum bucket size for the server names hash tables.
18892 @item @code{extra-content} (default: @code{""})
18893 Extra content for the @code{http} block. Should be string or a string
18894 valued G-expression.
18899 @deftp {Data Type} nginx-server-configuration
18900 Data type representing the configuration of an nginx server block.
18901 This type has the following parameters:
18904 @item @code{listen} (default: @code{'("80" "443 ssl")})
18905 Each @code{listen} directive sets the address and port for IP, or the
18906 path for a UNIX-domain socket on which the server will accept requests.
18907 Both address and port, or only address or only port can be specified.
18908 An address may also be a hostname, for example:
18911 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18914 @item @code{server-name} (default: @code{(list 'default)})
18915 A list of server names this server represents. @code{'default} represents the
18916 default server for connections matching no other server.
18918 @item @code{root} (default: @code{"/srv/http"})
18919 Root of the website nginx will serve.
18921 @item @code{locations} (default: @code{'()})
18922 A list of @dfn{nginx-location-configuration} or
18923 @dfn{nginx-named-location-configuration} records to use within this
18926 @item @code{index} (default: @code{(list "index.html")})
18927 Index files to look for when clients ask for a directory. If it cannot be found,
18928 Nginx will send the list of files in the directory.
18930 @item @code{try-files} (default: @code{'()})
18931 A list of files whose existence is checked in the specified order.
18932 @code{nginx} will use the first file it finds to process the request.
18934 @item @code{ssl-certificate} (default: @code{#f})
18935 Where to find the certificate for secure connections. Set it to @code{#f} if
18936 you don't have a certificate or you don't want to use HTTPS.
18938 @item @code{ssl-certificate-key} (default: @code{#f})
18939 Where to find the private key for secure connections. Set it to @code{#f} if
18940 you don't have a key or you don't want to use HTTPS.
18942 @item @code{server-tokens?} (default: @code{#f})
18943 Whether the server should add its configuration to response.
18945 @item @code{raw-content} (default: @code{'()})
18946 A list of raw lines added to the server block.
18951 @deftp {Data Type} nginx-upstream-configuration
18952 Data type representing the configuration of an nginx @code{upstream}
18953 block. This type has the following parameters:
18957 Name for this group of servers.
18959 @item @code{servers}
18960 Specify the addresses of the servers in the group. The address can be
18961 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18962 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18963 prefix @samp{unix:}. For addresses using an IP address or domain name,
18964 the default port is 80, and a different port can be specified
18970 @deftp {Data Type} nginx-location-configuration
18971 Data type representing the configuration of an nginx @code{location}
18972 block. This type has the following parameters:
18976 URI which this location block matches.
18978 @anchor{nginx-location-configuration body}
18980 Body of the location block, specified as a list of strings. This can contain
18982 configuration directives. For example, to pass requests to a upstream
18983 server group defined using an @code{nginx-upstream-configuration} block,
18984 the following directive would be specified in the body @samp{(list "proxy_pass
18985 http://upstream-name;")}.
18990 @deftp {Data Type} nginx-named-location-configuration
18991 Data type representing the configuration of an nginx named location
18992 block. Named location blocks are used for request redirection, and not
18993 used for regular request processing. This type has the following
18998 Name to identify this location block.
19001 @xref{nginx-location-configuration body}, as the body for named location
19002 blocks can be used in a similar way to the
19003 @code{nginx-location-configuration body}. One restriction is that the
19004 body of a named location block cannot contain location blocks.
19009 @subsubheading Varnish Cache
19011 Varnish is a fast cache server that sits in between web applications
19012 and end users. It proxies requests from clients and caches the
19013 accessed URLs such that multiple requests for the same resource only
19014 creates one request to the back-end.
19016 @defvr {Scheme Variable} varnish-service-type
19017 Service type for the Varnish daemon.
19020 @deftp {Data Type} varnish-configuration
19021 Data type representing the @code{varnish} service configuration.
19022 This type has the following parameters:
19025 @item @code{package} (default: @code{varnish})
19026 The Varnish package to use.
19028 @item @code{name} (default: @code{"default"})
19029 A name for this Varnish instance. Varnish will create a directory in
19030 @file{/var/varnish/} with this name and keep temporary files there. If
19031 the name starts with a forward slash, it is interpreted as an absolute
19034 Pass the @code{-n} argument to other Varnish programs to connect to the
19035 named instance, e.g.@: @command{varnishncsa -n default}.
19037 @item @code{backend} (default: @code{"localhost:8080"})
19038 The backend to use. This option has no effect if @code{vcl} is set.
19040 @item @code{vcl} (default: #f)
19041 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19042 is @code{#f}, Varnish will proxy @code{backend} using the default
19043 configuration. Otherwise this must be a file-like object with valid
19046 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19047 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19048 can do something along these lines:
19051 (define %gnu-mirror
19055 backend gnu @{ .host = "www.gnu.org"; @}"))
19059 (services (cons (service varnish-service-type
19060 (varnish-configuration
19062 (vcl %gnu-mirror)))
19066 The configuration of an already running Varnish instance can be inspected
19067 and changed using the @command{varnishadm} program.
19069 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19070 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19071 comprehensive documentation on Varnish and its configuration language.
19073 @item @code{listen} (default: @code{'("localhost:80")})
19074 List of addresses Varnish will listen on.
19076 @item @code{storage} (default: @code{'("malloc,128m")})
19077 List of storage backends that will be available in VCL.
19079 @item @code{parameters} (default: @code{'()})
19080 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19082 @item @code{extra-options} (default: @code{'()})
19083 Additional arguments to pass to the @command{varnishd} process.
19088 @subsubheading FastCGI
19091 FastCGI is an interface between the front-end and the back-end of a web
19092 service. It is a somewhat legacy facility; new web services should
19093 generally just talk HTTP between the front-end and the back-end.
19094 However there are a number of back-end services such as PHP or the
19095 optimized HTTP Git repository access that use FastCGI, so we have
19096 support for it in Guix.
19098 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19099 dispatch some subset of its requests to the fastcgi backend, which
19100 listens on a local TCP or UNIX socket. There is an intermediary
19101 @code{fcgiwrap} program that sits between the actual backend process and
19102 the web server. The front-end indicates which backend program to run,
19103 passing that information to the @code{fcgiwrap} process.
19105 @defvr {Scheme Variable} fcgiwrap-service-type
19106 A service type for the @code{fcgiwrap} FastCGI proxy.
19109 @deftp {Data Type} fcgiwrap-configuration
19110 Data type representing the configuration of the @code{fcgiwrap} service.
19111 This type has the following parameters:
19113 @item @code{package} (default: @code{fcgiwrap})
19114 The fcgiwrap package to use.
19116 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19117 The socket on which the @code{fcgiwrap} process should listen, as a
19118 string. Valid @var{socket} values include
19119 @code{unix:@var{/path/to/unix/socket}},
19120 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19121 @code{tcp6:[@var{ipv6_addr}]:port}.
19123 @item @code{user} (default: @code{fcgiwrap})
19124 @itemx @code{group} (default: @code{fcgiwrap})
19125 The user and group names, as strings, under which to run the
19126 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19127 the user asks for the specific user or group names @code{fcgiwrap} that
19128 the corresponding user and/or group is present on the system.
19130 It is possible to configure a FastCGI-backed web service to pass HTTP
19131 authentication information from the front-end to the back-end, and to
19132 allow @code{fcgiwrap} to run the back-end process as a corresponding
19133 local user. To enable this capability on the back-end., run
19134 @code{fcgiwrap} as the @code{root} user and group. Note that this
19135 capability also has to be configured on the front-end as well.
19140 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19141 with some additional features useful for sites of any size.
19143 These features include:
19145 @item Adaptive process spawning
19146 @item Basic statistics (similar to Apache's mod_status)
19147 @item Advanced process management with graceful stop/start
19148 @item Ability to start workers with different uid/gid/chroot/environment
19149 and different php.ini (replaces safe_mode)
19150 @item Stdout & stderr logging
19151 @item Emergency restart in case of accidental opcode cache destruction
19152 @item Accelerated upload support
19153 @item Support for a "slowlog"
19154 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19155 a special function to finish request & flush all data while continuing to do
19156 something time-consuming (video converting, stats processing, etc.)
19158 ...@: and much more.
19160 @defvr {Scheme Variable} php-fpm-service-type
19161 A Service type for @code{php-fpm}.
19164 @deftp {Data Type} php-fpm-configuration
19165 Data Type for php-fpm service configuration.
19167 @item @code{php} (default: @code{php})
19168 The php package to use.
19169 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19170 The address on which to accept FastCGI requests. Valid syntaxes are:
19172 @item @code{"ip.add.re.ss:port"}
19173 Listen on a TCP socket to a specific address on a specific port.
19174 @item @code{"port"}
19175 Listen on a TCP socket to all addresses on a specific port.
19176 @item @code{"/path/to/unix/socket"}
19177 Listen on a unix socket.
19180 @item @code{user} (default: @code{php-fpm})
19181 User who will own the php worker processes.
19182 @item @code{group} (default: @code{php-fpm})
19183 Group of the worker processes.
19184 @item @code{socket-user} (default: @code{php-fpm})
19185 User who can speak to the php-fpm socket.
19186 @item @code{socket-group} (default: @code{php-fpm})
19187 Group that can speak to the php-fpm socket.
19188 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19189 The process id of the php-fpm process is written to this file
19190 once the service has started.
19191 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19192 Log for the php-fpm master process.
19193 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19194 Detailed settings for the php-fpm process manager.
19197 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19198 @item @code{<php-fpm-static-process-manager-configuration>}
19199 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19201 @item @code{display-errors} (default @code{#f})
19202 Determines whether php errors and warning should be sent to clients
19203 and displayed in their browsers.
19204 This is useful for local php development, but a security risk for public sites,
19205 as error messages can reveal passwords and personal data.
19206 @item @code{timezone} (default @code{#f})
19207 Specifies @code{php_admin_value[date.timezone]} parameter.
19208 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19209 This file will log the @code{stderr} outputs of php worker processes.
19210 Can be set to @code{#f} to disable logging.
19211 @item @code{file} (default @code{#f})
19212 An optional override of the whole configuration.
19213 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19217 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19218 Data Type for the @code{dynamic} php-fpm process manager. With the
19219 @code{dynamic} process manager, spare worker processes are kept around
19220 based on it's configured limits.
19222 @item @code{max-children} (default: @code{5})
19223 Maximum of worker processes.
19224 @item @code{start-servers} (default: @code{2})
19225 How many worker processes should be started on start-up.
19226 @item @code{min-spare-servers} (default: @code{1})
19227 How many spare worker processes should be kept around at minimum.
19228 @item @code{max-spare-servers} (default: @code{3})
19229 How many spare worker processes should be kept around at maximum.
19233 @deftp {Data type} php-fpm-static-process-manager-configuration
19234 Data Type for the @code{static} php-fpm process manager. With the
19235 @code{static} process manager, an unchanging number of worker processes
19238 @item @code{max-children} (default: @code{5})
19239 Maximum of worker processes.
19243 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19244 Data Type for the @code{on-demand} php-fpm process manager. With the
19245 @code{on-demand} process manager, worker processes are only created as
19248 @item @code{max-children} (default: @code{5})
19249 Maximum of worker processes.
19250 @item @code{process-idle-timeout} (default: @code{10})
19251 The time in seconds after which a process with no requests is killed.
19256 @deffn {Scheme Procedure} nginx-php-fpm-location @
19257 [#:nginx-package nginx] @
19258 [socket (string-append "/var/run/php" @
19259 (version-major (package-version php)) @
19261 A helper function to quickly add php to an @code{nginx-server-configuration}.
19264 A simple services setup for nginx with php can look like this:
19266 (services (cons* (service dhcp-client-service-type)
19267 (service php-fpm-service-type)
19268 (service nginx-service-type
19269 (nginx-server-configuration
19270 (server-name '("example.com"))
19271 (root "/srv/http/")
19273 (list (nginx-php-location)))
19275 (ssl-certificate #f)
19276 (ssl-certificate-key #f)))
19280 @cindex cat-avatar-generator
19281 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19282 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19283 the hash of a user's email address.
19285 @deffn {Scheme Procedure} cat-avatar-generator-service @
19286 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19287 [#:package cat-avatar-generator] @
19288 [#:configuration (nginx-server-configuration)]
19289 Returns an nginx-server-configuration that inherits @code{configuration}. It
19290 extends the nginx configuration to add a server block that serves @code{package},
19291 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19292 be able to use @code{cache-dir} as its cache directory.
19295 A simple setup for cat-avatar-generator can look like this:
19297 (services (cons* (cat-avatar-generator-service
19299 (nginx-server-configuration
19300 (server-name '("example.com"))))
19305 @subsubheading Hpcguix-web
19307 @cindex hpcguix-web
19308 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19309 program is a customizable web interface to browse Guix packages,
19310 initially designed for users of high-performance computing (HPC)
19313 @defvr {Scheme Variable} hpcguix-web-service-type
19314 The service type for @code{hpcguix-web}.
19317 @deftp {Data Type} hpcguix-web-configuration
19318 Data type for the hpcguix-web service configuration.
19322 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19323 configuration. The main items available in this spec are:
19326 @item @code{title-prefix} (default: @code{"hpcguix | "})
19327 The page title prefix.
19329 @item @code{guix-command} (default: @code{"guix"})
19330 The @command{guix} command.
19332 @item @code{package-filter-proc} (default: @code{(const #t)})
19333 A procedure specifying how to filter packages that are displayed.
19335 @item @code{package-page-extension-proc} (default: @code{(const '())})
19336 Extension package for @code{hpcguix-web}.
19338 @item @code{menu} (default: @code{'()})
19339 Additional entry in page @code{menu}.
19341 @item @code{channels} (default: @code{%default-channels})
19342 List of channels from which the package list is built (@pxref{Channels}).
19344 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19345 The expiration time, in seconds, after which the package list is rebuilt from
19346 the latest instances of the given channels.
19349 See the hpcguix-web repository for a
19350 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19353 @item @code{package} (default: @code{hpcguix-web})
19354 The hpcguix-web package to use.
19358 A typical hpcguix-web service declaration looks like this:
19361 (service hpcguix-web-service-type
19362 (hpcguix-web-configuration
19364 #~(define site-config
19365 (hpcweb-configuration
19366 (title-prefix "Guix-HPC - ")
19367 (menu '(("/about" "ABOUT"))))))))
19371 The hpcguix-web service periodically updates the package list it publishes by
19372 pulling channels from Git. To that end, it needs to access X.509 certificates
19373 so that it can authenticate Git servers when communicating over HTTPS, and it
19374 assumes that @file{/etc/ssl/certs} contains those certificates.
19376 Thus, make sure to add @code{nss-certs} or another certificate package to the
19377 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19378 more information on X.509 certificates.
19381 @node Certificate Services
19382 @subsection Certificate Services
19385 @cindex HTTP, HTTPS
19386 @cindex Let's Encrypt
19387 @cindex TLS certificates
19388 The @code{(gnu services certbot)} module provides a service to
19389 automatically obtain a valid TLS certificate from the Let's Encrypt
19390 certificate authority. These certificates can then be used to serve
19391 content securely over HTTPS or other TLS-based protocols, with the
19392 knowledge that the client will be able to verify the server's
19395 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19396 @code{certbot} tool to automate the certification process. This tool
19397 first securely generates a key on the server. It then makes a request
19398 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19399 checks that the request originates from the host in question by using a
19400 challenge-response protocol, requiring the server to provide its
19401 response over HTTP. If that protocol completes successfully, the CA
19402 signs the key, resulting in a certificate. That certificate is valid
19403 for a limited period of time, and therefore to continue to provide TLS
19404 services, the server needs to periodically ask the CA to renew its
19407 The certbot service automates this process: the initial key
19408 generation, the initial certification request to the Let's Encrypt
19409 service, the web server challenge/response integration, writing the
19410 certificate to disk, the automated periodic renewals, and the deployment
19411 tasks associated with the renewal (e.g.@: reloading services, copying keys
19412 with different permissions).
19414 Certbot is run twice a day, at a random minute within the hour. It
19415 won't do anything until your certificates are due for renewal or
19416 revoked, but running it regularly would give your service a chance of
19417 staying online in case a Let's Encrypt-initiated revocation happened for
19420 By using this service, you agree to the ACME Subscriber Agreement, which
19421 can be found there:
19422 @url{https://acme-v01.api.letsencrypt.org/directory}.
19424 @defvr {Scheme Variable} certbot-service-type
19425 A service type for the @code{certbot} Let's Encrypt client. Its value
19426 must be a @code{certbot-configuration} record as in this example:
19429 (define %nginx-deploy-hook
19431 "nginx-deploy-hook"
19432 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19433 (kill pid SIGHUP))))
19435 (service certbot-service-type
19436 (certbot-configuration
19437 (email "foo@@example.net")
19440 (certificate-configuration
19441 (domains '("example.net" "www.example.net"))
19442 (deploy-hook %nginx-deploy-hook))
19443 (certificate-configuration
19444 (domains '("bar.example.net")))))))
19447 See below for details about @code{certbot-configuration}.
19450 @deftp {Data Type} certbot-configuration
19451 Data type representing the configuration of the @code{certbot} service.
19452 This type has the following parameters:
19455 @item @code{package} (default: @code{certbot})
19456 The certbot package to use.
19458 @item @code{webroot} (default: @code{/var/www})
19459 The directory from which to serve the Let's Encrypt challenge/response
19462 @item @code{certificates} (default: @code{()})
19463 A list of @code{certificates-configuration}s for which to generate
19464 certificates and request signatures. Each certificate has a @code{name}
19465 and several @code{domains}.
19468 Mandatory email used for registration, recovery contact, and important
19469 account notifications.
19471 @item @code{rsa-key-size} (default: @code{2048})
19472 Size of the RSA key.
19474 @item @code{default-location} (default: @i{see below})
19475 The default @code{nginx-location-configuration}. Because @code{certbot}
19476 needs to be able to serve challenges and responses, it needs to be able
19477 to run a web server. It does so by extending the @code{nginx} web
19478 service with an @code{nginx-server-configuration} listening on the
19479 @var{domains} on port 80, and which has a
19480 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19481 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19482 these nginx configuration data types.
19484 Requests to other URL paths will be matched by the
19485 @code{default-location}, which if present is added to all
19486 @code{nginx-server-configuration}s.
19488 By default, the @code{default-location} will issue a redirect from
19489 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19490 you to define what to serve on your site via @code{https}.
19492 Pass @code{#f} to not issue a default location.
19496 @deftp {Data Type} certificate-configuration
19497 Data type representing the configuration of a certificate.
19498 This type has the following parameters:
19501 @item @code{name} (default: @i{see below})
19502 This name is used by Certbot for housekeeping and in file paths; it
19503 doesn't affect the content of the certificate itself. To see
19504 certificate names, run @code{certbot certificates}.
19506 Its default is the first provided domain.
19508 @item @code{domains} (default: @code{()})
19509 The first domain provided will be the subject CN of the certificate, and
19510 all domains will be Subject Alternative Names on the certificate.
19512 @item @code{challenge} (default: @code{#f})
19513 The challenge type that has to be run by certbot. If @code{#f} is specified,
19514 default to the HTTP challenge. If a value is specified, defaults to the
19515 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
19516 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
19518 @item @code{authentication-hook} (default: @code{#f})
19519 Command to be run in a shell once for each certificate challenge to be
19520 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
19521 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
19522 contains the validation string and @code{$CERTBOT_TOKEN} contains the
19523 file name of the resource requested when performing an HTTP-01 challenge.
19525 @item @code{cleanup-hook} (default: @code{#f})
19526 Command to be run in a shell once for each certificate challenge that
19527 have been answered by the @code{auth-hook}. For this command, the shell
19528 variables available in the @code{auth-hook} script are still available, and
19529 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
19530 of the @code{auth-hook} script.
19532 @item @code{deploy-hook} (default: @code{#f})
19533 Command to be run in a shell once for each successfully issued
19534 certificate. For this command, the shell variable
19535 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19536 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19537 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19538 contain a space-delimited list of renewed certificate domains (for
19539 example, @samp{"example.com www.example.com"}.
19544 For each @code{certificate-configuration}, the certificate is saved to
19545 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19546 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19548 @subsection DNS Services
19549 @cindex DNS (domain name system)
19550 @cindex domain name system (DNS)
19552 The @code{(gnu services dns)} module provides services related to the
19553 @dfn{domain name system} (DNS). It provides a server service for hosting
19554 an @emph{authoritative} DNS server for multiple zones, slave or master.
19555 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19556 caching and forwarding DNS server for the LAN, which uses
19557 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19559 @subsubheading Knot Service
19561 An example configuration of an authoritative server for two zones, one master
19565 (define-zone-entries example.org.zone
19566 ;; Name TTL Class Type Data
19567 ("@@" "" "IN" "A" "127.0.0.1")
19568 ("@@" "" "IN" "NS" "ns")
19569 ("ns" "" "IN" "A" "127.0.0.1"))
19571 (define master-zone
19572 (knot-zone-configuration
19573 (domain "example.org")
19575 (origin "example.org")
19576 (entries example.org.zone)))))
19579 (knot-zone-configuration
19580 (domain "plop.org")
19581 (dnssec-policy "default")
19582 (master (list "plop-master"))))
19584 (define plop-master
19585 (knot-remote-configuration
19587 (address (list "208.76.58.171"))))
19591 (services (cons* (service knot-service-type
19592 (knot-configuration
19593 (remotes (list plop-master))
19594 (zones (list master-zone slave-zone))))
19599 @deffn {Scheme Variable} knot-service-type
19600 This is the type for the Knot DNS server.
19602 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19603 zones, that is to say domain names you would buy from a registrar. This server
19604 is not a resolver, meaning that it can only resolve names for which it is
19605 authoritative. This server can be configured to serve zones as a master server
19606 or a slave server as a per-zone basis. Slave zones will get their data from
19607 masters, and will serve it as an authoritative server. From the point of view
19608 of a resolver, there is no difference between master and slave.
19610 The following data types are used to configure the Knot DNS server:
19613 @deftp {Data Type} knot-key-configuration
19614 Data type representing a key.
19615 This type has the following parameters:
19618 @item @code{id} (default: @code{""})
19619 An identifier for other configuration fields to refer to this key. IDs must
19620 be unique and must not be empty.
19622 @item @code{algorithm} (default: @code{#f})
19623 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19624 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19625 and @code{'hmac-sha512}.
19627 @item @code{secret} (default: @code{""})
19628 The secret key itself.
19633 @deftp {Data Type} knot-acl-configuration
19634 Data type representing an Access Control List (ACL) configuration.
19635 This type has the following parameters:
19638 @item @code{id} (default: @code{""})
19639 An identifier for ether configuration fields to refer to this key. IDs must be
19640 unique and must not be empty.
19642 @item @code{address} (default: @code{'()})
19643 An ordered list of IP addresses, network subnets, or network ranges represented
19644 with strings. The query must match one of them. Empty value means that
19645 address match is not required.
19647 @item @code{key} (default: @code{'()})
19648 An ordered list of references to keys represented with strings. The string
19649 must match a key ID defined in a @code{knot-key-configuration}. No key means
19650 that a key is not require to match that ACL.
19652 @item @code{action} (default: @code{'()})
19653 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19654 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19655 and @code{'update}.
19657 @item @code{deny?} (default: @code{#f})
19658 When true, the ACL defines restrictions. Listed actions are forbidden. When
19659 false, listed actions are allowed.
19664 @deftp {Data Type} zone-entry
19665 Data type represnting a record entry in a zone file.
19666 This type has the following parameters:
19669 @item @code{name} (default: @code{"@@"})
19670 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19671 are relative to the origin of the zone. For example, in the @code{example.org}
19672 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19673 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19674 refers to @code{ns.example.org}.
19676 @item @code{ttl} (default: @code{""})
19677 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19679 @item @code{class} (default: @code{"IN"})
19680 The class of the record. Knot currently supports only @code{"IN"} and
19681 partially @code{"CH"}.
19683 @item @code{type} (default: @code{"A"})
19684 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19685 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19688 @item @code{data} (default: @code{""})
19689 The data contained in the record. For instance an IP address associated with
19690 an A record, or a domain name associated with an NS record. Remember that
19691 domain names are relative to the origin unless they end with a dot.
19696 @deftp {Data Type} zone-file
19697 Data type representing the content of a zone file.
19698 This type has the following parameters:
19701 @item @code{entries} (default: @code{'()})
19702 The list of entries. The SOA record is taken care of, so you don't need to
19703 put it in the list of entries. This list should probably contain an entry
19704 for your primary authoritative DNS server. Other than using a list of entries
19705 directly, you can use @code{define-zone-entries} to define a object containing
19706 the list of entries more easily, that you can later pass to the @code{entries}
19707 field of the @code{zone-file}.
19709 @item @code{origin} (default: @code{""})
19710 The name of your zone. This parameter cannot be empty.
19712 @item @code{ns} (default: @code{"ns"})
19713 The domain of your primary authoritative DNS server. The name is relative to
19714 the origin, unless it ends with a dot. It is mandatory that this primary
19715 DNS server corresponds to an NS record in the zone and that it is associated
19716 to an IP address in the list of entries.
19718 @item @code{mail} (default: @code{"hostmaster"})
19719 An email address people can contact you at, as the owner of the zone. This
19720 is translated as @code{<mail>@@<origin>}.
19722 @item @code{serial} (default: @code{1})
19723 The serial number of the zone. As this is used to keep track of changes by
19724 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19725 Always increment it when you make a change in your zone.
19727 @item @code{refresh} (default: @code{(* 2 24 3600)})
19728 The frequency at which slaves will do a zone transfer. This value is a number
19729 of seconds. It can be computed by multiplications or with
19730 @code{(string->duration)}.
19732 @item @code{retry} (default: @code{(* 15 60)})
19733 The period after which a slave will retry to contact its master when it fails
19734 to do so a first time.
19736 @item @code{expiry} (default: @code{(* 14 24 3600)})
19737 Default TTL of records. Existing records are considered correct for at most
19738 this amount of time. After this period, resolvers will invalidate their cache
19739 and check again that it still exists.
19741 @item @code{nx} (default: @code{3600})
19742 Default TTL of inexistant records. This delay is usually short because you want
19743 your new domains to reach everyone quickly.
19748 @deftp {Data Type} knot-remote-configuration
19749 Data type representing a remote configuration.
19750 This type has the following parameters:
19753 @item @code{id} (default: @code{""})
19754 An identifier for other configuration fields to refer to this remote. IDs must
19755 be unique and must not be empty.
19757 @item @code{address} (default: @code{'()})
19758 An ordered list of destination IP addresses. Addresses are tried in sequence.
19759 An optional port can be given with the @@ separator. For instance:
19760 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19762 @item @code{via} (default: @code{'()})
19763 An ordered list of source IP addresses. An empty list will have Knot choose
19764 an appropriate source IP. An optional port can be given with the @@ separator.
19765 The default is to choose at random.
19767 @item @code{key} (default: @code{#f})
19768 A reference to a key, that is a string containing the identifier of a key
19769 defined in a @code{knot-key-configuration} field.
19774 @deftp {Data Type} knot-keystore-configuration
19775 Data type representing a keystore to hold dnssec keys.
19776 This type has the following parameters:
19779 @item @code{id} (default: @code{""})
19780 The id of the keystore. It must not be empty.
19782 @item @code{backend} (default: @code{'pem})
19783 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19785 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19786 The configuration string of the backend. An example for the PKCS#11 is:
19787 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19788 For the pem backend, the string reprensents a path in the file system.
19793 @deftp {Data Type} knot-policy-configuration
19794 Data type representing a dnssec policy. Knot DNS is able to automatically
19795 sign your zones. It can either generate and manage your keys automatically or
19796 use keys that you generate.
19798 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19799 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19800 zone. In order to be trusted, the KSK needs to be present in the parent zone
19801 (usually a top-level domain). If your registrar supports dnssec, you will
19802 have to send them your KSK's hash so they can add a DS record in their zone.
19803 This is not automated and need to be done each time you change your KSK.
19805 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19806 easily and use weaker cryptographic functions (they use lower parameters) in
19807 order to sign records quickly, so they are changed often. The KSK however
19808 requires manual interaction with the registrar, so they are changed less often
19809 and use stronger parameters because they sign only one record.
19811 This type has the following parameters:
19814 @item @code{id} (default: @code{""})
19815 The id of the policy. It must not be empty.
19817 @item @code{keystore} (default: @code{"default"})
19818 A reference to a keystore, that is a string containing the identifier of a
19819 keystore defined in a @code{knot-keystore-configuration} field. The
19820 @code{"default"} identifier means the default keystore (a kasp database that
19821 was setup by this service).
19823 @item @code{manual?} (default: @code{#f})
19824 Whether the key management is manual or automatic.
19826 @item @code{single-type-signing?} (default: @code{#f})
19827 When @code{#t}, use the Single-Type Signing Scheme.
19829 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19830 An algorithm of signing keys and issued signatures.
19832 @item @code{ksk-size} (default: @code{256})
19833 The length of the KSK. Note that this value is correct for the default
19834 algorithm, but would be unsecure for other algorithms.
19836 @item @code{zsk-size} (default: @code{256})
19837 The length of the ZSK. Note that this value is correct for the default
19838 algorithm, but would be unsecure for other algorithms.
19840 @item @code{dnskey-ttl} (default: @code{'default})
19841 The TTL value for DNSKEY records added into zone apex. The special
19842 @code{'default} value means same as the zone SOA TTL.
19844 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19845 The period between ZSK publication and the next rollover initiation.
19847 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19848 An extra delay added for each key rollover step. This value should be high
19849 enough to cover propagation of data from the master server to all slaves.
19851 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19852 A validity period of newly issued signatures.
19854 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19855 A period how long before a signature expiration the signature will be refreshed.
19857 @item @code{nsec3?} (default: @code{#f})
19858 When @code{#t}, NSEC3 will be used instead of NSEC.
19860 @item @code{nsec3-iterations} (default: @code{5})
19861 The number of additional times the hashing is performed.
19863 @item @code{nsec3-salt-length} (default: @code{8})
19864 The length of a salt field in octets, which is appended to the original owner
19865 name before hashing.
19867 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19868 The validity period of newly issued salt field.
19873 @deftp {Data Type} knot-zone-configuration
19874 Data type representing a zone served by Knot.
19875 This type has the following parameters:
19878 @item @code{domain} (default: @code{""})
19879 The domain served by this configuration. It must not be empty.
19881 @item @code{file} (default: @code{""})
19882 The file where this zone is saved. This parameter is ignored by master zones.
19883 Empty means default location that depends on the domain name.
19885 @item @code{zone} (default: @code{(zone-file)})
19886 The content of the zone file. This parameter is ignored by slave zones. It
19887 must contain a zone-file record.
19889 @item @code{master} (default: @code{'()})
19890 A list of master remotes. When empty, this zone is a master. When set, this
19891 zone is a slave. This is a list of remotes identifiers.
19893 @item @code{ddns-master} (default: @code{#f})
19894 The main master. When empty, it defaults to the first master in the list of
19897 @item @code{notify} (default: @code{'()})
19898 A list of slave remote identifiers.
19900 @item @code{acl} (default: @code{'()})
19901 A list of acl identifiers.
19903 @item @code{semantic-checks?} (default: @code{#f})
19904 When set, this adds more semantic checks to the zone.
19906 @item @code{disable-any?} (default: @code{#f})
19907 When set, this forbids queries of the ANY type.
19909 @item @code{zonefile-sync} (default: @code{0})
19910 The delay between a modification in memory and on disk. 0 means immediate
19913 @item @code{zonefile-load} (default: @code{#f})
19914 The way the zone file contents are applied during zone load. Possible values
19918 @item @code{#f} for using the default value from Knot,
19919 @item @code{'none} for not using the zone file at all,
19920 @item @code{'difference} for computing the difference between already available
19921 contents and zone contents and applying it to the current zone contents,
19922 @item @code{'difference-no-serial} for the same as @code{'difference}, but
19923 ignoring the SOA serial in the zone file, while the server takes care of it
19925 @item @code{'whole} for loading zone contents from the zone file.
19928 @item @code{journal-content} (default: @code{#f})
19929 The way the journal is used to store zone and its changes. Possible values
19930 are @code{'none} to not use it at all, @code{'changes} to store changes and
19931 @code{'all} to store contents. @code{#f} does not set this option, so the
19932 default value from Knot is used.
19934 @item @code{max-journal-usage} (default: @code{#f})
19935 The maximum size for the journal on disk. @code{#f} does not set this option,
19936 so the default value from Knot is used.
19938 @item @code{max-journal-depth} (default: @code{#f})
19939 The maximum size of the history. @code{#f} does not set this option, so the
19940 default value from Knot is used.
19942 @item @code{max-zone-size} (default: @code{#f})
19943 The maximum size of the zone file. This limit is enforced for incoming
19944 transfer and updates. @code{#f} does not set this option, so the default
19945 value from Knot is used.
19947 @item @code{dnssec-policy} (default: @code{#f})
19948 A reference to a @code{knot-policy-configuration} record, or the special
19949 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
19952 @item @code{serial-policy} (default: @code{'increment})
19953 A policy between @code{'increment} and @code{'unixtime}.
19958 @deftp {Data Type} knot-configuration
19959 Data type representing the Knot configuration.
19960 This type has the following parameters:
19963 @item @code{knot} (default: @code{knot})
19966 @item @code{run-directory} (default: @code{"/var/run/knot"})
19967 The run directory. This directory will be used for pid file and sockets.
19969 @item @code{includes} (default: @code{'()})
19970 A list of strings or file-like objects denoting other files that must be
19971 included at the top of the configuration file.
19973 @cindex secrets, Knot service
19974 This can be used to manage secrets out-of-band. For example, secret
19975 keys may be stored in an out-of-band file not managed by Guix, and
19976 thus not visible in @file{/gnu/store}---e.g., you could store secret
19977 key configuration in @file{/etc/knot/secrets.conf} and add this file
19978 to the @code{includes} list.
19980 It can also be used to add configuration not supported by this interface.
19982 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19983 An ip address on which to listen.
19985 @item @code{listen-v6} (default: @code{"::"})
19986 An ip address on which to listen.
19988 @item @code{listen-port} (default: @code{53})
19989 A port on which to listen.
19991 @item @code{keys} (default: @code{'()})
19992 The list of knot-key-configuration used by this configuration.
19994 @item @code{acls} (default: @code{'()})
19995 The list of knot-acl-configuration used by this configuration.
19997 @item @code{remotes} (default: @code{'()})
19998 The list of knot-remote-configuration used by this configuration.
20000 @item @code{zones} (default: @code{'()})
20001 The list of knot-zone-configuration used by this configuration.
20006 @subsubheading Dnsmasq Service
20008 @deffn {Scheme Variable} dnsmasq-service-type
20009 This is the type of the dnsmasq service, whose value should be an
20010 @code{dnsmasq-configuration} object as in this example:
20013 (service dnsmasq-service-type
20014 (dnsmasq-configuration
20016 (servers '("192.168.1.1"))))
20020 @deftp {Data Type} dnsmasq-configuration
20021 Data type representing the configuration of dnsmasq.
20024 @item @code{package} (default: @var{dnsmasq})
20025 Package object of the dnsmasq server.
20027 @item @code{no-hosts?} (default: @code{#f})
20028 When true, don't read the hostnames in /etc/hosts.
20030 @item @code{port} (default: @code{53})
20031 The port to listen on. Setting this to zero completely disables DNS
20032 responses, leaving only DHCP and/or TFTP functions.
20034 @item @code{local-service?} (default: @code{#t})
20035 Accept DNS queries only from hosts whose address is on a local subnet,
20036 ie a subnet for which an interface exists on the server.
20038 @item @code{listen-addresses} (default: @code{'()})
20039 Listen on the given IP addresses.
20041 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20042 The file to read the IP address of the upstream nameservers from.
20044 @item @code{no-resolv?} (default: @code{#f})
20045 When true, don't read @var{resolv-file}.
20047 @item @code{servers} (default: @code{'()})
20048 Specify IP address of upstream servers directly.
20050 @item @code{cache-size} (default: @code{150})
20051 Set the size of dnsmasq's cache. Setting the cache size to zero
20054 @item @code{negative-cache?} (default: @code{#t})
20055 When false, disable negative caching.
20060 @subsubheading ddclient Service
20063 The ddclient service described below runs the ddclient daemon, which takes
20064 care of automatically updating DNS entries for service providers such as
20065 @uref{https://dyn.com/dns/, Dyn}.
20067 The following example show instantiates the service with its default
20071 (service ddclient-service-type)
20074 Note that ddclient needs to access credentials that are stored in a
20075 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20076 @code{secret-file} below.) You are expected to create this file manually, in
20077 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20078 service configuration, for instance by using @code{plain-file}, but it will be
20079 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20080 @file{share/ddclient} directory of the @code{ddclient} package.
20082 @c %start of fragment
20084 Available @code{ddclient-configuration} fields are:
20086 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20087 The ddclient package.
20091 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20092 The period after which ddclient will retry to check IP and domain name.
20094 Defaults to @samp{300}.
20098 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20099 Use syslog for the output.
20101 Defaults to @samp{#t}.
20105 @deftypevr {@code{ddclient-configuration} parameter} string mail
20108 Defaults to @samp{"root"}.
20112 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20113 Mail failed update to user.
20115 Defaults to @samp{"root"}.
20119 @deftypevr {@code{ddclient-configuration} parameter} string pid
20120 The ddclient PID file.
20122 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20126 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20127 Enable SSL support.
20129 Defaults to @samp{#t}.
20133 @deftypevr {@code{ddclient-configuration} parameter} string user
20134 Specifies the user name or ID that is used when running ddclient
20137 Defaults to @samp{"ddclient"}.
20141 @deftypevr {@code{ddclient-configuration} parameter} string group
20142 Group of the user who will run the ddclient program.
20144 Defaults to @samp{"ddclient"}.
20148 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20149 Secret file which will be appended to @file{ddclient.conf} file. This
20150 file contains credentials for use by ddclient. You are expected to
20151 create it manually.
20153 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20157 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20158 Extra options will be appended to @file{ddclient.conf} file.
20160 Defaults to @samp{()}.
20165 @c %end of fragment
20169 @subsection VPN Services
20170 @cindex VPN (virtual private network)
20171 @cindex virtual private network (VPN)
20173 The @code{(gnu services vpn)} module provides services related to
20174 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20175 your machine to connect to a VPN, and a @emph{server} service for your machine
20176 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20178 @deffn {Scheme Procedure} openvpn-client-service @
20179 [#:config (openvpn-client-configuration)]
20181 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20184 @deffn {Scheme Procedure} openvpn-server-service @
20185 [#:config (openvpn-server-configuration)]
20187 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20189 Both can be run simultaneously.
20192 @c %automatically generated documentation
20194 Available @code{openvpn-client-configuration} fields are:
20196 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20197 The OpenVPN package.
20201 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20202 The OpenVPN pid file.
20204 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20208 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20209 The protocol (UDP or TCP) used to open a channel between clients and
20212 Defaults to @samp{udp}.
20216 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20217 The device type used to represent the VPN connection.
20219 Defaults to @samp{tun}.
20223 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20224 The certificate authority to check connections against.
20226 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20230 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20231 The certificate of the machine the daemon is running on. It should be
20232 signed by the authority given in @code{ca}.
20234 Defaults to @samp{"/etc/openvpn/client.crt"}.
20238 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20239 The key of the machine the daemon is running on. It must be the key whose
20240 certificate is @code{cert}.
20242 Defaults to @samp{"/etc/openvpn/client.key"}.
20246 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20247 Whether to use the lzo compression algorithm.
20249 Defaults to @samp{#t}.
20253 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20254 Don't re-read key files across SIGUSR1 or --ping-restart.
20256 Defaults to @samp{#t}.
20260 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20261 Don't close and reopen TUN/TAP device or run up/down scripts across
20262 SIGUSR1 or --ping-restart restarts.
20264 Defaults to @samp{#t}.
20268 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20271 Defaults to @samp{3}.
20275 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20276 Add an additional layer of HMAC authentication on top of the TLS control
20277 channel to protect against DoS attacks.
20279 Defaults to @samp{#f}.
20283 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20284 Whether to check the server certificate has server usage extension.
20286 Defaults to @samp{#t}.
20290 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20291 Bind to a specific local port number.
20293 Defaults to @samp{#f}.
20297 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20298 Retry resolving server address.
20300 Defaults to @samp{#t}.
20304 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20305 A list of remote servers to connect to.
20307 Defaults to @samp{()}.
20309 Available @code{openvpn-remote-configuration} fields are:
20311 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20314 Defaults to @samp{"my-server"}.
20318 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20319 Port number the server listens to.
20321 Defaults to @samp{1194}.
20326 @c %end of automatic openvpn-client documentation
20328 @c %automatically generated documentation
20330 Available @code{openvpn-server-configuration} fields are:
20332 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20333 The OpenVPN package.
20337 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20338 The OpenVPN pid file.
20340 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20344 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20345 The protocol (UDP or TCP) used to open a channel between clients and
20348 Defaults to @samp{udp}.
20352 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20353 The device type used to represent the VPN connection.
20355 Defaults to @samp{tun}.
20359 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20360 The certificate authority to check connections against.
20362 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20366 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20367 The certificate of the machine the daemon is running on. It should be
20368 signed by the authority given in @code{ca}.
20370 Defaults to @samp{"/etc/openvpn/client.crt"}.
20374 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20375 The key of the machine the daemon is running on. It must be the key whose
20376 certificate is @code{cert}.
20378 Defaults to @samp{"/etc/openvpn/client.key"}.
20382 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20383 Whether to use the lzo compression algorithm.
20385 Defaults to @samp{#t}.
20389 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20390 Don't re-read key files across SIGUSR1 or --ping-restart.
20392 Defaults to @samp{#t}.
20396 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20397 Don't close and reopen TUN/TAP device or run up/down scripts across
20398 SIGUSR1 or --ping-restart restarts.
20400 Defaults to @samp{#t}.
20404 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20407 Defaults to @samp{3}.
20411 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20412 Add an additional layer of HMAC authentication on top of the TLS control
20413 channel to protect against DoS attacks.
20415 Defaults to @samp{#f}.
20419 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20420 Specifies the port number on which the server listens.
20422 Defaults to @samp{1194}.
20426 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20427 An ip and mask specifying the subnet inside the virtual network.
20429 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20433 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20434 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20436 Defaults to @samp{#f}.
20440 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20441 The Diffie-Hellman parameters file.
20443 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20447 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20448 The file that records client IPs.
20450 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20454 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20455 When true, the server will act as a gateway for its clients.
20457 Defaults to @samp{#f}.
20461 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20462 When true, clients are allowed to talk to each other inside the VPN.
20464 Defaults to @samp{#f}.
20468 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20469 Causes ping-like messages to be sent back and forth over the link so
20470 that each side knows when the other side has gone down. @code{keepalive}
20471 requires a pair. The first element is the period of the ping sending,
20472 and the second element is the timeout before considering the other side
20477 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20478 The maximum number of clients.
20480 Defaults to @samp{100}.
20484 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20485 The status file. This file shows a small report on current connection.
20486 It is truncated and rewritten every minute.
20488 Defaults to @samp{"/var/run/openvpn/status"}.
20492 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20493 The list of configuration for some clients.
20495 Defaults to @samp{()}.
20497 Available @code{openvpn-ccd-configuration} fields are:
20499 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20502 Defaults to @samp{"client"}.
20506 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20509 Defaults to @samp{#f}.
20513 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20516 Defaults to @samp{#f}.
20523 @c %end of automatic openvpn-server documentation
20526 @node Network File System
20527 @subsection Network File System
20530 The @code{(gnu services nfs)} module provides the following services,
20531 which are most commonly used in relation to mounting or exporting
20532 directory trees as @dfn{network file systems} (NFS).
20534 @subsubheading RPC Bind Service
20537 The RPC Bind service provides a facility to map program numbers into
20538 universal addresses.
20539 Many NFS related services use this facility. Hence it is automatically
20540 started when a dependent service starts.
20542 @defvr {Scheme Variable} rpcbind-service-type
20543 A service type for the RPC portmapper daemon.
20547 @deftp {Data Type} rpcbind-configuration
20548 Data type representing the configuration of the RPC Bind Service.
20549 This type has the following parameters:
20551 @item @code{rpcbind} (default: @code{rpcbind})
20552 The rpcbind package to use.
20554 @item @code{warm-start?} (default: @code{#t})
20555 If this parameter is @code{#t}, then the daemon will read a
20556 state file on startup thus reloading state information saved by a previous
20562 @subsubheading Pipefs Pseudo File System
20566 The pipefs file system is used to transfer NFS related data
20567 between the kernel and user space programs.
20569 @defvr {Scheme Variable} pipefs-service-type
20570 A service type for the pipefs pseudo file system.
20573 @deftp {Data Type} pipefs-configuration
20574 Data type representing the configuration of the pipefs pseudo file system service.
20575 This type has the following parameters:
20577 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20578 The directory to which the file system is to be attached.
20583 @subsubheading GSS Daemon Service
20586 @cindex global security system
20588 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20590 Before exchanging RPC requests an RPC client must establish a security
20591 context. Typically this is done using the Kerberos command @command{kinit}
20592 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20594 @defvr {Scheme Variable} gss-service-type
20595 A service type for the Global Security System (GSS) daemon.
20598 @deftp {Data Type} gss-configuration
20599 Data type representing the configuration of the GSS daemon service.
20600 This type has the following parameters:
20602 @item @code{nfs-utils} (default: @code{nfs-utils})
20603 The package in which the @command{rpc.gssd} command is to be found.
20605 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20606 The directory where the pipefs file system is mounted.
20612 @subsubheading IDMAP Daemon Service
20614 @cindex name mapper
20616 The idmap daemon service provides mapping between user IDs and user names.
20617 Typically it is required in order to access file systems mounted via NFSv4.
20619 @defvr {Scheme Variable} idmap-service-type
20620 A service type for the Identity Mapper (IDMAP) daemon.
20623 @deftp {Data Type} idmap-configuration
20624 Data type representing the configuration of the IDMAP daemon service.
20625 This type has the following parameters:
20627 @item @code{nfs-utils} (default: @code{nfs-utils})
20628 The package in which the @command{rpc.idmapd} command is to be found.
20630 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20631 The directory where the pipefs file system is mounted.
20633 @item @code{domain} (default: @code{#f})
20634 The local NFSv4 domain name.
20635 This must be a string or @code{#f}.
20636 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20641 @node Continuous Integration
20642 @subsection Continuous Integration
20644 @cindex continuous integration
20645 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20646 continuous integration tool for Guix. It can be used both for development and
20647 for providing substitutes to others (@pxref{Substitutes}).
20649 The @code{(gnu services cuirass)} module provides the following service.
20651 @defvr {Scheme Procedure} cuirass-service-type
20652 The type of the Cuirass service. Its value must be a
20653 @code{cuirass-configuration} object, as described below.
20656 To add build jobs, you have to set the @code{specifications} field of the
20657 configuration. Here is an example of a service that polls the Guix repository
20658 and builds the packages from a manifest. Some of the packages are defined in
20659 the @code{"custom-packages"} input, which is the equivalent of
20660 @code{GUIX_PACKAGE_PATH}.
20663 (define %cuirass-specs
20665 '((#:name . "my-manifest")
20666 (#:load-path-inputs . ("guix"))
20667 (#:package-path-inputs . ("custom-packages"))
20668 (#:proc-input . "guix")
20669 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20670 (#:proc . cuirass-jobs)
20671 (#:proc-args . ((subset . "manifests")
20672 (systems . ("x86_64-linux"))
20673 (manifests . (("config" . "guix/manifest.scm")))))
20674 (#:inputs . (((#:name . "guix")
20675 (#:url . "git://git.savannah.gnu.org/guix.git")
20676 (#:load-path . ".")
20677 (#:branch . "master")
20678 (#:no-compile? . #t))
20679 ((#:name . "config")
20680 (#:url . "git://git.example.org/config.git")
20681 (#:load-path . ".")
20682 (#:branch . "master")
20683 (#:no-compile? . #t))
20684 ((#:name . "custom-packages")
20685 (#:url . "git://git.example.org/custom-packages.git")
20686 (#:load-path . ".")
20687 (#:branch . "master")
20688 (#:no-compile? . #t)))))))
20690 (service cuirass-service-type
20691 (cuirass-configuration
20692 (specifications %cuirass-specs)))
20695 While information related to build jobs is located directly in the
20696 specifications, global settings for the @command{cuirass} process are
20697 accessible in other @code{cuirass-configuration} fields.
20699 @deftp {Data Type} cuirass-configuration
20700 Data type representing the configuration of Cuirass.
20703 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20704 Location of the log file.
20706 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20707 Location of the repository cache.
20709 @item @code{user} (default: @code{"cuirass"})
20710 Owner of the @code{cuirass} process.
20712 @item @code{group} (default: @code{"cuirass"})
20713 Owner's group of the @code{cuirass} process.
20715 @item @code{interval} (default: @code{60})
20716 Number of seconds between the poll of the repositories followed by the
20719 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20720 Location of sqlite database which contains the build results and previously
20721 added specifications.
20723 @item @code{ttl} (default: @code{(* 30 24 3600)})
20724 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20725 are registered for build results. This means that build results are protected
20726 from garbage collection for at least @var{ttl} seconds.
20728 @item @code{port} (default: @code{8081})
20729 Port number used by the HTTP server.
20731 @item --listen=@var{host}
20732 Listen on the network interface for @var{host}. The default is to
20733 accept connections from localhost.
20735 @item @code{specifications} (default: @code{#~'()})
20736 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20737 where a specification is an association list
20738 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20739 keys are keywords (@code{#:keyword-example}) as shown in the example
20742 @item @code{use-substitutes?} (default: @code{#f})
20743 This allows using substitutes to avoid building every dependencies of a job
20746 @item @code{one-shot?} (default: @code{#f})
20747 Only evaluate specifications and build derivations once.
20749 @item @code{fallback?} (default: @code{#f})
20750 When substituting a pre-built binary fails, fall back to building
20753 @item @code{cuirass} (default: @code{cuirass})
20754 The Cuirass package to use.
20758 @node Power Management Services
20759 @subsection Power Management Services
20762 @cindex power management with TLP
20763 @subsubheading TLP daemon
20765 The @code{(gnu services pm)} module provides a Guix service definition
20766 for the Linux power management tool TLP.
20768 TLP enables various powersaving modes in userspace and kernel.
20769 Contrary to @code{upower-service}, it is not a passive,
20770 monitoring tool, as it will apply custom settings each time a new power
20771 source is detected. More information can be found at
20772 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
20774 @deffn {Scheme Variable} tlp-service-type
20775 The service type for the TLP tool. Its value should be a valid
20776 TLP configuration (see below). To use the default settings, simply
20779 (service tlp-service-type)
20783 By default TLP does not need much configuration but most TLP parameters
20784 can be tweaked using @code{tlp-configuration}.
20786 Each parameter definition is preceded by its type; for example,
20787 @samp{boolean foo} indicates that the @code{foo} parameter
20788 should be specified as a boolean. Types starting with
20789 @code{maybe-} denote parameters that won't show up in TLP config file
20790 when their value is @code{'disabled}.
20792 @c The following documentation was initially generated by
20793 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20794 @c documentation is better, so we shouldn't hesitate to edit below as
20795 @c needed. However if the change you want to make to this documentation
20796 @c can be done in an automated way, it's probably easier to change
20797 @c (generate-documentation) than to make it below and have to deal with
20798 @c the churn as TLP updates.
20800 Available @code{tlp-configuration} fields are:
20802 @deftypevr {@code{tlp-configuration} parameter} package tlp
20807 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20808 Set to true if you wish to enable TLP.
20810 Defaults to @samp{#t}.
20814 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20815 Default mode when no power supply can be detected. Alternatives are AC
20818 Defaults to @samp{"AC"}.
20822 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20823 Number of seconds Linux kernel has to wait after the disk goes idle,
20824 before syncing on AC.
20826 Defaults to @samp{0}.
20830 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20831 Same as @code{disk-idle-ac} but on BAT mode.
20833 Defaults to @samp{2}.
20837 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20838 Dirty pages flushing periodicity, expressed in seconds.
20840 Defaults to @samp{15}.
20844 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20845 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20847 Defaults to @samp{60}.
20851 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20852 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20853 alternatives are powersave and performance. With acpi-cpufreq driver,
20854 alternatives are ondemand, powersave, performance and conservative.
20856 Defaults to @samp{disabled}.
20860 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20861 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20863 Defaults to @samp{disabled}.
20867 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20868 Set the min available frequency for the scaling governor on AC.
20870 Defaults to @samp{disabled}.
20874 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20875 Set the max available frequency for the scaling governor on AC.
20877 Defaults to @samp{disabled}.
20881 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20882 Set the min available frequency for the scaling governor on BAT.
20884 Defaults to @samp{disabled}.
20888 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20889 Set the max available frequency for the scaling governor on BAT.
20891 Defaults to @samp{disabled}.
20895 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20896 Limit the min P-state to control the power dissipation of the CPU, in AC
20897 mode. Values are stated as a percentage of the available performance.
20899 Defaults to @samp{disabled}.
20903 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20904 Limit the max P-state to control the power dissipation of the CPU, in AC
20905 mode. Values are stated as a percentage of the available performance.
20907 Defaults to @samp{disabled}.
20911 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20912 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20914 Defaults to @samp{disabled}.
20918 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20919 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20921 Defaults to @samp{disabled}.
20925 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20926 Enable CPU turbo boost feature on AC mode.
20928 Defaults to @samp{disabled}.
20932 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20933 Same as @code{cpu-boost-on-ac?} on BAT mode.
20935 Defaults to @samp{disabled}.
20939 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20940 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20941 used under light load conditions.
20943 Defaults to @samp{#f}.
20947 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20948 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20950 Defaults to @samp{#t}.
20954 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20955 Enable Linux kernel NMI watchdog.
20957 Defaults to @samp{#f}.
20961 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20962 For Linux kernels with PHC patch applied, change CPU voltages. An
20963 example value would be @samp{"F:V F:V F:V F:V"}.
20965 Defaults to @samp{disabled}.
20969 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20970 Set CPU performance versus energy saving policy on AC. Alternatives are
20971 performance, normal, powersave.
20973 Defaults to @samp{"performance"}.
20977 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20978 Same as @code{energy-perf-policy-ac} but on BAT mode.
20980 Defaults to @samp{"powersave"}.
20984 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20989 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20990 Hard disk advanced power management level.
20994 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20995 Same as @code{disk-apm-bat} but on BAT mode.
20999 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
21000 Hard disk spin down timeout. One value has to be specified for each
21001 declared hard disk.
21003 Defaults to @samp{disabled}.
21007 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
21008 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
21010 Defaults to @samp{disabled}.
21014 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
21015 Select IO scheduler for disk devices. One value has to be specified for
21016 each declared hard disk. Example alternatives are cfq, deadline and
21019 Defaults to @samp{disabled}.
21023 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21024 SATA aggressive link power management (ALPM) level. Alternatives are
21025 min_power, medium_power, max_performance.
21027 Defaults to @samp{"max_performance"}.
21031 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21032 Same as @code{sata-linkpwr-ac} but on BAT mode.
21034 Defaults to @samp{"min_power"}.
21038 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21039 Exclude specified SATA host devices for link power management.
21041 Defaults to @samp{disabled}.
21045 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21046 Enable Runtime Power Management for AHCI controller and disks on AC
21049 Defaults to @samp{disabled}.
21053 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21054 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21056 Defaults to @samp{disabled}.
21060 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21061 Seconds of inactivity before disk is suspended.
21063 Defaults to @samp{15}.
21067 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21068 PCI Express Active State Power Management level. Alternatives are
21069 default, performance, powersave.
21071 Defaults to @samp{"performance"}.
21075 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21076 Same as @code{pcie-aspm-ac} but on BAT mode.
21078 Defaults to @samp{"powersave"}.
21082 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21083 Radeon graphics clock speed level. Alternatives are low, mid, high,
21086 Defaults to @samp{"high"}.
21090 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21091 Same as @code{radeon-power-ac} but on BAT mode.
21093 Defaults to @samp{"low"}.
21097 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21098 Radeon dynamic power management method (DPM). Alternatives are battery,
21101 Defaults to @samp{"performance"}.
21105 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21106 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21108 Defaults to @samp{"battery"}.
21112 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21113 Radeon DPM performance level. Alternatives are auto, low, high.
21115 Defaults to @samp{"auto"}.
21119 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21120 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21122 Defaults to @samp{"auto"}.
21126 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21127 Wifi power saving mode.
21129 Defaults to @samp{#f}.
21133 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21134 Same as @code{wifi-power-ac?} but on BAT mode.
21136 Defaults to @samp{#t}.
21140 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21141 Disable wake on LAN.
21143 Defaults to @samp{#t}.
21147 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21148 Timeout duration in seconds before activating audio power saving on
21149 Intel HDA and AC97 devices. A value of 0 disables power saving.
21151 Defaults to @samp{0}.
21155 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21156 Same as @code{sound-powersave-ac} but on BAT mode.
21158 Defaults to @samp{1}.
21162 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21163 Disable controller in powersaving mode on Intel HDA devices.
21165 Defaults to @samp{#t}.
21169 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21170 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21171 powered on again by releasing (and reinserting) the eject lever or by
21172 pressing the disc eject button on newer models.
21174 Defaults to @samp{#f}.
21178 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21179 Name of the optical drive device to power off.
21181 Defaults to @samp{"sr0"}.
21185 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21186 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21189 Defaults to @samp{"on"}.
21193 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21194 Same as @code{runtime-pm-ac} but on BAT mode.
21196 Defaults to @samp{"auto"}.
21200 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21201 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21204 Defaults to @samp{#t}.
21208 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21209 Exclude specified PCI(e) device addresses from Runtime Power Management.
21211 Defaults to @samp{disabled}.
21215 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21216 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21221 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21222 Enable USB autosuspend feature.
21224 Defaults to @samp{#t}.
21228 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21229 Exclude specified devices from USB autosuspend.
21231 Defaults to @samp{disabled}.
21235 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21236 Exclude WWAN devices from USB autosuspend.
21238 Defaults to @samp{#t}.
21242 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21243 Include specified devices into USB autosuspend, even if they are already
21244 excluded by the driver or via @code{usb-blacklist-wwan?}.
21246 Defaults to @samp{disabled}.
21250 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21251 Enable USB autosuspend before shutdown.
21253 Defaults to @samp{disabled}.
21257 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21258 Restore radio device state (bluetooth, wifi, wwan) from previous
21259 shutdown on system startup.
21261 Defaults to @samp{#f}.
21266 @cindex CPU frequency scaling with thermald
21267 @subsubheading Thermald daemon
21269 The @code{(gnu services pm)} module provides an interface to
21270 thermald, a CPU frequency scaling service which helps prevent overheating.
21272 @defvr {Scheme Variable} thermald-service-type
21273 This is the service type for
21274 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21275 Thermal Daemon, which is responsible for controlling the thermal state
21276 of processors and preventing overheating.
21279 @deftp {Data Type} thermald-configuration
21280 Data type representing the configuration of @code{thermald-service-type}.
21283 @item @code{ignore-cpuid-check?} (default: @code{#f})
21284 Ignore cpuid check for supported CPU models.
21286 @item @code{thermald} (default: @var{thermald})
21287 Package object of thermald.
21292 @node Audio Services
21293 @subsection Audio Services
21295 The @code{(gnu services audio)} module provides a service to start MPD
21296 (the Music Player Daemon).
21299 @subsubheading Music Player Daemon
21301 The Music Player Daemon (MPD) is a service that can play music while
21302 being controlled from the local machine or over the network by a variety
21305 The following example shows how one might run @code{mpd} as user
21306 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21309 (service mpd-service-type
21315 @defvr {Scheme Variable} mpd-service-type
21316 The service type for @command{mpd}
21319 @deftp {Data Type} mpd-configuration
21320 Data type representing the configuration of @command{mpd}.
21323 @item @code{user} (default: @code{"mpd"})
21324 The user to run mpd as.
21326 @item @code{music-dir} (default: @code{"~/Music"})
21327 The directory to scan for music files.
21329 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21330 The directory to store playlists.
21332 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21333 The location of the music database.
21335 @item @code{state-file} (default: @code{"~/.mpd/state"})
21336 The location of the file that stores current MPD's state.
21338 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21339 The location of the sticker database.
21341 @item @code{port} (default: @code{"6600"})
21342 The port to run mpd on.
21344 @item @code{address} (default: @code{"any"})
21345 The address that mpd will bind to. To use a Unix domain socket,
21346 an absolute path can be specified here.
21351 @node Virtualization Services
21352 @subsection Virtualization services
21354 The @code{(gnu services virtualization)} module provides services for
21355 the libvirt and virtlog daemons, as well as other virtualization-related
21358 @subsubheading Libvirt daemon
21359 @code{libvirtd} is the server side daemon component of the libvirt
21360 virtualization management system. This daemon runs on host servers
21361 and performs required management tasks for virtualized guests.
21363 @deffn {Scheme Variable} libvirt-service-type
21364 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21365 Its value must be a @code{libvirt-configuration}.
21368 (service libvirt-service-type
21369 (libvirt-configuration
21370 (unix-sock-group "libvirt")
21371 (tls-port "16555")))
21375 @c Auto-generated with (generate-libvirt-documentation)
21376 Available @code{libvirt-configuration} fields are:
21378 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21383 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21384 Flag listening for secure TLS connections on the public TCP/IP port.
21385 must set @code{listen} for this to have any effect.
21387 It is necessary to setup a CA and issue server certificates before using
21390 Defaults to @samp{#t}.
21394 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21395 Listen for unencrypted TCP connections on the public TCP/IP port. must
21396 set @code{listen} for this to have any effect.
21398 Using the TCP socket requires SASL authentication by default. Only SASL
21399 mechanisms which support data encryption are allowed. This is
21400 DIGEST_MD5 and GSSAPI (Kerberos5)
21402 Defaults to @samp{#f}.
21406 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21407 Port for accepting secure TLS connections This can be a port number, or
21410 Defaults to @samp{"16514"}.
21414 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21415 Port for accepting insecure TCP connections This can be a port number,
21418 Defaults to @samp{"16509"}.
21422 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21423 IP address or hostname used for client connections.
21425 Defaults to @samp{"0.0.0.0"}.
21429 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21430 Flag toggling mDNS advertisement of the libvirt service.
21432 Alternatively can disable for all services on a host by stopping the
21435 Defaults to @samp{#f}.
21439 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21440 Default mDNS advertisement name. This must be unique on the immediate
21443 Defaults to @samp{"Virtualization Host <hostname>"}.
21447 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21448 UNIX domain socket group ownership. This can be used to allow a
21449 'trusted' set of users access to management capabilities without
21452 Defaults to @samp{"root"}.
21456 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21457 UNIX socket permissions for the R/O socket. This is used for monitoring
21460 Defaults to @samp{"0777"}.
21464 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21465 UNIX socket permissions for the R/W socket. Default allows only root.
21466 If PolicyKit is enabled on the socket, the default will change to allow
21467 everyone (eg, 0777)
21469 Defaults to @samp{"0770"}.
21473 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21474 UNIX socket permissions for the admin socket. Default allows only owner
21475 (root), do not change it unless you are sure to whom you are exposing
21478 Defaults to @samp{"0777"}.
21482 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21483 The directory in which sockets will be found/created.
21485 Defaults to @samp{"/var/run/libvirt"}.
21489 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21490 Authentication scheme for UNIX read-only sockets. By default socket
21491 permissions allow anyone to connect
21493 Defaults to @samp{"polkit"}.
21497 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21498 Authentication scheme for UNIX read-write sockets. By default socket
21499 permissions only allow root. If PolicyKit support was compiled into
21500 libvirt, the default will be to use 'polkit' auth.
21502 Defaults to @samp{"polkit"}.
21506 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21507 Authentication scheme for TCP sockets. If you don't enable SASL, then
21508 all TCP traffic is cleartext. Don't do this outside of a dev/test
21511 Defaults to @samp{"sasl"}.
21515 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21516 Authentication scheme for TLS sockets. TLS sockets already have
21517 encryption provided by the TLS layer, and limited authentication is done
21520 It is possible to make use of any SASL authentication mechanism as well,
21521 by using 'sasl' for this option
21523 Defaults to @samp{"none"}.
21527 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21528 API access control scheme.
21530 By default an authenticated user is allowed access to all APIs. Access
21531 drivers can place restrictions on this.
21533 Defaults to @samp{()}.
21537 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21538 Server key file path. If set to an empty string, then no private key is
21541 Defaults to @samp{""}.
21545 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21546 Server key file path. If set to an empty string, then no certificate is
21549 Defaults to @samp{""}.
21553 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21554 Server key file path. If set to an empty string, then no CA certificate
21557 Defaults to @samp{""}.
21561 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21562 Certificate revocation list path. If set to an empty string, then no
21565 Defaults to @samp{""}.
21569 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21570 Disable verification of our own server certificates.
21572 When libvirtd starts it performs some sanity checks against its own
21575 Defaults to @samp{#f}.
21579 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21580 Disable verification of client certificates.
21582 Client certificate verification is the primary authentication mechanism.
21583 Any client which does not present a certificate signed by the CA will be
21586 Defaults to @samp{#f}.
21590 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21591 Whitelist of allowed x509 Distinguished Name.
21593 Defaults to @samp{()}.
21597 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21598 Whitelist of allowed SASL usernames. The format for username depends on
21599 the SASL authentication mechanism.
21601 Defaults to @samp{()}.
21605 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21606 Override the compile time default TLS priority string. The default is
21607 usually "NORMAL" unless overridden at build time. Only set this is it
21608 is desired for libvirt to deviate from the global default settings.
21610 Defaults to @samp{"NORMAL"}.
21614 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21615 Maximum number of concurrent client connections to allow over all
21618 Defaults to @samp{5000}.
21622 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21623 Maximum length of queue of connections waiting to be accepted by the
21624 daemon. Note, that some protocols supporting retransmission may obey
21625 this so that a later reattempt at connection succeeds.
21627 Defaults to @samp{1000}.
21631 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21632 Maximum length of queue of accepted but not yet authenticated clients.
21633 Set this to zero to turn this feature off
21635 Defaults to @samp{20}.
21639 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21640 Number of workers to start up initially.
21642 Defaults to @samp{5}.
21646 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21647 Maximum number of worker threads.
21649 If the number of active clients exceeds @code{min-workers}, then more
21650 threads are spawned, up to max_workers limit. Typically you'd want
21651 max_workers to equal maximum number of clients allowed.
21653 Defaults to @samp{20}.
21657 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21658 Number of priority workers. If all workers from above pool are stuck,
21659 some calls marked as high priority (notably domainDestroy) can be
21660 executed in this pool.
21662 Defaults to @samp{5}.
21666 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21667 Total global limit on concurrent RPC calls.
21669 Defaults to @samp{20}.
21673 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21674 Limit on concurrent requests from a single client connection. To avoid
21675 one client monopolizing the server this should be a small fraction of
21676 the global max_requests and max_workers parameter.
21678 Defaults to @samp{5}.
21682 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21683 Same as @code{min-workers} but for the admin interface.
21685 Defaults to @samp{1}.
21689 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21690 Same as @code{max-workers} but for the admin interface.
21692 Defaults to @samp{5}.
21696 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21697 Same as @code{max-clients} but for the admin interface.
21699 Defaults to @samp{5}.
21703 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21704 Same as @code{max-queued-clients} but for the admin interface.
21706 Defaults to @samp{5}.
21710 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21711 Same as @code{max-client-requests} but for the admin interface.
21713 Defaults to @samp{5}.
21717 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21718 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21720 Defaults to @samp{3}.
21724 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21727 A filter allows to select a different logging level for a given category
21728 of logs The format for a filter is one of:
21739 where @code{name} is a string which is matched against the category
21740 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21741 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21742 be a substring of the full category name, in order to match multiple
21743 similar categories), the optional "+" prefix tells libvirt to log stack
21744 trace for each message matching name, and @code{x} is the minimal level
21745 where matching messages should be logged:
21762 Multiple filters can be defined in a single filters statement, they just
21763 need to be separated by spaces.
21765 Defaults to @samp{"3:remote 4:event"}.
21769 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21772 An output is one of the places to save logging information. The format
21773 for an output can be:
21777 output goes to stderr
21779 @item x:syslog:name
21780 use syslog for the output and use the given name as the ident
21782 @item x:file:file_path
21783 output to a file, with the given filepath
21786 output to journald logging system
21790 In all case the x prefix is the minimal level, acting as a filter
21807 Multiple outputs can be defined, they just need to be separated by
21810 Defaults to @samp{"3:stderr"}.
21814 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21815 Allows usage of the auditing subsystem to be altered
21819 0: disable all auditing
21822 1: enable auditing, only if enabled on host
21825 2: enable auditing, and exit if disabled on host.
21829 Defaults to @samp{1}.
21833 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21834 Send audit messages via libvirt logging infrastructure.
21836 Defaults to @samp{#f}.
21840 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21841 Host UUID. UUID must not have all digits be the same.
21843 Defaults to @samp{""}.
21847 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21848 Source to read host UUID.
21852 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21855 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21859 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21862 Defaults to @samp{"smbios"}.
21866 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21867 A keepalive message is sent to a client after @code{keepalive_interval}
21868 seconds of inactivity to check if the client is still responding. If
21869 set to -1, libvirtd will never send keepalive requests; however clients
21870 can still send them and the daemon will send responses.
21872 Defaults to @samp{5}.
21876 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21877 Maximum number of keepalive messages that are allowed to be sent to the
21878 client without getting any response before the connection is considered
21881 In other words, the connection is automatically closed approximately
21882 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21883 the last message received from the client. When @code{keepalive-count}
21884 is set to 0, connections will be automatically closed after
21885 @code{keepalive-interval} seconds of inactivity without sending any
21886 keepalive messages.
21888 Defaults to @samp{5}.
21892 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21893 Same as above but for admin interface.
21895 Defaults to @samp{5}.
21899 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21900 Same as above but for admin interface.
21902 Defaults to @samp{5}.
21906 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21907 Timeout for Open vSwitch calls.
21909 The @code{ovs-vsctl} utility is used for the configuration and its
21910 timeout option is set by default to 5 seconds to avoid potential
21911 infinite waits blocking libvirt.
21913 Defaults to @samp{5}.
21917 @c %end of autogenerated docs
21919 @subsubheading Virtlog daemon
21920 The virtlogd service is a server side daemon component of libvirt that is
21921 used to manage logs from virtual machine consoles.
21923 This daemon is not used directly by libvirt client applications, rather it
21924 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21925 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21926 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21927 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21929 @deffn {Scheme Variable} virtlog-service-type
21930 This is the type of the virtlog daemon.
21931 Its value must be a @code{virtlog-configuration}.
21934 (service virtlog-service-type
21935 (virtlog-configuration
21936 (max-clients 1000)))
21940 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21941 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21943 Defaults to @samp{3}.
21947 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21950 A filter allows to select a different logging level for a given category
21951 of logs The format for a filter is one of:
21962 where @code{name} is a string which is matched against the category
21963 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21964 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21965 be a substring of the full category name, in order to match multiple
21966 similar categories), the optional "+" prefix tells libvirt to log stack
21967 trace for each message matching name, and @code{x} is the minimal level
21968 where matching messages should be logged:
21985 Multiple filters can be defined in a single filters statement, they just
21986 need to be separated by spaces.
21988 Defaults to @samp{"3:remote 4:event"}.
21992 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21995 An output is one of the places to save logging information The format
21996 for an output can be:
22000 output goes to stderr
22002 @item x:syslog:name
22003 use syslog for the output and use the given name as the ident
22005 @item x:file:file_path
22006 output to a file, with the given filepath
22009 output to journald logging system
22013 In all case the x prefix is the minimal level, acting as a filter
22030 Multiple outputs can be defined, they just need to be separated by
22033 Defaults to @samp{"3:stderr"}.
22037 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22038 Maximum number of concurrent client connections to allow over all
22041 Defaults to @samp{1024}.
22045 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22046 Maximum file size before rolling over.
22048 Defaults to @samp{2MB}
22052 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22053 Maximum number of backup files to keep.
22055 Defaults to @samp{3}
22059 @subsubheading Transparent Emulation with QEMU
22062 @cindex @code{binfmt_misc}
22063 @code{qemu-binfmt-service-type} provides support for transparent
22064 emulation of program binaries built for different architectures---e.g.,
22065 it allows you to transparently execute an ARMv7 program on an x86_64
22066 machine. It achieves this by combining the @uref{https://www.qemu.org,
22067 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22069 @defvr {Scheme Variable} qemu-binfmt-service-type
22070 This is the type of the QEMU/binfmt service for transparent emulation.
22071 Its value must be a @code{qemu-binfmt-configuration} object, which
22072 specifies the QEMU package to use as well as the architecture we want to
22076 (service qemu-binfmt-service-type
22077 (qemu-binfmt-configuration
22078 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22081 In this example, we enable transparent emulation for the ARM and aarch64
22082 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22083 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22084 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22087 @deftp {Data Type} qemu-binfmt-configuration
22088 This is the configuration for the @code{qemu-binfmt} service.
22091 @item @code{platforms} (default: @code{'()})
22092 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22093 object} as returned by @code{lookup-qemu-platforms} (see below).
22095 @item @code{guix-support?} (default: @code{#f})
22096 When it is true, QEMU and all its dependencies are added to the build
22097 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22098 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22099 handlers to be used within the build environment, which in turn means
22100 that you can transparently build programs for another architecture.
22102 For example, let's suppose you're on an x86_64 machine and you have this
22106 (service qemu-binfmt-service-type
22107 (qemu-binfmt-configuration
22108 (platforms (lookup-qemu-platforms "arm"))
22109 (guix-support? #t)))
22115 guix build -s armhf-linux inkscape
22119 and it will build Inkscape for ARMv7 @emph{as if it were a native
22120 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22121 if you'd like to test a package build for an architecture you don't have
22124 @item @code{qemu} (default: @code{qemu})
22125 The QEMU package to use.
22129 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22130 Return the list of QEMU platform objects corresponding to
22131 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22132 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22133 @code{"mips64el"}, and so on.
22136 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22137 Return true if @var{obj} is a platform object.
22140 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22141 Return the name of @var{platform}---a string such as @code{"arm"}.
22144 @node Version Control Services
22145 @subsection Version Control Services
22147 The @code{(gnu services version-control)} module provides a service to
22148 allow remote access to local Git repositories. There are three options:
22149 the @code{git-daemon-service}, which provides access to repositories via
22150 the @code{git://} unsecured TCP-based protocol, extending the
22151 @code{nginx} web server to proxy some requests to
22152 @code{git-http-backend}, or providing a web interface with
22153 @code{cgit-service-type}.
22155 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22157 Return a service that runs @command{git daemon}, a simple TCP server to
22158 expose repositories over the Git protocol for anonymous access.
22160 The optional @var{config} argument should be a
22161 @code{<git-daemon-configuration>} object, by default it allows read-only
22162 access to exported@footnote{By creating the magic file
22163 "git-daemon-export-ok" in the repository directory.} repositories under
22168 @deftp {Data Type} git-daemon-configuration
22169 Data type representing the configuration for @code{git-daemon-service}.
22172 @item @code{package} (default: @var{git})
22173 Package object of the Git distributed version control system.
22175 @item @code{export-all?} (default: @var{#f})
22176 Whether to allow access for all Git repositories, even if they do not
22177 have the @file{git-daemon-export-ok} file.
22179 @item @code{base-path} (default: @file{/srv/git})
22180 Whether to remap all the path requests as relative to the given path.
22181 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22182 then if you later try to pull @code{git://example.com/hello.git}, git
22183 daemon will interpret the path as @code{/srv/git/hello.git}.
22185 @item @code{user-path} (default: @var{#f})
22186 Whether to allow @code{~user} notation to be used in requests. When
22187 specified with empty string, requests to @code{git://host/~alice/foo} is
22188 taken as a request to access @code{foo} repository in the home directory
22189 of user @code{alice}. If @var{(user-path "path")} is specified, the
22190 same request is taken as a request to access @code{path/foo} repository
22191 in the home directory of user @code{alice}.
22193 @item @code{listen} (default: @var{'()})
22194 Whether to listen on specific IP addresses or hostnames, defaults to
22197 @item @code{port} (default: @var{#f})
22198 Whether to listen on an alternative port, which defaults to 9418.
22200 @item @code{whitelist} (default: @var{'()})
22201 If not empty, only allow access to this list of directories.
22203 @item @code{extra-options} (default: @var{'()})
22204 Extra options will be passed to @code{git daemon}, please run
22205 @command{man git-daemon} for more information.
22210 The @code{git://} protocol lacks authentication. When you pull from a
22211 repository fetched via @code{git://}, you don't know that the data you
22212 receive was modified is really coming from the specified host, and you
22213 have your connection is subject to eavesdropping. It's better to use an
22214 authenticated and encrypted transport, such as @code{https}. Although Git allows you
22215 to serve repositories using unsophisticated file-based web servers,
22216 there is a faster protocol implemented by the @code{git-http-backend}
22217 program. This program is the back-end of a proper Git web service. It
22218 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22219 on running the necessary @code{fcgiwrap} daemon.
22221 Guix has a separate configuration data type for serving Git repositories
22224 @deftp {Data Type} git-http-configuration
22225 Data type representing the configuration for @code{git-http-service}.
22228 @item @code{package} (default: @var{git})
22229 Package object of the Git distributed version control system.
22231 @item @code{git-root} (default: @file{/srv/git})
22232 Directory containing the Git repositories to expose to the world.
22234 @item @code{export-all?} (default: @var{#f})
22235 Whether to expose access for all Git repositories in @var{git-root},
22236 even if they do not have the @file{git-daemon-export-ok} file.
22238 @item @code{uri-path} (default: @file{/git/})
22239 Path prefix for Git access. With the default @code{/git/} prefix, this
22240 will map @code{http://@var{server}/git/@var{repo}.git} to
22241 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22242 with this prefix are not passed on to this Git instance.
22244 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22245 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22250 There is no @code{git-http-service-type}, currently; instead you can
22251 create an @code{nginx-location-configuration} from a
22252 @code{git-http-configuration} and then add that location to a web
22255 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22256 [config=(git-http-configuration)]
22257 Compute an @code{nginx-location-configuration} that corresponds to the
22258 given Git http configuration. An example nginx service definition to
22259 serve the default @file{/srv/git} over HTTPS might be:
22262 (service nginx-service-type
22263 (nginx-configuration
22266 (nginx-server-configuration
22267 (listen '("443 ssl"))
22268 (server-name "git.my-host.org")
22270 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22271 (ssl-certificate-key
22272 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22275 (git-http-nginx-location-configuration
22276 (git-http-configuration (uri-path "/"))))))))))
22279 This example assumes that you are using Let's Encrypt to get your TLS
22280 certificate. @xref{Certificate Services}. The default @code{certbot}
22281 service will redirect all HTTP traffic on @code{git.my-host.org} to
22282 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22283 system services. @xref{Web Services}.
22286 @subsubheading Cgit Service
22288 @cindex Cgit service
22289 @cindex Git, web interface
22290 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22291 repositories written in C.
22293 The following example will configure the service with default values.
22294 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22297 (service cgit-service-type)
22300 The @code{file-object} type designates either a file-like object
22301 (@pxref{G-Expressions, file-like objects}) or a string.
22303 @c %start of fragment
22305 Available @code{cgit-configuration} fields are:
22307 @deftypevr {@code{cgit-configuration} parameter} package package
22312 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22313 NGINX configuration.
22317 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22318 Specifies a command which will be invoked to format the content of about
22319 pages (both top-level and for each repository).
22321 Defaults to @samp{""}.
22325 @deftypevr {@code{cgit-configuration} parameter} string agefile
22326 Specifies a path, relative to each repository path, which can be used to
22327 specify the date and time of the youngest commit in the repository.
22329 Defaults to @samp{""}.
22333 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22334 Specifies a command that will be invoked for authenticating repository
22337 Defaults to @samp{""}.
22341 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22342 Flag which, when set to @samp{age}, enables date ordering in the branch
22343 ref list, and when set @samp{name} enables ordering by branch name.
22345 Defaults to @samp{"name"}.
22349 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22350 Path used to store the cgit cache entries.
22352 Defaults to @samp{"/var/cache/cgit"}.
22356 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22357 Number which specifies the time-to-live, in minutes, for the cached
22358 version of repository pages accessed with a fixed SHA1.
22360 Defaults to @samp{-1}.
22364 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22365 Number which specifies the time-to-live, in minutes, for the cached
22366 version of repository pages accessed without a fixed SHA1.
22368 Defaults to @samp{5}.
22372 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22373 Number which specifies the time-to-live, in minutes, for the cached
22374 version of the repository summary page.
22376 Defaults to @samp{5}.
22380 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22381 Number which specifies the time-to-live, in minutes, for the cached
22382 version of the repository index page.
22384 Defaults to @samp{5}.
22388 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22389 Number which specifies the time-to-live, in minutes, for the result of
22390 scanning a path for Git repositories.
22392 Defaults to @samp{15}.
22396 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22397 Number which specifies the time-to-live, in minutes, for the cached
22398 version of the repository about page.
22400 Defaults to @samp{15}.
22404 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22405 Number which specifies the time-to-live, in minutes, for the cached
22406 version of snapshots.
22408 Defaults to @samp{5}.
22412 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22413 The maximum number of entries in the cgit cache. When set to @samp{0},
22414 caching is disabled.
22416 Defaults to @samp{0}.
22420 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22421 Sort items in the repo list case sensitively.
22423 Defaults to @samp{#t}.
22427 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22428 List of common prefixes which, when combined with a repository URL,
22429 generates valid clone URLs for the repository.
22431 Defaults to @samp{()}.
22435 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22436 List of @code{clone-url} templates.
22438 Defaults to @samp{()}.
22442 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22443 Command which will be invoked to format commit messages.
22445 Defaults to @samp{""}.
22449 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22450 Flag which, when set to @samp{date}, enables strict date ordering in the
22451 commit log, and when set to @samp{topo} enables strict topological
22454 Defaults to @samp{"git log"}.
22458 @deftypevr {@code{cgit-configuration} parameter} file-object css
22459 URL which specifies the css document to include in all cgit pages.
22461 Defaults to @samp{"/share/cgit/cgit.css"}.
22465 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22466 Specifies a command which will be invoked to format names and email
22467 address of committers, authors, and taggers, as represented in various
22468 places throughout the cgit interface.
22470 Defaults to @samp{""}.
22474 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22475 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22476 fragment suitable for embedding in other HTML pages.
22478 Defaults to @samp{#f}.
22482 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22483 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22484 commit history graph to the left of the commit messages in the
22485 repository log page.
22487 Defaults to @samp{#f}.
22491 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22492 Flag which, when set to @samp{#t}, allows all filter settings to be
22493 overridden in repository-specific cgitrc files.
22495 Defaults to @samp{#f}.
22499 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22500 Flag which, when set to @samp{#t}, allows users to follow a file in the
22503 Defaults to @samp{#f}.
22507 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22508 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22511 Defaults to @samp{#t}.
22515 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22516 Flag which, when set to @samp{#t}, will make cgit generate extra links
22517 "summary", "commit", "tree" for each repo in the repository index.
22519 Defaults to @samp{#f}.
22523 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22524 Flag which, when set to @samp{#t}, will make cgit display the owner of
22525 each repo in the repository index.
22527 Defaults to @samp{#t}.
22531 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22532 Flag which, when set to @samp{#t}, will make cgit print the number of
22533 modified files for each commit on the repository log page.
22535 Defaults to @samp{#f}.
22539 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22540 Flag which, when set to @samp{#t}, will make cgit print the number of
22541 added and removed lines for each commit on the repository log page.
22543 Defaults to @samp{#f}.
22547 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22548 Flag which, when set to @code{#t}, will make cgit display remote
22549 branches in the summary and refs views.
22551 Defaults to @samp{#f}.
22555 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22556 Flag which, when set to @code{1}, will make cgit use the subject of the
22557 parent commit as link text when generating links to parent commits in
22560 Defaults to @samp{#f}.
22564 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22565 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22566 parent commit as link text when generating links to parent commits in
22569 Defaults to @samp{#f}.
22573 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22574 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22575 links for plaintext blobs printed in the tree view.
22577 Defaults to @samp{#t}.
22581 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22582 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22583 set any repo specific settings.
22585 Defaults to @samp{#f}.
22589 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22590 URL used as link to a shortcut icon for cgit.
22592 Defaults to @samp{"/favicon.ico"}.
22596 @deftypevr {@code{cgit-configuration} parameter} string footer
22597 The content of the file specified with this option will be included
22598 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22599 "generated by..."@: message).
22601 Defaults to @samp{""}.
22605 @deftypevr {@code{cgit-configuration} parameter} string head-include
22606 The content of the file specified with this option will be included
22607 verbatim in the HTML HEAD section on all pages.
22609 Defaults to @samp{""}.
22613 @deftypevr {@code{cgit-configuration} parameter} string header
22614 The content of the file specified with this option will be included
22615 verbatim at the top of all pages.
22617 Defaults to @samp{""}.
22621 @deftypevr {@code{cgit-configuration} parameter} file-object include
22622 Name of a configfile to include before the rest of the current config-
22625 Defaults to @samp{""}.
22629 @deftypevr {@code{cgit-configuration} parameter} string index-header
22630 The content of the file specified with this option will be included
22631 verbatim above the repository index.
22633 Defaults to @samp{""}.
22637 @deftypevr {@code{cgit-configuration} parameter} string index-info
22638 The content of the file specified with this option will be included
22639 verbatim below the heading on the repository index page.
22641 Defaults to @samp{""}.
22645 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22646 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22647 in the servers timezone.
22649 Defaults to @samp{#f}.
22653 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22654 URL which specifies the source of an image which will be used as a logo
22657 Defaults to @samp{"/share/cgit/cgit.png"}.
22661 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22662 URL loaded when clicking on the cgit logo image.
22664 Defaults to @samp{""}.
22668 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22669 Command which will be invoked to format the Owner column of the main
22672 Defaults to @samp{""}.
22676 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22677 Number of items to display in atom feeds view.
22679 Defaults to @samp{10}.
22683 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22684 Number of entries to list per page in "log" view.
22686 Defaults to @samp{50}.
22690 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22691 Number of commit message characters to display in "log" view.
22693 Defaults to @samp{80}.
22697 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22698 Specifies the number of entries to list per page on the repository index
22701 Defaults to @samp{50}.
22705 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22706 Specifies the maximum number of repo description characters to display
22707 on the repository index page.
22709 Defaults to @samp{80}.
22713 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22714 Specifies the maximum size of a blob to display HTML for in KBytes.
22716 Defaults to @samp{0}.
22720 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22721 Maximum statistics period. Valid values are @samp{week},@samp{month},
22722 @samp{quarter} and @samp{year}.
22724 Defaults to @samp{""}.
22728 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22729 Mimetype for the specified filename extension.
22731 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22732 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22733 "image/png") (svg "image/svg+xml"))}.
22737 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22738 Specifies the file to use for automatic mimetype lookup.
22740 Defaults to @samp{""}.
22744 @deftypevr {@code{cgit-configuration} parameter} string module-link
22745 Text which will be used as the formatstring for a hyperlink when a
22746 submodule is printed in a directory listing.
22748 Defaults to @samp{""}.
22752 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22753 If set to the value @samp{#t} caching will be disabled.
22755 Defaults to @samp{#f}.
22759 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22760 If set to @samp{#t} showing full author email addresses will be
22763 Defaults to @samp{#f}.
22767 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22768 Flag which, when set to @samp{#t}, will make cgit omit the standard
22769 header on all pages.
22771 Defaults to @samp{#f}.
22775 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22776 A list of subdirectories inside of @code{repository-directory}, relative
22777 to it, that should loaded as Git repositories. An empty list means that
22778 all subdirectories will be loaded.
22780 Defaults to @samp{()}.
22784 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22785 Text which will be used as default value for @code{cgit-repo-readme}.
22787 Defaults to @samp{""}.
22791 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22792 If set to @code{#t} and @code{repository-directory} is enabled, if any
22793 repositories are found with a suffix of @code{.git}, this suffix will be
22794 removed for the URL and name.
22796 Defaults to @samp{#f}.
22800 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22801 Maximum number of files to consider when detecting renames.
22803 Defaults to @samp{-1}.
22807 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22808 The way in which repositories in each section are sorted.
22810 Defaults to @samp{""}.
22814 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22815 Text used as content for the @code{robots} meta-tag.
22817 Defaults to @samp{("noindex" "nofollow")}.
22821 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22822 Text printed below the heading on the repository index page.
22824 Defaults to @samp{"a fast webinterface for the git dscm"}.
22828 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22829 The content of the file specified with this option will be included
22830 verbatim below thef "about" link on the repository index page.
22832 Defaults to @samp{""}.
22836 @deftypevr {@code{cgit-configuration} parameter} string root-title
22837 Text printed as heading on the repository index page.
22839 Defaults to @samp{""}.
22843 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22844 If set to @samp{#t} and repository-directory is enabled,
22845 repository-directory will recurse into directories whose name starts
22846 with a period. Otherwise, repository-directory will stay away from such
22847 directories, considered as "hidden". Note that this does not apply to
22848 the ".git" directory in non-bare repos.
22850 Defaults to @samp{#f}.
22854 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22855 Text which specifies the default set of snapshot formats that cgit
22856 generates links for.
22858 Defaults to @samp{()}.
22862 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22863 Name of the directory to scan for repositories (represents
22866 Defaults to @samp{"/srv/git"}.
22870 @deftypevr {@code{cgit-configuration} parameter} string section
22871 The name of the current repository section - all repositories defined
22872 after this option will inherit the current section name.
22874 Defaults to @samp{""}.
22878 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22879 Flag which, when set to @samp{1}, will sort the sections on the
22880 repository listing by name.
22882 Defaults to @samp{""}.
22886 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22887 A number which, if defined prior to repository-directory, specifies how
22888 many path elements from each repo path to use as a default section name.
22890 Defaults to @samp{0}.
22894 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22895 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22898 Defaults to @samp{#f}.
22902 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22903 Specifies a command which will be invoked to format plaintext blobs in
22906 Defaults to @samp{""}.
22910 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22911 Specifies the number of branches to display in the repository "summary"
22914 Defaults to @samp{10}.
22918 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22919 Specifies the number of log entries to display in the repository
22922 Defaults to @samp{10}.
22926 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22927 Specifies the number of tags to display in the repository "summary"
22930 Defaults to @samp{10}.
22934 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22935 Filename which, if specified, needs to be present within the repository
22936 for cgit to allow access to that repository.
22938 Defaults to @samp{""}.
22942 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22943 URL which, if specified, will be used as root for all cgit links.
22945 Defaults to @samp{"/"}.
22949 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22950 A list of @dfn{cgit-repo} records to use with config.
22952 Defaults to @samp{()}.
22954 Available @code{repository-cgit-configuration} fields are:
22956 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22957 A mask of snapshot formats for this repo that cgit generates links for,
22958 restricted by the global @code{snapshots} setting.
22960 Defaults to @samp{()}.
22964 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22965 Override the default @code{source-filter}.
22967 Defaults to @samp{""}.
22971 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22972 The relative URL used to access the repository.
22974 Defaults to @samp{""}.
22978 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22979 Override the default @code{about-filter}.
22981 Defaults to @samp{""}.
22985 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22986 Flag which, when set to @samp{age}, enables date ordering in the branch
22987 ref list, and when set to @samp{name} enables ordering by branch name.
22989 Defaults to @samp{""}.
22993 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22994 A list of URLs which can be used to clone repo.
22996 Defaults to @samp{()}.
23000 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
23001 Override the default @code{commit-filter}.
23003 Defaults to @samp{""}.
23007 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
23008 Flag which, when set to @samp{date}, enables strict date ordering in the
23009 commit log, and when set to @samp{topo} enables strict topological
23012 Defaults to @samp{""}.
23016 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
23017 The name of the default branch for this repository. If no such branch
23018 exists in the repository, the first branch name (when sorted) is used as
23019 default instead. By default branch pointed to by HEAD, or "master" if
23020 there is no suitable HEAD.
23022 Defaults to @samp{""}.
23026 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23027 The value to show as repository description.
23029 Defaults to @samp{""}.
23033 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23034 The value to show as repository homepage.
23036 Defaults to @samp{""}.
23040 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23041 Override the default @code{email-filter}.
23043 Defaults to @samp{""}.
23047 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23048 A flag which can be used to disable the global setting
23049 @code{enable-commit-graph?}.
23051 Defaults to @samp{disabled}.
23055 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23056 A flag which can be used to disable the global setting
23057 @code{enable-log-filecount?}.
23059 Defaults to @samp{disabled}.
23063 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23064 A flag which can be used to disable the global setting
23065 @code{enable-log-linecount?}.
23067 Defaults to @samp{disabled}.
23071 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23072 Flag which, when set to @code{#t}, will make cgit display remote
23073 branches in the summary and refs views.
23075 Defaults to @samp{disabled}.
23079 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23080 A flag which can be used to override the global setting
23081 @code{enable-subject-links?}.
23083 Defaults to @samp{disabled}.
23087 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23088 A flag which can be used to override the global setting
23089 @code{enable-html-serving?}.
23091 Defaults to @samp{disabled}.
23095 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23096 Flag which, when set to @code{#t}, hides the repository from the
23099 Defaults to @samp{#f}.
23103 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23104 Flag which, when set to @samp{#t}, ignores the repository.
23106 Defaults to @samp{#f}.
23110 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23111 URL which specifies the source of an image which will be used as a logo
23112 on this repo’s pages.
23114 Defaults to @samp{""}.
23118 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23119 URL loaded when clicking on the cgit logo image.
23121 Defaults to @samp{""}.
23125 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23126 Override the default @code{owner-filter}.
23128 Defaults to @samp{""}.
23132 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23133 Text which will be used as the formatstring for a hyperlink when a
23134 submodule is printed in a directory listing. The arguments for the
23135 formatstring are the path and SHA1 of the submodule commit.
23137 Defaults to @samp{""}.
23141 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23142 Text which will be used as the formatstring for a hyperlink when a
23143 submodule with the specified subdirectory path is printed in a directory
23146 Defaults to @samp{()}.
23150 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23151 Override the default maximum statistics period.
23153 Defaults to @samp{""}.
23157 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23158 The value to show as repository name.
23160 Defaults to @samp{""}.
23164 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23165 A value used to identify the owner of the repository.
23167 Defaults to @samp{""}.
23171 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23172 An absolute path to the repository directory.
23174 Defaults to @samp{""}.
23178 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23179 A path (relative to repo) which specifies a file to include verbatim as
23180 the "About" page for this repo.
23182 Defaults to @samp{""}.
23186 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23187 The name of the current repository section - all repositories defined
23188 after this option will inherit the current section name.
23190 Defaults to @samp{""}.
23194 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23195 Extra options will be appended to cgitrc file.
23197 Defaults to @samp{()}.
23203 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23204 Extra options will be appended to cgitrc file.
23206 Defaults to @samp{()}.
23211 @c %end of fragment
23213 However, it could be that you just want to get a @code{cgitrc} up and
23214 running. In that case, you can pass an @code{opaque-cgit-configuration}
23215 as a record to @code{cgit-service-type}. As its name indicates, an
23216 opaque configuration does not have easy reflective capabilities.
23218 Available @code{opaque-cgit-configuration} fields are:
23220 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23224 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23225 The contents of the @code{cgitrc}, as a string.
23228 For example, if your @code{cgitrc} is just the empty string, you
23229 could instantiate a cgit service like this:
23232 (service cgit-service-type
23233 (opaque-cgit-configuration
23237 @subsubheading Gitolite Service
23239 @cindex Gitolite service
23240 @cindex Git, hosting
23241 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23242 repositories on a central server.
23244 Gitolite can handle multiple repositories and users, and supports flexible
23245 configuration of the permissions for the users on the repositories.
23247 The following example will configure Gitolite using the default @code{git}
23248 user, and the provided SSH public key.
23251 (service gitolite-service-type
23252 (gitolite-configuration
23253 (admin-pubkey (plain-file
23255 "ssh-rsa AAAA... guix@@example.com"))))
23258 Gitolite is configured through a special admin repository which you can clone,
23259 for example, if you setup Gitolite on @code{example.com}, you would run the
23260 following command to clone the admin repository.
23263 git clone git@@example.com:gitolite-admin
23266 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23267 be inserted in to the @file{keydir} directory in the gitolite-admin
23268 repository. If this results in a change in the repository, it will be
23269 committed using the message ``gitolite setup by GNU Guix''.
23271 @deftp {Data Type} gitolite-configuration
23272 Data type representing the configuration for @code{gitolite-service-type}.
23275 @item @code{package} (default: @var{gitolite})
23276 Gitolite package to use.
23278 @item @code{user} (default: @var{git})
23279 User to use for Gitolite. This will be user that you use when accessing
23282 @item @code{group} (default: @var{git})
23283 Group to use for Gitolite.
23285 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23286 Directory in which to store the Gitolite configuration and repositories.
23288 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23289 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23290 representing the configuration for Gitolite.
23292 @item @code{admin-pubkey} (default: @var{#f})
23293 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23294 setup Gitolite. This will be inserted in to the @file{keydir} directory
23295 within the gitolite-admin repository.
23297 To specify the SSH key as a string, use the @code{plain-file} function.
23300 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23306 @deftp {Data Type} gitolite-rc-file
23307 Data type representing the Gitolite RC file.
23310 @item @code{umask} (default: @code{#o0077})
23311 This controls the permissions Gitolite sets on the repositories and their
23314 A value like @code{#o0027} will give read access to the group used by Gitolite
23315 (by default: @code{git}). This is necessary when using Gitolite with software
23316 like cgit or gitweb.
23318 @item @code{git-config-keys} (default: @code{""})
23319 Gitolite allows you to set git config values using the "config" keyword. This
23320 setting allows control over the config keys to accept.
23322 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23323 Set the role names allowed to be used by users running the perms command.
23325 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23326 This setting controls the commands and features to enable within Gitolite.
23332 @node Game Services
23333 @subsection Game Services
23335 @subsubheading The Battle for Wesnoth Service
23337 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23338 based tactical strategy game, with several single player campaigns, and
23339 multiplayer games (both networked and local).
23341 @defvar {Scheme Variable} wesnothd-service-type
23342 Service type for the wesnothd service. Its value must be a
23343 @code{wesnothd-configuration} object. To run wesnothd in the default
23344 configuration, instantiate it as:
23347 (service wesnothd-service-type)
23351 @deftp {Data Type} wesnothd-configuration
23352 Data type representing the configuration of @command{wesnothd}.
23355 @item @code{package} (default: @code{wesnoth-server})
23356 The wesnoth server package to use.
23358 @item @code{port} (default: @code{15000})
23359 The port to bind the server to.
23363 @node Miscellaneous Services
23364 @subsection Miscellaneous Services
23366 @cindex fingerprint
23367 @subsubheading Fingerprint Service
23369 The @code{(gnu services authentication)} module provides a DBus service to
23370 read and identify fingerprints via a fingerprint sensor.
23372 @defvr {Scheme Variable} fprintd-service-type
23373 The service type for @command{fprintd}, which provides the fingerprint
23374 reading capability.
23377 (service fprintd-service-type)
23382 @subsubheading System Control Service
23384 The @code{(gnu services sysctl)} provides a service to configure kernel
23385 parameters at boot.
23387 @defvr {Scheme Variable} sysctl-service-type
23388 The service type for @command{sysctl}, which modifies kernel parameters
23389 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23393 (service sysctl-service-type
23394 (sysctl-configuration
23395 (settings '(("net.ipv4.ip_forward" . "1")))))
23399 @deftp {Data Type} sysctl-configuration
23400 The data type representing the configuration of @command{sysctl}.
23403 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23404 The @command{sysctl} executable to use.
23406 @item @code{settings} (default: @code{'()})
23407 An association list specifies kernel parameters and their values.
23412 @subsubheading PC/SC Smart Card Daemon Service
23414 The @code{(gnu services security-token)} module provides the following service
23415 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23416 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23417 manager that coordinates communications with smart card readers, smart cards
23418 and cryptographic tokens that are connected to the system.
23420 @defvr {Scheme Variable} pcscd-service-type
23421 Service type for the @command{pcscd} service. Its value must be a
23422 @code{pcscd-configuration} object. To run pcscd in the default
23423 configuration, instantiate it as:
23426 (service pcscd-service-type)
23430 @deftp {Data Type} pcscd-configuration
23431 The data type representing the configuration of @command{pcscd}.
23434 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23435 The pcsc-lite package that provides pcscd.
23436 @item @code{usb-drivers} (default: @code{(list ccid)})
23437 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23438 under @file{pcsc/drivers} in the store directory of the package.
23443 @subsubheading Lirc Service
23445 The @code{(gnu services lirc)} module provides the following service.
23447 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23448 [#:device #f] [#:driver #f] [#:config-file #f] @
23449 [#:extra-options '()]
23450 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23451 decodes infrared signals from remote controls.
23453 Optionally, @var{device}, @var{driver} and @var{config-file}
23454 (configuration file name) may be specified. See @command{lircd} manual
23457 Finally, @var{extra-options} is a list of additional command-line options
23458 passed to @command{lircd}.
23462 @subsubheading Spice Service
23464 The @code{(gnu services spice)} module provides the following service.
23466 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23467 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
23468 that enables sharing the clipboard with a vm and setting the guest display
23469 resolution when the graphical console window resizes.
23472 @cindex inputattach
23473 @subsubheading inputattach Service
23475 @cindex tablet input, for Xorg
23476 @cindex touchscreen input, for Xorg
23477 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23478 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23479 Xorg display server.
23481 @deffn {Scheme Variable} inputattach-service-type
23482 Type of a service that runs @command{inputattach} on a device and
23483 dispatches events from it.
23486 @deftp {Data Type} inputattach-configuration
23488 @item @code{device-type} (default: @code{"wacom"})
23489 The type of device to connect to. Run @command{inputattach --help}, from the
23490 @code{inputattach} package, to see the list of supported device types.
23492 @item @code{device} (default: @code{"/dev/ttyS0"})
23493 The device file to connect to the device.
23495 @item @code{log-file} (default: @code{#f})
23496 If true, this must be the name of a file to log messages to.
23500 @subsection Dictionary Services
23502 The @code{(gnu services dict)} module provides the following service:
23504 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23505 Return a service that runs the @command{dicod} daemon, an implementation
23506 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23508 The optional @var{config} argument specifies the configuration for
23509 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23510 default it serves the GNU Collaborative International Dictonary of English.
23512 You can add @command{open localhost} to your @file{~/.dico} file to make
23513 @code{localhost} the default server for @command{dico} client
23514 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23517 @deftp {Data Type} dicod-configuration
23518 Data type representing the configuration of dicod.
23521 @item @code{dico} (default: @var{dico})
23522 Package object of the GNU Dico dictionary server.
23524 @item @code{interfaces} (default: @var{'("localhost")})
23525 This is the list of IP addresses and ports and possibly socket file
23526 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23527 dico, GNU Dico Manual}).
23529 @item @code{handlers} (default: @var{'()})
23530 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23532 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23533 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23537 @deftp {Data Type} dicod-handler
23538 Data type representing a dictionary handler (module instance).
23542 Name of the handler (module instance).
23544 @item @code{module} (default: @var{#f})
23545 Name of the dicod module of the handler (instance). If it is @code{#f},
23546 the module has the same name as the handler.
23547 (@pxref{Modules,,, dico, GNU Dico Manual}).
23549 @item @code{options}
23550 List of strings or gexps representing the arguments for the module handler
23554 @deftp {Data Type} dicod-database
23555 Data type representing a dictionary database.
23559 Name of the database, will be used in DICT commands.
23561 @item @code{handler}
23562 Name of the dicod handler (module instance) used by this database
23563 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23565 @item @code{complex?} (default: @var{#f})
23566 Whether the database configuration complex. The complex configuration
23567 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23569 @item @code{options}
23570 List of strings or gexps representing the arguments for the database
23571 (@pxref{Databases,,, dico, GNU Dico Manual}).
23575 @defvr {Scheme Variable} %dicod-database:gcide
23576 A @code{<dicod-database>} object serving the GNU Collaborative International
23577 Dictionary of English using the @code{gcide} package.
23580 The following is an example @code{dicod-service} configuration.
23583 (dicod-service #:config
23584 (dicod-configuration
23585 (handlers (list (dicod-handler
23589 (list #~(string-append "dbdir=" #$wordnet))))))
23590 (databases (list (dicod-database
23593 (handler "wordnet")
23594 (options '("database=wn")))
23595 %dicod-database:gcide))))
23599 @subsubheading Docker Service
23601 The @code{(gnu services docker)} module provides the following service.
23603 @defvr {Scheme Variable} docker-service-type
23605 This is the type of the service that runs @url{https://www.docker.com,Docker},
23606 a daemon that can execute application bundles (sometimes referred to as
23607 ``containers'') in isolated environments.
23611 @deftp {Data Type} docker-configuration
23612 This is the data type representing the configuration of Docker and Containerd.
23616 @item @code{package} (default: @code{docker})
23617 The Docker package to use.
23619 @item @code{containerd} (default: @var{containerd})
23620 The Containerd package to use.
23625 @node Setuid Programs
23626 @section Setuid Programs
23628 @cindex setuid programs
23629 Some programs need to run with ``root'' privileges, even when they are
23630 launched by unprivileged users. A notorious example is the
23631 @command{passwd} program, which users can run to change their
23632 password, and which needs to access the @file{/etc/passwd} and
23633 @file{/etc/shadow} files---something normally restricted to root, for
23634 obvious security reasons. To address that, these executables are
23635 @dfn{setuid-root}, meaning that they always run with root privileges
23636 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23637 for more info about the setuid mechanism.)
23639 The store itself @emph{cannot} contain setuid programs: that would be a
23640 security issue since any user on the system can write derivations that
23641 populate the store (@pxref{The Store}). Thus, a different mechanism is
23642 used: instead of changing the setuid bit directly on files that are in
23643 the store, we let the system administrator @emph{declare} which programs
23644 should be setuid root.
23646 The @code{setuid-programs} field of an @code{operating-system}
23647 declaration contains a list of G-expressions denoting the names of
23648 programs to be setuid-root (@pxref{Using the Configuration System}).
23649 For instance, the @command{passwd} program, which is part of the Shadow
23650 package, can be designated by this G-expression (@pxref{G-Expressions}):
23653 #~(string-append #$shadow "/bin/passwd")
23656 A default set of setuid programs is defined by the
23657 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23659 @defvr {Scheme Variable} %setuid-programs
23660 A list of G-expressions denoting common programs that are setuid-root.
23662 The list includes commands such as @command{passwd}, @command{ping},
23663 @command{su}, and @command{sudo}.
23666 Under the hood, the actual setuid programs are created in the
23667 @file{/run/setuid-programs} directory at system activation time. The
23668 files in this directory refer to the ``real'' binaries, which are in the
23671 @node X.509 Certificates
23672 @section X.509 Certificates
23674 @cindex HTTPS, certificates
23675 @cindex X.509 certificates
23677 Web servers available over HTTPS (that is, HTTP over the transport-layer
23678 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23679 that the client can then use to @emph{authenticate} the server. To do
23680 that, clients verify that the server's certificate is signed by a
23681 so-called @dfn{certificate authority} (CA). But to verify the CA's
23682 signature, clients must have first acquired the CA's certificate.
23684 Web browsers such as GNU@tie{}IceCat include their own set of CA
23685 certificates, such that they are able to verify CA signatures
23688 However, most other programs that can talk HTTPS---@command{wget},
23689 @command{git}, @command{w3m}, etc.---need to be told where CA
23690 certificates can be found.
23692 @cindex @code{nss-certs}
23693 In Guix, this is done by adding a package that provides certificates
23694 to the @code{packages} field of the @code{operating-system} declaration
23695 (@pxref{operating-system Reference}). Guix includes one such package,
23696 @code{nss-certs}, which is a set of CA certificates provided as part of
23697 Mozilla's Network Security Services.
23699 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23700 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23701 most applications and libraries look for certificates by default, points
23702 to the certificates installed globally.
23704 Unprivileged users, including users of Guix on a foreign distro,
23705 can also install their own certificate package in
23706 their profile. A number of environment variables need to be defined so
23707 that applications and libraries know where to find them. Namely, the
23708 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23709 variables. Some applications add their own environment variables; for
23710 instance, the Git version control system honors the certificate bundle
23711 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23712 would typically run something like:
23715 $ guix install nss-certs
23716 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23717 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23718 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23721 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23722 variable to point to a certificate bundle, so you would have to run
23723 something like this:
23726 $ guix install nss-certs
23727 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23730 For other applications you may want to look up the required environment
23731 variable in the relevant documentation.
23734 @node Name Service Switch
23735 @section Name Service Switch
23737 @cindex name service switch
23739 The @code{(gnu system nss)} module provides bindings to the
23740 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23741 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23742 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23743 extended with new ``name'' lookup methods for system databases, which
23744 includes host names, service names, user accounts, and more (@pxref{Name
23745 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23746 C Library Reference Manual}).
23748 The NSS configuration specifies, for each system database, which lookup
23749 method is to be used, and how the various methods are chained
23750 together---for instance, under which circumstances NSS should try the
23751 next method in the list. The NSS configuration is given in the
23752 @code{name-service-switch} field of @code{operating-system} declarations
23753 (@pxref{operating-system Reference, @code{name-service-switch}}).
23756 @cindex .local, host name lookup
23757 As an example, the declaration below configures the NSS to use the
23758 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23759 back-end}, which supports host name lookups over multicast DNS (mDNS)
23760 for host names ending in @code{.local}:
23763 (name-service-switch
23764 (hosts (list %files ;first, check /etc/hosts
23766 ;; If the above did not succeed, try
23767 ;; with 'mdns_minimal'.
23769 (name "mdns_minimal")
23771 ;; 'mdns_minimal' is authoritative for
23772 ;; '.local'. When it returns "not found",
23773 ;; no need to try the next methods.
23774 (reaction (lookup-specification
23775 (not-found => return))))
23777 ;; Then fall back to DNS.
23781 ;; Finally, try with the "full" 'mdns'.
23786 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23787 contains this configuration, so you will not have to type it if all you
23788 want is to have @code{.local} host lookup working.
23790 Note that, in this case, in addition to setting the
23791 @code{name-service-switch} of the @code{operating-system} declaration,
23792 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23793 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23794 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23795 to the name service cache daemon (@pxref{Base Services,
23796 @code{nscd-service}}).
23798 For convenience, the following variables provide typical NSS
23801 @defvr {Scheme Variable} %default-nss
23802 This is the default name service switch configuration, a
23803 @code{name-service-switch} object.
23806 @defvr {Scheme Variable} %mdns-host-lookup-nss
23807 This is the name service switch configuration with support for host name
23808 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23811 The reference for name service switch configuration is given below. It
23812 is a direct mapping of the configuration file format of the C library , so
23813 please refer to the C library manual for more information (@pxref{NSS
23814 Configuration File,,, libc, The GNU C Library Reference Manual}).
23815 Compared to the configuration file format of libc NSS, it has the advantage
23816 not only of adding this warm parenthetic feel that we like, but also
23817 static checks: you will know about syntax errors and typos as soon as you
23818 run @command{guix system}.
23820 @deftp {Data Type} name-service-switch
23822 This is the data type representation the configuration of libc's name
23823 service switch (NSS). Each field below represents one of the supported
23840 The system databases handled by the NSS. Each of these fields must be a
23841 list of @code{<name-service>} objects (see below).
23845 @deftp {Data Type} name-service
23847 This is the data type representing an actual name service and the
23848 associated lookup action.
23852 A string denoting the name service (@pxref{Services in the NSS
23853 configuration,,, libc, The GNU C Library Reference Manual}).
23855 Note that name services listed here must be visible to nscd. This is
23856 achieved by passing the @code{#:name-services} argument to
23857 @code{nscd-service} the list of packages providing the needed name
23858 services (@pxref{Base Services, @code{nscd-service}}).
23861 An action specified using the @code{lookup-specification} macro
23862 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23863 Reference Manual}). For example:
23866 (lookup-specification (unavailable => continue)
23867 (success => return))
23872 @node Initial RAM Disk
23873 @section Initial RAM Disk
23876 @cindex initial RAM disk
23877 For bootstrapping purposes, the Linux-Libre kernel is passed an
23878 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23879 root file system as well as an initialization script. The latter is
23880 responsible for mounting the real root file system, and for loading any
23881 kernel modules that may be needed to achieve that.
23883 The @code{initrd-modules} field of an @code{operating-system}
23884 declaration allows you to specify Linux-libre kernel modules that must
23885 be available in the initrd. In particular, this is where you would list
23886 modules needed to actually drive the hard disk where your root partition
23887 is---although the default value of @code{initrd-modules} should cover
23888 most use cases. For example, assuming you need the @code{megaraid_sas}
23889 module in addition to the default modules to be able to access your root
23890 file system, you would write:
23895 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23898 @defvr {Scheme Variable} %base-initrd-modules
23899 This is the list of kernel modules included in the initrd by default.
23902 Furthermore, if you need lower-level customization, the @code{initrd}
23903 field of an @code{operating-system} declaration allows
23904 you to specify which initrd you would like to use. The @code{(gnu
23905 system linux-initrd)} module provides three ways to build an initrd: the
23906 high-level @code{base-initrd} procedure and the low-level
23907 @code{raw-initrd} and @code{expression->initrd} procedures.
23909 The @code{base-initrd} procedure is intended to cover most common uses.
23910 For example, if you want to add a bunch of kernel modules to be loaded
23911 at boot time, you can define the @code{initrd} field of the operating
23912 system declaration like this:
23915 (initrd (lambda (file-systems . rest)
23916 ;; Create a standard initrd but set up networking
23917 ;; with the parameters QEMU expects by default.
23918 (apply base-initrd file-systems
23919 #:qemu-networking? #t
23923 The @code{base-initrd} procedure also handles common use cases that
23924 involves using the system as a QEMU guest, or as a ``live'' system with
23925 volatile root file system.
23927 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23928 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23929 such as trying to guess which kernel modules and packages should be included
23930 to the initrd. An example use of @code{raw-initrd} is when a user has
23931 a custom Linux kernel configuration and default kernel modules included by
23932 @code{base-initrd} are not available.
23934 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23935 honors several options passed on the Linux kernel command line
23936 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23937 @code{-append} option of QEMU), notably:
23940 @item --load=@var{boot}
23941 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23942 program, once it has mounted the root file system.
23944 Guix uses this option to yield control to a boot program that runs the
23945 service activation programs and then spawns the GNU@tie{}Shepherd, the
23946 initialization system.
23948 @item --root=@var{root}
23949 Mount @var{root} as the root file system. @var{root} can be a
23950 device name like @code{/dev/sda1}, a file system label, or a file system
23953 @item --system=@var{system}
23954 Have @file{/run/booted-system} and @file{/run/current-system} point to
23957 @item modprobe.blacklist=@var{modules}@dots{}
23958 @cindex module, black-listing
23959 @cindex black list, of kernel modules
23960 Instruct the initial RAM disk as well as the @command{modprobe} command
23961 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23962 must be a comma-separated list of module names---e.g.,
23963 @code{usbkbd,9pnet}.
23966 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23967 tries to load kernel modules and to mount the root file system. Our
23968 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23969 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23970 Manual}, for more information on Guile's REPL.
23974 Now that you know all the features that initial RAM disks produced by
23975 @code{base-initrd} and @code{raw-initrd} provide,
23976 here is how to use it and customize it further.
23979 @cindex initial RAM disk
23980 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23981 [#:linux-modules '()] [#:mapped-devices '()] @
23982 [#:keyboard-layout #f] @
23983 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23984 Return a derivation that builds a raw initrd. @var{file-systems} is
23985 a list of file systems to be mounted by the initrd, possibly in addition to
23986 the root file system specified on the kernel command line via @code{--root}.
23987 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23988 @var{mapped-devices} is a list of device mappings to realize before
23989 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23990 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23991 include @code{e2fsck/static} or other packages needed by the initrd to check
23992 the root file system.
23994 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23995 the desired console keyboard layout. This is done before @var{mapped-devices}
23996 are set up and before @var{file-systems} are mounted such that, should the
23997 user need to enter a passphrase or use the REPL, this happens using the
23998 intended keyboard layout.
24000 When @var{qemu-networking?} is true, set up networking with the standard QEMU
24001 parameters. When @var{virtio?} is true, load additional modules so that the
24002 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
24004 When @var{volatile-root?} is true, the root file system is writable but any changes
24008 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
24009 [#:mapped-devices '()] [#:keyboard-layout #f] @
24010 [#:qemu-networking? #f] [#:volatile-root? #f] @
24011 [#:linux-modules '()]
24012 Return as a file-like object a generic initrd, with kernel
24013 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
24014 mounted by the initrd, possibly in addition to the root file system specified
24015 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
24016 mappings to realize before @var{file-systems} are mounted.
24018 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24019 the desired console keyboard layout. This is done before @var{mapped-devices}
24020 are set up and before @var{file-systems} are mounted such that, should the
24021 user need to enter a passphrase or use the REPL, this happens using the
24022 intended keyboard layout.
24024 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24026 The initrd is automatically populated with all the kernel modules necessary
24027 for @var{file-systems} and for the given options. Additional kernel
24028 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24029 loaded at boot time in the order in which they appear.
24032 Needless to say, the initrds we produce and use embed a
24033 statically-linked Guile, and the initialization program is a Guile
24034 program. That gives a lot of flexibility. The
24035 @code{expression->initrd} procedure builds such an initrd, given the
24036 program to run in that initrd.
24038 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24039 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24040 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24041 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24042 upon booting. All the derivations referenced by @var{exp} are
24043 automatically copied to the initrd.
24046 @node Bootloader Configuration
24047 @section Bootloader Configuration
24050 @cindex boot loader
24052 The operating system supports multiple bootloaders. The bootloader is
24053 configured using @code{bootloader-configuration} declaration. All the
24054 fields of this structure are bootloader agnostic except for one field,
24055 @code{bootloader} that indicates the bootloader to be configured and
24058 Some of the bootloaders do not honor every field of
24059 @code{bootloader-configuration}. For instance, the extlinux
24060 bootloader does not support themes and thus ignores the @code{theme}
24063 @deftp {Data Type} bootloader-configuration
24064 The type of a bootloader configuration declaration.
24068 @item @code{bootloader}
24069 @cindex EFI, bootloader
24070 @cindex UEFI, bootloader
24071 @cindex BIOS, bootloader
24072 The bootloader to use, as a @code{bootloader} object. For now
24073 @code{grub-bootloader}, @code{grub-efi-bootloader},
24074 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24076 @vindex grub-efi-bootloader
24077 @code{grub-efi-bootloader} allows to boot on modern systems using the
24078 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24079 use if the installation image contains a @file{/sys/firmware/efi} directory
24080 when you boot it on your system.
24082 @vindex grub-bootloader
24083 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24084 in ``legacy'' BIOS mode.
24086 @cindex ARM, bootloaders
24087 @cindex AArch64, bootloaders
24088 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24089 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24090 of bootloaders for a wide range of ARM and AArch64 systems, using the
24091 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24093 @item @code{target}
24094 This is a string denoting the target onto which to install the
24097 The interpretation depends on the bootloader in question. For
24098 @code{grub-bootloader}, for example, it should be a device name understood by
24099 the bootloader @command{installer} command, such as @code{/dev/sda} or
24100 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24101 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24102 system, usually @file{/boot/efi}.
24104 @item @code{menu-entries} (default: @code{()})
24105 A possibly empty list of @code{menu-entry} objects (see below), denoting
24106 entries to appear in the bootloader menu, in addition to the current
24107 system entry and the entry pointing to previous system generations.
24109 @item @code{default-entry} (default: @code{0})
24110 The index of the default boot menu entry. Index 0 is for the entry of the
24113 @item @code{timeout} (default: @code{5})
24114 The number of seconds to wait for keyboard input before booting. Set to
24115 0 to boot immediately, and to -1 to wait indefinitely.
24117 @cindex keyboard layout, for the bootloader
24118 @item @code{keyboard-layout} (default: @code{#f})
24119 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24120 layout, usually US@tie{}English (``qwerty'').
24122 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24126 This option is currently ignored by bootloaders other than @code{grub} and
24130 @item @code{theme} (default: @var{#f})
24131 The bootloader theme object describing the theme to use. If no theme
24132 is provided, some bootloaders might use a default theme, that's true
24135 @item @code{terminal-outputs} (default: @code{'gfxterm})
24136 The output terminals used for the bootloader boot menu, as a list of
24137 symbols. GRUB accepts the values: @code{console}, @code{serial},
24138 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24139 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24140 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24141 configuration,,, grub,GNU GRUB manual}).
24143 @item @code{terminal-inputs} (default: @code{'()})
24144 The input terminals used for the bootloader boot menu, as a list of
24145 symbols. For GRUB, the default is the native platform terminal as
24146 determined at run-time. GRUB accepts the values: @code{console},
24147 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24148 @code{usb_keyboard}. This field corresponds to the GRUB variable
24149 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24152 @item @code{serial-unit} (default: @code{#f})
24153 The serial unit used by the bootloader, as an integer from 0 to 3.
24154 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24155 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24157 @item @code{serial-speed} (default: @code{#f})
24158 The speed of the serial interface, as an integer. For GRUB, the
24159 default value is chosen at run-time; currently GRUB chooses
24160 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24167 Should you want to list additional boot menu entries @i{via} the
24168 @code{menu-entries} field above, you will need to create them with the
24169 @code{menu-entry} form. For example, imagine you want to be able to
24170 boot another distro (hard to imagine!), you can define a menu entry
24175 (label "The Other Distro")
24176 (linux "/boot/old/vmlinux-2.6.32")
24177 (linux-arguments '("root=/dev/sda2"))
24178 (initrd "/boot/old/initrd"))
24183 @deftp {Data Type} menu-entry
24184 The type of an entry in the bootloader menu.
24189 The label to show in the menu---e.g., @code{"GNU"}.
24192 The Linux kernel image to boot, for example:
24195 (file-append linux-libre "/bzImage")
24198 For GRUB, it is also possible to specify a device explicitly in the
24199 file path using GRUB's device naming convention (@pxref{Naming
24200 convention,,, grub, GNU GRUB manual}), for example:
24203 "(hd0,msdos1)/boot/vmlinuz"
24206 If the device is specified explicitly as above, then the @code{device}
24207 field is ignored entirely.
24209 @item @code{linux-arguments} (default: @code{()})
24210 The list of extra Linux kernel command-line arguments---e.g.,
24211 @code{("console=ttyS0")}.
24213 @item @code{initrd}
24214 A G-Expression or string denoting the file name of the initial RAM disk
24215 to use (@pxref{G-Expressions}).
24216 @item @code{device} (default: @code{#f})
24217 The device where the kernel and initrd are to be found---i.e., for GRUB,
24218 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24220 This may be a file system label (a string), a file system UUID (a
24221 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24222 the bootloader will search the device containing the file specified by
24223 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24224 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24229 @c FIXME: Write documentation once it's stable.
24230 For now only GRUB has theme support. GRUB themes are created using
24231 the @code{grub-theme} form, which is not documented yet.
24233 @defvr {Scheme Variable} %default-theme
24234 This is the default GRUB theme used by the operating system if no
24235 @code{theme} field is specified in @code{bootloader-configuration}
24238 It comes with a fancy background image displaying the GNU and Guix
24243 @node Invoking guix system
24244 @section Invoking @code{guix system}
24246 Once you have written an operating system declaration as seen in the
24247 previous section, it can be @dfn{instantiated} using the @command{guix
24248 system} command. The synopsis is:
24251 guix system @var{options}@dots{} @var{action} @var{file}
24254 @var{file} must be the name of a file containing an
24255 @code{operating-system} declaration. @var{action} specifies how the
24256 operating system is instantiated. Currently the following values are
24261 Display available service type definitions that match the given regular
24262 expressions, sorted by relevance:
24265 $ guix system search console font
24266 name: console-fonts
24267 location: gnu/services/base.scm:729:2
24268 extends: shepherd-root
24269 description: Install the given fonts on the specified ttys (fonts are
24270 + per virtual console on GNU/Linux). The value of this service is a list
24271 + of tty/font pairs like:
24273 + '(("tty1" . "LatGrkCyr-8x16"))
24277 location: gnu/services/base.scm:1048:2
24278 extends: shepherd-root
24279 description: Provide console login using the `mingetty' program.
24283 location: gnu/services/base.scm:775:2
24285 description: Provide a console log-in service as specified by its
24286 + configuration value, a `login-configuration' object.
24292 As for @command{guix package --search}, the result is written in
24293 @code{recutils} format, which makes it easy to filter the output
24294 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24297 Build the operating system described in @var{file}, activate it, and
24298 switch to it@footnote{This action (and the related actions
24299 @code{switch-generation} and @code{roll-back}) are usable only on
24300 systems already running Guix System.}.
24302 This effects all the configuration specified in @var{file}: user
24303 accounts, system services, global package list, setuid programs, etc.
24304 The command starts system services specified in @var{file} that are not
24305 currently running; if a service is currently running this command will
24306 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24307 @code{herd stop X} or @code{herd restart X}).
24309 This command creates a new generation whose number is one greater than
24310 the current generation (as reported by @command{guix system
24311 list-generations}). If that generation already exists, it will be
24312 overwritten. This behavior mirrors that of @command{guix package}
24313 (@pxref{Invoking guix package}).
24315 It also adds a bootloader menu entry for the new OS configuration,
24316 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24317 entries for older configurations to a submenu, allowing you to choose
24318 an older system generation at boot time should you need it.
24321 @c The paragraph below refers to the problem discussed at
24322 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24323 It is highly recommended to run @command{guix pull} once before you run
24324 @command{guix system reconfigure} for the first time (@pxref{Invoking
24325 guix pull}). Failing to do that you would see an older version of Guix
24326 once @command{reconfigure} has completed.
24329 @item switch-generation
24330 @cindex generations
24331 Switch to an existing system generation. This action atomically
24332 switches the system profile to the specified system generation. It
24333 also rearranges the system's existing bootloader menu entries. It
24334 makes the menu entry for the specified system generation the default,
24335 and it moves the entries for the other generatiors to a submenu, if
24336 supported by the bootloader being used. The next time the system
24337 boots, it will use the specified system generation.
24339 The bootloader itself is not being reinstalled when using this
24340 command. Thus, the installed bootloader is used with an updated
24341 configuration file.
24343 The target generation can be specified explicitly by its generation
24344 number. For example, the following invocation would switch to system
24348 guix system switch-generation 7
24351 The target generation can also be specified relative to the current
24352 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24353 ``3 generations ahead of the current generation,'' and @code{-1} means
24354 ``1 generation prior to the current generation.'' When specifying a
24355 negative value such as @code{-1}, you must precede it with @code{--} to
24356 prevent it from being parsed as an option. For example:
24359 guix system switch-generation -- -1
24362 Currently, the effect of invoking this action is @emph{only} to switch
24363 the system profile to an existing generation and rearrange the
24364 bootloader menu entries. To actually start using the target system
24365 generation, you must reboot after running this action. In the future,
24366 it will be updated to do the same things as @command{reconfigure},
24367 like activating and deactivating services.
24369 This action will fail if the specified generation does not exist.
24372 @cindex rolling back
24373 Switch to the preceding system generation. The next time the system
24374 boots, it will use the preceding system generation. This is the inverse
24375 of @command{reconfigure}, and it is exactly the same as invoking
24376 @command{switch-generation} with an argument of @code{-1}.
24378 Currently, as with @command{switch-generation}, you must reboot after
24379 running this action to actually start using the preceding system
24382 @item delete-generations
24383 @cindex deleting system generations
24384 @cindex saving space
24385 Delete system generations, making them candidates for garbage collection
24386 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24389 This works in the same way as @command{guix package --delete-generations}
24390 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24391 arguments, all system generations but the current one are deleted:
24394 guix system delete-generations
24397 You can also select the generations you want to delete. The example below
24398 deletes all the system generations that are more than two month old:
24401 guix system delete-generations 2m
24404 Running this command automatically reinstalls the bootloader with an updated
24405 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24406 longer lists the generations that have been deleted.
24409 Build the derivation of the operating system, which includes all the
24410 configuration files and programs needed to boot and run the system.
24411 This action does not actually install anything.
24414 Populate the given directory with all the files necessary to run the
24415 operating system specified in @var{file}. This is useful for first-time
24416 installations of Guix System. For instance:
24419 guix system init my-os-config.scm /mnt
24422 copies to @file{/mnt} all the store items required by the configuration
24423 specified in @file{my-os-config.scm}. This includes configuration
24424 files, packages, and so on. It also creates other essential files
24425 needed for the system to operate correctly---e.g., the @file{/etc},
24426 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24428 This command also installs bootloader on the target specified in
24429 @file{my-os-config}, unless the @option{--no-bootloader} option was
24433 @cindex virtual machine
24435 @anchor{guix system vm}
24436 Build a virtual machine that contains the operating system declared in
24437 @var{file}, and return a script to run that virtual machine (VM).
24440 The @code{vm} action and others below
24441 can use KVM support in the Linux-libre kernel. Specifically, if the
24442 machine has hardware virtualization support, the corresponding
24443 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24444 must exist and be readable and writable by the user and by the
24445 build users of the daemon (@pxref{Build Environment Setup}).
24448 Arguments given to the script are passed to QEMU as in the example
24449 below, which enables networking and requests 1@tie{}GiB of RAM for the
24453 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24456 The VM shares its store with the host system.
24458 Additional file systems can be shared between the host and the VM using
24459 the @code{--share} and @code{--expose} command-line options: the former
24460 specifies a directory to be shared with write access, while the latter
24461 provides read-only access to the shared directory.
24463 The example below creates a VM in which the user's home directory is
24464 accessible read-only, and where the @file{/exchange} directory is a
24465 read-write mapping of @file{$HOME/tmp} on the host:
24468 guix system vm my-config.scm \
24469 --expose=$HOME --share=$HOME/tmp=/exchange
24472 On GNU/Linux, the default is to boot directly to the kernel; this has
24473 the advantage of requiring only a very tiny root disk image since the
24474 store of the host can then be mounted.
24476 The @code{--full-boot} option forces a complete boot sequence, starting
24477 with the bootloader. This requires more disk space since a root image
24478 containing at least the kernel, initrd, and bootloader data files must
24479 be created. The @code{--image-size} option can be used to specify the
24482 @cindex System images, creation in various formats
24483 @cindex Creating system images in various formats
24486 @itemx docker-image
24487 Return a virtual machine, disk image, or Docker image of the operating
24488 system declared in @var{file} that stands alone. By default,
24489 @command{guix system} estimates the size of the image needed to store
24490 the system, but you can use the @option{--image-size} option to specify
24491 a value. Docker images are built to contain exactly what they need, so
24492 the @option{--image-size} option is ignored in the case of
24493 @code{docker-image}.
24495 You can specify the root file system type by using the
24496 @option{--file-system-type} option. It defaults to @code{ext4}.
24498 When using @code{vm-image}, the returned image is in qcow2 format, which
24499 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24500 for more information on how to run the image in a virtual machine.
24502 When using @code{disk-image}, a raw disk image is produced; it can be
24503 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24504 the device corresponding to a USB stick, one can copy the image to it
24505 using the following command:
24508 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24511 When using @code{docker-image}, a Docker image is produced. Guix builds
24512 the image from scratch, not from a pre-existing Docker base image. As a
24513 result, it contains @emph{exactly} what you define in the operating
24514 system configuration file. You can then load the image and launch a
24515 Docker container using commands like the following:
24518 image_id="`docker load < guix-system-docker-image.tar.gz`"
24519 container_id="`docker create $image_id`"
24520 docker start $container_id
24523 This command starts a new Docker container from the specified image. It
24524 will boot the Guix system in the usual manner, which means it will
24525 start any services you have defined in the operating system
24526 configuration. You can get an interactive shell running in the container
24527 using @command{docker exec}:
24530 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
24533 Depending on what you run in the Docker container, it
24534 may be necessary to give the container additional permissions. For
24535 example, if you intend to build software using Guix inside of the Docker
24536 container, you may need to pass the @option{--privileged} option to
24537 @code{docker create}.
24540 Return a script to run the operating system declared in @var{file}
24541 within a container. Containers are a set of lightweight isolation
24542 mechanisms provided by the kernel Linux-libre. Containers are
24543 substantially less resource-demanding than full virtual machines since
24544 the kernel, shared objects, and other resources can be shared with the
24545 host system; this also means they provide thinner isolation.
24547 Currently, the script must be run as root in order to support more than
24548 a single user and group. The container shares its store with the host
24551 As with the @code{vm} action (@pxref{guix system vm}), additional file
24552 systems to be shared between the host and container can be specified
24553 using the @option{--share} and @option{--expose} options:
24556 guix system container my-config.scm \
24557 --expose=$HOME --share=$HOME/tmp=/exchange
24561 This option requires Linux-libre 3.19 or newer.
24566 @var{options} can contain any of the common build options (@pxref{Common
24567 Build Options}). In addition, @var{options} can contain one of the
24571 @item --expression=@var{expr}
24572 @itemx -e @var{expr}
24573 Consider the operating-system @var{expr} evaluates to.
24574 This is an alternative to specifying a file which evaluates to an
24576 This is used to generate the Guix system installer @pxref{Building the
24577 Installation Image}).
24579 @item --system=@var{system}
24580 @itemx -s @var{system}
24581 Attempt to build for @var{system} instead of the host system type.
24582 This works as per @command{guix build} (@pxref{Invoking guix build}).
24586 Return the derivation file name of the given operating system without
24589 @item --file-system-type=@var{type}
24590 @itemx -t @var{type}
24591 For the @code{disk-image} action, create a file system of the given
24592 @var{type} on the image.
24594 When this option is omitted, @command{guix system} uses @code{ext4}.
24596 @cindex ISO-9660 format
24597 @cindex CD image format
24598 @cindex DVD image format
24599 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24600 for burning on CDs and DVDs.
24602 @item --image-size=@var{size}
24603 For the @code{vm-image} and @code{disk-image} actions, create an image
24604 of the given @var{size}. @var{size} may be a number of bytes, or it may
24605 include a unit as a suffix (@pxref{Block size, size specifications,,
24606 coreutils, GNU Coreutils}).
24608 When this option is omitted, @command{guix system} computes an estimate
24609 of the image size as a function of the size of the system declared in
24614 For the @code{container} action, allow containers to access the host network,
24615 that is, do not create a network namespace.
24617 @item --root=@var{file}
24618 @itemx -r @var{file}
24619 Make @var{file} a symlink to the result, and register it as a garbage
24622 @item --skip-checks
24623 Skip pre-installation safety checks.
24625 By default, @command{guix system init} and @command{guix system
24626 reconfigure} perform safety checks: they make sure the file systems that
24627 appear in the @code{operating-system} declaration actually exist
24628 (@pxref{File Systems}), and that any Linux kernel modules that may be
24629 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24630 RAM Disk}). Passing this option skips these tests altogether.
24633 @cindex on-error strategy
24634 @cindex error strategy
24635 @item --on-error=@var{strategy}
24636 Apply @var{strategy} when an error occurs when reading @var{file}.
24637 @var{strategy} may be one of the following:
24640 @item nothing-special
24641 Report the error concisely and exit. This is the default strategy.
24644 Likewise, but also display a backtrace.
24647 Report the error and enter Guile's debugger. From there, you can run
24648 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24649 display local variable values, and more generally inspect the state of the
24650 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24651 a list of available debugging commands.
24655 Once you have built, configured, re-configured, and re-re-configured
24656 your Guix installation, you may find it useful to list the operating
24657 system generations available on disk---and that you can choose from the
24658 bootloader boot menu:
24662 @item list-generations
24663 List a summary of each generation of the operating system available on
24664 disk, in a human-readable way. This is similar to the
24665 @option{--list-generations} option of @command{guix package}
24666 (@pxref{Invoking guix package}).
24668 Optionally, one can specify a pattern, with the same syntax that is used
24669 in @command{guix package --list-generations}, to restrict the list of
24670 generations displayed. For instance, the following command displays
24671 generations that are up to 10 days old:
24674 $ guix system list-generations 10d
24679 The @command{guix system} command has even more to offer! The following
24680 sub-commands allow you to visualize how your system services relate to
24683 @anchor{system-extension-graph}
24686 @item extension-graph
24687 Emit in Dot/Graphviz format to standard output the @dfn{service
24688 extension graph} of the operating system defined in @var{file}
24689 (@pxref{Service Composition}, for more information on service
24695 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24698 produces a PDF file showing the extension relations among services.
24700 @anchor{system-shepherd-graph}
24701 @item shepherd-graph
24702 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24703 graph} of shepherd services of the operating system defined in
24704 @var{file}. @xref{Shepherd Services}, for more information and for an
24709 @node Running Guix in a VM
24710 @section Running Guix in a Virtual Machine
24712 @cindex virtual machine
24713 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
24715 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
24716 This image is a compressed image in QCOW format. You will first need to
24717 decompress with @command{xz -d}, and then you can pass it to an emulator such
24718 as QEMU (see below for details).
24720 This image boots the Xfce graphical environment and it contains some
24721 commonly-used tools. You can install more software in the image by running
24722 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
24723 also reconfigure the system based on its initial configuration file available
24724 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
24726 Instead of using this pre-built image, one can also build their own virtual
24727 machine image using @command{guix system vm-image} (@pxref{Invoking guix
24728 system}). The returned image is in qcow2 format, which the
24729 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
24732 If you built your own image, you must copy it out of the store
24733 (@pxref{The Store}) and give yourself permission to write to the copy
24734 before you can use it. When invoking QEMU, you must choose a system
24735 emulator that is suitable for your hardware platform. Here is a minimal
24736 QEMU invocation that will boot the result of @command{guix system
24737 vm-image} on x86_64 hardware:
24740 $ qemu-system-x86_64 \
24741 -net user -net nic,model=virtio \
24742 -enable-kvm -m 512 \
24743 -device virtio-blk,drive=myhd \
24744 -drive if=none,file=/tmp/qemu-image,id=myhd
24747 Here is what each of these options means:
24750 @item qemu-system-x86_64
24751 This specifies the hardware platform to emulate. This should match the
24755 Enable the unprivileged user-mode network stack. The guest OS can
24756 access the host but not vice versa. This is the simplest way to get the
24759 @item -net nic,model=virtio
24760 You must create a network interface of a given model. If you do not
24761 create a NIC, the boot will fail. Assuming your hardware platform is
24762 x86_64, you can get a list of available NIC models by running
24763 @command{qemu-system-x86_64 -net nic,model=help}.
24766 If your system has hardware virtualization extensions, enabling the
24767 virtual machine support (KVM) of the Linux kernel will make things run
24770 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
24772 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24773 which may be insufficient for some operations.
24775 @item -device virtio-blk,drive=myhd
24776 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
24777 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
24778 better performance than if it were emulating a complete disk drive. See the
24779 QEMU and KVM documentation for more info.
24781 @item -drive if=none,file=/tmp/qemu-image,id=myhd
24782 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
24783 the ``myhd'' drive.
24786 The default @command{run-vm.sh} script that is returned by an invocation of
24787 @command{guix system vm} does not add a @command{-net user} flag by default.
24788 To get network access from within the vm add the @code{(dhcp-client-service)}
24789 to your system definition and start the VM using
24790 @command{`guix system vm config.scm` -net user}. An important caveat of using
24791 @command{-net user} for networking is that @command{ping} will not work, because
24792 it uses the ICMP protocol. You'll have to use a different command to check for
24793 network connectivity, for example @command{guix download}.
24795 @subsection Connecting Through SSH
24799 To enable SSH inside a VM you need to add an SSH server like
24800 @code{openssh-service-type} to your VM (@pxref{Networking Services,
24801 @code{openssh-service-type}}). In addition you need to forward the SSH port,
24802 22 by default, to the host. You can do this with
24805 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24808 To connect to the VM you can run
24811 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24814 The @command{-p} tells @command{ssh} the port you want to connect to.
24815 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24816 every time you modify your @command{config.scm} file and the
24817 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24818 connection to an unknown host every time you connect.
24820 @subsection Using @command{virt-viewer} with Spice
24822 As an alternative to the default @command{qemu} graphical client you can
24823 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24824 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24825 @command{qemu}. See previous section for further information on how to do this.
24827 Spice also allows you to do some nice stuff like share your clipboard with your
24828 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24831 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24832 -chardev spicevmc,name=vdagent,id=vdagent
24833 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24834 name=com.redhat.spice.0
24837 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24839 @node Defining Services
24840 @section Defining Services
24842 The previous sections show the available services and how one can combine
24843 them in an @code{operating-system} declaration. But how do we define
24844 them in the first place? And what is a service anyway?
24847 * Service Composition:: The model for composing services.
24848 * Service Types and Services:: Types and services.
24849 * Service Reference:: API reference.
24850 * Shepherd Services:: A particular type of service.
24853 @node Service Composition
24854 @subsection Service Composition
24858 Here we define a @dfn{service} as, broadly, something that extends the
24859 functionality of the operating system. Often a service is a process---a
24860 @dfn{daemon}---started when the system boots: a secure shell server, a
24861 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24862 whose execution can be triggered by another daemon---e.g., an FTP server
24863 started by @command{inetd} or a D-Bus service activated by
24864 @command{dbus-daemon}. Occasionally, a service does not map to a
24865 daemon. For instance, the ``account'' service collects user accounts
24866 and makes sure they exist when the system runs; the ``udev'' service
24867 collects device management rules and makes them available to the eudev
24868 daemon; the @file{/etc} service populates the @file{/etc} directory
24871 @cindex service extensions
24872 Guix system services are connected by @dfn{extensions}. For instance, the
24873 secure shell service @emph{extends} the Shepherd---the
24874 initialization system, running as PID@tie{}1---by giving it the command
24875 lines to start and stop the secure shell daemon (@pxref{Networking
24876 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24877 service by passing it its @file{.service} specification, and extends the
24878 udev service by passing it device management rules (@pxref{Desktop
24879 Services, @code{upower-service}}); the Guix daemon service extends the
24880 Shepherd by passing it the command lines to start and stop the daemon,
24881 and extends the account service by passing it a list of required build
24882 user accounts (@pxref{Base Services}).
24884 All in all, services and their ``extends'' relations form a directed
24885 acyclic graph (DAG). If we represent services as boxes and extensions
24886 as arrows, a typical system might provide something like this:
24888 @image{images/service-graph,,5in,Typical service extension graph.}
24890 @cindex system service
24891 At the bottom, we see the @dfn{system service}, which produces the
24892 directory containing everything to run and boot the system, as returned
24893 by the @command{guix system build} command. @xref{Service Reference},
24894 to learn about the other service types shown here.
24895 @xref{system-extension-graph, the @command{guix system extension-graph}
24896 command}, for information on how to generate this representation for a
24897 particular operating system definition.
24899 @cindex service types
24900 Technically, developers can define @dfn{service types} to express these
24901 relations. There can be any number of services of a given type on the
24902 system---for instance, a system running two instances of the GNU secure
24903 shell server (lsh) has two instances of @code{lsh-service-type}, with
24904 different parameters.
24906 The following section describes the programming interface for service
24907 types and services.
24909 @node Service Types and Services
24910 @subsection Service Types and Services
24912 A @dfn{service type} is a node in the DAG described above. Let us start
24913 with a simple example, the service type for the Guix build daemon
24914 (@pxref{Invoking guix-daemon}):
24917 (define guix-service-type
24921 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24922 (service-extension account-service-type guix-accounts)
24923 (service-extension activation-service-type guix-activation)))
24924 (default-value (guix-configuration))))
24928 It defines three things:
24932 A name, whose sole purpose is to make inspection and debugging easier.
24935 A list of @dfn{service extensions}, where each extension designates the
24936 target service type and a procedure that, given the parameters of the
24937 service, returns a list of objects to extend the service of that type.
24939 Every service type has at least one service extension. The only
24940 exception is the @dfn{boot service type}, which is the ultimate service.
24943 Optionally, a default value for instances of this type.
24946 In this example, @code{guix-service-type} extends three services:
24949 @item shepherd-root-service-type
24950 The @code{guix-shepherd-service} procedure defines how the Shepherd
24951 service is extended. Namely, it returns a @code{<shepherd-service>}
24952 object that defines how @command{guix-daemon} is started and stopped
24953 (@pxref{Shepherd Services}).
24955 @item account-service-type
24956 This extension for this service is computed by @code{guix-accounts},
24957 which returns a list of @code{user-group} and @code{user-account}
24958 objects representing the build user accounts (@pxref{Invoking
24961 @item activation-service-type
24962 Here @code{guix-activation} is a procedure that returns a gexp, which is
24963 a code snippet to run at ``activation time''---e.g., when the service is
24967 A service of this type is instantiated like this:
24970 (service guix-service-type
24971 (guix-configuration
24973 (use-substitutes? #f)))
24976 The second argument to the @code{service} form is a value representing
24977 the parameters of this specific service instance.
24978 @xref{guix-configuration-type, @code{guix-configuration}}, for
24979 information about the @code{guix-configuration} data type. When the
24980 value is omitted, the default value specified by
24981 @code{guix-service-type} is used:
24984 (service guix-service-type)
24987 @code{guix-service-type} is quite simple because it extends other
24988 services but is not extensible itself.
24990 @c @subsubsubsection Extensible Service Types
24992 The service type for an @emph{extensible} service looks like this:
24995 (define udev-service-type
24996 (service-type (name 'udev)
24998 (list (service-extension shepherd-root-service-type
24999 udev-shepherd-service)))
25001 (compose concatenate) ;concatenate the list of rules
25002 (extend (lambda (config rules)
25004 (($ <udev-configuration> udev initial-rules)
25005 (udev-configuration
25006 (udev udev) ;the udev package to use
25007 (rules (append initial-rules rules)))))))))
25010 This is the service type for the
25011 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
25012 management daemon}. Compared to the previous example, in addition to an
25013 extension of @code{shepherd-root-service-type}, we see two new fields:
25017 This is the procedure to @dfn{compose} the list of extensions to
25018 services of this type.
25020 Services can extend the udev service by passing it lists of rules; we
25021 compose those extensions simply by concatenating them.
25024 This procedure defines how the value of the service is @dfn{extended} with
25025 the composition of the extensions.
25027 Udev extensions are composed into a list of rules, but the udev service
25028 value is itself a @code{<udev-configuration>} record. So here, we
25029 extend that record by appending the list of rules it contains to the
25030 list of contributed rules.
25033 This is a string giving an overview of the service type. The string can
25034 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25035 @command{guix system search} command searches these strings and displays
25036 them (@pxref{Invoking guix system}).
25039 There can be only one instance of an extensible service type such as
25040 @code{udev-service-type}. If there were more, the
25041 @code{service-extension} specifications would be ambiguous.
25043 Still here? The next section provides a reference of the programming
25044 interface for services.
25046 @node Service Reference
25047 @subsection Service Reference
25049 We have seen an overview of service types (@pxref{Service Types and
25050 Services}). This section provides a reference on how to manipulate
25051 services and service types. This interface is provided by the
25052 @code{(gnu services)} module.
25054 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25055 Return a new service of @var{type}, a @code{<service-type>} object (see
25056 below.) @var{value} can be any object; it represents the parameters of
25057 this particular service instance.
25059 When @var{value} is omitted, the default value specified by @var{type}
25060 is used; if @var{type} does not specify a default value, an error is
25063 For instance, this:
25066 (service openssh-service-type)
25070 is equivalent to this:
25073 (service openssh-service-type
25074 (openssh-configuration))
25077 In both cases the result is an instance of @code{openssh-service-type}
25078 with the default configuration.
25081 @deffn {Scheme Procedure} service? @var{obj}
25082 Return true if @var{obj} is a service.
25085 @deffn {Scheme Procedure} service-kind @var{service}
25086 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25089 @deffn {Scheme Procedure} service-value @var{service}
25090 Return the value associated with @var{service}. It represents its
25094 Here is an example of how a service is created and manipulated:
25098 (service nginx-service-type
25099 (nginx-configuration
25101 (log-directory log-directory)
25102 (run-directory run-directory)
25103 (file config-file))))
25108 (eq? (service-kind s) nginx-service-type)
25112 The @code{modify-services} form provides a handy way to change the
25113 parameters of some of the services of a list such as
25114 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25115 evaluates to a list of services. Of course, you could always use
25116 standard list combinators such as @code{map} and @code{fold} to do that
25117 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25118 @code{modify-services} simply provides a more concise form for this
25121 @deffn {Scheme Syntax} modify-services @var{services} @
25122 (@var{type} @var{variable} => @var{body}) @dots{}
25124 Modify the services listed in @var{services} according to the given
25125 clauses. Each clause has the form:
25128 (@var{type} @var{variable} => @var{body})
25131 where @var{type} is a service type---e.g.,
25132 @code{guix-service-type}---and @var{variable} is an identifier that is
25133 bound within the @var{body} to the service parameters---e.g., a
25134 @code{guix-configuration} instance---of the original service of that
25137 The @var{body} should evaluate to the new service parameters, which will
25138 be used to configure the new service. This new service will replace the
25139 original in the resulting list. Because a service's service parameters
25140 are created using @code{define-record-type*}, you can write a succinct
25141 @var{body} that evaluates to the new service parameters by using the
25142 @code{inherit} feature that @code{define-record-type*} provides.
25144 @xref{Using the Configuration System}, for example usage.
25148 Next comes the programming interface for service types. This is
25149 something you want to know when writing new service definitions, but not
25150 necessarily when simply looking for ways to customize your
25151 @code{operating-system} declaration.
25153 @deftp {Data Type} service-type
25154 @cindex service type
25155 This is the representation of a @dfn{service type} (@pxref{Service Types
25160 This is a symbol, used only to simplify inspection and debugging.
25162 @item @code{extensions}
25163 A non-empty list of @code{<service-extension>} objects (see below).
25165 @item @code{compose} (default: @code{#f})
25166 If this is @code{#f}, then the service type denotes services that cannot
25167 be extended---i.e., services that do not receive ``values'' from other
25170 Otherwise, it must be a one-argument procedure. The procedure is called
25171 by @code{fold-services} and is passed a list of values collected from
25172 extensions. It may return any single value.
25174 @item @code{extend} (default: @code{#f})
25175 If this is @code{#f}, services of this type cannot be extended.
25177 Otherwise, it must be a two-argument procedure: @code{fold-services}
25178 calls it, passing it the initial value of the service as the first
25179 argument and the result of applying @code{compose} to the extension
25180 values as the second argument. It must return a value that is a valid
25181 parameter value for the service instance.
25184 @xref{Service Types and Services}, for examples.
25187 @deffn {Scheme Procedure} service-extension @var{target-type} @
25189 Return a new extension for services of type @var{target-type}.
25190 @var{compute} must be a one-argument procedure: @code{fold-services}
25191 calls it, passing it the value associated with the service that provides
25192 the extension; it must return a valid value for the target service.
25195 @deffn {Scheme Procedure} service-extension? @var{obj}
25196 Return true if @var{obj} is a service extension.
25199 Occasionally, you might want to simply extend an existing service. This
25200 involves creating a new service type and specifying the extension of
25201 interest, which can be verbose; the @code{simple-service} procedure
25202 provides a shorthand for this.
25204 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25205 Return a service that extends @var{target} with @var{value}. This works
25206 by creating a singleton service type @var{name}, of which the returned
25207 service is an instance.
25209 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25213 (simple-service 'my-mcron-job mcron-service-type
25214 #~(job '(next-hour (3)) "guix gc -F 2G"))
25218 At the core of the service abstraction lies the @code{fold-services}
25219 procedure, which is responsible for ``compiling'' a list of services
25220 down to a single directory that contains everything needed to boot and
25221 run the system---the directory shown by the @command{guix system build}
25222 command (@pxref{Invoking guix system}). In essence, it propagates
25223 service extensions down the service graph, updating each node parameters
25224 on the way, until it reaches the root node.
25226 @deffn {Scheme Procedure} fold-services @var{services} @
25227 [#:target-type @var{system-service-type}]
25228 Fold @var{services} by propagating their extensions down to the root of
25229 type @var{target-type}; return the root service adjusted accordingly.
25232 Lastly, the @code{(gnu services)} module also defines several essential
25233 service types, some of which are listed below.
25235 @defvr {Scheme Variable} system-service-type
25236 This is the root of the service graph. It produces the system directory
25237 as returned by the @command{guix system build} command.
25240 @defvr {Scheme Variable} boot-service-type
25241 The type of the ``boot service'', which produces the @dfn{boot script}.
25242 The boot script is what the initial RAM disk runs when booting.
25245 @defvr {Scheme Variable} etc-service-type
25246 The type of the @file{/etc} service. This service is used to create
25247 files under @file{/etc} and can be extended by
25248 passing it name/file tuples such as:
25251 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25254 In this example, the effect would be to add an @file{/etc/issue} file
25255 pointing to the given file.
25258 @defvr {Scheme Variable} setuid-program-service-type
25259 Type for the ``setuid-program service''. This service collects lists of
25260 executable file names, passed as gexps, and adds them to the set of
25261 setuid-root programs on the system (@pxref{Setuid Programs}).
25264 @defvr {Scheme Variable} profile-service-type
25265 Type of the service that populates the @dfn{system profile}---i.e., the
25266 programs under @file{/run/current-system/profile}. Other services can
25267 extend it by passing it lists of packages to add to the system profile.
25271 @node Shepherd Services
25272 @subsection Shepherd Services
25274 @cindex shepherd services
25276 @cindex init system
25277 The @code{(gnu services shepherd)} module provides a way to define
25278 services managed by the GNU@tie{}Shepherd, which is the
25279 initialization system---the first process that is started when the
25280 system boots, also known as PID@tie{}1
25281 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25283 Services in the Shepherd can depend on each other. For instance, the
25284 SSH daemon may need to be started after the syslog daemon has been
25285 started, which in turn can only happen once all the file systems have
25286 been mounted. The simple operating system defined earlier (@pxref{Using
25287 the Configuration System}) results in a service graph like this:
25289 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25291 You can actually generate such a graph for any operating system
25292 definition using the @command{guix system shepherd-graph} command
25293 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25295 The @code{%shepherd-root-service} is a service object representing
25296 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25297 by passing it lists of @code{<shepherd-service>} objects.
25299 @deftp {Data Type} shepherd-service
25300 The data type representing a service managed by the Shepherd.
25303 @item @code{provision}
25304 This is a list of symbols denoting what the service provides.
25306 These are the names that may be passed to @command{herd start},
25307 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25308 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25309 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25311 @item @code{requirement} (default: @code{'()})
25312 List of symbols denoting the Shepherd services this one depends on.
25314 @cindex one-shot services, for the Shepherd
25315 @item @code{one-shot?} (default: @code{#f})
25316 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25317 after their @code{start} action has completed. @xref{Slots of services,,,
25318 shepherd, The GNU Shepherd Manual}, for more info.
25320 @item @code{respawn?} (default: @code{#t})
25321 Whether to restart the service when it stops, for instance when the
25322 underlying process dies.
25325 @itemx @code{stop} (default: @code{#~(const #f)})
25326 The @code{start} and @code{stop} fields refer to the Shepherd's
25327 facilities to start and stop processes (@pxref{Service De- and
25328 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25329 G-expressions that get expanded in the Shepherd configuration file
25330 (@pxref{G-Expressions}).
25332 @item @code{actions} (default: @code{'()})
25333 @cindex actions, of Shepherd services
25334 This is a list of @code{shepherd-action} objects (see below) defining
25335 @dfn{actions} supported by the service, in addition to the standard
25336 @code{start} and @code{stop} actions. Actions listed here become available as
25337 @command{herd} sub-commands:
25340 herd @var{action} @var{service} [@var{arguments}@dots{}]
25343 @item @code{auto-start?} (default: @code{#t})
25344 Whether this service should be started automatically by the Shepherd. If it
25345 is @code{#f} the service has to be started manually with @code{herd start}.
25347 @item @code{documentation}
25348 A documentation string, as shown when running:
25351 herd doc @var{service-name}
25354 where @var{service-name} is one of the symbols in @code{provision}
25355 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25357 @item @code{modules} (default: @code{%default-modules})
25358 This is the list of modules that must be in scope when @code{start} and
25359 @code{stop} are evaluated.
25364 @deftp {Data Type} shepherd-action
25365 This is the data type that defines additional actions implemented by a
25366 Shepherd service (see above).
25370 Symbol naming the action.
25372 @item documentation
25373 This is a documentation string for the action. It can be viewed by running:
25376 herd doc @var{service} action @var{action}
25380 This should be a gexp that evaluates to a procedure of at least one argument,
25381 which is the ``running value'' of the service (@pxref{Slots of services,,,
25382 shepherd, The GNU Shepherd Manual}).
25385 The following example defines an action called @code{say-hello} that kindly
25391 (documentation "Say hi!")
25392 (procedure #~(lambda (running . args)
25393 (format #t "Hello, friend! arguments: ~s\n"
25398 Assuming this action is added to the @code{example} service, then you can do:
25401 # herd say-hello example
25402 Hello, friend! arguments: ()
25403 # herd say-hello example a b c
25404 Hello, friend! arguments: ("a" "b" "c")
25407 This, as you can see, is a fairly sophisticated way to say hello.
25408 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25412 @defvr {Scheme Variable} shepherd-root-service-type
25413 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25415 This is the service type that extensions target when they want to create
25416 shepherd services (@pxref{Service Types and Services}, for an example).
25417 Each extension must pass a list of @code{<shepherd-service>}.
25420 @defvr {Scheme Variable} %shepherd-root-service
25421 This service represents PID@tie{}1.
25425 @node Documentation
25426 @chapter Documentation
25428 @cindex documentation, searching for
25429 @cindex searching for documentation
25430 @cindex Info, documentation format
25432 @cindex manual pages
25433 In most cases packages installed with Guix come with documentation.
25434 There are two main documentation formats: ``Info'', a browseable
25435 hypertext format used for GNU software, and ``manual pages'' (or ``man
25436 pages''), the linear documentation format traditionally found on Unix.
25437 Info manuals are accessed with the @command{info} command or with Emacs,
25438 and man pages are accessed using @command{man}.
25440 You can look for documentation of software installed on your system by
25441 keyword. For example, the following command searches for information
25442 about ``TLS'' in Info manuals:
25446 "(emacs)Network Security" -- STARTTLS
25447 "(emacs)Network Security" -- TLS
25448 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25449 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25454 The command below searches for the same keyword in man pages:
25458 SSL (7) - OpenSSL SSL/TLS library
25459 certtool (1) - GnuTLS certificate tool
25463 These searches are purely local to your computer so you have the
25464 guarantee that documentation you find corresponds to what you have
25465 actually installed, you can access it off-line, and your privacy is
25468 Once you have these results, you can view the relevant documentation by
25472 $ info "(gnutls)Core TLS API"
25482 Info manuals contain sections and indices as well as hyperlinks like
25483 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25484 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25485 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25486 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25487 Introduction}, for an introduction to Info navigation.
25489 @node Installing Debugging Files
25490 @chapter Installing Debugging Files
25492 @cindex debugging files
25493 Program binaries, as produced by the GCC compilers for instance, are
25494 typically written in the ELF format, with a section containing
25495 @dfn{debugging information}. Debugging information is what allows the
25496 debugger, GDB, to map binary code to source code; it is required to
25497 debug a compiled program in good conditions.
25499 The problem with debugging information is that is takes up a fair amount
25500 of disk space. For example, debugging information for the GNU C Library
25501 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25502 debugging info of all the installed programs is usually not an option.
25503 Yet, space savings should not come at the cost of an impediment to
25504 debugging---especially in the GNU system, which should make it easier
25505 for users to exert their computing freedom (@pxref{GNU Distribution}).
25507 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25508 mechanism that allows users to get the best of both worlds: debugging
25509 information can be stripped from the binaries and stored in separate
25510 files. GDB is then able to load debugging information from those files,
25511 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25514 The GNU distribution takes advantage of this by storing debugging
25515 information in the @code{lib/debug} sub-directory of a separate package
25516 output unimaginatively called @code{debug} (@pxref{Packages with
25517 Multiple Outputs}). Users can choose to install the @code{debug} output
25518 of a package when they need it. For instance, the following command
25519 installs the debugging information for the GNU C Library and for GNU
25523 guix install glibc:debug guile:debug
25526 GDB must then be told to look for debug files in the user's profile, by
25527 setting the @code{debug-file-directory} variable (consider setting it
25528 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25532 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25535 From there on, GDB will pick up debugging information from the
25536 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25538 In addition, you will most likely want GDB to be able to show the source
25539 code being debugged. To do that, you will have to unpack the source
25540 code of the package of interest (obtained with @code{guix build
25541 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25542 directory using the @code{directory} command (@pxref{Source Path,
25543 @code{directory},, gdb, Debugging with GDB}).
25545 @c XXX: keep me up-to-date
25546 The @code{debug} output mechanism in Guix is implemented by the
25547 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25548 opt-in---debugging information is available only for the packages
25549 with definitions explicitly declaring a @code{debug} output. This may be
25550 changed to opt-out in the future if our build farm servers can handle
25551 the load. To check whether a package has a @code{debug} output, use
25552 @command{guix package --list-available} (@pxref{Invoking guix package}).
25555 @node Security Updates
25556 @chapter Security Updates
25558 @cindex security updates
25559 @cindex security vulnerabilities
25560 Occasionally, important security vulnerabilities are discovered in software
25561 packages and must be patched. Guix developers try hard to keep track of
25562 known vulnerabilities and to apply fixes as soon as possible in the
25563 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25564 containing only security updates.) The @command{guix lint} tool helps
25565 developers find out about vulnerable versions of software packages in the
25570 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25571 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25572 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25576 @xref{Invoking guix lint}, for more information.
25579 As of version @value{VERSION}, the feature described below is considered
25583 Guix follows a functional
25584 package management discipline (@pxref{Introduction}), which implies
25585 that, when a package is changed, @emph{every package that depends on it}
25586 must be rebuilt. This can significantly slow down the deployment of
25587 fixes in core packages such as libc or Bash, since basically the whole
25588 distribution would need to be rebuilt. Using pre-built binaries helps
25589 (@pxref{Substitutes}), but deployment may still take more time than
25593 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25594 for fast deployment of critical updates without the costs associated
25595 with a whole-distribution rebuild. The idea is to rebuild only the
25596 package that needs to be patched, and then to ``graft'' it onto packages
25597 explicitly installed by the user and that were previously referring to
25598 the original package. The cost of grafting is typically very low, and
25599 order of magnitudes lower than a full rebuild of the dependency chain.
25601 @cindex replacements of packages, for grafts
25602 For instance, suppose a security update needs to be applied to Bash.
25603 Guix developers will provide a package definition for the ``fixed''
25604 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
25605 Packages}). Then, the original package definition is augmented with a
25606 @code{replacement} field pointing to the package containing the bug fix:
25613 (replacement bash-fixed)))
25616 From there on, any package depending directly or indirectly on Bash---as
25617 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25618 gc})---that is installed is automatically ``rewritten'' to refer to
25619 @code{bash-fixed} instead of @code{bash}. This grafting process takes
25620 time proportional to the size of the package, usually less than a
25621 minute for an ``average'' package on a recent machine. Grafting is
25622 recursive: when an indirect dependency requires grafting, then grafting
25623 ``propagates'' up to the package that the user is installing.
25625 Currently, the length of the name and version of the graft and that of
25626 the package it replaces (@code{bash-fixed} and @code{bash} in the example
25627 above) must be equal. This restriction mostly comes from the fact that
25628 grafting works by patching files, including binary files, directly.
25629 Other restrictions may apply: for instance, when adding a graft to a
25630 package providing a shared library, the original shared library and its
25631 replacement must have the same @code{SONAME} and be binary-compatible.
25633 The @option{--no-grafts} command-line option allows you to forcefully
25634 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25638 guix build bash --no-grafts
25642 returns the store file name of the original Bash, whereas:
25649 returns the store file name of the ``fixed'', replacement Bash. This
25650 allows you to distinguish between the two variants of Bash.
25652 To verify which Bash your whole profile refers to, you can run
25653 (@pxref{Invoking guix gc}):
25656 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25660 @dots{} and compare the store file names that you get with those above.
25661 Likewise for a complete Guix system generation:
25664 guix gc -R `guix system build my-config.scm` | grep bash
25667 Lastly, to check which Bash running processes are using, you can use the
25668 @command{lsof} command:
25671 lsof | grep /gnu/store/.*bash
25675 @node Bootstrapping
25676 @chapter Bootstrapping
25678 @c Adapted from the ELS 2013 paper.
25680 @cindex bootstrapping
25682 Bootstrapping in our context refers to how the distribution gets built
25683 ``from nothing''. Remember that the build environment of a derivation
25684 contains nothing but its declared inputs (@pxref{Introduction}). So
25685 there's an obvious chicken-and-egg problem: how does the first package
25686 get built? How does the first compiler get compiled? Note that this is
25687 a question of interest only to the curious hacker, not to the regular
25688 user, so you can shamelessly skip this section if you consider yourself
25689 a ``regular user''.
25691 @cindex bootstrap binaries
25692 The GNU system is primarily made of C code, with libc at its core. The
25693 GNU build system itself assumes the availability of a Bourne shell and
25694 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25695 `grep'. Furthermore, build programs---programs that run
25696 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25697 (@pxref{Derivations}). Consequently, to be able to build anything at
25698 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25699 Binutils, libc, and the other packages mentioned above---the
25700 @dfn{bootstrap binaries}.
25702 These bootstrap binaries are ``taken for granted'', though we can also
25703 re-create them if needed (more on that later).
25705 @unnumberedsec Preparing to Use the Bootstrap Binaries
25707 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25708 @c large image, it's hard to scroll. Oh well.
25709 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25711 The figure above shows the very beginning of the dependency graph of the
25712 distribution, corresponding to the package definitions of the @code{(gnu
25713 packages bootstrap)} module. A similar figure can be generated with
25714 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25717 guix graph -t derivation \
25718 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25722 At this level of detail, things are
25723 slightly complex. First, Guile itself consists of an ELF executable,
25724 along with many source and compiled Scheme files that are dynamically
25725 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25726 tarball shown in this graph. This tarball is part of Guix's ``source''
25727 distribution, and gets inserted into the store with @code{add-to-store}
25728 (@pxref{The Store}).
25730 But how do we write a derivation that unpacks this tarball and adds it
25731 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25732 derivation---the first one that gets built---uses @code{bash} as its
25733 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25734 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25735 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25736 the Guix source distribution, whose sole purpose is to allow the Guile
25737 tarball to be unpacked.
25739 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25740 Guile that can be used to run subsequent build programs. Its first task
25741 is to download tarballs containing the other pre-built binaries---this
25742 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25743 @code{ftp-client.scm} are used for this purpose. The
25744 @code{module-import.drv} derivations import those modules in a directory
25745 in the store, using the original layout. The
25746 @code{module-import-compiled.drv} derivations compile those modules, and
25747 write them in an output directory with the right layout. This
25748 corresponds to the @code{#:modules} argument of
25749 @code{build-expression->derivation} (@pxref{Derivations}).
25751 Finally, the various tarballs are unpacked by the
25752 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25753 etc., at which point we have a working C tool chain.
25756 @unnumberedsec Building the Build Tools
25758 Bootstrapping is complete when we have a full tool chain that does not
25759 depend on the pre-built bootstrap tools discussed above. This
25760 no-dependency requirement is verified by checking whether the files of
25761 the final tool chain contain references to the @file{/gnu/store}
25762 directories of the bootstrap inputs. The process that leads to this
25763 ``final'' tool chain is described by the package definitions found in
25764 the @code{(gnu packages commencement)} module.
25766 The @command{guix graph} command allows us to ``zoom out'' compared to
25767 the graph above, by looking at the level of package objects instead of
25768 individual derivations---remember that a package may translate to
25769 several derivations, typically one derivation to download its source,
25770 one to build the Guile modules it needs, and one to actually build the
25771 package from source. The command:
25774 guix graph -t bag \
25775 -e '(@@@@ (gnu packages commencement)
25776 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25780 produces the dependency graph leading to the ``final'' C
25781 library@footnote{You may notice the @code{glibc-intermediate} label,
25782 suggesting that it is not @emph{quite} final, but as a good
25783 approximation, we will consider it final.}, depicted below.
25785 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25787 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25788 The first tool that gets built with the bootstrap binaries is
25789 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25790 for all the following packages. From there Findutils and Diffutils get
25793 Then come the first-stage Binutils and GCC, built as pseudo cross
25794 tools---i.e., with @code{--target} equal to @code{--host}. They are
25795 used to build libc. Thanks to this cross-build trick, this libc is
25796 guaranteed not to hold any reference to the initial tool chain.
25798 From there the final Binutils and GCC (not shown above) are built.
25800 from the final Binutils, and links programs against the just-built libc.
25801 This tool chain is used to build the other packages used by Guix and by
25802 the GNU Build System: Guile, Bash, Coreutils, etc.
25804 And voilà! At this point we have the complete set of build tools that
25805 the GNU Build System expects. These are in the @code{%final-inputs}
25806 variable of the @code{(gnu packages commencement)} module, and are
25807 implicitly used by any package that uses @code{gnu-build-system}
25808 (@pxref{Build Systems, @code{gnu-build-system}}).
25811 @unnumberedsec Building the Bootstrap Binaries
25813 @cindex bootstrap binaries
25814 Because the final tool chain does not depend on the bootstrap binaries,
25815 those rarely need to be updated. Nevertheless, it is useful to have an
25816 automated way to produce them, should an update occur, and this is what
25817 the @code{(gnu packages make-bootstrap)} module provides.
25819 The following command builds the tarballs containing the bootstrap
25820 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25821 of Coreutils and other basic command-line tools):
25824 guix build bootstrap-tarballs
25827 The generated tarballs are those that should be referred to in the
25828 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25831 Still here? Then perhaps by now you've started to wonder: when do we
25832 reach a fixed point? That is an interesting question! The answer is
25833 unknown, but if you would like to investigate further (and have
25834 significant computational and storage resources to do so), then let us
25837 @unnumberedsec Reducing the Set of Bootstrap Binaries
25839 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25840 of binary code! Why is that a problem? It's a problem because these
25841 big chunks of binary code are practically non-auditable, which makes it
25842 hard to establish what source code produced them. Every unauditable
25843 binary also leaves us vulnerable to compiler backdoors as described by
25844 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25846 This is mitigated by the fact that our bootstrap binaries were generated
25847 from an earlier Guix revision. Nevertheless it lacks the level of
25848 transparency that we get in the rest of the package dependency graph,
25849 where Guix always gives us a source-to-binary mapping. Thus, our goal
25850 is to reduce the set of bootstrap binaries to the bare minimum.
25852 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25853 on-going projects to do that. One of these is about replacing the
25854 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25855 of increasing complexity, which could be built from source starting from
25856 a simple and auditable assembler. Your help is welcome!
25860 @chapter Porting to a New Platform
25862 As discussed above, the GNU distribution is self-contained, and
25863 self-containment is achieved by relying on pre-built ``bootstrap
25864 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25865 operating system kernel, CPU architecture, and application binary
25866 interface (ABI). Thus, to port the distribution to a platform that is
25867 not yet supported, one must build those bootstrap binaries, and update
25868 the @code{(gnu packages bootstrap)} module to use them on that platform.
25870 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25871 When everything goes well, and assuming the GNU tool chain supports the
25872 target platform, this can be as simple as running a command like this
25876 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25879 For this to work, the @code{glibc-dynamic-linker} procedure in
25880 @code{(gnu packages bootstrap)} must be augmented to return the right
25881 file name for libc's dynamic linker on that platform; likewise,
25882 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25883 taught about the new platform.
25885 Once these are built, the @code{(gnu packages bootstrap)} module needs
25886 to be updated to refer to these binaries on the target platform. That
25887 is, the hashes and URLs of the bootstrap tarballs for the new platform
25888 must be added alongside those of the currently supported platforms. The
25889 bootstrap Guile tarball is treated specially: it is expected to be
25890 available locally, and @file{gnu/local.mk} has rules to download it for
25891 the supported architectures; a rule for the new platform must be added
25894 In practice, there may be some complications. First, it may be that the
25895 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25896 above) is not recognized by all the GNU tools. Typically, glibc
25897 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25898 configure flag (see @code{gcc.scm} for examples of how to handle this).
25899 Second, some of the required packages could fail to build for that
25900 platform. Lastly, the generated binaries could be broken for some
25903 @c *********************************************************************
25904 @include contributing.texi
25906 @c *********************************************************************
25907 @node Acknowledgments
25908 @chapter Acknowledgments
25910 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
25911 which was designed and
25912 implemented by Eelco Dolstra, with contributions from other people (see
25913 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25914 management, and promoted unprecedented features, such as transactional
25915 package upgrades and rollbacks, per-user profiles, and referentially
25916 transparent build processes. Without this work, Guix would not exist.
25918 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25919 an inspiration for Guix.
25921 GNU@tie{}Guix itself is a collective work with contributions from a
25922 number of people. See the @file{AUTHORS} file in Guix for more
25923 information on these fine people. The @file{THANKS} file lists people
25924 who have helped by reporting bugs, taking care of the infrastructure,
25925 providing artwork and themes, making suggestions, and more---thank you!
25928 @c *********************************************************************
25929 @node GNU Free Documentation License
25930 @appendix GNU Free Documentation License
25931 @cindex license, GNU Free Documentation License
25932 @include fdl-1.3.texi
25934 @c *********************************************************************
25935 @node Concept Index
25936 @unnumbered Concept Index
25939 @node Programming Index
25940 @unnumbered Programming Index
25941 @syncodeindex tp fn
25942 @syncodeindex vr fn
25947 @c Local Variables:
25948 @c ispell-local-dictionary: "american";