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 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
66 Permission is granted to copy, distribute and/or modify this document
67 under the terms of the GNU Free Documentation License, Version 1.3 or
68 any later version published by the Free Software Foundation; with no
69 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
70 copy of the license is included in the section entitled ``GNU Free
71 Documentation License''.
74 @dircategory System administration
76 * Guix: (guix). Manage installed software and system configuration.
77 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
78 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
79 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
80 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
83 @dircategory Software development
85 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
86 * guix build: (guix)Invoking guix build. Building packages.
87 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
91 @title GNU Guix Reference Manual
92 @subtitle Using the GNU Guix Functional Package Manager
93 @author The GNU Guix Developers
96 @vskip 0pt plus 1filll
97 Edition @value{EDITION} @*
105 @c *********************************************************************
109 This document describes GNU Guix version @value{VERSION}, a functional
110 package management tool written for the GNU system.
112 @c TRANSLATORS: You can replace the following paragraph with information on
113 @c how to join your own translation team and how to report issues with the
115 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
116 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
117 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}), and
118 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}). If you
119 would like to translate it in your native language, consider joining the
120 @uref{https://translationproject.org/domain/guix-manual.html, Translation
124 * Introduction:: What is Guix about?
125 * Installation:: Installing Guix.
126 * System Installation:: Installing the whole operating system.
127 * Package Management:: Package installation, upgrade, etc.
128 * Development:: Guix-aided software development.
129 * Programming Interface:: Using Guix in Scheme.
130 * Utilities:: Package management commands.
131 * System Configuration:: Configuring the operating system.
132 * Documentation:: Browsing software user manuals.
133 * Installing Debugging Files:: Feeding the debugger.
134 * Security Updates:: Deploying security fixes quickly.
135 * Bootstrapping:: GNU/Linux built from scratch.
136 * Porting:: Targeting another platform or kernel.
137 * Contributing:: Your help needed!
139 * Acknowledgments:: Thanks!
140 * GNU Free Documentation License:: The license of this manual.
141 * Concept Index:: Concepts.
142 * Programming Index:: Data types, functions, and variables.
145 --- The Detailed Node Listing ---
149 * Managing Software the Guix Way:: What's special.
150 * GNU Distribution:: The packages and tools.
154 * Binary Installation:: Getting Guix running in no time!
155 * Requirements:: Software needed to build and run Guix.
156 * Running the Test Suite:: Testing Guix.
157 * Setting Up the Daemon:: Preparing the build daemon's environment.
158 * Invoking guix-daemon:: Running the build daemon.
159 * Application Setup:: Application-specific setup.
161 Setting Up the Daemon
163 * Build Environment Setup:: Preparing the isolated build environment.
164 * Daemon Offload Setup:: Offloading builds to remote machines.
165 * SELinux Support:: Using an SELinux policy for the daemon.
169 * Limitations:: What you can expect.
170 * Hardware Considerations:: Supported hardware.
171 * USB Stick and DVD Installation:: Preparing the installation medium.
172 * Preparing for Installation:: Networking, partitioning, etc.
173 * Guided Graphical Installation:: Easy graphical installation.
174 * Manual Installation:: Manual installation for wizards.
175 * After System Installation:: When installation succeeded.
176 * Installing Guix in a VM:: Guix System playground.
177 * Building the Installation Image:: How this comes to be.
181 * Keyboard Layout and Networking and Partitioning:: Initial setup.
182 * Proceeding with the Installation:: Installing.
186 * Features:: How Guix will make your life brighter.
187 * Invoking guix package:: Package installation, removal, etc.
188 * Substitutes:: Downloading pre-built binaries.
189 * Packages with Multiple Outputs:: Single source package, multiple outputs.
190 * Invoking guix gc:: Running the garbage collector.
191 * Invoking guix pull:: Fetching the latest Guix and distribution.
192 * Channels:: Customizing the package collection.
193 * Inferiors:: Interacting with another revision of Guix.
194 * Invoking guix describe:: Display information about your Guix revision.
195 * Invoking guix archive:: Exporting and importing store files.
199 * Official Substitute Server:: One particular source of substitutes.
200 * Substitute Server Authorization:: How to enable or disable substitutes.
201 * Substitute Authentication:: How Guix verifies substitutes.
202 * Proxy Settings:: How to get substitutes via proxy.
203 * Substitution Failure:: What happens when substitution fails.
204 * On Trusting Binaries:: How can you trust that binary blob?
208 * Invoking guix environment:: Setting up development environments.
209 * Invoking guix pack:: Creating software bundles.
211 Programming Interface
213 * Package Modules:: Packages from the programmer's viewpoint.
214 * Defining Packages:: Defining new packages.
215 * Build Systems:: Specifying how packages are built.
216 * The Store:: Manipulating the package store.
217 * Derivations:: Low-level interface to package derivations.
218 * The Store Monad:: Purely functional interface to the store.
219 * G-Expressions:: Manipulating build expressions.
220 * Invoking guix repl:: Fiddling with Guix interactively.
224 * package Reference:: The package data type.
225 * origin Reference:: The origin data type.
229 * Invoking guix build:: Building packages from the command line.
230 * Invoking guix edit:: Editing package definitions.
231 * Invoking guix download:: Downloading a file and printing its hash.
232 * Invoking guix hash:: Computing the cryptographic hash of a file.
233 * Invoking guix import:: Importing package definitions.
234 * Invoking guix refresh:: Updating package definitions.
235 * Invoking guix lint:: Finding errors in package definitions.
236 * Invoking guix size:: Profiling disk usage.
237 * Invoking guix graph:: Visualizing the graph of packages.
238 * Invoking guix publish:: Sharing substitutes.
239 * Invoking guix challenge:: Challenging substitute servers.
240 * Invoking guix copy:: Copying to and from a remote store.
241 * Invoking guix container:: Process isolation.
242 * Invoking guix weather:: Assessing substitute availability.
243 * Invoking guix processes:: Listing client processes.
245 Invoking @command{guix build}
247 * Common Build Options:: Build options for most commands.
248 * Package Transformation Options:: Creating variants of packages.
249 * Additional Build Options:: Options specific to 'guix build'.
250 * Debugging Build Failures:: Real life packaging experience.
254 * Using the Configuration System:: Customizing your GNU system.
255 * operating-system Reference:: Detail of operating-system declarations.
256 * File Systems:: Configuring file system mounts.
257 * Mapped Devices:: Block device extra processing.
258 * User Accounts:: Specifying user accounts.
259 * Keyboard Layout:: How the system interprets key strokes.
260 * Locales:: Language and cultural convention settings.
261 * Services:: Specifying system services.
262 * Setuid Programs:: Programs running with root privileges.
263 * X.509 Certificates:: Authenticating HTTPS servers.
264 * Name Service Switch:: Configuring libc's name service switch.
265 * Initial RAM Disk:: Linux-Libre bootstrapping.
266 * Bootloader Configuration:: Configuring the boot loader.
267 * Invoking guix system:: Instantiating a system configuration.
268 * Running Guix in a VM:: How to run Guix System in a virtual machine.
269 * Defining Services:: Adding new service definitions.
273 * Base Services:: Essential system services.
274 * Scheduled Job Execution:: The mcron service.
275 * Log Rotation:: The rottlog service.
276 * Networking Services:: Network setup, SSH daemon, etc.
277 * X Window:: Graphical display.
278 * Printing Services:: Local and remote printer support.
279 * Desktop Services:: D-Bus and desktop services.
280 * Sound Services:: ALSA and Pulseaudio services.
281 * Database Services:: SQL databases, key-value stores, etc.
282 * Mail Services:: IMAP, POP3, SMTP, and all that.
283 * Messaging Services:: Messaging services.
284 * Telephony Services:: Telephony services.
285 * Monitoring Services:: Monitoring services.
286 * Kerberos Services:: Kerberos services.
287 * Web Services:: Web servers.
288 * Certificate Services:: TLS certificates via Let's Encrypt.
289 * DNS Services:: DNS daemons.
290 * VPN Services:: VPN daemons.
291 * Network File System:: NFS related services.
292 * Continuous Integration:: The Cuirass service.
293 * Power Management Services:: Extending battery life.
294 * Audio Services:: The MPD.
295 * Virtualization Services:: Virtualization services.
296 * Version Control Services:: Providing remote access to Git repositories.
297 * Game Services:: Game servers.
298 * Miscellaneous Services:: Other services.
302 * Service Composition:: The model for composing services.
303 * Service Types and Services:: Types and services.
304 * Service Reference:: API reference.
305 * Shepherd Services:: A particular type of service.
310 @c *********************************************************************
312 @chapter Introduction
315 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
316 using the international phonetic alphabet (IPA).} is a package
317 management tool for and distribution of the GNU system.
318 Guix makes it easy for unprivileged
319 users to install, upgrade, or remove software packages, to roll back to a
320 previous package set, to build packages from source, and generally
321 assists with the creation and maintenance of software environments.
324 @cindex GuixSD, now Guix System
325 @cindex Guix System Distribution, now Guix System
326 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
327 complements the available tools without interference (@pxref{Installation}),
328 or you can use it as a standalone operating system distribution,
329 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
330 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
331 group everything under the ``Guix'' banner since, after all, Guix System is
332 readily available through the @command{guix system} command, even if you're
333 using a different distro underneath!}. @xref{GNU Distribution}.
336 * Managing Software the Guix Way:: What's special.
337 * GNU Distribution:: The packages and tools.
340 @node Managing Software the Guix Way
341 @section Managing Software the Guix Way
343 @cindex user interfaces
344 Guix provides a command-line package management interface
345 (@pxref{Package Management}), tools to help with software development
346 (@pxref{Development}), command-line utilities for more advanced usage,
347 (@pxref{Utilities}), as well as Scheme programming interfaces
348 (@pxref{Programming Interface}).
350 Its @dfn{build daemon} is responsible for building packages on behalf of
351 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
352 binaries from authorized sources (@pxref{Substitutes}).
354 @cindex extensibility of the distribution
355 @cindex customization, of packages
356 Guix includes package definitions for many GNU and non-GNU packages, all
357 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
358 user's computing freedom}. It is @emph{extensible}: users can write
359 their own package definitions (@pxref{Defining Packages}) and make them
360 available as independent package modules (@pxref{Package Modules}). It
361 is also @emph{customizable}: users can @emph{derive} specialized package
362 definitions from existing ones, including from the command line
363 (@pxref{Package Transformation Options}).
365 @cindex functional package management
367 Under the hood, Guix implements the @dfn{functional package management}
368 discipline pioneered by Nix (@pxref{Acknowledgments}).
369 In Guix, the package build and installation process is seen
370 as a @emph{function}, in the mathematical sense. That function takes inputs,
371 such as build scripts, a compiler, and libraries, and
372 returns an installed package. As a pure function, its result depends
373 solely on its inputs---for instance, it cannot refer to software or
374 scripts that were not explicitly passed as inputs. A build function
375 always produces the same result when passed a given set of inputs. It
376 cannot alter the environment of the running system in
377 any way; for instance, it cannot create, modify, or delete files outside
378 of its build and installation directories. This is achieved by running
379 build processes in isolated environments (or @dfn{containers}), where only their
380 explicit inputs are visible.
383 The result of package build functions is @dfn{cached} in the file
384 system, in a special directory called @dfn{the store} (@pxref{The
385 Store}). Each package is installed in a directory of its own in the
386 store---by default under @file{/gnu/store}. The directory name contains
387 a hash of all the inputs used to build that package; thus, changing an
388 input yields a different directory name.
390 This approach is the foundation for the salient features of Guix: support
391 for transactional package upgrade and rollback, per-user installation, and
392 garbage collection of packages (@pxref{Features}).
395 @node GNU Distribution
396 @section GNU Distribution
399 Guix comes with a distribution of the GNU system consisting entirely of
400 free software@footnote{The term ``free'' here refers to the
401 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
402 users of that software}.}. The
403 distribution can be installed on its own (@pxref{System Installation}),
404 but it is also possible to install Guix as a package manager on top of
405 an installed GNU/Linux system (@pxref{Installation}). When we need to
406 distinguish between the two, we refer to the standalone distribution as
409 The distribution provides core GNU packages such as GNU libc, GCC, and
410 Binutils, as well as many GNU and non-GNU applications. The complete
411 list of available packages can be browsed
412 @url{https://www.gnu.org/software/guix/packages,on-line} or by
413 running @command{guix package} (@pxref{Invoking guix package}):
416 guix package --list-available
419 Our goal is to provide a practical 100% free software distribution of
420 Linux-based and other variants of GNU, with a focus on the promotion and
421 tight integration of GNU components, and an emphasis on programs and
422 tools that help users exert that freedom.
424 Packages are currently available on the following platforms:
429 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
432 Intel 32-bit architecture (IA32), Linux-Libre kernel;
435 ARMv7-A architecture with hard float, Thumb-2 and NEON,
436 using the EABI hard-float application binary interface (ABI),
437 and Linux-Libre kernel.
440 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
441 currently in an experimental stage, with limited support.
442 @xref{Contributing}, for how to help!
445 little-endian 64-bit MIPS processors, specifically the Loongson series,
446 n32 ABI, and Linux-Libre kernel.
450 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
451 configuration and Guix takes care of instantiating the configuration in a
452 transactional, reproducible, and stateless fashion (@pxref{System
453 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
454 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
455 Manual}), the well-known GNU utilities and tool chain, as well as the
456 graphical environment or system services of your choice.
458 Guix System is available on all the above platforms except
459 @code{mips64el-linux}.
462 For information on porting to other architectures or kernels,
465 Building this distribution is a cooperative effort, and you are invited
466 to join! @xref{Contributing}, for information about how you can help.
469 @c *********************************************************************
471 @chapter Installation
473 @cindex installing Guix
476 We recommend the use of this
477 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
478 shell installer script} to install Guix on top of a running GNU/Linux system,
479 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
480 with the installation of the package manager, which can be done on top of a
481 running GNU/Linux system. If, instead, you want to install the complete GNU
482 operating system, @pxref{System Installation}.} The script automates the
483 download, installation, and initial configuration of Guix. It should be run
487 @cindex foreign distro
488 @cindex directories related to foreign distro
489 When installed on a foreign distro, GNU@tie{}Guix complements the available
490 tools without interference. Its data lives exclusively in two directories,
491 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
492 such as @file{/etc}, are left untouched.
494 Once installed, Guix can be updated by running @command{guix pull}
495 (@pxref{Invoking guix pull}).
497 If you prefer to perform the installation steps manually or want to tweak
498 them, you may find the following subsections useful. They describe the
499 software requirements of Guix, as well as how to install it manually and get
503 * Binary Installation:: Getting Guix running in no time!
504 * Requirements:: Software needed to build and run Guix.
505 * Running the Test Suite:: Testing Guix.
506 * Setting Up the Daemon:: Preparing the build daemon's environment.
507 * Invoking guix-daemon:: Running the build daemon.
508 * Application Setup:: Application-specific setup.
511 @node Binary Installation
512 @section Binary Installation
514 @cindex installing Guix from binaries
515 @cindex installer script
516 This section describes how to install Guix on an arbitrary system from a
517 self-contained tarball providing binaries for Guix and for all its
518 dependencies. This is often quicker than installing from source, which
519 is described in the next sections. The only requirement is to have
522 @c Note duplicated from the ``Installation'' node.
524 We recommend the use of this
525 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
526 shell installer script}. The script automates the download, installation, and
527 initial configuration steps described below. It should be run as the root
531 Installing goes along these lines:
535 @cindex downloading Guix binary
536 Download the binary tarball from
537 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
538 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
539 already running the kernel Linux, and so on.
541 @c The following is somewhat duplicated in ``System Installation''.
542 Make sure to download the associated @file{.sig} file and to verify the
543 authenticity of the tarball against it, along these lines:
546 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
547 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
550 If that command fails because you do not have the required public key,
551 then run this command to import it:
554 $ gpg --keyserver @value{KEY-SERVER} \
555 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
559 and rerun the @code{gpg --verify} command.
560 @c end authentication part
563 Now, you need to become the @code{root} user. Depending on your distribution,
564 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
568 # tar --warning=no-timestamp -xf \
569 guix-binary-@value{VERSION}.@var{system}.tar.xz
570 # mv var/guix /var/ && mv gnu /
573 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
574 The latter contains a ready-to-use profile for @code{root} (see next
577 Do @emph{not} unpack the tarball on a working Guix system since that
578 would overwrite its own essential files.
580 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
581 not emit warnings about ``implausibly old time stamps'' (such
582 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
584 They stem from the fact that all the
585 files in the archive have their modification time set to zero (which
586 means January 1st, 1970.) This is done on purpose to make sure the
587 archive content is independent of its creation time, thus making it
591 Make the profile available under @file{~root/.config/guix/current}, which is
592 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
595 # mkdir -p ~root/.config/guix
596 # ln -sf /var/guix/profiles/per-user/root/current-guix \
597 ~root/.config/guix/current
600 Source @file{etc/profile} to augment @code{PATH} and other relevant
601 environment variables:
604 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
605 source $GUIX_PROFILE/etc/profile
609 Create the group and user accounts for build users as explained below
610 (@pxref{Build Environment Setup}).
613 Run the daemon, and set it to automatically start on boot.
615 If your host distro uses the systemd init system, this can be achieved
618 @c Versions of systemd that supported symlinked service files are not
619 @c yet widely deployed, so we should suggest that users copy the service
622 @c See this thread for more information:
623 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
626 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
628 # systemctl start guix-daemon && systemctl enable guix-daemon
631 If your host distro uses the Upstart init system:
634 # initctl reload-configuration
635 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
640 Otherwise, you can still start the daemon manually with:
643 # ~root/.config/guix/current/bin/guix-daemon \
644 --build-users-group=guixbuild
648 Make the @command{guix} command available to other users on the machine,
652 # mkdir -p /usr/local/bin
654 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
657 It is also a good idea to make the Info version of this manual available
661 # mkdir -p /usr/local/share/info
662 # cd /usr/local/share/info
663 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
667 That way, assuming @file{/usr/local/share/info} is in the search path,
668 running @command{info guix} will open this manual (@pxref{Other Info
669 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
673 @cindex substitutes, authorization thereof
674 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
675 (@pxref{Substitutes}), authorize them:
678 # guix archive --authorize < \
679 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
683 Each user may need to perform a few additional steps to make their Guix
684 environment ready for use, @pxref{Application Setup}.
687 Voilà, the installation is complete!
689 You can confirm that Guix is working by installing a sample package into
696 The binary installation tarball can be (re)produced and verified simply
697 by running the following command in the Guix source tree:
700 make guix-binary.@var{system}.tar.xz
704 ...@: which, in turn, runs:
707 guix pack -s @var{system} --localstatedir \
708 --profile-name=current-guix guix
711 @xref{Invoking guix pack}, for more info on this handy tool.
714 @section Requirements
716 This section lists requirements when building Guix from source. The
717 build procedure for Guix is the same as for other GNU software, and is
718 not covered here. Please see the files @file{README} and @file{INSTALL}
719 in the Guix source tree for additional details.
721 @cindex official website
722 GNU Guix is available for download from its website at
723 @url{https://www.gnu.org/software/guix/}.
725 GNU Guix depends on the following packages:
728 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
729 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
732 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
733 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
734 Guile,, gnutls-guile, GnuTLS-Guile});
736 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
739 @c FIXME: Specify a version number once a release has been made.
740 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
742 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
743 @item @url{https://zlib.net, zlib};
744 @item @url{https://www.gnu.org/software/make/, GNU Make}.
747 The following dependencies are optional:
751 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
752 Support for build offloading (@pxref{Daemon Offload Setup}) and
753 @command{guix copy} (@pxref{Invoking guix copy}) depends on
754 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
755 version 0.10.2 or later.
758 When @url{http://www.bzip.org, libbz2} is available,
759 @command{guix-daemon} can use it to compress build logs.
762 Unless @code{--disable-daemon} was passed to @command{configure}, the
763 following packages are also needed:
766 @item @url{https://gnupg.org/, GNU libgcrypt};
767 @item @url{https://sqlite.org, SQLite 3};
768 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
772 @cindex state directory
773 When configuring Guix on a system that already has a Guix installation,
774 be sure to specify the same state directory as the existing installation
775 using the @code{--localstatedir} option of the @command{configure}
776 script (@pxref{Directory Variables, @code{localstatedir},, standards,
777 GNU Coding Standards}). The @command{configure} script protects against
778 unintended misconfiguration of @var{localstatedir} so you do not
779 inadvertently corrupt your store (@pxref{The Store}).
781 @cindex Nix, compatibility
782 When a working installation of @url{https://nixos.org/nix/, the Nix package
783 manager} is available, you
784 can instead configure Guix with @code{--disable-daemon}. In that case,
785 Nix replaces the three dependencies above.
787 Guix is compatible with Nix, so it is possible to share the same store
788 between both. To do so, you must pass @command{configure} not only the
789 same @code{--with-store-dir} value, but also the same
790 @code{--localstatedir} value. The latter is essential because it
791 specifies where the database that stores metadata about the store is
792 located, among other things. The default values for Nix are
793 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
794 Note that @code{--disable-daemon} is not required if
795 your goal is to share the store with Nix.
797 @node Running the Test Suite
798 @section Running the Test Suite
801 After a successful @command{configure} and @code{make} run, it is a good
802 idea to run the test suite. It can help catch issues with the setup or
803 environment, or bugs in Guix itself---and really, reporting test
804 failures is a good way to help improve the software. To run the test
811 Test cases can run in parallel: you can use the @code{-j} option of
812 GNU@tie{}make to speed things up. The first run may take a few minutes
813 on a recent machine; subsequent runs will be faster because the store
814 that is created for test purposes will already have various things in
817 It is also possible to run a subset of the tests by defining the
818 @code{TESTS} makefile variable as in this example:
821 make check TESTS="tests/store.scm tests/cpio.scm"
824 By default, tests results are displayed at a file level. In order to
825 see the details of every individual test cases, it is possible to define
826 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
829 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
832 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
833 @file{test-suite.log} file. Please specify the Guix version being used
834 as well as version numbers of the dependencies (@pxref{Requirements}) in
837 Guix also comes with a whole-system test suite that tests complete
838 Guix System instances. It can only run on systems where
839 Guix is already installed, using:
846 or, again, by defining @code{TESTS} to select a subset of tests to run:
849 make check-system TESTS="basic mcron"
852 These system tests are defined in the @code{(gnu tests @dots{})}
853 modules. They work by running the operating systems under test with
854 lightweight instrumentation in a virtual machine (VM). They can be
855 computationally intensive or rather cheap, depending on whether
856 substitutes are available for their dependencies (@pxref{Substitutes}).
857 Some of them require a lot of storage space to hold VM images.
859 Again in case of test failures, please send @email{bug-guix@@gnu.org}
862 @node Setting Up the Daemon
863 @section Setting Up the Daemon
866 Operations such as building a package or running the garbage collector
867 are all performed by a specialized process, the @dfn{build daemon}, on
868 behalf of clients. Only the daemon may access the store and its
869 associated database. Thus, any operation that manipulates the store
870 goes through the daemon. For instance, command-line tools such as
871 @command{guix package} and @command{guix build} communicate with the
872 daemon (@i{via} remote procedure calls) to instruct it what to do.
874 The following sections explain how to prepare the build daemon's
875 environment. See also @ref{Substitutes}, for information on how to allow
876 the daemon to download pre-built binaries.
879 * Build Environment Setup:: Preparing the isolated build environment.
880 * Daemon Offload Setup:: Offloading builds to remote machines.
881 * SELinux Support:: Using an SELinux policy for the daemon.
884 @node Build Environment Setup
885 @subsection Build Environment Setup
887 @cindex build environment
888 In a standard multi-user setup, Guix and its daemon---the
889 @command{guix-daemon} program---are installed by the system
890 administrator; @file{/gnu/store} is owned by @code{root} and
891 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
892 Guix tools to build packages or otherwise access the store, and the
893 daemon will do it on their behalf, ensuring that the store is kept in a
894 consistent state, and allowing built packages to be shared among users.
897 When @command{guix-daemon} runs as @code{root}, you may not want package
898 build processes themselves to run as @code{root} too, for obvious
899 security reasons. To avoid that, a special pool of @dfn{build users}
900 should be created for use by build processes started by the daemon.
901 These build users need not have a shell and a home directory: they will
902 just be used when the daemon drops @code{root} privileges in build
903 processes. Having several such users allows the daemon to launch
904 distinct build processes under separate UIDs, which guarantees that they
905 do not interfere with each other---an essential feature since builds are
906 regarded as pure functions (@pxref{Introduction}).
908 On a GNU/Linux system, a build user pool may be created like this (using
909 Bash syntax and the @code{shadow} commands):
911 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
912 @c for why `-G' is needed.
914 # groupadd --system guixbuild
915 # for i in `seq -w 1 10`;
917 useradd -g guixbuild -G guixbuild \
918 -d /var/empty -s `which nologin` \
919 -c "Guix build user $i" --system \
925 The number of build users determines how many build jobs may run in
926 parallel, as specified by the @option{--max-jobs} option
927 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
928 @command{guix system vm} and related commands, you may need to add the
929 build users to the @code{kvm} group so they can access @file{/dev/kvm},
930 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
931 (@pxref{Invoking guix system}).
933 The @code{guix-daemon} program may then be run as @code{root} with the
934 following command@footnote{If your machine uses the systemd init system,
935 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
936 file in @file{/etc/systemd/system} will ensure that
937 @command{guix-daemon} is automatically started. Similarly, if your
938 machine uses the Upstart init system, drop the
939 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
940 file in @file{/etc/init}.}:
943 # guix-daemon --build-users-group=guixbuild
948 This way, the daemon starts build processes in a chroot, under one of
949 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
950 environment contains nothing but:
952 @c Keep this list in sync with libstore/build.cc! -----------------------
955 a minimal @code{/dev} directory, created mostly independently from the
956 host @code{/dev}@footnote{``Mostly'', because while the set of files
957 that appear in the chroot's @code{/dev} is fixed, most of these files
958 can only be created if the host has them.};
961 the @code{/proc} directory; it only shows the processes of the container
962 since a separate PID name space is used;
965 @file{/etc/passwd} with an entry for the current user and an entry for
969 @file{/etc/group} with an entry for the user's group;
972 @file{/etc/hosts} with an entry that maps @code{localhost} to
976 a writable @file{/tmp} directory.
979 You can influence the directory where the daemon stores build trees
980 @i{via} the @code{TMPDIR} environment variable. However, the build tree
981 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
982 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
983 This way, the value of @code{TMPDIR} does not leak inside build
984 environments, which avoids discrepancies in cases where build processes
985 capture the name of their build tree.
988 The daemon also honors the @code{http_proxy} environment variable for
989 HTTP downloads it performs, be it for fixed-output derivations
990 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
992 If you are installing Guix as an unprivileged user, it is still possible
993 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
994 However, build processes will not be isolated from one another, and not
995 from the rest of the system. Thus, build processes may interfere with
996 each other, and may access programs, libraries, and other files
997 available on the system---making it much harder to view them as
998 @emph{pure} functions.
1001 @node Daemon Offload Setup
1002 @subsection Using the Offload Facility
1006 When desired, the build daemon can @dfn{offload} derivation builds to
1007 other machines running Guix, using the @code{offload} @dfn{build
1008 hook}@footnote{This feature is available only when
1009 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1010 present.}. When that
1011 feature is enabled, a list of user-specified build machines is read from
1012 @file{/etc/guix/machines.scm}; every time a build is requested, for
1013 instance via @code{guix build}, the daemon attempts to offload it to one
1014 of the machines that satisfy the constraints of the derivation, in
1015 particular its system type---e.g., @file{x86_64-linux}. Missing
1016 prerequisites for the build are copied over SSH to the target machine,
1017 which then proceeds with the build; upon success the output(s) of the
1018 build are copied back to the initial machine.
1020 The @file{/etc/guix/machines.scm} file typically looks like this:
1023 (list (build-machine
1024 (name "eightysix.example.org")
1025 (system "x86_64-linux")
1026 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1028 (speed 2.)) ;incredibly fast!
1031 (name "meeps.example.org")
1032 (system "mips64el-linux")
1033 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1036 (string-append (getenv "HOME")
1037 "/.ssh/identity-for-guix"))))
1041 In the example above we specify a list of two build machines, one for
1042 the @code{x86_64} architecture and one for the @code{mips64el}
1045 In fact, this file is---not surprisingly!---a Scheme file that is
1046 evaluated when the @code{offload} hook is started. Its return value
1047 must be a list of @code{build-machine} objects. While this example
1048 shows a fixed list of build machines, one could imagine, say, using
1049 DNS-SD to return a list of potential build machines discovered in the
1050 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1051 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1054 @deftp {Data Type} build-machine
1055 This data type represents build machines to which the daemon may offload
1056 builds. The important fields are:
1061 The host name of the remote machine.
1064 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1067 The user account to use when connecting to the remote machine over SSH.
1068 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1069 allow non-interactive logins.
1072 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1073 This is used to authenticate the machine when we connect to it. It is a
1074 long string that looks like this:
1077 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1080 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1081 key can be found in a file such as
1082 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1084 If the machine is running the SSH daemon of GNU@tie{}lsh,
1085 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1086 similar file. It can be converted to the OpenSSH format using
1087 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1090 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1091 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1096 A number of optional fields may be specified:
1100 @item @code{port} (default: @code{22})
1101 Port number of SSH server on the machine.
1103 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1104 The SSH private key file to use when connecting to the machine, in
1105 OpenSSH format. This key must not be protected with a passphrase.
1107 Note that the default value is the private key @emph{of the root
1108 account}. Make sure it exists if you use the default.
1110 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1111 @itemx @code{compression-level} (default: @code{3})
1112 The SSH-level compression methods and compression level requested.
1114 Note that offloading relies on SSH compression to reduce bandwidth usage
1115 when transferring files to and from build machines.
1117 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1118 File name of the Unix-domain socket @command{guix-daemon} is listening
1121 @item @code{parallel-builds} (default: @code{1})
1122 The number of builds that may run in parallel on the machine.
1124 @item @code{speed} (default: @code{1.0})
1125 A ``relative speed factor''. The offload scheduler will tend to prefer
1126 machines with a higher speed factor.
1128 @item @code{features} (default: @code{'()})
1129 A list of strings denoting specific features supported by the machine.
1130 An example is @code{"kvm"} for machines that have the KVM Linux modules
1131 and corresponding hardware support. Derivations can request features by
1132 name, and they will be scheduled on matching build machines.
1137 The @command{guix} command must be in the search path on the build
1138 machines. You can check whether this is the case by running:
1141 ssh build-machine guix repl --version
1144 There is one last thing to do once @file{machines.scm} is in place. As
1145 explained above, when offloading, files are transferred back and forth
1146 between the machine stores. For this to work, you first need to
1147 generate a key pair on each machine to allow the daemon to export signed
1148 archives of files from the store (@pxref{Invoking guix archive}):
1151 # guix archive --generate-key
1155 Each build machine must authorize the key of the master machine so that
1156 it accepts store items it receives from the master:
1159 # guix archive --authorize < master-public-key.txt
1163 Likewise, the master machine must authorize the key of each build machine.
1165 All the fuss with keys is here to express pairwise mutual trust
1166 relations between the master and the build machines. Concretely, when
1167 the master receives files from a build machine (and @i{vice versa}), its
1168 build daemon can make sure they are genuine, have not been tampered
1169 with, and that they are signed by an authorized key.
1171 @cindex offload test
1172 To test whether your setup is operational, run this command on the
1179 This will attempt to connect to each of the build machines specified in
1180 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1181 available on each machine, attempt to export to the machine and import
1182 from it, and report any error in the process.
1184 If you want to test a different machine file, just specify it on the
1188 # guix offload test machines-qualif.scm
1191 Last, you can test the subset of the machines whose name matches a
1192 regular expression like this:
1195 # guix offload test machines.scm '\.gnu\.org$'
1198 @cindex offload status
1199 To display the current load of all build hosts, run this command on the
1203 # guix offload status
1207 @node SELinux Support
1208 @subsection SELinux Support
1210 @cindex SELinux, daemon policy
1211 @cindex mandatory access control, SELinux
1212 @cindex security, guix-daemon
1213 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1214 can be installed on a system where SELinux is enabled, in order to label
1215 Guix files and to specify the expected behavior of the daemon. Since
1216 Guix System does not provide an SELinux base policy, the daemon policy cannot
1217 be used on Guix System.
1219 @subsubsection Installing the SELinux policy
1220 @cindex SELinux, policy installation
1221 To install the policy run this command as root:
1224 semodule -i etc/guix-daemon.cil
1227 Then relabel the file system with @code{restorecon} or by a different
1228 mechanism provided by your system.
1230 Once the policy is installed, the file system has been relabeled, and
1231 the daemon has been restarted, it should be running in the
1232 @code{guix_daemon_t} context. You can confirm this with the following
1236 ps -Zax | grep guix-daemon
1239 Monitor the SELinux log files as you run a command like @code{guix build
1240 hello} to convince yourself that SELinux permits all necessary
1243 @subsubsection Limitations
1244 @cindex SELinux, limitations
1246 This policy is not perfect. Here is a list of limitations or quirks
1247 that should be considered when deploying the provided SELinux policy for
1252 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1253 operations involve contexts that have anything to do with
1254 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1255 but it would be preferrable to define socket rules for only this label.
1258 @code{guix gc} cannot access arbitrary links to profiles. By design,
1259 the file label of the destination of a symlink is independent of the
1260 file label of the link itself. Although all profiles under
1261 $localstatedir are labelled, the links to these profiles inherit the
1262 label of the directory they are in. For links in the user’s home
1263 directory this will be @code{user_home_t}. But for links from the root
1264 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1265 directory, etc, this won’t work. @code{guix gc} would be prevented from
1266 reading and following these links.
1269 The daemon’s feature to listen for TCP connections might no longer work.
1270 This might require extra rules, because SELinux treats network sockets
1271 differently from files.
1274 Currently all files with a name matching the regular expression
1275 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1276 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1277 that name in any profile would be permitted to run in the
1278 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1279 build a package that provides this executable and convince a user to
1280 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1281 At that point SELinux could not prevent it from accessing files that are
1282 allowed for processes in that domain.
1284 We could generate a much more restrictive policy at installation time,
1285 so that only the @emph{exact} file name of the currently installed
1286 @code{guix-daemon} executable would be labelled with
1287 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1288 The downside is that root would have to install or upgrade the policy at
1289 installation time whenever the Guix package that provides the
1290 effectively running @code{guix-daemon} executable is upgraded.
1293 @node Invoking guix-daemon
1294 @section Invoking @command{guix-daemon}
1296 The @command{guix-daemon} program implements all the functionality to
1297 access the store. This includes launching build processes, running the
1298 garbage collector, querying the availability of a build result, etc. It
1299 is normally run as @code{root} like this:
1302 # guix-daemon --build-users-group=guixbuild
1306 For details on how to set it up, @pxref{Setting Up the Daemon}.
1309 @cindex container, build environment
1310 @cindex build environment
1311 @cindex reproducible builds
1312 By default, @command{guix-daemon} launches build processes under
1313 different UIDs, taken from the build group specified with
1314 @code{--build-users-group}. In addition, each build process is run in a
1315 chroot environment that only contains the subset of the store that the
1316 build process depends on, as specified by its derivation
1317 (@pxref{Programming Interface, derivation}), plus a set of specific
1318 system directories. By default, the latter contains @file{/dev} and
1319 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1320 @dfn{container}: in addition to having its own file system tree, it has
1321 a separate mount name space, its own PID name space, network name space,
1322 etc. This helps achieve reproducible builds (@pxref{Features}).
1324 When the daemon performs a build on behalf of the user, it creates a
1325 build directory under @file{/tmp} or under the directory specified by
1326 its @code{TMPDIR} environment variable. This directory is shared with
1327 the container for the duration of the build, though within the container,
1328 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1330 The build directory is automatically deleted upon completion, unless the
1331 build failed and the client specified @option{--keep-failed}
1332 (@pxref{Invoking guix build, @option{--keep-failed}}).
1334 The daemon listens for connections and spawns one sub-process for each session
1335 started by a client (one of the @command{guix} sub-commands.) The
1336 @command{guix processes} command allows you to get an overview of the activity
1337 on your system by viewing each of the active sessions and clients.
1338 @xref{Invoking guix processes}, for more information.
1340 The following command-line options are supported:
1343 @item --build-users-group=@var{group}
1344 Take users from @var{group} to run build processes (@pxref{Setting Up
1345 the Daemon, build users}).
1347 @item --no-substitutes
1349 Do not use substitutes for build products. That is, always build things
1350 locally instead of allowing downloads of pre-built binaries
1351 (@pxref{Substitutes}).
1353 When the daemon runs with @code{--no-substitutes}, clients can still
1354 explicitly enable substitution @i{via} the @code{set-build-options}
1355 remote procedure call (@pxref{The Store}).
1357 @item --substitute-urls=@var{urls}
1358 @anchor{daemon-substitute-urls}
1359 Consider @var{urls} the default whitespace-separated list of substitute
1360 source URLs. When this option is omitted,
1361 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1363 This means that substitutes may be downloaded from @var{urls}, as long
1364 as they are signed by a trusted signature (@pxref{Substitutes}).
1367 @item --no-build-hook
1368 Do not use the @dfn{build hook}.
1370 The build hook is a helper program that the daemon can start and to
1371 which it submits build requests. This mechanism is used to offload
1372 builds to other machines (@pxref{Daemon Offload Setup}).
1374 @item --cache-failures
1375 Cache build failures. By default, only successful builds are cached.
1377 When this option is used, @command{guix gc --list-failures} can be used
1378 to query the set of store items marked as failed; @command{guix gc
1379 --clear-failures} removes store items from the set of cached failures.
1380 @xref{Invoking guix gc}.
1382 @item --cores=@var{n}
1384 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1387 The default value is @code{0}, but it may be overridden by clients, such
1388 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1391 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1392 in the build process, which can then use it to exploit internal
1393 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1395 @item --max-jobs=@var{n}
1397 Allow at most @var{n} build jobs in parallel. The default value is
1398 @code{1}. Setting it to @code{0} means that no builds will be performed
1399 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1400 Setup}), or simply fail.
1402 @item --max-silent-time=@var{seconds}
1403 When the build or substitution process remains silent for more than
1404 @var{seconds}, terminate it and report a build failure.
1406 The default value is @code{0}, which disables the timeout.
1408 The value specified here can be overridden by clients (@pxref{Common
1409 Build Options, @code{--max-silent-time}}).
1411 @item --timeout=@var{seconds}
1412 Likewise, when the build or substitution process lasts for more than
1413 @var{seconds}, terminate it and report a build failure.
1415 The default value is @code{0}, which disables the timeout.
1417 The value specified here can be overridden by clients (@pxref{Common
1418 Build Options, @code{--timeout}}).
1420 @item --rounds=@var{N}
1421 Build each derivation @var{n} times in a row, and raise an error if
1422 consecutive build results are not bit-for-bit identical. Note that this
1423 setting can be overridden by clients such as @command{guix build}
1424 (@pxref{Invoking guix build}).
1426 When used in conjunction with @option{--keep-failed}, the differing
1427 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1428 This makes it easy to look for differences between the two results.
1431 Produce debugging output.
1433 This is useful to debug daemon start-up issues, but then it may be
1434 overridden by clients, for example the @code{--verbosity} option of
1435 @command{guix build} (@pxref{Invoking guix build}).
1437 @item --chroot-directory=@var{dir}
1438 Add @var{dir} to the build chroot.
1440 Doing this may change the result of build processes---for instance if
1441 they use optional dependencies found in @var{dir} when it is available,
1442 and not otherwise. For that reason, it is not recommended to do so.
1443 Instead, make sure that each derivation declares all the inputs that it
1446 @item --disable-chroot
1447 Disable chroot builds.
1449 Using this option is not recommended since, again, it would allow build
1450 processes to gain access to undeclared dependencies. It is necessary,
1451 though, when @command{guix-daemon} is running under an unprivileged user
1454 @item --log-compression=@var{type}
1455 Compress build logs according to @var{type}, one of @code{gzip},
1456 @code{bzip2}, or @code{none}.
1458 Unless @code{--lose-logs} is used, all the build logs are kept in the
1459 @var{localstatedir}. To save space, the daemon automatically compresses
1460 them with bzip2 by default.
1462 @item --disable-deduplication
1463 @cindex deduplication
1464 Disable automatic file ``deduplication'' in the store.
1466 By default, files added to the store are automatically ``deduplicated'':
1467 if a newly added file is identical to another one found in the store,
1468 the daemon makes the new file a hard link to the other file. This can
1469 noticeably reduce disk usage, at the expense of slightly increased
1470 input/output load at the end of a build process. This option disables
1473 @item --gc-keep-outputs[=yes|no]
1474 Tell whether the garbage collector (GC) must keep outputs of live
1478 @cindex garbage collector roots
1479 When set to ``yes'', the GC will keep the outputs of any live derivation
1480 available in the store---the @code{.drv} files. The default is ``no'',
1481 meaning that derivation outputs are kept only if they are reachable from a GC
1482 root. @xref{Invoking guix gc}, for more on GC roots.
1484 @item --gc-keep-derivations[=yes|no]
1485 Tell whether the garbage collector (GC) must keep derivations
1486 corresponding to live outputs.
1488 When set to ``yes'', as is the case by default, the GC keeps
1489 derivations---i.e., @code{.drv} files---as long as at least one of their
1490 outputs is live. This allows users to keep track of the origins of
1491 items in their store. Setting it to ``no'' saves a bit of disk space.
1493 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1494 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1495 ``yes'' causes liveness to flow from derivations to outputs. When both are
1496 set to ``yes'', the effect is to keep all the build prerequisites (the
1497 sources, compiler, libraries, and other build-time tools) of live objects in
1498 the store, regardless of whether these prerequisites are reachable from a GC
1499 root. This is convenient for developers since it saves rebuilds or downloads.
1501 @item --impersonate-linux-2.6
1502 On Linux-based systems, impersonate Linux 2.6. This means that the
1503 kernel's @code{uname} system call will report 2.6 as the release number.
1505 This might be helpful to build programs that (usually wrongfully) depend
1506 on the kernel version number.
1509 Do not keep build logs. By default they are kept under
1510 @code{@var{localstatedir}/guix/log}.
1512 @item --system=@var{system}
1513 Assume @var{system} as the current system type. By default it is the
1514 architecture/kernel pair found at configure time, such as
1515 @code{x86_64-linux}.
1517 @item --listen=@var{endpoint}
1518 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1519 as the file name of a Unix-domain socket if it starts with
1520 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1521 host name or host name and port to listen to. Here are a few examples:
1524 @item --listen=/gnu/var/daemon
1525 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1526 creating it if needed.
1528 @item --listen=localhost
1529 @cindex daemon, remote access
1530 @cindex remote access to the daemon
1531 @cindex daemon, cluster setup
1532 @cindex clusters, daemon setup
1533 Listen for TCP connections on the network interface corresponding to
1534 @code{localhost}, on port 44146.
1536 @item --listen=128.0.0.42:1234
1537 Listen for TCP connections on the network interface corresponding to
1538 @code{128.0.0.42}, on port 1234.
1541 This option can be repeated multiple times, in which case
1542 @command{guix-daemon} accepts connections on all the specified
1543 endpoints. Users can tell client commands what endpoint to connect to
1544 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1545 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1548 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1549 @code{--listen=@var{host}} is suitable on local networks, such as
1550 clusters, where only trusted nodes may connect to the build daemon. In
1551 other cases where remote access to the daemon is needed, we recommend
1552 using Unix-domain sockets along with SSH.
1555 When @code{--listen} is omitted, @command{guix-daemon} listens for
1556 connections on the Unix-domain socket located at
1557 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1561 @node Application Setup
1562 @section Application Setup
1564 @cindex foreign distro
1565 When using Guix on top of GNU/Linux distribution other than Guix System---a
1566 so-called @dfn{foreign distro}---a few additional steps are needed to
1567 get everything in place. Here are some of them.
1571 @anchor{locales-and-locpath}
1572 @cindex locales, when not on Guix System
1574 @vindex GUIX_LOCPATH
1575 Packages installed @i{via} Guix will not use the locale data of the
1576 host system. Instead, you must first install one of the locale packages
1577 available with Guix and then define the @code{GUIX_LOCPATH} environment
1581 $ guix install glibc-locales
1582 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1585 Note that the @code{glibc-locales} package contains data for all the
1586 locales supported by the GNU@tie{}libc and weighs in at around
1587 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1588 limited to a few UTF-8 locales.
1590 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1591 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1592 Manual}). There are two important differences though:
1596 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1597 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1598 to make sure the programs of the foreign distro will not end up loading
1599 incompatible locale data.
1602 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1603 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1604 should your Guix profile contain a mixture of programs linked against
1605 different libc version, each libc version will only try to load locale
1606 data in the right format.
1609 This is important because the locale data format used by different libc
1610 versions may be incompatible.
1612 @subsection Name Service Switch
1614 @cindex name service switch, glibc
1615 @cindex NSS (name service switch), glibc
1616 @cindex nscd (name service caching daemon)
1617 @cindex name service caching daemon (nscd)
1618 When using Guix on a foreign distro, we @emph{strongly recommend} that
1619 the system run the GNU C library's @dfn{name service cache daemon},
1620 @command{nscd}, which should be listening on the
1621 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1622 installed with Guix may fail to look up host names or user accounts, or
1623 may even crash. The next paragraphs explain why.
1625 @cindex @file{nsswitch.conf}
1626 The GNU C library implements a @dfn{name service switch} (NSS), which is
1627 an extensible mechanism for ``name lookups'' in general: host name
1628 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1629 The GNU C Library Reference Manual}).
1631 @cindex Network information service (NIS)
1632 @cindex NIS (Network information service)
1633 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1634 lookup implementations: for example, the @code{nss-mdns} plugin allow
1635 resolution of @code{.local} host names, the @code{nis} plugin allows
1636 user account lookup using the Network information service (NIS), and so
1637 on. These extra ``lookup services'' are configured system-wide in
1638 @file{/etc/nsswitch.conf}, and all the programs running on the system
1639 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1642 When they perform a name lookup---for instance by calling the
1643 @code{getaddrinfo} function in C---applications first try to connect to
1644 the nscd; on success, nscd performs name lookups on their behalf. If
1645 the nscd is not running, then they perform the name lookup by
1646 themselves, by loading the name lookup services into their own address
1647 space and running it. These name lookup services---the
1648 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1649 the host system's C library, rather than from the C library the
1650 application is linked against (the C library coming from Guix).
1652 And this is where the problem is: if your application is linked against
1653 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1654 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1655 likely crash or have its name lookups fail unexpectedly.
1657 Running @command{nscd} on the system, among other advantages, eliminates
1658 this binary incompatibility problem because those @code{libnss_*.so}
1659 files are loaded in the @command{nscd} process, not in applications
1662 @subsection X11 Fonts
1665 The majority of graphical applications use Fontconfig to locate and
1666 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1667 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1668 by default. Thus, to allow graphical applications installed with Guix
1669 to display fonts, you have to install fonts with Guix as well.
1670 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1671 @code{font-gnu-freefont-ttf}.
1673 To display text written in Chinese languages, Japanese, or Korean in
1674 graphical applications, consider installing
1675 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1676 has multiple outputs, one per language family (@pxref{Packages with
1677 Multiple Outputs}). For instance, the following command installs fonts
1678 for Chinese languages:
1681 guix install font-adobe-source-han-sans:cn
1684 @cindex @code{xterm}
1685 Older programs such as @command{xterm} do not use Fontconfig and instead
1686 rely on server-side font rendering. Such programs require to specify a
1687 full name of a font using XLFD (X Logical Font Description), like this:
1690 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1693 To be able to use such full names for the TrueType fonts installed in
1694 your Guix profile, you need to extend the font path of the X server:
1696 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1697 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1699 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1702 @cindex @code{xlsfonts}
1703 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1704 to make sure your TrueType fonts are listed there.
1706 @cindex @code{fc-cache}
1708 After installing fonts you may have to refresh the font cache to use
1709 them in applications. The same applies when applications installed via
1710 Guix do not seem to find fonts. To force rebuilding of the font cache
1711 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1712 @code{fontconfig} package.
1714 @subsection X.509 Certificates
1716 @cindex @code{nss-certs}
1717 The @code{nss-certs} package provides X.509 certificates, which allow
1718 programs to authenticate Web servers accessed over HTTPS.
1720 When using Guix on a foreign distro, you can install this package and
1721 define the relevant environment variables so that packages know where to
1722 look for certificates. @xref{X.509 Certificates}, for detailed
1725 @subsection Emacs Packages
1727 @cindex @code{emacs}
1728 When you install Emacs packages with Guix, the elisp files may be placed
1729 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1731 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1732 directory exists because potentially there may exist thousands of Emacs
1733 packages and storing all their files in a single directory may not be
1734 reliable (because of name conflicts). So we think using a separate
1735 directory for each package is a good idea. It is very similar to how
1736 the Emacs package system organizes the file structure (@pxref{Package
1737 Files,,, emacs, The GNU Emacs Manual}).
1739 By default, Emacs (installed with Guix) ``knows'' where these packages
1740 are placed, so you do not need to perform any configuration. If, for
1741 some reason, you want to avoid auto-loading Emacs packages installed
1742 with Guix, you can do so by running Emacs with @code{--no-site-file}
1743 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1745 @subsection The GCC toolchain
1750 Guix offers individual compiler packages such as @code{gcc} but if you
1751 are in need of a complete toolchain for compiling and linking source
1752 code what you really want is the @code{gcc-toolchain} package. This
1753 package provides a complete GCC toolchain for C/C++ development,
1754 including GCC itself, the GNU C Library (headers and binaries, plus
1755 debugging symbols in the @code{debug} output), Binutils, and a linker
1758 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1759 passed to the linker, add corresponding @code{-rpath} arguments, and
1760 invoke the actual linker with this new set of arguments. You can instruct the
1761 wrapper to refuse to link against libraries not in the store by setting the
1762 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1766 @c *********************************************************************
1767 @node System Installation
1768 @chapter System Installation
1770 @cindex installing Guix System
1771 @cindex Guix System, installation
1772 This section explains how to install Guix System
1773 on a machine. Guix, as a package manager, can
1774 also be installed on top of a running GNU/Linux system,
1775 @pxref{Installation}.
1779 @c This paragraph is for people reading this from tty2 of the
1780 @c installation image.
1781 You are reading this documentation with an Info reader. For details on
1782 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1783 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1784 Info}. Hit @kbd{l} afterwards to come back here.
1786 Alternately, run @command{info info} in another tty to keep the manual
1792 * Limitations:: What you can expect.
1793 * Hardware Considerations:: Supported hardware.
1794 * USB Stick and DVD Installation:: Preparing the installation medium.
1795 * Preparing for Installation:: Networking, partitioning, etc.
1796 * Guided Graphical Installation:: Easy graphical installation.
1797 * Manual Installation:: Manual installation for wizards.
1798 * After System Installation:: When installation succeeded.
1799 * Installing Guix in a VM:: Guix System playground.
1800 * Building the Installation Image:: How this comes to be.
1804 @section Limitations
1806 We consider Guix System to be ready for a wide range of ``desktop'' and server
1807 use cases. The reliability guarantees it provides---transactional upgrades
1808 and rollbacks, reproducibility---make it a solid foundation.
1810 Nevertheless, before you proceed with the installation, be aware of the
1811 following noteworthy limitations applicable to version @value{VERSION}:
1815 Support for the Logical Volume Manager (LVM) is missing.
1818 More and more system services are provided (@pxref{Services}), but some
1822 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1823 as well as a number of X11 window managers. However, KDE is currently
1827 More than a disclaimer, this is an invitation to report issues (and success
1828 stories!), and to join us in improving it. @xref{Contributing}, for more
1832 @node Hardware Considerations
1833 @section Hardware Considerations
1835 @cindex hardware support on Guix System
1836 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1837 builds around the kernel Linux-libre, which means that only hardware for
1838 which free software drivers and firmware exist is supported. Nowadays,
1839 a wide range of off-the-shelf hardware is supported on
1840 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1841 Ethernet controllers. Unfortunately, there are still areas where
1842 hardware vendors deny users control over their own computing, and such
1843 hardware is not supported on Guix System.
1845 @cindex WiFi, hardware support
1846 One of the main areas where free drivers or firmware are lacking is WiFi
1847 devices. WiFi devices known to work include those using Atheros chips
1848 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1849 driver, and those using Broadcom/AirForce chips (BCM43xx with
1850 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1851 Linux-libre driver. Free firmware exists for both and is available
1852 out-of-the-box on Guix System, as part of @code{%base-firmware}
1853 (@pxref{operating-system Reference, @code{firmware}}).
1855 @cindex RYF, Respects Your Freedom
1856 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1857 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1858 certification program for hardware products that respect your freedom
1859 and your privacy and ensure that you have control over your device. We
1860 encourage you to check the list of RYF-certified devices.
1862 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1863 web site. It contains a catalog of hardware devices with information
1864 about their support in GNU/Linux.
1867 @node USB Stick and DVD Installation
1868 @section USB Stick and DVD Installation
1870 An ISO-9660 installation image that can be written to a USB stick or
1871 burnt to a DVD can be downloaded from
1872 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1873 where @var{system} is one of:
1877 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1880 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1883 @c start duplication of authentication part from ``Binary Installation''
1884 Make sure to download the associated @file{.sig} file and to verify the
1885 authenticity of the image against it, along these lines:
1888 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1889 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1892 If that command fails because you do not have the required public key,
1893 then run this command to import it:
1896 $ gpg --keyserver @value{KEY-SERVER} \
1897 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1901 and rerun the @code{gpg --verify} command.
1904 This image contains the tools necessary for an installation.
1905 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1907 @unnumberedsubsec Copying to a USB Stick
1909 To copy the image to a USB stick, follow these steps:
1913 Decompress the image using the @command{xz} command:
1916 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1920 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1921 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1922 copy the image with:
1925 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1929 Access to @file{/dev/sdX} usually requires root privileges.
1932 @unnumberedsubsec Burning on a DVD
1934 To copy the image to a DVD, follow these steps:
1938 Decompress the image using the @command{xz} command:
1941 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1945 Insert a blank DVD into your machine, and determine
1946 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1947 copy the image with:
1950 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1953 Access to @file{/dev/srX} usually requires root privileges.
1956 @unnumberedsubsec Booting
1958 Once this is done, you should be able to reboot the system and boot from
1959 the USB stick or DVD. The latter usually requires you to get in the
1960 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1962 @xref{Installing Guix in a VM}, if, instead, you would like to install
1963 Guix System in a virtual machine (VM).
1966 @node Preparing for Installation
1967 @section Preparing for Installation
1969 Once you have booted, you can use the guided graphical installer, which makes
1970 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1971 if you are already familiar with GNU/Linux and if you want more control than
1972 what the graphical installer provides, you can choose the ``manual''
1973 installation process (@pxref{Manual Installation}).
1975 The graphical installer is available on TTY1. You can obtain root shells on
1976 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1977 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1978 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1979 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1980 which allows you to select text with the left mouse button and to paste it
1981 with the middle button.
1984 Installation requires access to the Internet so that any missing
1985 dependencies of your system configuration can be downloaded. See the
1986 ``Networking'' section below.
1989 @node Guided Graphical Installation
1990 @section Guided Graphical Installation
1992 The graphical installer is a text-based user interface. It will guide you,
1993 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
1995 The first dialog boxes allow you to set up the system as you use it during the
1996 installation: you can choose the language, keyboard layout, and set up
1997 networking, which will be used during the installation. The image below shows
1998 the networking dialog.
2000 @image{images/installer-network,5in,, networking setup with the graphical installer}
2002 Later steps allow you to partition your hard disk, as shown in the image
2003 below, to choose whether or not to use encrypted file systems, to enter the
2004 host name and root password, and to create an additional account, among other
2007 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2009 Note that, at any time, the installer allows you to exit the current
2010 installation step and resume at a previous step, as show in the image below.
2012 @image{images/installer-resume,5in,, resuming the installation process}
2014 Once you're done, the installer produces an operating system configuration and
2015 displays it (@pxref{Using the Configuration System}). At that point you can
2016 hit ``OK'' and installation will proceed. On success, you can reboot into the
2017 new system and enjoy. @xref{After System Installation}, for what's next!
2020 @node Manual Installation
2021 @section Manual Installation
2023 This section describes how you would ``manually'' install GNU@tie{}Guix System
2024 on your machine. This option requires familiarity with GNU/Linux, with the
2025 shell, and with common administration tools. If you think this is not for
2026 you, consider using the guided graphical installer (@pxref{Guided Graphical
2029 The installation system provides root shells on TTYs 3 to 6; press
2030 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2031 many common tools needed to install the system. But it is also a full-blown
2032 Guix System, which means that you can install additional packages, should you
2033 need it, using @command{guix package} (@pxref{Invoking guix package}).
2036 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2037 * Proceeding with the Installation:: Installing.
2040 @node Keyboard Layout and Networking and Partitioning
2041 @subsection Keyboard Layout, Networking, and Partitioning
2043 Before you can install the system, you may want to adjust the keyboard layout,
2044 set up networking, and partition your target hard disk. This section will
2045 guide you through this.
2047 @subsubsection Keyboard Layout
2049 @cindex keyboard layout
2050 The installation image uses the US qwerty keyboard layout. If you want
2051 to change it, you can use the @command{loadkeys} command. For example,
2052 the following command selects the Dvorak keyboard layout:
2058 See the files under @file{/run/current-system/profile/share/keymaps} for
2059 a list of available keyboard layouts. Run @command{man loadkeys} for
2062 @subsubsection Networking
2064 Run the following command to see what your network interfaces are called:
2071 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2077 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2078 Wired interfaces have a name starting with @samp{e}; for example, the
2079 interface corresponding to the first on-board Ethernet controller is
2080 called @samp{eno1}. Wireless interfaces have a name starting with
2081 @samp{w}, like @samp{w1p2s0}.
2084 @item Wired connection
2085 To configure a wired network run the following command, substituting
2086 @var{interface} with the name of the wired interface you want to use.
2089 ifconfig @var{interface} up
2092 @item Wireless connection
2095 To configure wireless networking, you can create a configuration file
2096 for the @command{wpa_supplicant} configuration tool (its location is not
2097 important) using one of the available text editors such as
2101 nano wpa_supplicant.conf
2104 As an example, the following stanza can go to this file and will work
2105 for many wireless networks, provided you give the actual SSID and
2106 passphrase for the network you are connecting to:
2110 ssid="@var{my-ssid}"
2112 psk="the network's secret passphrase"
2116 Start the wireless service and run it in the background with the
2117 following command (substitute @var{interface} with the name of the
2118 network interface you want to use):
2121 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2124 Run @command{man wpa_supplicant} for more information.
2128 At this point, you need to acquire an IP address. On a network where IP
2129 addresses are automatically assigned @i{via} DHCP, you can run:
2132 dhclient -v @var{interface}
2135 Try to ping a server to see if networking is up and running:
2141 Setting up network access is almost always a requirement because the
2142 image does not contain all the software and tools that may be needed.
2144 @cindex installing over SSH
2145 If you want to, you can continue the installation remotely by starting
2149 herd start ssh-daemon
2152 Make sure to either set a password with @command{passwd}, or configure
2153 OpenSSH public key authentication before logging in.
2155 @subsubsection Disk Partitioning
2157 Unless this has already been done, the next step is to partition, and
2158 then format the target partition(s).
2160 The installation image includes several partitioning tools, including
2161 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2162 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2163 the partition layout you want:
2169 If your disk uses the GUID Partition Table (GPT) format and you plan to
2170 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2171 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2174 @cindex EFI, installation
2175 @cindex UEFI, installation
2176 @cindex ESP, EFI system partition
2177 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2178 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2179 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2182 parted /dev/sda set 1 esp on
2186 @vindex grub-bootloader
2187 @vindex grub-efi-bootloader
2188 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2189 @file{/sys/firmware/efi} exists in the installation image, then you should
2190 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2191 Otherwise you should use the BIOS-based GRUB, known as
2192 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2196 Once you are done partitioning the target hard disk drive, you have to
2197 create a file system on the relevant partition(s)@footnote{Currently
2198 Guix System only supports ext4 and btrfs file systems. In particular, code
2199 that reads file system UUIDs and labels only works for these file system
2200 types.}. For the ESP, if you have one and assuming it is
2201 @file{/dev/sda1}, run:
2204 mkfs.fat -F32 /dev/sda1
2207 Preferably, assign file systems a label so that you can easily and
2208 reliably refer to them in @code{file-system} declarations (@pxref{File
2209 Systems}). This is typically done using the @code{-L} option of
2210 @command{mkfs.ext4} and related commands. So, assuming the target root
2211 partition lives at @file{/dev/sda2}, a file system with the label
2212 @code{my-root} can be created with:
2215 mkfs.ext4 -L my-root /dev/sda2
2218 @cindex encrypted disk
2219 If you are instead planning to encrypt the root partition, you can use
2220 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2221 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2222 @code{man cryptsetup}} for more information.) Assuming you want to
2223 store the root partition on @file{/dev/sda2}, the command sequence would
2224 be along these lines:
2227 cryptsetup luksFormat /dev/sda2
2228 cryptsetup open --type luks /dev/sda2 my-partition
2229 mkfs.ext4 -L my-root /dev/mapper/my-partition
2232 Once that is done, mount the target file system under @file{/mnt}
2233 with a command like (again, assuming @code{my-root} is the label of the
2237 mount LABEL=my-root /mnt
2240 Also mount any other file systems you would like to use on the target
2241 system relative to this path. If you have opted for @file{/boot/efi} as an
2242 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2243 found by @code{guix system init} afterwards.
2245 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2246 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2247 sure to initialize them with @command{mkswap}. Assuming you have one
2248 swap partition on @file{/dev/sda3}, you would run:
2255 Alternatively, you may use a swap file. For example, assuming that in
2256 the new system you want to use the file @file{/swapfile} as a swap file,
2257 you would run@footnote{This example will work for many types of file
2258 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2259 btrfs), the required steps may be different. For details, see the
2260 manual pages for @command{mkswap} and @command{swapon}.}:
2263 # This is 10 GiB of swap space. Adjust "count" to change the size.
2264 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2265 # For security, make the file readable and writable only by root.
2266 chmod 600 /mnt/swapfile
2267 mkswap /mnt/swapfile
2268 swapon /mnt/swapfile
2271 Note that if you have encrypted the root partition and created a swap
2272 file in its file system as described above, then the encryption also
2273 protects the swap file, just like any other file in that file system.
2275 @node Proceeding with the Installation
2276 @subsection Proceeding with the Installation
2278 With the target partitions ready and the target root mounted on
2279 @file{/mnt}, we're ready to go. First, run:
2282 herd start cow-store /mnt
2285 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2286 during the installation phase are written to the target disk on @file{/mnt}
2287 rather than kept in memory. This is necessary because the first phase of
2288 the @command{guix system init} command (see below) entails downloads or
2289 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2291 Next, you have to edit a file and
2292 provide the declaration of the operating system to be installed. To
2293 that end, the installation system comes with three text editors. We
2294 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2295 supports syntax highlighting and parentheses matching; other editors
2296 include GNU Zile (an Emacs clone), and
2297 nvi (a clone of the original BSD @command{vi} editor).
2298 We strongly recommend storing that file on the target root file system, say,
2299 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2300 configuration file once you have rebooted into the newly-installed system.
2302 @xref{Using the Configuration System}, for an overview of the
2303 configuration file. The example configurations discussed in that
2304 section are available under @file{/etc/configuration} in the
2305 installation image. Thus, to get started with a system configuration
2306 providing a graphical display server (a ``desktop'' system), you can run
2307 something along these lines:
2311 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2312 # nano /mnt/etc/config.scm
2315 You should pay attention to what your configuration file contains, and
2320 Make sure the @code{bootloader-configuration} form refers to the target
2321 you want to install GRUB on. It should mention @code{grub-bootloader} if
2322 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2323 for newer UEFI systems. For legacy systems, the @code{target} field
2324 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2325 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2326 currently mounted and a @code{file-system} entry is specified in your
2330 Be sure that your file system labels match the value of their respective
2331 @code{device} fields in your @code{file-system} configuration, assuming
2332 your @code{file-system} configuration uses the @code{file-system-label}
2333 procedure in its @code{device} field.
2336 If there are encrypted or RAID partitions, make sure to add a
2337 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2340 Once you are done preparing the configuration file, the new system must
2341 be initialized (remember that the target root file system is mounted
2345 guix system init /mnt/etc/config.scm /mnt
2349 This copies all the necessary files and installs GRUB on
2350 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2351 more information, @pxref{Invoking guix system}. This command may trigger
2352 downloads or builds of missing packages, which can take some time.
2354 Once that command has completed---and hopefully succeeded!---you can run
2355 @command{reboot} and boot into the new system. The @code{root} password
2356 in the new system is initially empty; other users' passwords need to be
2357 initialized by running the @command{passwd} command as @code{root},
2358 unless your configuration specifies otherwise
2359 (@pxref{user-account-password, user account passwords}).
2360 @xref{After System Installation}, for what's next!
2363 @node After System Installation
2364 @section After System Installation
2366 Success, you've now booted into Guix System! From then on, you can update the
2367 system whenever you want by running, say:
2371 sudo guix system reconfigure /etc/config.scm
2375 This builds a new system generation with the latest packages and services
2376 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2377 your system includes the latest security updates (@pxref{Security Updates}).
2379 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2381 @cindex sudo vs. @command{guix pull}
2382 Note that @command{sudo guix} runs your user's @command{guix} command and
2383 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2384 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2387 Join us on @code{#guix} on the Freenode IRC network or on
2388 @email{guix-devel@@gnu.org} to share your experience!
2391 @node Installing Guix in a VM
2392 @section Installing Guix in a Virtual Machine
2394 @cindex virtual machine, Guix System installation
2395 @cindex virtual private server (VPS)
2396 @cindex VPS (virtual private server)
2397 If you'd like to install Guix System in a virtual machine (VM) or on a
2398 virtual private server (VPS) rather than on your beloved machine, this
2401 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2402 disk image, follow these steps:
2406 First, retrieve and decompress the Guix system installation image as
2407 described previously (@pxref{USB Stick and DVD Installation}).
2410 Create a disk image that will hold the installed system. To make a
2411 qcow2-formatted disk image, use the @command{qemu-img} command:
2414 qemu-img create -f qcow2 guixsd.img 50G
2417 The resulting file will be much smaller than 50 GB (typically less than
2418 1 MB), but it will grow as the virtualized storage device is filled up.
2421 Boot the USB installation image in an VM:
2424 qemu-system-x86_64 -m 1024 -smp 1 \
2425 -net user -net nic,model=virtio -boot menu=on \
2426 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2427 -drive file=guixsd.img
2430 The ordering of the drives matters.
2432 In the VM console, quickly press the @kbd{F12} key to enter the boot
2433 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2437 You're now root in the VM, proceed with the installation process.
2438 @xref{Preparing for Installation}, and follow the instructions.
2441 Once installation is complete, you can boot the system that's on your
2442 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2445 @node Building the Installation Image
2446 @section Building the Installation Image
2448 @cindex installation image
2449 The installation image described above was built using the @command{guix
2450 system} command, specifically:
2453 guix system disk-image --file-system-type=iso9660 \
2454 gnu/system/install.scm
2457 Have a look at @file{gnu/system/install.scm} in the source tree,
2458 and see also @ref{Invoking guix system} for more information
2459 about the installation image.
2461 @section Building the Installation Image for ARM Boards
2463 Many ARM boards require a specific variant of the
2464 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2466 If you build a disk image and the bootloader is not available otherwise
2467 (on another boot drive etc), it's advisable to build an image that
2468 includes the bootloader, specifically:
2471 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2474 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2475 board, a list of possible boards will be printed.
2477 @c *********************************************************************
2478 @node Package Management
2479 @chapter Package Management
2482 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2483 remove software packages, without having to know about their build
2484 procedures or dependencies. Guix also goes beyond this obvious set of
2487 This chapter describes the main features of Guix, as well as the
2488 package management tools it provides. Along with the command-line
2489 interface described below (@pxref{Invoking guix package, @code{guix
2490 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2491 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2492 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2496 guix install emacs-guix
2500 * Features:: How Guix will make your life brighter.
2501 * Invoking guix package:: Package installation, removal, etc.
2502 * Substitutes:: Downloading pre-built binaries.
2503 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2504 * Invoking guix gc:: Running the garbage collector.
2505 * Invoking guix pull:: Fetching the latest Guix and distribution.
2506 * Channels:: Customizing the package collection.
2507 * Inferiors:: Interacting with another revision of Guix.
2508 * Invoking guix describe:: Display information about your Guix revision.
2509 * Invoking guix archive:: Exporting and importing store files.
2515 When using Guix, each package ends up in the @dfn{package store}, in its
2516 own directory---something that resembles
2517 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2519 Instead of referring to these directories, users have their own
2520 @dfn{profile}, which points to the packages that they actually want to
2521 use. These profiles are stored within each user's home directory, at
2522 @code{$HOME/.guix-profile}.
2524 For example, @code{alice} installs GCC 4.7.2. As a result,
2525 @file{/home/alice/.guix-profile/bin/gcc} points to
2526 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2527 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2528 simply continues to point to
2529 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2530 coexist on the same system without any interference.
2532 The @command{guix package} command is the central tool to manage
2533 packages (@pxref{Invoking guix package}). It operates on the per-user
2534 profiles, and can be used @emph{with normal user privileges}.
2536 @cindex transactions
2537 The command provides the obvious install, remove, and upgrade
2538 operations. Each invocation is actually a @emph{transaction}: either
2539 the specified operation succeeds, or nothing happens. Thus, if the
2540 @command{guix package} process is terminated during the transaction,
2541 or if a power outage occurs during the transaction, then the user's
2542 profile remains in its previous state, and remains usable.
2544 In addition, any package transaction may be @emph{rolled back}. So, if,
2545 for example, an upgrade installs a new version of a package that turns
2546 out to have a serious bug, users may roll back to the previous instance
2547 of their profile, which was known to work well. Similarly, the global
2548 system configuration on Guix is subject to
2549 transactional upgrades and roll-back
2550 (@pxref{Using the Configuration System}).
2552 All packages in the package store may be @emph{garbage-collected}.
2553 Guix can determine which packages are still referenced by user
2554 profiles, and remove those that are provably no longer referenced
2555 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2556 generations of their profile so that the packages they refer to can be
2559 @cindex reproducibility
2560 @cindex reproducible builds
2561 Guix takes a @dfn{purely functional} approach to package
2562 management, as described in the introduction (@pxref{Introduction}).
2563 Each @file{/gnu/store} package directory name contains a hash of all the
2564 inputs that were used to build that package---compiler, libraries, build
2565 scripts, etc. This direct correspondence allows users to make sure a
2566 given package installation matches the current state of their
2567 distribution. It also helps maximize @dfn{build reproducibility}:
2568 thanks to the isolated build environments that are used, a given build
2569 is likely to yield bit-identical files when performed on different
2570 machines (@pxref{Invoking guix-daemon, container}).
2573 This foundation allows Guix to support @dfn{transparent binary/source
2574 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2575 available from an external source---a @dfn{substitute}, Guix just
2576 downloads it and unpacks it;
2577 otherwise, it builds the package from source, locally
2578 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2579 reproducible, users do not have to trust servers that provide
2580 substitutes: they can force a local build and @emph{challenge} providers
2581 (@pxref{Invoking guix challenge}).
2583 Control over the build environment is a feature that is also useful for
2584 developers. The @command{guix environment} command allows developers of
2585 a package to quickly set up the right development environment for their
2586 package, without having to manually install the dependencies of the
2587 package into their profile (@pxref{Invoking guix environment}).
2589 @cindex replication, of software environments
2590 @cindex provenance tracking, of software artifacts
2591 All of Guix and its package definitions is version-controlled, and
2592 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2593 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2594 Guix instance on a different machine or at a later point in time, which in
2595 turn allows you to @emph{replicate complete software environments}, while
2596 retaining precise @dfn{provenance tracking} of the software.
2598 @node Invoking guix package
2599 @section Invoking @command{guix package}
2601 @cindex installing packages
2602 @cindex removing packages
2603 @cindex package installation
2604 @cindex package removal
2605 The @command{guix package} command is the tool that allows users to
2606 install, upgrade, and remove packages, as well as rolling back to
2607 previous configurations. It operates only on the user's own profile,
2608 and works with normal user privileges (@pxref{Features}). Its syntax
2612 guix package @var{options}
2615 @cindex transactions
2616 Primarily, @var{options} specifies the operations to be performed during
2617 the transaction. Upon completion, a new profile is created, but
2618 previous @dfn{generations} of the profile remain available, should the user
2621 For example, to remove @code{lua} and install @code{guile} and
2622 @code{guile-cairo} in a single transaction:
2625 guix package -r lua -i guile guile-cairo
2628 @cindex aliases, for @command{guix package}
2629 For your convenience, we also provide the following aliases:
2633 @command{guix search} is an alias for @command{guix package -s},
2635 @command{guix install} is an alias for @command{guix package -i},
2637 @command{guix remove} is an alias for @command{guix package -r},
2639 and @command{guix upgrade} is an alias for @command{guix package -u}.
2642 These aliases are less expressive than @command{guix package} and provide
2643 fewer options, so in some cases you'll probably want to use @command{guix
2646 @command{guix package} also supports a @dfn{declarative approach}
2647 whereby the user specifies the exact set of packages to be available and
2648 passes it @i{via} the @option{--manifest} option
2649 (@pxref{profile-manifest, @option{--manifest}}).
2652 For each user, a symlink to the user's default profile is automatically
2653 created in @file{$HOME/.guix-profile}. This symlink always points to the
2654 current generation of the user's default profile. Thus, users can add
2655 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2656 variable, and so on.
2657 @cindex search paths
2658 If you are not using Guix System, consider adding the
2659 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2660 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2661 shells get all the right environment variable definitions:
2664 GUIX_PROFILE="$HOME/.guix-profile" ; \
2665 source "$HOME/.guix-profile/etc/profile"
2668 In a multi-user setup, user profiles are stored in a place registered as
2669 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2670 to (@pxref{Invoking guix gc}). That directory is normally
2671 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2672 @var{localstatedir} is the value passed to @code{configure} as
2673 @code{--localstatedir}, and @var{user} is the user name. The
2674 @file{per-user} directory is created when @command{guix-daemon} is
2675 started, and the @var{user} sub-directory is created by @command{guix
2678 The @var{options} can be among the following:
2682 @item --install=@var{package} @dots{}
2683 @itemx -i @var{package} @dots{}
2684 Install the specified @var{package}s.
2686 Each @var{package} may specify either a simple package name, such as
2687 @code{guile}, or a package name followed by an at-sign and version number,
2688 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2689 case, the newest version prefixed by @code{1.8} is selected.)
2691 If no version number is specified, the
2692 newest available version will be selected. In addition, @var{package}
2693 may contain a colon, followed by the name of one of the outputs of the
2694 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2695 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2696 name (and optionally version) are searched for among the GNU
2697 distribution modules (@pxref{Package Modules}).
2699 @cindex propagated inputs
2700 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2701 that automatically get installed along with the required package
2702 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2703 @code{package} objects}, for information about propagated inputs in
2704 package definitions).
2706 @anchor{package-cmd-propagated-inputs}
2707 An example is the GNU MPC library: its C header files refer to those of
2708 the GNU MPFR library, which in turn refer to those of the GMP library.
2709 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2710 in the profile; removing MPC also removes MPFR and GMP---unless they had
2711 also been explicitly installed by the user.
2713 Besides, packages sometimes rely on the definition of environment
2714 variables for their search paths (see explanation of
2715 @code{--search-paths} below). Any missing or possibly incorrect
2716 environment variable definitions are reported here.
2718 @item --install-from-expression=@var{exp}
2720 Install the package @var{exp} evaluates to.
2722 @var{exp} must be a Scheme expression that evaluates to a
2723 @code{<package>} object. This option is notably useful to disambiguate
2724 between same-named variants of a package, with expressions such as
2725 @code{(@@ (gnu packages base) guile-final)}.
2727 Note that this option installs the first output of the specified
2728 package, which may be insufficient when needing a specific output of a
2729 multiple-output package.
2731 @item --install-from-file=@var{file}
2732 @itemx -f @var{file}
2733 Install the package that the code within @var{file} evaluates to.
2735 As an example, @var{file} might contain a definition like this
2736 (@pxref{Defining Packages}):
2739 @verbatiminclude package-hello.scm
2742 Developers may find it useful to include such a @file{guix.scm} file
2743 in the root of their project source tree that can be used to test
2744 development snapshots and create reproducible development environments
2745 (@pxref{Invoking guix environment}).
2747 @item --remove=@var{package} @dots{}
2748 @itemx -r @var{package} @dots{}
2749 Remove the specified @var{package}s.
2751 As for @code{--install}, each @var{package} may specify a version number
2752 and/or output name in addition to the package name. For instance,
2753 @code{-r glibc:debug} would remove the @code{debug} output of
2756 @item --upgrade[=@var{regexp} @dots{}]
2757 @itemx -u [@var{regexp} @dots{}]
2758 @cindex upgrading packages
2759 Upgrade all the installed packages. If one or more @var{regexp}s are
2760 specified, upgrade only installed packages whose name matches a
2761 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2763 Note that this upgrades package to the latest version of packages found
2764 in the distribution currently installed. To update your distribution,
2765 you should regularly run @command{guix pull} (@pxref{Invoking guix
2768 @item --do-not-upgrade[=@var{regexp} @dots{}]
2769 When used together with the @code{--upgrade} option, do @emph{not}
2770 upgrade any packages whose name matches a @var{regexp}. For example, to
2771 upgrade all packages in the current profile except those containing the
2772 substring ``emacs'':
2775 $ guix package --upgrade . --do-not-upgrade emacs
2778 @item @anchor{profile-manifest}--manifest=@var{file}
2779 @itemx -m @var{file}
2780 @cindex profile declaration
2781 @cindex profile manifest
2782 Create a new generation of the profile from the manifest object
2783 returned by the Scheme code in @var{file}.
2785 This allows you to @emph{declare} the profile's contents rather than
2786 constructing it through a sequence of @code{--install} and similar
2787 commands. The advantage is that @var{file} can be put under version
2788 control, copied to different machines to reproduce the same profile, and
2791 @c FIXME: Add reference to (guix profile) documentation when available.
2792 @var{file} must return a @dfn{manifest} object, which is roughly a list
2795 @findex packages->manifest
2797 (use-package-modules guile emacs)
2802 ;; Use a specific package output.
2803 (list guile-2.0 "debug")))
2806 @findex specifications->manifest
2807 In this example we have to know which modules define the @code{emacs}
2808 and @code{guile-2.0} variables to provide the right
2809 @code{use-package-modules} line, which can be cumbersome. We can
2810 instead provide regular package specifications and let
2811 @code{specifications->manifest} look up the corresponding package
2815 (specifications->manifest
2816 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2820 @cindex rolling back
2821 @cindex undoing transactions
2822 @cindex transactions, undoing
2823 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2824 the last transaction.
2826 When combined with options such as @code{--install}, roll back occurs
2827 before any other actions.
2829 When rolling back from the first generation that actually contains
2830 installed packages, the profile is made to point to the @dfn{zeroth
2831 generation}, which contains no files apart from its own metadata.
2833 After having rolled back, installing, removing, or upgrading packages
2834 overwrites previous future generations. Thus, the history of the
2835 generations in a profile is always linear.
2837 @item --switch-generation=@var{pattern}
2838 @itemx -S @var{pattern}
2840 Switch to a particular generation defined by @var{pattern}.
2842 @var{pattern} may be either a generation number or a number prefixed
2843 with ``+'' or ``-''. The latter means: move forward/backward by a
2844 specified number of generations. For example, if you want to return to
2845 the latest generation after @code{--roll-back}, use
2846 @code{--switch-generation=+1}.
2848 The difference between @code{--roll-back} and
2849 @code{--switch-generation=-1} is that @code{--switch-generation} will
2850 not make a zeroth generation, so if a specified generation does not
2851 exist, the current generation will not be changed.
2853 @item --search-paths[=@var{kind}]
2854 @cindex search paths
2855 Report environment variable definitions, in Bash syntax, that may be
2856 needed in order to use the set of installed packages. These environment
2857 variables are used to specify @dfn{search paths} for files used by some
2858 of the installed packages.
2860 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2861 environment variables to be defined so it can look for headers and
2862 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2863 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2864 library are installed in the profile, then @code{--search-paths} will
2865 suggest setting these variables to @code{@var{profile}/include} and
2866 @code{@var{profile}/lib}, respectively.
2868 The typical use case is to define these environment variables in the
2872 $ eval `guix package --search-paths`
2875 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2876 meaning that the returned environment variable definitions will either
2877 be exact settings, or prefixes or suffixes of the current value of these
2878 variables. When omitted, @var{kind} defaults to @code{exact}.
2880 This option can also be used to compute the @emph{combined} search paths
2881 of several profiles. Consider this example:
2884 $ guix package -p foo -i guile
2885 $ guix package -p bar -i guile-json
2886 $ guix package -p foo -p bar --search-paths
2889 The last command above reports about the @code{GUILE_LOAD_PATH}
2890 variable, even though, taken individually, neither @file{foo} nor
2891 @file{bar} would lead to that recommendation.
2894 @item --profile=@var{profile}
2895 @itemx -p @var{profile}
2896 Use @var{profile} instead of the user's default profile.
2898 @cindex collisions, in a profile
2899 @cindex colliding packages in profiles
2900 @cindex profile collisions
2901 @item --allow-collisions
2902 Allow colliding packages in the new profile. Use at your own risk!
2904 By default, @command{guix package} reports as an error @dfn{collisions}
2905 in the profile. Collisions happen when two or more different versions
2906 or variants of a given package end up in the profile.
2909 Use the bootstrap Guile to build the profile. This option is only
2910 useful to distribution developers.
2914 In addition to these actions, @command{guix package} supports the
2915 following options to query the current state of a profile, or the
2916 availability of packages:
2920 @item --search=@var{regexp}
2921 @itemx -s @var{regexp}
2922 @cindex searching for packages
2923 List the available packages whose name, synopsis, or description matches
2924 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2925 Print all the metadata of matching packages in
2926 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2927 GNU recutils manual}).
2929 This allows specific fields to be extracted using the @command{recsel}
2930 command, for instance:
2933 $ guix package -s malloc | recsel -p name,version,relevance
2947 Similarly, to show the name of all the packages available under the
2948 terms of the GNU@tie{}LGPL version 3:
2951 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2958 It is also possible to refine search results using several @code{-s} flags to
2959 @command{guix package}, or several arguments to @command{guix search}. For
2960 example, the following command returns a list of board games (this time using
2961 the @command{guix search} alias):
2964 $ guix search '\<board\>' game | recsel -p name
2969 If we were to omit @code{-s game}, we would also get software packages
2970 that deal with printed circuit boards; removing the angle brackets
2971 around @code{board} would further add packages that have to do with
2974 And now for a more elaborate example. The following command searches
2975 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2976 libraries, and prints the name and synopsis of the matching packages:
2979 $ guix search crypto library | \
2980 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2984 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2985 information on @dfn{selection expressions} for @code{recsel -e}.
2987 @item --show=@var{package}
2988 Show details about @var{package}, taken from the list of available packages, in
2989 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2993 $ guix package --show=python | recsel -p name,version
3001 You may also specify the full name of a package to only get details about a
3002 specific version of it:
3004 $ guix package --show=python@@3.4 | recsel -p name,version
3011 @item --list-installed[=@var{regexp}]
3012 @itemx -I [@var{regexp}]
3013 List the currently installed packages in the specified profile, with the
3014 most recently installed packages shown last. When @var{regexp} is
3015 specified, list only installed packages whose name matches @var{regexp}.
3017 For each installed package, print the following items, separated by
3018 tabs: the package name, its version string, the part of the package that
3019 is installed (for instance, @code{out} for the default output,
3020 @code{include} for its headers, etc.), and the path of this package in
3023 @item --list-available[=@var{regexp}]
3024 @itemx -A [@var{regexp}]
3025 List packages currently available in the distribution for this system
3026 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3027 installed packages whose name matches @var{regexp}.
3029 For each package, print the following items separated by tabs: its name,
3030 its version string, the parts of the package (@pxref{Packages with
3031 Multiple Outputs}), and the source location of its definition.
3033 @item --list-generations[=@var{pattern}]
3034 @itemx -l [@var{pattern}]
3036 Return a list of generations along with their creation dates; for each
3037 generation, show the installed packages, with the most recently
3038 installed packages shown last. Note that the zeroth generation is never
3041 For each installed package, print the following items, separated by
3042 tabs: the name of a package, its version string, the part of the package
3043 that is installed (@pxref{Packages with Multiple Outputs}), and the
3044 location of this package in the store.
3046 When @var{pattern} is used, the command returns only matching
3047 generations. Valid patterns include:
3050 @item @emph{Integers and comma-separated integers}. Both patterns denote
3051 generation numbers. For instance, @code{--list-generations=1} returns
3054 And @code{--list-generations=1,8,2} outputs three generations in the
3055 specified order. Neither spaces nor trailing commas are allowed.
3057 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3058 specified generations and everything in between. Note that the start of
3059 a range must be smaller than its end.
3061 It is also possible to omit the endpoint. For example,
3062 @code{--list-generations=2..}, returns all generations starting from the
3065 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3066 or months by passing an integer along with the first letter of the
3067 duration. For example, @code{--list-generations=20d} lists generations
3068 that are up to 20 days old.
3071 @item --delete-generations[=@var{pattern}]
3072 @itemx -d [@var{pattern}]
3073 When @var{pattern} is omitted, delete all generations except the current
3076 This command accepts the same patterns as @option{--list-generations}.
3077 When @var{pattern} is specified, delete the matching generations. When
3078 @var{pattern} specifies a duration, generations @emph{older} than the
3079 specified duration match. For instance, @code{--delete-generations=1m}
3080 deletes generations that are more than one month old.
3082 If the current generation matches, it is @emph{not} deleted. Also, the
3083 zeroth generation is never deleted.
3085 Note that deleting generations prevents rolling back to them.
3086 Consequently, this command must be used with care.
3090 Finally, since @command{guix package} may actually start build
3091 processes, it supports all the common build options (@pxref{Common Build
3092 Options}). It also supports package transformation options, such as
3093 @option{--with-source} (@pxref{Package Transformation Options}).
3094 However, note that package transformations are lost when upgrading; to
3095 preserve transformations across upgrades, you should define your own
3096 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3097 (@pxref{Defining Packages}).
3100 @section Substitutes
3103 @cindex pre-built binaries
3104 Guix supports transparent source/binary deployment, which means that it
3105 can either build things locally, or download pre-built items from a
3106 server, or both. We call these pre-built items @dfn{substitutes}---they
3107 are substitutes for local build results. In many cases, downloading a
3108 substitute is much faster than building things locally.
3110 Substitutes can be anything resulting from a derivation build
3111 (@pxref{Derivations}). Of course, in the common case, they are
3112 pre-built package binaries, but source tarballs, for instance, which
3113 also result from derivation builds, can be available as substitutes.
3116 * Official Substitute Server:: One particular source of substitutes.
3117 * Substitute Server Authorization:: How to enable or disable substitutes.
3118 * Substitute Authentication:: How Guix verifies substitutes.
3119 * Proxy Settings:: How to get substitutes via proxy.
3120 * Substitution Failure:: What happens when substitution fails.
3121 * On Trusting Binaries:: How can you trust that binary blob?
3124 @node Official Substitute Server
3125 @subsection Official Substitute Server
3129 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3130 that builds packages from Guix continuously for some
3131 architectures, and makes them available as substitutes. This is the
3132 default source of substitutes; it can be overridden by passing the
3133 @option{--substitute-urls} option either to @command{guix-daemon}
3134 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3135 or to client tools such as @command{guix package}
3136 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3139 Substitute URLs can be either HTTP or HTTPS.
3140 HTTPS is recommended because communications are encrypted; conversely,
3141 using HTTP makes all communications visible to an eavesdropper, who
3142 could use the information gathered to determine, for instance, whether
3143 your system has unpatched security vulnerabilities.
3145 Substitutes from the official build farm are enabled by default when
3146 using Guix System (@pxref{GNU Distribution}). However,
3147 they are disabled by default when using Guix on a foreign distribution,
3148 unless you have explicitly enabled them via one of the recommended
3149 installation steps (@pxref{Installation}). The following paragraphs
3150 describe how to enable or disable substitutes for the official build
3151 farm; the same procedure can also be used to enable substitutes for any
3152 other substitute server.
3154 @node Substitute Server Authorization
3155 @subsection Substitute Server Authorization
3158 @cindex substitutes, authorization thereof
3159 @cindex access control list (ACL), for substitutes
3160 @cindex ACL (access control list), for substitutes
3161 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3163 must add its public key to the access control list (ACL) of archive
3164 imports, using the @command{guix archive} command (@pxref{Invoking guix
3165 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3166 be compromised and to serve genuine substitutes.
3168 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3169 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3170 the installation prefix of Guix. If you installed Guix from source,
3171 make sure you checked the GPG signature of
3172 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3173 Then, you can run something like this:
3176 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3180 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3181 of an independent build farm also run by the project, reachable at
3182 @indicateurl{https://mirror.hydra.gnu.org}.
3185 Once this is in place, the output of a command like @code{guix build}
3186 should change from something like:
3189 $ guix build emacs --dry-run
3190 The following derivations would be built:
3191 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3192 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3193 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3194 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3202 $ guix build emacs --dry-run
3203 112.3 MB would be downloaded:
3204 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3205 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3206 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3207 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3212 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3213 will be downloaded, when possible, for future builds.
3215 @cindex substitutes, how to disable
3216 The substitute mechanism can be disabled globally by running
3217 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3218 guix-daemon}). It can also be disabled temporarily by passing the
3219 @code{--no-substitutes} option to @command{guix package}, @command{guix
3220 build}, and other command-line tools.
3222 @node Substitute Authentication
3223 @subsection Substitute Authentication
3225 @cindex digital signatures
3226 Guix detects and raises an error when attempting to use a substitute
3227 that has been tampered with. Likewise, it ignores substitutes that are
3228 not signed, or that are not signed by one of the keys listed in the ACL.
3230 There is one exception though: if an unauthorized server provides
3231 substitutes that are @emph{bit-for-bit identical} to those provided by
3232 an authorized server, then the unauthorized server becomes eligible for
3233 downloads. For example, assume we have chosen two substitute servers
3237 --substitute-urls="https://a.example.org https://b.example.org"
3241 @cindex reproducible builds
3242 If the ACL contains only the key for @code{b.example.org}, and if
3243 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3244 then Guix will download substitutes from @code{a.example.org} because it
3245 comes first in the list and can be considered a mirror of
3246 @code{b.example.org}. In practice, independent build machines usually
3247 produce the same binaries, thanks to bit-reproducible builds (see
3250 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3251 (in other words, the server is not authenticated), contrary to what
3252 HTTPS clients such as Web browsers usually do. This is because Guix
3253 authenticates substitute information itself, as explained above, which
3254 is what we care about (whereas X.509 certificates are about
3255 authenticating bindings between domain names and public keys.)
3257 @node Proxy Settings
3258 @subsection Proxy Settings
3261 Substitutes are downloaded over HTTP or HTTPS.
3262 The @code{http_proxy} environment
3263 variable can be set in the environment of @command{guix-daemon} and is
3264 honored for downloads of substitutes. Note that the value of
3265 @code{http_proxy} in the environment where @command{guix build},
3266 @command{guix package}, and other client commands are run has
3267 @emph{absolutely no effect}.
3269 @node Substitution Failure
3270 @subsection Substitution Failure
3272 Even when a substitute for a derivation is available, sometimes the
3273 substitution attempt will fail. This can happen for a variety of
3274 reasons: the substitute server might be offline, the substitute may
3275 recently have been deleted, the connection might have been interrupted,
3278 When substitutes are enabled and a substitute for a derivation is
3279 available, but the substitution attempt fails, Guix will attempt to
3280 build the derivation locally depending on whether or not
3281 @code{--fallback} was given (@pxref{fallback-option,, common build
3282 option @code{--fallback}}). Specifically, if @code{--fallback} was
3283 omitted, then no local build will be performed, and the derivation is
3284 considered to have failed. However, if @code{--fallback} was given,
3285 then Guix will attempt to build the derivation locally, and the success
3286 or failure of the derivation depends on the success or failure of the
3287 local build. Note that when substitutes are disabled or no substitute
3288 is available for the derivation in question, a local build will
3289 @emph{always} be performed, regardless of whether or not
3290 @code{--fallback} was given.
3292 To get an idea of how many substitutes are available right now, you can
3293 try running the @command{guix weather} command (@pxref{Invoking guix
3294 weather}). This command provides statistics on the substitutes provided
3297 @node On Trusting Binaries
3298 @subsection On Trusting Binaries
3300 @cindex trust, of pre-built binaries
3301 Today, each individual's control over their own computing is at the
3302 mercy of institutions, corporations, and groups with enough power and
3303 determination to subvert the computing infrastructure and exploit its
3304 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3305 convenient, we encourage users to also build on their own, or even run
3306 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3307 interesting target. One way to help is by publishing the software you
3308 build using @command{guix publish} so that others have one more choice
3309 of server to download substitutes from (@pxref{Invoking guix publish}).
3311 Guix has the foundations to maximize build reproducibility
3312 (@pxref{Features}). In most cases, independent builds of a given
3313 package or derivation should yield bit-identical results. Thus, through
3314 a diverse set of independent package builds, we can strengthen the
3315 integrity of our systems. The @command{guix challenge} command aims to
3316 help users assess substitute servers, and to assist developers in
3317 finding out about non-deterministic package builds (@pxref{Invoking guix
3318 challenge}). Similarly, the @option{--check} option of @command{guix
3319 build} allows users to check whether previously-installed substitutes
3320 are genuine by rebuilding them locally (@pxref{build-check,
3321 @command{guix build --check}}).
3323 In the future, we want Guix to have support to publish and retrieve
3324 binaries to/from other users, in a peer-to-peer fashion. If you would
3325 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3327 @node Packages with Multiple Outputs
3328 @section Packages with Multiple Outputs
3330 @cindex multiple-output packages
3331 @cindex package outputs
3334 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3335 source package leads to exactly one directory in the store. When running
3336 @command{guix install glibc}, one installs the default output of the
3337 GNU libc package; the default output is called @code{out}, but its name
3338 can be omitted as shown in this command. In this particular case, the
3339 default output of @code{glibc} contains all the C header files, shared
3340 libraries, static libraries, Info documentation, and other supporting
3343 Sometimes it is more appropriate to separate the various types of files
3344 produced from a single source package into separate outputs. For
3345 instance, the GLib C library (used by GTK+ and related packages)
3346 installs more than 20 MiB of reference documentation as HTML pages.
3347 To save space for users who do not need it, the documentation goes to a
3348 separate output, called @code{doc}. To install the main GLib output,
3349 which contains everything but the documentation, one would run:
3355 @cindex documentation
3356 The command to install its documentation is:
3359 guix install glib:doc
3362 Some packages install programs with different ``dependency footprints''.
3363 For instance, the WordNet package installs both command-line tools and
3364 graphical user interfaces (GUIs). The former depend solely on the C
3365 library, whereas the latter depend on Tcl/Tk and the underlying X
3366 libraries. In this case, we leave the command-line tools in the default
3367 output, whereas the GUIs are in a separate output. This allows users
3368 who do not need the GUIs to save space. The @command{guix size} command
3369 can help find out about such situations (@pxref{Invoking guix size}).
3370 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3372 There are several such multiple-output packages in the GNU distribution.
3373 Other conventional output names include @code{lib} for libraries and
3374 possibly header files, @code{bin} for stand-alone programs, and
3375 @code{debug} for debugging information (@pxref{Installing Debugging
3376 Files}). The outputs of a packages are listed in the third column of
3377 the output of @command{guix package --list-available} (@pxref{Invoking
3381 @node Invoking guix gc
3382 @section Invoking @command{guix gc}
3384 @cindex garbage collector
3386 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3387 The @command{guix gc} command allows users to explicitly run the garbage
3388 collector to reclaim space from the @file{/gnu/store} directory. It is
3389 the @emph{only} way to remove files from @file{/gnu/store}---removing
3390 files or directories manually may break it beyond repair!
3393 @cindex garbage collector roots
3394 The garbage collector has a set of known @dfn{roots}: any file under
3395 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3396 cannot be deleted; any other file is considered @dfn{dead} and may be
3397 deleted. The set of garbage collector roots (``GC roots'' for short)
3398 includes default user profiles; by default, the symlinks under
3399 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3400 added with @command{guix build --root}, for example (@pxref{Invoking
3401 guix build}). The @command{guix gc --list-roots} command lists them.
3403 Prior to running @code{guix gc --collect-garbage} to make space, it is
3404 often useful to remove old generations from user profiles; that way, old
3405 package builds referenced by those generations can be reclaimed. This
3406 is achieved by running @code{guix package --delete-generations}
3407 (@pxref{Invoking guix package}).
3409 Our recommendation is to run a garbage collection periodically, or when
3410 you are short on disk space. For instance, to guarantee that at least
3411 5@tie{}GB are available on your disk, simply run:
3417 It is perfectly safe to run as a non-interactive periodic job
3418 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3419 Running @command{guix gc} with no arguments will collect as
3420 much garbage as it can, but that is often inconvenient: you may find
3421 yourself having to rebuild or re-download software that is ``dead'' from
3422 the GC viewpoint but that is necessary to build other pieces of
3423 software---e.g., the compiler tool chain.
3425 The @command{guix gc} command has three modes of operation: it can be
3426 used to garbage-collect any dead files (the default), to delete specific
3427 files (the @code{--delete} option), to print garbage-collector
3428 information, or for more advanced queries. The garbage collection
3429 options are as follows:
3432 @item --collect-garbage[=@var{min}]
3433 @itemx -C [@var{min}]
3434 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3435 sub-directories. This is the default operation when no option is
3438 When @var{min} is given, stop once @var{min} bytes have been collected.
3439 @var{min} may be a number of bytes, or it may include a unit as a
3440 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3441 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3443 When @var{min} is omitted, collect all the garbage.
3445 @item --free-space=@var{free}
3446 @itemx -F @var{free}
3447 Collect garbage until @var{free} space is available under
3448 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3449 as @code{500MiB}, as described above.
3451 When @var{free} or more is already available in @file{/gnu/store}, do
3452 nothing and exit immediately.
3454 @item --delete-generations[=@var{duration}]
3455 @itemx -d [@var{duration}]
3456 Before starting the garbage collection process, delete all the generations
3457 older than @var{duration}, for all the user profiles; when run as root, this
3458 applies to all the profiles @emph{of all the users}.
3460 For example, this command deletes all the generations of all your profiles
3461 that are older than 2 months (except generations that are current), and then
3462 proceeds to free space until at least 10 GiB are available:
3465 guix gc -d 2m -F 10G
3470 Attempt to delete all the store files and directories specified as
3471 arguments. This fails if some of the files are not in the store, or if
3472 they are still live.
3474 @item --list-failures
3475 List store items corresponding to cached build failures.
3477 This prints nothing unless the daemon was started with
3478 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3479 @option{--cache-failures}}).
3482 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3485 @item --clear-failures
3486 Remove the specified store items from the failed-build cache.
3488 Again, this option only makes sense when the daemon is started with
3489 @option{--cache-failures}. Otherwise, it does nothing.
3492 Show the list of dead files and directories still present in the
3493 store---i.e., files and directories no longer reachable from any root.
3496 Show the list of live store files and directories.
3500 In addition, the references among existing store files can be queried:
3506 @cindex package dependencies
3507 List the references (respectively, the referrers) of store files given
3513 List the requisites of the store files passed as arguments. Requisites
3514 include the store files themselves, their references, and the references
3515 of these, recursively. In other words, the returned list is the
3516 @dfn{transitive closure} of the store files.
3518 @xref{Invoking guix size}, for a tool to profile the size of the closure
3519 of an element. @xref{Invoking guix graph}, for a tool to visualize
3520 the graph of references.
3524 Return the derivation(s) leading to the given store items
3525 (@pxref{Derivations}).
3527 For example, this command:
3530 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3534 returns the @file{.drv} file(s) leading to the @code{emacs} package
3535 installed in your profile.
3537 Note that there may be zero matching @file{.drv} files, for instance
3538 because these files have been garbage-collected. There can also be more
3539 than one matching @file{.drv} due to fixed-output derivations.
3542 Lastly, the following options allow you to check the integrity of the
3543 store and to control disk usage.
3547 @item --verify[=@var{options}]
3548 @cindex integrity, of the store
3549 @cindex integrity checking
3550 Verify the integrity of the store.
3552 By default, make sure that all the store items marked as valid in the
3553 database of the daemon actually exist in @file{/gnu/store}.
3555 When provided, @var{options} must be a comma-separated list containing one
3556 or more of @code{contents} and @code{repair}.
3558 When passing @option{--verify=contents}, the daemon computes the
3559 content hash of each store item and compares it against its hash in the
3560 database. Hash mismatches are reported as data corruptions. Because it
3561 traverses @emph{all the files in the store}, this command can take a
3562 long time, especially on systems with a slow disk drive.
3564 @cindex repairing the store
3565 @cindex corruption, recovering from
3566 Using @option{--verify=repair} or @option{--verify=contents,repair}
3567 causes the daemon to try to repair corrupt store items by fetching
3568 substitutes for them (@pxref{Substitutes}). Because repairing is not
3569 atomic, and thus potentially dangerous, it is available only to the
3570 system administrator. A lightweight alternative, when you know exactly
3571 which items in the store are corrupt, is @command{guix build --repair}
3572 (@pxref{Invoking guix build}).
3575 @cindex deduplication
3576 Optimize the store by hard-linking identical files---this is
3577 @dfn{deduplication}.
3579 The daemon performs deduplication after each successful build or archive
3580 import, unless it was started with @code{--disable-deduplication}
3581 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3582 this option is primarily useful when the daemon was running with
3583 @code{--disable-deduplication}.
3587 @node Invoking guix pull
3588 @section Invoking @command{guix pull}
3590 @cindex upgrading Guix
3591 @cindex updating Guix
3592 @cindex @command{guix pull}
3594 Packages are installed or upgraded to the latest version available in
3595 the distribution currently available on your local machine. To update
3596 that distribution, along with the Guix tools, you must run @command{guix
3597 pull}: the command downloads the latest Guix source code and package
3598 descriptions, and deploys it. Source code is downloaded from a
3599 @uref{https://git-scm.com, Git} repository, by default the official
3600 GNU@tie{}Guix repository, though this can be customized.
3602 On completion, @command{guix package} will use packages and package
3603 versions from this just-retrieved copy of Guix. Not only that, but all
3604 the Guix commands and Scheme modules will also be taken from that latest
3605 version. New @command{guix} sub-commands added by the update also
3608 Any user can update their Guix copy using @command{guix pull}, and the
3609 effect is limited to the user who run @command{guix pull}. For
3610 instance, when user @code{root} runs @command{guix pull}, this has no
3611 effect on the version of Guix that user @code{alice} sees, and vice
3614 The result of running @command{guix pull} is a @dfn{profile} available
3615 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3616 make sure to add it to the beginning of your search path so that you use
3617 the latest version, and similarly for the Info manual
3618 (@pxref{Documentation}):
3621 export PATH="$HOME/.config/guix/current/bin:$PATH"
3622 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3625 The @code{--list-generations} or @code{-l} option lists past generations
3626 produced by @command{guix pull}, along with details about their provenance:
3630 Generation 1 Jun 10 2018 00:18:18
3632 repository URL: https://git.savannah.gnu.org/git/guix.git
3633 branch: origin/master
3634 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3636 Generation 2 Jun 11 2018 11:02:49
3638 repository URL: https://git.savannah.gnu.org/git/guix.git
3639 branch: origin/master
3640 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3641 2 new packages: keepalived, libnfnetlink
3642 6 packages upgraded: emacs-nix-mode@@2.0.4,
3643 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3644 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3646 Generation 3 Jun 13 2018 23:31:07 (current)
3648 repository URL: https://git.savannah.gnu.org/git/guix.git
3649 branch: origin/master
3650 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3651 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3652 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3655 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3656 describe the current status of Guix.
3658 This @code{~/.config/guix/current} profile works like any other profile
3659 created by @command{guix package} (@pxref{Invoking guix package}). That
3660 is, you can list generations, roll back to the previous
3661 generation---i.e., the previous Guix---and so on:
3664 $ guix package -p ~/.config/guix/current --roll-back
3665 switched from generation 3 to 2
3666 $ guix package -p ~/.config/guix/current --delete-generations=1
3667 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3670 The @command{guix pull} command is usually invoked with no arguments,
3671 but it supports the following options:
3674 @item --url=@var{url}
3675 @itemx --commit=@var{commit}
3676 @itemx --branch=@var{branch}
3677 Download code for the @code{guix} channel from the specified @var{url}, at the
3678 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3679 string), or @var{branch}.
3681 @cindex @file{channels.scm}, configuration file
3682 @cindex configuration file for channels
3683 These options are provided for convenience, but you can also specify your
3684 configuration in the @file{~/.config/guix/channels.scm} file or using the
3685 @option{--channels} option (see below).
3687 @item --channels=@var{file}
3688 @itemx -C @var{file}
3689 Read the list of channels from @var{file} instead of
3690 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3691 evaluates to a list of channel objects. @xref{Channels}, for more
3696 Display the list of packages added or upgraded since the previous generation.
3698 This is the same information as displayed upon @command{guix pull} completion,
3699 but without ellipses; it is also similar to the output of @command{guix pull
3700 -l} for the last generation (see below).
3702 @item --list-generations[=@var{pattern}]
3703 @itemx -l [@var{pattern}]
3704 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3705 is provided, the subset of generations that match @var{pattern}.
3706 The syntax of @var{pattern} is the same as with @code{guix package
3707 --list-generations} (@pxref{Invoking guix package}).
3709 @xref{Invoking guix describe}, for a way to display information about the
3710 current generation only.
3712 @item --profile=@var{profile}
3713 @itemx -p @var{profile}
3714 Use @var{profile} instead of @file{~/.config/guix/current}.
3718 Show which channel commit(s) would be used and what would be built or
3719 substituted but do not actually do it.
3721 @item --system=@var{system}
3722 @itemx -s @var{system}
3723 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3724 the system type of the build host.
3727 Produce verbose output, writing build logs to the standard error output.
3730 Use the bootstrap Guile to build the latest Guix. This option is only
3731 useful to Guix developers.
3734 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3735 repository and branch to pull from, as well as @emph{additional} repositories
3736 containing package modules that should be deployed. @xref{Channels}, for more
3739 In addition, @command{guix pull} supports all the common build options
3740 (@pxref{Common Build Options}).
3746 @cindex @file{channels.scm}, configuration file
3747 @cindex configuration file for channels
3748 @cindex @command{guix pull}, configuration file
3749 @cindex configuration of @command{guix pull}
3750 Guix and its package collection are updated by running @command{guix pull}
3751 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3752 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3753 customized by defining @dfn{channels} in the
3754 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3755 of a Git repository to be deployed, and @command{guix pull} can be instructed
3756 to pull from one or more channels. In other words, channels can be used to
3757 @emph{customize} and to @emph{extend} Guix, as we will see below.
3759 @subsection Using a Custom Guix Channel
3761 The channel called @code{guix} specifies where Guix itself---its command-line
3762 tools as well as its package collection---should be downloaded. For instance,
3763 suppose you want to update from your own copy of the Guix repository at
3764 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3765 write in @code{~/.config/guix/channels.scm} this specification:
3768 ;; Tell 'guix pull' to use my own repo.
3771 (url "https://example.org/my-guix.git")
3772 (branch "super-hacks")))
3776 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3777 branch of the repository at @code{example.org}.
3779 @subsection Specifying Additional Channels
3781 @cindex extending the package collection (channels)
3782 @cindex personal packages (channels)
3783 @cindex channels, for personal packages
3784 You can also specify @emph{additional channels} to pull from. Let's say you
3785 have a bunch of custom package variants or personal packages that you think
3786 would make little sense to contribute to the Guix project, but would like to
3787 have these packages transparently available to you at the command line. You
3788 would first write modules containing those package definitions (@pxref{Package
3789 Modules}), maintain them in a Git repository, and then you and anyone else can
3790 use it as an additional channel to get packages from. Neat, no?
3792 @c What follows stems from discussions at
3793 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3794 @c earlier discussions on guix-devel@gnu.org.
3796 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3797 publish your personal channel to the world, we would like to share a few words
3802 Before publishing a channel, please consider contributing your package
3803 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3804 to free software of all sorts, and packages in Guix proper are readily
3805 available to all Guix users and benefit from the project's quality assurance
3809 When you maintain package definitions outside Guix, we, Guix developers,
3810 consider that @emph{the compatibility burden is on you}. Remember that
3811 package modules and package definitions are just Scheme code that uses various
3812 programming interfaces (APIs). We want to remain free to change these APIs to
3813 keep improving Guix, possibly in ways that break your channel. We never
3814 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3818 Corollary: if you're using an external channel and that channel breaks, please
3819 @emph{report the issue to the channel authors}, not to the Guix project.
3822 You've been warned! Having said this, we believe external channels are a
3823 practical way to exert your freedom to augment Guix' package collection and to
3824 share your improvements, which are basic tenets of
3825 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3826 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3829 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3830 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3833 @vindex %default-channels
3835 ;; Add my personal packages to those Guix provides.
3837 (name 'my-personal-packages)
3838 (url "https://example.org/personal-packages.git"))
3843 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3844 add a channel the list of channels that the variable @code{%default-channels}
3845 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3846 Manual}). With this file in place, @command{guix pull} builds not only Guix
3847 but also the package modules from your own repository. The result in
3848 @file{~/.config/guix/current} is the union of Guix with your own package
3852 $ guix pull --list-generations
3854 Generation 19 Aug 27 2018 16:20:48
3856 repository URL: https://git.savannah.gnu.org/git/guix.git
3858 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3859 my-personal-packages dd3df5e
3860 repository URL: https://example.org/personal-packages.git
3862 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3863 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3864 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3868 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3869 both Guix and packages from the @code{my-personal-packages} channel. Among
3870 the new and upgraded packages that are listed, some like @code{my-gimp} and
3871 @code{my-emacs-with-cool-features} might come from
3872 @code{my-personal-packages}, while others come from the Guix default channel.
3874 To create a channel, create a Git repository containing your own package
3875 modules and make it available. The repository can contain anything, but a
3876 useful channel will contain Guile modules that export packages. Once you
3877 start using a channel, Guix will behave as if the root directory of that
3878 channel's Git repository has been added to the Guile load path (@pxref{Load
3879 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3880 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3881 module, then the module will be available under the name @code{(my-packages
3882 my-tools)}, and you will be able to use it like any other module
3883 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3885 @cindex dependencies, channels
3886 @cindex meta-data, channels
3887 @subsection Declaring Channel Dependencies
3889 Channel authors may decide to augment a package collection provided by other
3890 channels. They can declare their channel to be dependent on other channels in
3891 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3892 the channel repository.
3894 The meta-data file should contain a simple S-expression like this:
3901 (name some-collection)
3902 (url "https://example.org/first-collection.git"))
3904 (name some-other-collection)
3905 (url "https://example.org/second-collection.git")
3906 (branch "testing"))))
3909 In the above example this channel is declared to depend on two other channels,
3910 which will both be fetched automatically. The modules provided by the channel
3911 will be compiled in an environment where the modules of all these declared
3912 channels are available.
3914 For the sake of reliability and maintainability, you should avoid dependencies
3915 on channels that you don't control, and you should aim to keep the number of
3916 dependencies to a minimum.
3918 @subsection Replicating Guix
3920 @cindex pinning, channels
3921 @cindex replicating Guix
3922 @cindex reproducibility, of Guix
3923 The @command{guix pull --list-generations} output above shows precisely which
3924 commits were used to build this instance of Guix. We can thus replicate it,
3925 say, on another machine, by providing a channel specification in
3926 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3929 ;; Deploy specific commits of my channels of interest.
3932 (url "https://git.savannah.gnu.org/git/guix.git")
3933 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3935 (name 'my-personal-packages)
3936 (url "https://example.org/personal-packages.git")
3937 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3940 The @command{guix describe --format=channels} command can even generate this
3941 list of channels directly (@pxref{Invoking guix describe}).
3943 At this point the two machines run the @emph{exact same Guix}, with access to
3944 the @emph{exact same packages}. The output of @command{guix build gimp} on
3945 one machine will be exactly the same, bit for bit, as the output of the same
3946 command on the other machine. It also means both machines have access to all
3947 the source code of Guix and, transitively, to all the source code of every
3950 This gives you super powers, allowing you to track the provenance of binary
3951 artifacts with very fine grain, and to reproduce software environments at
3952 will---some sort of ``meta reproducibility'' capabilities, if you will.
3953 @xref{Inferiors}, for another way to take advantage of these super powers.
3958 @c TODO: Remove this once we're more confident about API stability.
3960 The functionality described here is a ``technology preview'' as of version
3961 @value{VERSION}. As such, the interface is subject to change.
3965 @cindex composition of Guix revisions
3966 Sometimes you might need to mix packages from the revision of Guix you're
3967 currently running with packages available in a different revision of Guix.
3968 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3969 revisions in arbitrary ways.
3971 @cindex inferior packages
3972 Technically, an ``inferior'' is essentially a separate Guix process connected
3973 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3974 @code{(guix inferior)} module allows you to create inferiors and to
3975 communicate with them. It also provides a high-level interface to browse and
3976 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3978 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3979 to interact with a separate revision of Guix. For example, let's assume you
3980 want to install in your profile the current @code{guile} package, along with
3981 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3982 because the newer @code{guile-json} has an incompatible API and you want to
3983 run your code against the old API@. To do that, you could write a manifest for
3984 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3985 manifest, you would create an inferior for that old Guix revision you care
3986 about, and you would look up the @code{guile-json} package in the inferior:
3989 (use-modules (guix inferior) (guix channels)
3990 (srfi srfi-1)) ;for 'first'
3993 ;; This is the old revision from which we want to
3994 ;; extract guile-json.
3997 (url "https://git.savannah.gnu.org/git/guix.git")
3999 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4002 ;; An inferior representing the above revision.
4003 (inferior-for-channels channels))
4005 ;; Now create a manifest with the current "guile" package
4006 ;; and the old "guile-json" package.
4008 (list (first (lookup-inferior-packages inferior "guile-json"))
4009 (specification->package "guile")))
4012 On its first run, @command{guix package --manifest} might have to build the
4013 channel you specified before it can create the inferior; subsequent runs will
4014 be much faster because the Guix revision will be cached.
4016 The @code{(guix inferior)} module provides the following procedures to open an
4019 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4020 [#:cache-directory] [#:ttl]
4021 Return an inferior for @var{channels}, a list of channels. Use the cache at
4022 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4023 This procedure opens a new connection to the build daemon.
4025 As a side effect, this procedure may build or substitute binaries for
4026 @var{channels}, which can take time.
4029 @deffn {Scheme Procedure} open-inferior @var{directory} @
4030 [#:command "bin/guix"]
4031 Open the inferior Guix in @var{directory}, running
4032 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4033 the inferior could not be launched.
4036 @cindex inferior packages
4037 The procedures listed below allow you to obtain and manipulate inferior
4040 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4041 Return the list of packages known to @var{inferior}.
4044 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4046 Return the sorted list of inferior packages matching @var{name} in
4047 @var{inferior}, with highest version numbers first. If @var{version} is true,
4048 return only packages with a version number prefixed by @var{version}.
4051 @deffn {Scheme Procedure} inferior-package? @var{obj}
4052 Return true if @var{obj} is an inferior package.
4055 @deffn {Scheme Procedure} inferior-package-name @var{package}
4056 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4057 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4058 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4059 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4060 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4061 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4062 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4063 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4064 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4065 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4066 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4067 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4068 These procedures are the counterpart of package record accessors
4069 (@pxref{package Reference}). Most of them work by querying the inferior
4070 @var{package} comes from, so the inferior must still be live when you call
4074 Inferior packages can be used transparently like any other package or
4075 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4076 transparently handled by the @code{packages->manifest} procedure, which is
4077 commonly use in manifests (@pxref{Invoking guix package, the
4078 @option{--manifest} option of @command{guix package}}). Thus you can insert
4079 an inferior package pretty much anywhere you would insert a regular package:
4080 in manifests, in the @code{packages} field of your @code{operating-system}
4081 declaration, and so on.
4083 @node Invoking guix describe
4084 @section Invoking @command{guix describe}
4086 @cindex reproducibility
4087 @cindex replicating Guix
4088 Often you may want to answer questions like: ``Which revision of Guix am I
4089 using?'' or ``Which channels am I using?'' This is useful information in many
4090 situations: if you want to @emph{replicate} an environment on a different
4091 machine or user account, if you want to report a bug or to determine what
4092 change in the channels you are using caused it, or if you want to record your
4093 system state for reproducibility purposes. The @command{guix describe}
4094 command answers these questions.
4096 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4097 displays the channel(s) that it was built from, including their repository URL
4098 and commit IDs (@pxref{Channels}):
4102 Generation 10 Sep 03 2018 17:32:44 (current)
4104 repository URL: https://git.savannah.gnu.org/git/guix.git
4106 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4109 If you're familiar with the Git version control system, this is similar in
4110 spirit to @command{git describe}; the output is also similar to that of
4111 @command{guix pull --list-generations}, but limited to the current generation
4112 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4113 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4114 information is all it takes to describe the revision of Guix you're using, and
4115 also to replicate it.
4117 To make it easier to replicate Guix, @command{guix describe} can also be asked
4118 to return a list of channels instead of the human-readable description above:
4121 $ guix describe -f channels
4124 (url "https://git.savannah.gnu.org/git/guix.git")
4126 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4130 You can save this to a file and feed it to @command{guix pull -C} on some
4131 other machine or at a later point in time, which will instantiate @emph{this
4132 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4133 From there on, since you're able to deploy the same revision of Guix, you can
4134 just as well @emph{replicate a complete software environment}. We humbly
4135 think that this is @emph{awesome}, and we hope you'll like it too!
4137 The details of the options supported by @command{guix describe} are as
4141 @item --format=@var{format}
4142 @itemx -f @var{format}
4143 Produce output in the specified @var{format}, one of:
4147 produce human-readable output;
4149 produce a list of channel specifications that can be passed to @command{guix
4150 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4154 produce a list of channel specifications in JSON format;
4156 produce a list of channel specifications in Recutils format.
4159 @item --profile=@var{profile}
4160 @itemx -p @var{profile}
4161 Display information about @var{profile}.
4164 @node Invoking guix archive
4165 @section Invoking @command{guix archive}
4167 @cindex @command{guix archive}
4169 The @command{guix archive} command allows users to @dfn{export} files
4170 from the store into a single archive, and to later @dfn{import} them on
4171 a machine that runs Guix.
4172 In particular, it allows store files to be transferred from one machine
4173 to the store on another machine.
4176 If you're looking for a way to produce archives in a format suitable for
4177 tools other than Guix, @pxref{Invoking guix pack}.
4180 @cindex exporting store items
4181 To export store files as an archive to standard output, run:
4184 guix archive --export @var{options} @var{specifications}...
4187 @var{specifications} may be either store file names or package
4188 specifications, as for @command{guix package} (@pxref{Invoking guix
4189 package}). For instance, the following command creates an archive
4190 containing the @code{gui} output of the @code{git} package and the main
4191 output of @code{emacs}:
4194 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4197 If the specified packages are not built yet, @command{guix archive}
4198 automatically builds them. The build process may be controlled with the
4199 common build options (@pxref{Common Build Options}).
4201 To transfer the @code{emacs} package to a machine connected over SSH,
4205 guix archive --export -r emacs | ssh the-machine guix archive --import
4209 Similarly, a complete user profile may be transferred from one machine
4210 to another like this:
4213 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4214 ssh the-machine guix-archive --import
4218 However, note that, in both examples, all of @code{emacs} and the
4219 profile as well as all of their dependencies are transferred (due to
4220 @code{-r}), regardless of what is already available in the store on the
4221 target machine. The @code{--missing} option can help figure out which
4222 items are missing from the target store. The @command{guix copy}
4223 command simplifies and optimizes this whole process, so this is probably
4224 what you should use in this case (@pxref{Invoking guix copy}).
4226 @cindex nar, archive format
4227 @cindex normalized archive (nar)
4228 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4229 comparable in spirit to `tar', but with differences
4230 that make it more appropriate for our purposes. First, rather than
4231 recording all Unix metadata for each file, the nar format only mentions
4232 the file type (regular, directory, or symbolic link); Unix permissions
4233 and owner/group are dismissed. Second, the order in which directory
4234 entries are stored always follows the order of file names according to
4235 the C locale collation order. This makes archive production fully
4238 When exporting, the daemon digitally signs the contents of the archive,
4239 and that digital signature is appended. When importing, the daemon
4240 verifies the signature and rejects the import in case of an invalid
4241 signature or if the signing key is not authorized.
4242 @c FIXME: Add xref to daemon doc about signatures.
4244 The main options are:
4248 Export the specified store files or packages (see below.) Write the
4249 resulting archive to the standard output.
4251 Dependencies are @emph{not} included in the output, unless
4252 @code{--recursive} is passed.
4256 When combined with @code{--export}, this instructs @command{guix
4257 archive} to include dependencies of the given items in the archive.
4258 Thus, the resulting archive is self-contained: it contains the closure
4259 of the exported store items.
4262 Read an archive from the standard input, and import the files listed
4263 therein into the store. Abort if the archive has an invalid digital
4264 signature, or if it is signed by a public key not among the authorized
4265 keys (see @code{--authorize} below.)
4268 Read a list of store file names from the standard input, one per line,
4269 and write on the standard output the subset of these files missing from
4272 @item --generate-key[=@var{parameters}]
4273 @cindex signing, archives
4274 Generate a new key pair for the daemon. This is a prerequisite before
4275 archives can be exported with @code{--export}. Note that this operation
4276 usually takes time, because it needs to gather enough entropy to
4277 generate the key pair.
4279 The generated key pair is typically stored under @file{/etc/guix}, in
4280 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4281 key, which must be kept secret.) When @var{parameters} is omitted,
4282 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4283 versions before 1.6.0, it is a 4096-bit RSA key.
4284 Alternatively, @var{parameters} can specify
4285 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4286 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4287 Libgcrypt Reference Manual}).
4290 @cindex authorizing, archives
4291 Authorize imports signed by the public key passed on standard input.
4292 The public key must be in ``s-expression advanced format''---i.e., the
4293 same format as the @file{signing-key.pub} file.
4295 The list of authorized keys is kept in the human-editable file
4296 @file{/etc/guix/acl}. The file contains
4297 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4298 s-expressions''} and is structured as an access-control list in the
4299 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4302 @item --extract=@var{directory}
4303 @itemx -x @var{directory}
4304 Read a single-item archive as served by substitute servers
4305 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4306 low-level operation needed in only very narrow use cases; see below.
4308 For example, the following command extracts the substitute for Emacs
4309 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4313 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4314 | bunzip2 | guix archive -x /tmp/emacs
4317 Single-item archives are different from multiple-item archives produced
4318 by @command{guix archive --export}; they contain a single store item,
4319 and they do @emph{not} embed a signature. Thus this operation does
4320 @emph{no} signature verification and its output should be considered
4323 The primary purpose of this operation is to facilitate inspection of
4324 archive contents coming from possibly untrusted substitute servers.
4329 @c *********************************************************************
4331 @chapter Development
4333 @cindex software development
4334 If you are a software developer, Guix provides tools that you should find
4335 helpful---independently of the language you're developing in. This is what
4336 this chapter is about.
4338 The @command{guix environment} command provides a convenient way to set up
4339 @dfn{development environments} containing all the dependencies and tools
4340 necessary to work on the software package of your choice. The @command{guix
4341 pack} command allows you to create @dfn{application bundles} that can be
4342 easily distributed to users who do not run Guix.
4345 * Invoking guix environment:: Setting up development environments.
4346 * Invoking guix pack:: Creating software bundles.
4349 @node Invoking guix environment
4350 @section Invoking @command{guix environment}
4352 @cindex reproducible build environments
4353 @cindex development environments
4354 @cindex @command{guix environment}
4355 @cindex environment, package build environment
4356 The purpose of @command{guix environment} is to assist hackers in
4357 creating reproducible development environments without polluting their
4358 package profile. The @command{guix environment} tool takes one or more
4359 packages, builds all of their inputs, and creates a shell
4360 environment to use them.
4362 The general syntax is:
4365 guix environment @var{options} @var{package}@dots{}
4368 The following example spawns a new shell set up for the development of
4372 guix environment guile
4375 If the needed dependencies are not built yet, @command{guix environment}
4376 automatically builds them. The environment of the new shell is an augmented
4377 version of the environment that @command{guix environment} was run in.
4378 It contains the necessary search paths for building the given package
4379 added to the existing environment variables. To create a ``pure''
4380 environment, in which the original environment variables have been unset,
4381 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4382 environment variables such as @code{PATH} in their @file{~/.bashrc}
4383 file. As a consequence, when @code{guix environment} launches it, Bash
4384 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4385 environment variables. It is an error to define such environment
4386 variables in @file{.bashrc}; instead, they should be defined in
4387 @file{.bash_profile}, which is sourced only by log-in shells.
4388 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4389 details on Bash start-up files.}.
4391 @vindex GUIX_ENVIRONMENT
4392 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4393 variable in the shell it spawns; its value is the file name of the
4394 profile of this environment. This allows users to, say, define a
4395 specific prompt for development environments in their @file{.bashrc}
4396 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4399 if [ -n "$GUIX_ENVIRONMENT" ]
4401 export PS1="\u@@\h \w [dev]\$ "
4406 ...@: or to browse the profile:
4409 $ ls "$GUIX_ENVIRONMENT/bin"
4412 Additionally, more than one package may be specified, in which case the
4413 union of the inputs for the given packages are used. For example, the
4414 command below spawns a shell where all of the dependencies of both Guile
4415 and Emacs are available:
4418 guix environment guile emacs
4421 Sometimes an interactive shell session is not desired. An arbitrary
4422 command may be invoked by placing the @code{--} token to separate the
4423 command from the rest of the arguments:
4426 guix environment guile -- make -j4
4429 In other situations, it is more convenient to specify the list of
4430 packages needed in the environment. For example, the following command
4431 runs @command{python} from an environment containing Python@tie{}2.7 and
4435 guix environment --ad-hoc python2-numpy python-2.7 -- python
4438 Furthermore, one might want the dependencies of a package and also some
4439 additional packages that are not build-time or runtime dependencies, but
4440 are useful when developing nonetheless. Because of this, the
4441 @code{--ad-hoc} flag is positional. Packages appearing before
4442 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4443 added to the environment. Packages appearing after are interpreted as
4444 packages that will be added to the environment directly. For example,
4445 the following command creates a Guix development environment that
4446 additionally includes Git and strace:
4449 guix environment guix --ad-hoc git strace
4452 Sometimes it is desirable to isolate the environment as much as
4453 possible, for maximal purity and reproducibility. In particular, when
4454 using Guix on a host distro that is not Guix System, it is desirable to
4455 prevent access to @file{/usr/bin} and other system-wide resources from
4456 the development environment. For example, the following command spawns
4457 a Guile REPL in a ``container'' where only the store and the current
4458 working directory are mounted:
4461 guix environment --ad-hoc --container guile -- guile
4465 The @code{--container} option requires Linux-libre 3.19 or newer.
4468 The available options are summarized below.
4471 @item --root=@var{file}
4472 @itemx -r @var{file}
4473 @cindex persistent environment
4474 @cindex garbage collector root, for environments
4475 Make @var{file} a symlink to the profile for this environment, and
4476 register it as a garbage collector root.
4478 This is useful if you want to protect your environment from garbage
4479 collection, to make it ``persistent''.
4481 When this option is omitted, the environment is protected from garbage
4482 collection only for the duration of the @command{guix environment}
4483 session. This means that next time you recreate the same environment,
4484 you could have to rebuild or re-download packages. @xref{Invoking guix
4485 gc}, for more on GC roots.
4487 @item --expression=@var{expr}
4488 @itemx -e @var{expr}
4489 Create an environment for the package or list of packages that
4490 @var{expr} evaluates to.
4492 For example, running:
4495 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4498 starts a shell with the environment for this specific variant of the
4504 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4507 starts a shell with all the base system packages available.
4509 The above commands only use the default output of the given packages.
4510 To select other outputs, two element tuples can be specified:
4513 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4516 @item --load=@var{file}
4517 @itemx -l @var{file}
4518 Create an environment for the package or list of packages that the code
4519 within @var{file} evaluates to.
4521 As an example, @var{file} might contain a definition like this
4522 (@pxref{Defining Packages}):
4525 @verbatiminclude environment-gdb.scm
4528 @item --manifest=@var{file}
4529 @itemx -m @var{file}
4530 Create an environment for the packages contained in the manifest object
4531 returned by the Scheme code in @var{file}.
4533 This is similar to the same-named option in @command{guix package}
4534 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4538 Include all specified packages in the resulting environment, as if an
4539 @i{ad hoc} package were defined with them as inputs. This option is
4540 useful for quickly creating an environment without having to write a
4541 package expression to contain the desired inputs.
4543 For instance, the command:
4546 guix environment --ad-hoc guile guile-sdl -- guile
4549 runs @command{guile} in an environment where Guile and Guile-SDL are
4552 Note that this example implicitly asks for the default output of
4553 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4554 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4555 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4557 This option may be composed with the default behavior of @command{guix
4558 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4559 as packages whose dependencies will be added to the environment, the
4560 default behavior. Packages appearing after are interpreted as packages
4561 that will be added to the environment directly.
4564 Unset existing environment variables when building the new environment, except
4565 those specified with @option{--preserve} (see below.) This has the effect of
4566 creating an environment in which search paths only contain package inputs.
4568 @item --preserve=@var{regexp}
4569 @itemx -E @var{regexp}
4570 When used alongside @option{--pure}, preserve the environment variables
4571 matching @var{regexp}---in other words, put them on a ``white list'' of
4572 environment variables that must be preserved. This option can be repeated
4576 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4580 This example runs @command{mpirun} in a context where the only environment
4581 variables defined are @code{PATH}, environment variables whose name starts
4582 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4585 @item --search-paths
4586 Display the environment variable definitions that make up the
4589 @item --system=@var{system}
4590 @itemx -s @var{system}
4591 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4596 Run @var{command} within an isolated container. The current working
4597 directory outside the container is mapped inside the container.
4598 Additionally, unless overridden with @code{--user}, a dummy home
4599 directory is created that matches the current user's home directory, and
4600 @file{/etc/passwd} is configured accordingly.
4602 The spawned process runs as the current user outside the container. Inside
4603 the container, it has the same UID and GID as the current user, unless
4604 @option{--user} is passed (see below.)
4608 For containers, share the network namespace with the host system.
4609 Containers created without this flag only have access to the loopback
4612 @item --link-profile
4614 For containers, link the environment profile to
4615 @file{~/.guix-profile} within the container. This is equivalent to
4616 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4617 within the container. Linking will fail and abort the environment if
4618 the directory already exists, which will certainly be the case if
4619 @command{guix environment} was invoked in the user's home directory.
4621 Certain packages are configured to look in
4622 @code{~/.guix-profile} for configuration files and data;@footnote{For
4623 example, the @code{fontconfig} package inspects
4624 @file{~/.guix-profile/share/fonts} for additional fonts.}
4625 @code{--link-profile} allows these programs to behave as expected within
4628 @item --user=@var{user}
4629 @itemx -u @var{user}
4630 For containers, use the username @var{user} in place of the current
4631 user. The generated @file{/etc/passwd} entry within the container will
4632 contain the name @var{user}, the home directory will be
4633 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4634 the UID and GID inside the container are 1000. @var{user}
4635 need not exist on the system.
4637 Additionally, any shared or exposed path (see @code{--share} and
4638 @code{--expose} respectively) whose target is within the current user's
4639 home directory will be remapped relative to @file{/home/USER}; this
4640 includes the automatic mapping of the current working directory.
4643 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4645 guix environment --container --user=foo \
4646 --expose=$HOME/test \
4647 --expose=/tmp/target=$HOME/target
4650 While this will limit the leaking of user identity through home paths
4651 and each of the user fields, this is only one useful component of a
4652 broader privacy/anonymity solution---not one in and of itself.
4654 @item --expose=@var{source}[=@var{target}]
4655 For containers, expose the file system @var{source} from the host system
4656 as the read-only file system @var{target} within the container. If
4657 @var{target} is not specified, @var{source} is used as the target mount
4658 point in the container.
4660 The example below spawns a Guile REPL in a container in which the user's
4661 home directory is accessible read-only via the @file{/exchange}
4665 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4668 @item --share=@var{source}[=@var{target}]
4669 For containers, share the file system @var{source} from the host system
4670 as the writable file system @var{target} within the container. If
4671 @var{target} is not specified, @var{source} is used as the target mount
4672 point in the container.
4674 The example below spawns a Guile REPL in a container in which the user's
4675 home directory is accessible for both reading and writing via the
4676 @file{/exchange} directory:
4679 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4683 @command{guix environment}
4684 also supports all of the common build options that @command{guix
4685 build} supports (@pxref{Common Build Options}) as well as package
4686 transformation options (@pxref{Package Transformation Options}).
4688 @node Invoking guix pack
4689 @section Invoking @command{guix pack}
4691 Occasionally you want to pass software to people who are not (yet!)
4692 lucky enough to be using Guix. You'd tell them to run @command{guix
4693 package -i @var{something}}, but that's not possible in this case. This
4694 is where @command{guix pack} comes in.
4697 If you are looking for ways to exchange binaries among machines that
4698 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4699 publish}, and @ref{Invoking guix archive}.
4704 @cindex application bundle
4705 @cindex software bundle
4706 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4707 @dfn{software bundle}: it creates a tarball or some other archive
4708 containing the binaries of the software you're interested in, and all
4709 its dependencies. The resulting archive can be used on any machine that
4710 does not have Guix, and people can run the exact same binaries as those
4711 you have with Guix. The pack itself is created in a bit-reproducible
4712 fashion, so anyone can verify that it really contains the build results
4713 that you pretend to be shipping.
4715 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4716 their dependencies, you can run:
4719 $ guix pack guile emacs geiser
4721 /gnu/store/@dots{}-pack.tar.gz
4724 The result here is a tarball containing a @file{/gnu/store} directory
4725 with all the relevant packages. The resulting tarball contains a
4726 @dfn{profile} with the three packages of interest; the profile is the
4727 same as would be created by @command{guix package -i}. It is this
4728 mechanism that is used to create Guix's own standalone binary tarball
4729 (@pxref{Binary Installation}).
4731 Users of this pack would have to run
4732 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4733 find inconvenient. To work around it, you can create, say, a
4734 @file{/opt/gnu/bin} symlink to the profile:
4737 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4741 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4743 @cindex relocatable binaries, with @command{guix pack}
4744 What if the recipient of your pack does not have root privileges on
4745 their machine, and thus cannot unpack it in the root file system? In
4746 that case, you will want to use the @code{--relocatable} option (see
4747 below). This option produces @dfn{relocatable binaries}, meaning they
4748 they can be placed anywhere in the file system hierarchy: in the example
4749 above, users can unpack your tarball in their home directory and
4750 directly run @file{./opt/gnu/bin/guile}.
4752 @cindex Docker, build an image with guix pack
4753 Alternatively, you can produce a pack in the Docker image format using
4754 the following command:
4757 guix pack -f docker guile emacs geiser
4761 The result is a tarball that can be passed to the @command{docker load}
4763 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4764 documentation} for more information.
4766 @cindex Singularity, build an image with guix pack
4767 @cindex SquashFS, build an image with guix pack
4768 Yet another option is to produce a SquashFS image with the following
4772 guix pack -f squashfs guile emacs geiser
4776 The result is a SquashFS file system image that can either be mounted or
4777 directly be used as a file system container image with the
4778 @uref{https://singularity.lbl.gov, Singularity container execution
4779 environment}, using commands like @command{singularity shell} or
4780 @command{singularity exec}.
4782 Several command-line options allow you to customize your pack:
4785 @item --format=@var{format}
4786 @itemx -f @var{format}
4787 Produce a pack in the given @var{format}.
4789 The available formats are:
4793 This is the default format. It produces a tarball containing all the
4794 specified binaries and symlinks.
4797 This produces a tarball that follows the
4798 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4799 Docker Image Specification}.
4802 This produces a SquashFS image containing all the specified binaries and
4803 symlinks, as well as empty mount points for virtual file systems like
4807 @cindex relocatable binaries
4810 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4811 anywhere in the file system hierarchy and run from there.
4813 When this option is passed once, the resulting binaries require support for
4814 @dfn{user namespaces} in the kernel Linux; when passed
4815 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4816 PRoot support, can be thought of as the abbreviation of ``Really
4817 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4818 if user namespaces are unavailable, and essentially work anywhere---see below
4819 for the implications.
4821 For example, if you create a pack containing Bash with:
4824 guix pack -RR -S /mybin=bin bash
4828 ...@: you can copy that pack to a machine that lacks Guix, and from your
4829 home directory as a normal user, run:
4837 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4838 @file{/gnu/store} shows up and contains all the dependencies of
4839 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4840 altogether! That is probably the simplest way to deploy Guix-built
4841 software on a non-Guix machine.
4844 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4845 the kernel Linux, which allows unprivileged users to mount or change root.
4846 Old versions of Linux did not support it, and some GNU/Linux distributions
4849 To produce relocatable binaries that work even in the absence of user
4850 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4851 case, binaries will try user namespace support and fall back to PRoot if user
4852 namespaces are not supported.
4854 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4855 support for file system virtualization. It achieves that by using the
4856 @code{ptrace} system call on the running program. This approach has the
4857 advantage to work without requiring special kernel support, but it incurs
4858 run-time overhead every time a system call is made.
4861 @item --expression=@var{expr}
4862 @itemx -e @var{expr}
4863 Consider the package @var{expr} evaluates to.
4865 This has the same purpose as the same-named option in @command{guix
4866 build} (@pxref{Additional Build Options, @code{--expression} in
4867 @command{guix build}}).
4869 @item --manifest=@var{file}
4870 @itemx -m @var{file}
4871 Use the packages contained in the manifest object returned by the Scheme
4874 This has a similar purpose as the same-named option in @command{guix
4875 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4876 same manifest files. It allows you to define a collection of packages
4877 once and use it both for creating profiles and for creating archives
4878 for use on machines that do not have Guix installed. Note that you can
4879 specify @emph{either} a manifest file @emph{or} a list of packages,
4882 @item --system=@var{system}
4883 @itemx -s @var{system}
4884 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4885 the system type of the build host.
4887 @item --target=@var{triplet}
4888 @cindex cross-compilation
4889 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4890 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4891 configuration triplets,, autoconf, Autoconf}).
4893 @item --compression=@var{tool}
4894 @itemx -C @var{tool}
4895 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4896 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4898 @item --symlink=@var{spec}
4899 @itemx -S @var{spec}
4900 Add the symlinks specified by @var{spec} to the pack. This option can
4901 appear several times.
4903 @var{spec} has the form @code{@var{source}=@var{target}}, where
4904 @var{source} is the symlink that will be created and @var{target} is the
4907 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4908 symlink pointing to the @file{bin} sub-directory of the profile.
4910 @item --save-provenance
4911 Save provenance information for the packages passed on the command line.
4912 Provenance information includes the URL and commit of the channels in use
4915 Provenance information is saved in the
4916 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4917 usual package metadata---the name and version of each package, their
4918 propagated inputs, and so on. It is useful information to the recipient of
4919 the pack, who then knows how the pack was (supposedly) obtained.
4921 This option is not enabled by default because, like timestamps, provenance
4922 information contributes nothing to the build process. In other words, there
4923 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4924 Recording such ``silent'' metadata in the output thus potentially breaks the
4925 source-to-binary bitwise reproducibility property.
4927 @item --localstatedir
4928 @itemx --profile-name=@var{name}
4929 Include the ``local state directory'', @file{/var/guix}, in the resulting
4930 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4931 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4932 @file{~root/.guix-profile}.
4934 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4935 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4936 the pack means that the store is ``complete'' and manageable by Guix;
4937 not providing it pack means that the store is ``dead'': items cannot be
4938 added to it or removed from it after extraction of the pack.
4940 One use case for this is the Guix self-contained binary tarball
4941 (@pxref{Binary Installation}).
4944 Use the bootstrap binaries to build the pack. This option is only
4945 useful to Guix developers.
4948 In addition, @command{guix pack} supports all the common build options
4949 (@pxref{Common Build Options}) and all the package transformation
4950 options (@pxref{Package Transformation Options}).
4953 @c *********************************************************************
4954 @node Programming Interface
4955 @chapter Programming Interface
4957 GNU Guix provides several Scheme programming interfaces (APIs) to
4958 define, build, and query packages. The first interface allows users to
4959 write high-level package definitions. These definitions refer to
4960 familiar packaging concepts, such as the name and version of a package,
4961 its build system, and its dependencies. These definitions can then be
4962 turned into concrete build actions.
4964 Build actions are performed by the Guix daemon, on behalf of users. In a
4965 standard setup, the daemon has write access to the store---the
4966 @file{/gnu/store} directory---whereas users do not. The recommended
4967 setup also has the daemon perform builds in chroots, under a specific
4968 build users, to minimize interference with the rest of the system.
4971 Lower-level APIs are available to interact with the daemon and the
4972 store. To instruct the daemon to perform a build action, users actually
4973 provide it with a @dfn{derivation}. A derivation is a low-level
4974 representation of the build actions to be taken, and the environment in
4975 which they should occur---derivations are to package definitions what
4976 assembly is to C programs. The term ``derivation'' comes from the fact
4977 that build results @emph{derive} from them.
4979 This chapter describes all these APIs in turn, starting from high-level
4980 package definitions.
4983 * Package Modules:: Packages from the programmer's viewpoint.
4984 * Defining Packages:: Defining new packages.
4985 * Build Systems:: Specifying how packages are built.
4986 * The Store:: Manipulating the package store.
4987 * Derivations:: Low-level interface to package derivations.
4988 * The Store Monad:: Purely functional interface to the store.
4989 * G-Expressions:: Manipulating build expressions.
4990 * Invoking guix repl:: Fiddling with Guix interactively.
4993 @node Package Modules
4994 @section Package Modules
4996 From a programming viewpoint, the package definitions of the
4997 GNU distribution are provided by Guile modules in the @code{(gnu packages
4998 @dots{})} name space@footnote{Note that packages under the @code{(gnu
4999 packages @dots{})} module name space are not necessarily ``GNU
5000 packages''. This module naming scheme follows the usual Guile module
5001 naming convention: @code{gnu} means that these modules are distributed
5002 as part of the GNU system, and @code{packages} identifies modules that
5003 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5004 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5005 module exports a variable named @code{emacs}, which is bound to a
5006 @code{<package>} object (@pxref{Defining Packages}).
5008 The @code{(gnu packages @dots{})} module name space is
5009 automatically scanned for packages by the command-line tools. For
5010 instance, when running @code{guix install emacs}, all the @code{(gnu
5011 packages @dots{})} modules are scanned until one that exports a package
5012 object whose name is @code{emacs} is found. This package search
5013 facility is implemented in the @code{(gnu packages)} module.
5015 @cindex customization, of packages
5016 @cindex package module search path
5017 Users can store package definitions in modules with different
5018 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5019 name and module name must match. For instance, the @code{(my-packages
5020 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5021 relative to the load path specified with @option{--load-path} or
5022 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5023 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5024 these package definitions visible to the user interfaces:
5028 By adding the directory containing your package modules to the search path
5029 with the @code{-L} flag of @command{guix package} and other commands
5030 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5031 environment variable described below.
5034 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5035 pulls from it. A channel is essentially a Git repository containing package
5036 modules. @xref{Channels}, for more information on how to define and use
5040 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5042 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5043 This is a colon-separated list of directories to search for additional
5044 package modules. Directories listed in this variable take precedence
5045 over the own modules of the distribution.
5048 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5049 each package is built based solely on other packages in the
5050 distribution. The root of this dependency graph is a small set of
5051 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5052 bootstrap)} module. For more information on bootstrapping,
5053 @pxref{Bootstrapping}.
5055 @node Defining Packages
5056 @section Defining Packages
5058 The high-level interface to package definitions is implemented in the
5059 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5060 example, the package definition, or @dfn{recipe}, for the GNU Hello
5061 package looks like this:
5064 (define-module (gnu packages hello)
5065 #:use-module (guix packages)
5066 #:use-module (guix download)
5067 #:use-module (guix build-system gnu)
5068 #:use-module (guix licenses)
5069 #:use-module (gnu packages gawk))
5071 (define-public hello
5077 (uri (string-append "mirror://gnu/hello/hello-" version
5081 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5082 (build-system gnu-build-system)
5083 (arguments '(#:configure-flags '("--enable-silent-rules")))
5084 (inputs `(("gawk" ,gawk)))
5085 (synopsis "Hello, GNU world: An example GNU package")
5086 (description "Guess what GNU Hello prints!")
5087 (home-page "https://www.gnu.org/software/hello/")
5092 Without being a Scheme expert, the reader may have guessed the meaning
5093 of the various fields here. This expression binds the variable
5094 @code{hello} to a @code{<package>} object, which is essentially a record
5095 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5096 This package object can be inspected using procedures found in the
5097 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5098 returns---surprise!---@code{"hello"}.
5100 With luck, you may be able to import part or all of the definition of
5101 the package you are interested in from another repository, using the
5102 @code{guix import} command (@pxref{Invoking guix import}).
5104 In the example above, @var{hello} is defined in a module of its own,
5105 @code{(gnu packages hello)}. Technically, this is not strictly
5106 necessary, but it is convenient to do so: all the packages defined in
5107 modules under @code{(gnu packages @dots{})} are automatically known to
5108 the command-line tools (@pxref{Package Modules}).
5110 There are a few points worth noting in the above package definition:
5114 The @code{source} field of the package is an @code{<origin>} object
5115 (@pxref{origin Reference}, for the complete reference).
5116 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5117 meaning that the source is a file to be downloaded over FTP or HTTP.
5119 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5120 the GNU mirrors defined in @code{(guix download)}.
5122 The @code{sha256} field specifies the expected SHA256 hash of the file
5123 being downloaded. It is mandatory, and allows Guix to check the
5124 integrity of the file. The @code{(base32 @dots{})} form introduces the
5125 base32 representation of the hash. You can obtain this information with
5126 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5127 hash} (@pxref{Invoking guix hash}).
5130 When needed, the @code{origin} form can also have a @code{patches} field
5131 listing patches to be applied, and a @code{snippet} field giving a
5132 Scheme expression to modify the source code.
5135 @cindex GNU Build System
5136 The @code{build-system} field specifies the procedure to build the
5137 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5138 represents the familiar GNU Build System, where packages may be
5139 configured, built, and installed with the usual @code{./configure &&
5140 make && make check && make install} command sequence.
5143 The @code{arguments} field specifies options for the build system
5144 (@pxref{Build Systems}). Here it is interpreted by
5145 @var{gnu-build-system} as a request run @file{configure} with the
5146 @code{--enable-silent-rules} flag.
5152 What about these quote (@code{'}) characters? They are Scheme syntax to
5153 introduce a literal list; @code{'} is synonymous with @code{quote}.
5154 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5155 for details. Here the value of the @code{arguments} field is a list of
5156 arguments passed to the build system down the road, as with @code{apply}
5157 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5160 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5161 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5162 @code{#:configure-flags} is a keyword used to pass a keyword argument
5163 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5167 The @code{inputs} field specifies inputs to the build process---i.e.,
5168 build-time or run-time dependencies of the package. Here, we define an
5169 input called @code{"gawk"} whose value is that of the @var{gawk}
5170 variable; @var{gawk} is itself bound to a @code{<package>} object.
5172 @cindex backquote (quasiquote)
5175 @cindex comma (unquote)
5179 @findex unquote-splicing
5180 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5181 us to introduce a literal list in the @code{inputs} field, while
5182 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5183 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5186 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5187 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5188 of ensuring that they are present (@pxref{Build Systems}).
5190 However, any other dependencies need to be specified in the
5191 @code{inputs} field. Any dependency not specified here will simply be
5192 unavailable to the build process, possibly leading to a build failure.
5195 @xref{package Reference}, for a full description of possible fields.
5197 Once a package definition is in place, the
5198 package may actually be built using the @code{guix build} command-line
5199 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5200 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5201 package definition using the @command{guix edit} command
5202 (@pxref{Invoking guix edit}).
5203 @xref{Packaging Guidelines}, for
5204 more information on how to test package definitions, and
5205 @ref{Invoking guix lint}, for information on how to check a definition
5206 for style conformance.
5207 @vindex GUIX_PACKAGE_PATH
5208 Lastly, @pxref{Channels}, for information
5209 on how to extend the distribution by adding your own package definitions
5212 Finally, updating the package definition to a new upstream version
5213 can be partly automated by the @command{guix refresh} command
5214 (@pxref{Invoking guix refresh}).
5216 Behind the scenes, a derivation corresponding to the @code{<package>}
5217 object is first computed by the @code{package-derivation} procedure.
5218 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5219 The build actions it prescribes may then be realized by using the
5220 @code{build-derivations} procedure (@pxref{The Store}).
5222 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5223 Return the @code{<derivation>} object of @var{package} for @var{system}
5224 (@pxref{Derivations}).
5226 @var{package} must be a valid @code{<package>} object, and @var{system}
5227 must be a string denoting the target system type---e.g.,
5228 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5229 must be a connection to the daemon, which operates on the store
5230 (@pxref{The Store}).
5234 @cindex cross-compilation
5235 Similarly, it is possible to compute a derivation that cross-builds a
5236 package for some other system:
5238 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5239 @var{package} @var{target} [@var{system}]
5240 Return the @code{<derivation>} object of @var{package} cross-built from
5241 @var{system} to @var{target}.
5243 @var{target} must be a valid GNU triplet denoting the target hardware
5244 and operating system, such as @code{"mips64el-linux-gnu"}
5245 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5248 @cindex package transformations
5249 @cindex input rewriting
5250 @cindex dependency tree rewriting
5251 Packages can be manipulated in arbitrary ways. An example of a useful
5252 transformation is @dfn{input rewriting}, whereby the dependency tree of
5253 a package is rewritten by replacing specific inputs by others:
5255 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5256 [@var{rewrite-name}]
5257 Return a procedure that, when passed a package, replaces its direct and
5258 indirect dependencies (but not its implicit inputs) according to
5259 @var{replacements}. @var{replacements} is a list of package pairs; the
5260 first element of each pair is the package to replace, and the second one
5263 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5264 the name of a package and returns its new name after rewrite.
5268 Consider this example:
5271 (define libressl-instead-of-openssl
5272 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5274 (package-input-rewriting `((,openssl . ,libressl))))
5276 (define git-with-libressl
5277 (libressl-instead-of-openssl git))
5281 Here we first define a rewriting procedure that replaces @var{openssl}
5282 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5283 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5284 This is exactly what the @option{--with-input} command-line option does
5285 (@pxref{Package Transformation Options, @option{--with-input}}).
5287 The following variant of @code{package-input-rewriting} can match packages to
5288 be replaced by name rather than by identity.
5290 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5291 Return a procedure that, given a package, applies the given @var{replacements} to
5292 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5293 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5294 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5295 replacement for that package.
5298 The example above could be rewritten this way:
5301 (define libressl-instead-of-openssl
5302 ;; Replace all the packages called "openssl" with LibreSSL.
5303 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5306 The key difference here is that, this time, packages are matched by spec and
5307 not by identity. In other words, any package in the graph that is called
5308 @code{openssl} will be replaced.
5310 A more generic procedure to rewrite a package dependency graph is
5311 @code{package-mapping}: it supports arbitrary changes to nodes in the
5314 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5315 Return a procedure that, given a package, applies @var{proc} to all the packages
5316 depended on and returns the resulting package. The procedure stops recursion
5317 when @var{cut?} returns true for a given package.
5321 * package Reference:: The package data type.
5322 * origin Reference:: The origin data type.
5326 @node package Reference
5327 @subsection @code{package} Reference
5329 This section summarizes all the options available in @code{package}
5330 declarations (@pxref{Defining Packages}).
5332 @deftp {Data Type} package
5333 This is the data type representing a package recipe.
5337 The name of the package, as a string.
5339 @item @code{version}
5340 The version of the package, as a string.
5343 An object telling how the source code for the package should be
5344 acquired. Most of the time, this is an @code{origin} object, which
5345 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5346 can also be any other ``file-like'' object such as a @code{local-file},
5347 which denotes a file from the local file system (@pxref{G-Expressions,
5348 @code{local-file}}).
5350 @item @code{build-system}
5351 The build system that should be used to build the package (@pxref{Build
5354 @item @code{arguments} (default: @code{'()})
5355 The arguments that should be passed to the build system. This is a
5356 list, typically containing sequential keyword-value pairs.
5358 @item @code{inputs} (default: @code{'()})
5359 @itemx @code{native-inputs} (default: @code{'()})
5360 @itemx @code{propagated-inputs} (default: @code{'()})
5361 @cindex inputs, of packages
5362 These fields list dependencies of the package. Each one is a list of
5363 tuples, where each tuple has a label for the input (a string) as its
5364 first element, a package, origin, or derivation as its second element,
5365 and optionally the name of the output thereof that should be used, which
5366 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5367 more on package outputs). For example, the list below specifies three
5371 `(("libffi" ,libffi)
5372 ("libunistring" ,libunistring)
5373 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5376 @cindex cross compilation, package dependencies
5377 The distinction between @code{native-inputs} and @code{inputs} is
5378 necessary when considering cross-compilation. When cross-compiling,
5379 dependencies listed in @code{inputs} are built for the @emph{target}
5380 architecture; conversely, dependencies listed in @code{native-inputs}
5381 are built for the architecture of the @emph{build} machine.
5383 @code{native-inputs} is typically used to list tools needed at
5384 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5385 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5386 this area (@pxref{Invoking guix lint}).
5388 @anchor{package-propagated-inputs}
5389 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5390 specified packages will be automatically installed alongside the package
5391 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5392 package}}, for information on how @command{guix package} deals with
5395 For example this is necessary when a C/C++ library needs headers of
5396 another library to compile, or when a pkg-config file refers to another
5397 one @i{via} its @code{Requires} field.
5399 Another example where @code{propagated-inputs} is useful is for languages
5400 that lack a facility to record the run-time search path akin to the
5401 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5402 more. To ensure that libraries written in those languages can find
5403 library code they depend on at run time, run-time dependencies must be
5404 listed in @code{propagated-inputs} rather than @code{inputs}.
5406 @item @code{outputs} (default: @code{'("out")})
5407 The list of output names of the package. @xref{Packages with Multiple
5408 Outputs}, for typical uses of additional outputs.
5410 @item @code{native-search-paths} (default: @code{'()})
5411 @itemx @code{search-paths} (default: @code{'()})
5412 A list of @code{search-path-specification} objects describing
5413 search-path environment variables honored by the package.
5415 @item @code{replacement} (default: @code{#f})
5416 This must be either @code{#f} or a package object that will be used as a
5417 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5420 @item @code{synopsis}
5421 A one-line description of the package.
5423 @item @code{description}
5424 A more elaborate description of the package.
5426 @item @code{license}
5427 @cindex license, of packages
5428 The license of the package; a value from @code{(guix licenses)},
5429 or a list of such values.
5431 @item @code{home-page}
5432 The URL to the home-page of the package, as a string.
5434 @item @code{supported-systems} (default: @var{%supported-systems})
5435 The list of systems supported by the package, as strings of the form
5436 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5438 @item @code{maintainers} (default: @code{'()})
5439 The list of maintainers of the package, as @code{maintainer} objects.
5441 @item @code{location} (default: source location of the @code{package} form)
5442 The source location of the package. It is useful to override this when
5443 inheriting from another package, in which case this field is not
5444 automatically corrected.
5448 @deffn {Scheme Syntax} this-package
5449 When used in the @emph{lexical scope} of a package field definition, this
5450 identifier resolves to the package being defined.
5452 The example below shows how to add a package as a native input of itself when
5460 ;; When cross-compiled, Guile, for example, depends on
5461 ;; a native version of itself. Add it here.
5462 (native-inputs (if (%current-target-system)
5463 `(("self" ,this-package))
5467 It is an error to refer to @code{this-package} outside a package definition.
5470 @node origin Reference
5471 @subsection @code{origin} Reference
5473 This section summarizes all the options available in @code{origin}
5474 declarations (@pxref{Defining Packages}).
5476 @deftp {Data Type} origin
5477 This is the data type representing a source code origin.
5481 An object containing the URI of the source. The object type depends on
5482 the @code{method} (see below). For example, when using the
5483 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5484 values are: a URL represented as a string, or a list thereof.
5487 A procedure that handles the URI.
5492 @item @var{url-fetch} from @code{(guix download)}
5493 download a file from the HTTP, HTTPS, or FTP URL specified in the
5497 @item @var{git-fetch} from @code{(guix git-download)}
5498 clone the Git version control repository, and check out the revision
5499 specified in the @code{uri} field as a @code{git-reference} object; a
5500 @code{git-reference} looks like this:
5504 (url "git://git.debian.org/git/pkg-shadow/shadow")
5505 (commit "v4.1.5.1"))
5510 A bytevector containing the SHA-256 hash of the source. Typically the
5511 @code{base32} form is used here to generate the bytevector from a
5514 You can obtain this information using @code{guix download}
5515 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5518 @item @code{file-name} (default: @code{#f})
5519 The file name under which the source code should be saved. When this is
5520 @code{#f}, a sensible default value will be used in most cases. In case
5521 the source is fetched from a URL, the file name from the URL will be
5522 used. For version control checkouts, it is recommended to provide the
5523 file name explicitly because the default is not very descriptive.
5525 @item @code{patches} (default: @code{'()})
5526 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5527 file-like objects}) pointing to patches to be applied to the source.
5529 This list of patches must be unconditional. In particular, it cannot
5530 depend on the value of @code{%current-system} or
5531 @code{%current-target-system}.
5533 @item @code{snippet} (default: @code{#f})
5534 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5535 in the source directory. This is a convenient way to modify the source,
5536 sometimes more convenient than a patch.
5538 @item @code{patch-flags} (default: @code{'("-p1")})
5539 A list of command-line flags that should be passed to the @code{patch}
5542 @item @code{patch-inputs} (default: @code{#f})
5543 Input packages or derivations to the patching process. When this is
5544 @code{#f}, the usual set of inputs necessary for patching are provided,
5545 such as GNU@tie{}Patch.
5547 @item @code{modules} (default: @code{'()})
5548 A list of Guile modules that should be loaded during the patching
5549 process and while running the code in the @code{snippet} field.
5551 @item @code{patch-guile} (default: @code{#f})
5552 The Guile package that should be used in the patching process. When
5553 this is @code{#f}, a sensible default is used.
5559 @section Build Systems
5561 @cindex build system
5562 Each package definition specifies a @dfn{build system} and arguments for
5563 that build system (@pxref{Defining Packages}). This @code{build-system}
5564 field represents the build procedure of the package, as well as implicit
5565 dependencies of that build procedure.
5567 Build systems are @code{<build-system>} objects. The interface to
5568 create and manipulate them is provided by the @code{(guix build-system)}
5569 module, and actual build systems are exported by specific modules.
5571 @cindex bag (low-level package representation)
5572 Under the hood, build systems first compile package objects to
5573 @dfn{bags}. A @dfn{bag} is like a package, but with less
5574 ornamentation---in other words, a bag is a lower-level representation of
5575 a package, which includes all the inputs of that package, including some
5576 that were implicitly added by the build system. This intermediate
5577 representation is then compiled to a derivation (@pxref{Derivations}).
5579 Build systems accept an optional list of @dfn{arguments}. In package
5580 definitions, these are passed @i{via} the @code{arguments} field
5581 (@pxref{Defining Packages}). They are typically keyword arguments
5582 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5583 Guile Reference Manual}). The value of these arguments is usually
5584 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5585 by the daemon (@pxref{Derivations}).
5587 The main build system is @var{gnu-build-system}, which implements the
5588 standard build procedure for GNU and many other packages. It
5589 is provided by the @code{(guix build-system gnu)} module.
5591 @defvr {Scheme Variable} gnu-build-system
5592 @var{gnu-build-system} represents the GNU Build System, and variants
5593 thereof (@pxref{Configuration, configuration and makefile conventions,,
5594 standards, GNU Coding Standards}).
5596 @cindex build phases
5597 In a nutshell, packages using it are configured, built, and installed with
5598 the usual @code{./configure && make && make check && make install}
5599 command sequence. In practice, a few additional steps are often needed.
5600 All these steps are split up in separate @dfn{phases},
5601 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5602 modules for more details about the build phases.}:
5606 Unpack the source tarball, and change the current directory to the
5607 extracted source tree. If the source is actually a directory, copy it
5608 to the build tree, and enter that directory.
5610 @item patch-source-shebangs
5611 Patch shebangs encountered in source files so they refer to the right
5612 store file names. For instance, this changes @code{#!/bin/sh} to
5613 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5616 Run the @file{configure} script with a number of default options, such
5617 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5618 by the @code{#:configure-flags} argument.
5621 Run @code{make} with the list of flags specified with
5622 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5623 (the default), build with @code{make -j}.
5626 Run @code{make check}, or some other target specified with
5627 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5628 @code{#:parallel-tests?} argument is true (the default), run @code{make
5632 Run @code{make install} with the flags listed in @code{#:make-flags}.
5634 @item patch-shebangs
5635 Patch shebangs on the installed executable files.
5638 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5639 is false), copying them to the @code{debug} output when available
5640 (@pxref{Installing Debugging Files}).
5643 @vindex %standard-phases
5644 The build-side module @code{(guix build gnu-build-system)} defines
5645 @var{%standard-phases} as the default list of build phases.
5646 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5647 procedure implements the actual phase.
5649 The list of phases used for a particular package can be changed with the
5650 @code{#:phases} parameter. For instance, passing:
5653 #:phases (modify-phases %standard-phases (delete 'configure))
5656 means that all the phases described above will be used, except the
5657 @code{configure} phase.
5659 In addition, this build system ensures that the ``standard'' environment
5660 for GNU packages is available. This includes tools such as GCC, libc,
5661 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5662 build-system gnu)} module for a complete list). We call these the
5663 @dfn{implicit inputs} of a package, because package definitions do not
5664 have to mention them.
5667 Other @code{<build-system>} objects are defined to support other
5668 conventions and tools used by free software packages. They inherit most
5669 of @var{gnu-build-system}, and differ mainly in the set of inputs
5670 implicitly added to the build process, and in the list of phases
5671 executed. Some of these build systems are listed below.
5673 @defvr {Scheme Variable} ant-build-system
5674 This variable is exported by @code{(guix build-system ant)}. It
5675 implements the build procedure for Java packages that can be built with
5676 @url{https://ant.apache.org/, Ant build tool}.
5678 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5679 provided by the @code{icedtea} package to the set of inputs. Different
5680 packages can be specified with the @code{#:ant} and @code{#:jdk}
5681 parameters, respectively.
5683 When the original package does not provide a suitable Ant build file,
5684 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5685 build file @file{build.xml} with tasks to build the specified jar
5686 archive. In this case the parameter @code{#:source-dir} can be used to
5687 specify the source sub-directory, defaulting to ``src''.
5689 The @code{#:main-class} parameter can be used with the minimal ant
5690 buildfile to specify the main class of the resulting jar. This makes the
5691 jar file executable. The @code{#:test-include} parameter can be used to
5692 specify the list of junit tests to run. It defaults to
5693 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5694 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5695 because abstract classes cannot be run as tests.
5697 The parameter @code{#:build-target} can be used to specify the Ant task
5698 that should be run during the @code{build} phase. By default the
5699 ``jar'' task will be run.
5703 @defvr {Scheme Variable} android-ndk-build-system
5704 @cindex Android distribution
5705 @cindex Android NDK build system
5706 This variable is exported by @code{(guix build-system android-ndk)}. It
5707 implements a build procedure for Android NDK (native development kit)
5708 packages using a Guix-specific build process.
5710 The build system assumes that packages install their public interface
5711 (header) files to the subdirectory "include" of the "out" output and
5712 their libraries to the subdirectory "lib" of the "out" output.
5714 It's also assumed that the union of all the dependencies of a package
5715 has no conflicting files.
5717 For the time being, cross-compilation is not supported - so right now
5718 the libraries and header files are assumed to be host tools.
5722 @defvr {Scheme Variable} asdf-build-system/source
5723 @defvrx {Scheme Variable} asdf-build-system/sbcl
5724 @defvrx {Scheme Variable} asdf-build-system/ecl
5726 These variables, exported by @code{(guix build-system asdf)}, implement
5727 build procedures for Common Lisp packages using
5728 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5729 definition facility for Common Lisp programs and libraries.
5731 The @code{asdf-build-system/source} system installs the packages in
5732 source form, and can be loaded using any common lisp implementation, via
5733 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5734 systems in the format which a particular implementation understands.
5735 These build systems can also be used to produce executable programs, or
5736 lisp images which contain a set of packages pre-loaded.
5738 The build system uses naming conventions. For binary packages, the
5739 package name should be prefixed with the lisp implementation, such as
5740 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5742 Additionally, the corresponding source package should be labeled using
5743 the same convention as python packages (see @ref{Python Modules}), using
5744 the @code{cl-} prefix.
5746 For binary packages, each system should be defined as a Guix package.
5747 If one package @code{origin} contains several systems, package variants
5748 can be created in order to build all the systems. Source packages,
5749 which use @code{asdf-build-system/source}, may contain several systems.
5751 In order to create executable programs and images, the build-side
5752 procedures @code{build-program} and @code{build-image} can be used.
5753 They should be called in a build phase after the @code{create-symlinks}
5754 phase, so that the system which was just built can be used within the
5755 resulting image. @code{build-program} requires a list of Common Lisp
5756 expressions to be passed as the @code{#:entry-program} argument.
5758 If the system is not defined within its own @code{.asd} file of the same
5759 name, then the @code{#:asd-file} parameter should be used to specify
5760 which file the system is defined in. Furthermore, if the package
5761 defines a system for its tests in a separate file, it will be loaded
5762 before the tests are run if it is specified by the
5763 @code{#:test-asd-file} parameter. If it is not set, the files
5764 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5765 and @code{test.asd} will be tried if they exist.
5767 If for some reason the package must be named in a different way than the
5768 naming conventions suggest, the @code{#:asd-system-name} parameter can
5769 be used to specify the name of the system.
5773 @defvr {Scheme Variable} cargo-build-system
5774 @cindex Rust programming language
5775 @cindex Cargo (Rust build system)
5776 This variable is exported by @code{(guix build-system cargo)}. It
5777 supports builds of packages using Cargo, the build tool of the
5778 @uref{https://www.rust-lang.org, Rust programming language}.
5780 In its @code{configure} phase, this build system replaces dependencies
5781 specified in the @file{Carto.toml} file with inputs to the Guix package.
5782 The @code{install} phase installs the binaries, and it also installs the
5783 source code and @file{Cargo.toml} file.
5786 @cindex Clojure (programming language)
5787 @cindex simple Clojure build system
5788 @defvr {Scheme Variable} clojure-build-system
5789 This variable is exported by @code{(guix build-system clojure)}. It implements
5790 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5791 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5794 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5795 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5796 @code{#:zip} parameters, respectively.
5798 A list of source directories, test directories and jar names can be specified
5799 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5800 parameters, respectively. Compile directory and main class can be specified
5801 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5802 Other parameters are documented below.
5804 This build system is an extension of @var{ant-build-system}, but with the
5805 following phases changed:
5810 This phase calls @code{compile} in Clojure to compile source files and runs
5811 @command{jar} to create jars from both source files and compiled files
5812 according to the include list and exclude list specified in
5813 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5814 has priority over the include list. These lists consist of symbols
5815 representing Clojure libraries or the special keyword @code{#:all} representing
5816 all Clojure libraries found under the source directories. The parameter
5817 @code{#:omit-source?} decides if source should be included into the jars.
5820 This phase runs tests according to the include list and exclude list specified
5821 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5822 meanings are analogous to that of @code{#:aot-include} and
5823 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5824 stands for all Clojure libraries found under the test directories. The
5825 parameter @code{#:tests?} decides if tests should be run.
5828 This phase installs all jars built previously.
5831 Apart from the above, this build system also contains an additional phase:
5836 This phase installs all top-level files with base name matching
5837 @var{%doc-regex}. A different regex can be specified with the
5838 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5839 directories specified in @code{#:doc-dirs} are installed as well.
5843 @defvr {Scheme Variable} cmake-build-system
5844 This variable is exported by @code{(guix build-system cmake)}. It
5845 implements the build procedure for packages using the
5846 @url{https://www.cmake.org, CMake build tool}.
5848 It automatically adds the @code{cmake} package to the set of inputs.
5849 Which package is used can be specified with the @code{#:cmake}
5852 The @code{#:configure-flags} parameter is taken as a list of flags
5853 passed to the @command{cmake} command. The @code{#:build-type}
5854 parameter specifies in abstract terms the flags passed to the compiler;
5855 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5856 debugging information''), which roughly means that code is compiled with
5857 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5860 @defvr {Scheme Variable} dune-build-system
5861 This variable is exported by @code{(guix build-system dune)}. It
5862 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5863 tool for the OCaml programming language. It is implemented as an extension
5864 of the @code{ocaml-build-system} which is described below. As such, the
5865 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5868 It automatically adds the @code{dune} package to the set of inputs.
5869 Which package is used can be specified with the @code{#:dune}
5872 There is no @code{configure} phase because dune packages typically don't
5873 need to be configured. The @code{#:build-flags} parameter is taken as a
5874 list of flags passed to the @code{dune} command during the build.
5876 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5877 command instead of the more recent @code{dune} command while building
5878 a package. Its default value is @code{#f}.
5880 The @code{#:package} parameter can be passed to specify a package name, which
5881 is useful when a package contains multiple packages and you want to build
5882 only one of them. This is equivalent to passing the @code{-p} argument to
5886 @defvr {Scheme Variable} go-build-system
5887 This variable is exported by @code{(guix build-system go)}. It
5888 implements a build procedure for Go packages using the standard
5889 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5890 Go build mechanisms}.
5892 The user is expected to provide a value for the key @code{#:import-path}
5893 and, in some cases, @code{#:unpack-path}. The
5894 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5895 corresponds to the file system path expected by the package's build
5896 scripts and any referring packages, and provides a unique way to
5897 refer to a Go package. It is typically based on a combination of the
5898 package source code's remote URI and file system hierarchy structure. In
5899 some cases, you will need to unpack the package's source code to a
5900 different directory structure than the one indicated by the import path,
5901 and @code{#:unpack-path} should be used in such cases.
5903 Packages that provide Go libraries should install their source code into
5904 the built output. The key @code{#:install-source?}, which defaults to
5905 @code{#t}, controls whether or not the source code is installed. It can
5906 be set to @code{#f} for packages that only provide executable files.
5909 @defvr {Scheme Variable} glib-or-gtk-build-system
5910 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5911 is intended for use with packages making use of GLib or GTK+.
5913 This build system adds the following two phases to the ones defined by
5914 @var{gnu-build-system}:
5917 @item glib-or-gtk-wrap
5918 The phase @code{glib-or-gtk-wrap} ensures that programs in
5919 @file{bin/} are able to find GLib ``schemas'' and
5920 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5921 modules}. This is achieved by wrapping the programs in launch scripts
5922 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5923 environment variables.
5925 It is possible to exclude specific package outputs from that wrapping
5926 process by listing their names in the
5927 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5928 when an output is known not to contain any GLib or GTK+ binaries, and
5929 where wrapping would gratuitously add a dependency of that output on
5932 @item glib-or-gtk-compile-schemas
5933 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5934 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5935 GSettings schemas} of GLib are compiled. Compilation is performed by the
5936 @command{glib-compile-schemas} program. It is provided by the package
5937 @code{glib:bin} which is automatically imported by the build system.
5938 The @code{glib} package providing @command{glib-compile-schemas} can be
5939 specified with the @code{#:glib} parameter.
5942 Both phases are executed after the @code{install} phase.
5945 @defvr {Scheme Variable} guile-build-system
5946 This build system is for Guile packages that consist exclusively of Scheme
5947 code and that are so lean that they don't even have a makefile, let alone a
5948 @file{configure} script. It compiles Scheme code using @command{guild
5949 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5950 installs the @file{.scm} and @file{.go} files in the right place. It also
5951 installs documentation.
5953 This build system supports cross-compilation by using the @code{--target}
5954 option of @command{guild compile}.
5956 Packages built with @code{guile-build-system} must provide a Guile package in
5957 their @code{native-inputs} field.
5960 @defvr {Scheme Variable} minify-build-system
5961 This variable is exported by @code{(guix build-system minify)}. It
5962 implements a minification procedure for simple JavaScript packages.
5964 It adds @code{uglify-js} to the set of inputs and uses it to compress
5965 all JavaScript files in the @file{src} directory. A different minifier
5966 package can be specified with the @code{#:uglify-js} parameter, but it
5967 is expected that the package writes the minified code to the standard
5970 When the input JavaScript files are not all located in the @file{src}
5971 directory, the parameter @code{#:javascript-files} can be used to
5972 specify a list of file names to feed to the minifier.
5975 @defvr {Scheme Variable} ocaml-build-system
5976 This variable is exported by @code{(guix build-system ocaml)}. It implements
5977 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5978 of choosing the correct set of commands to run for each package. OCaml
5979 packages can expect many different commands to be run. This build system will
5982 When the package has a @file{setup.ml} file present at the top-level, it will
5983 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5984 @code{ocaml setup.ml -install}. The build system will assume that this file
5985 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5986 care of setting the prefix and enabling tests if they are not disabled. You
5987 can pass configure and build flags with the @code{#:configure-flags} and
5988 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5989 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5990 bypass this system in the build and install phases.
5992 When the package has a @file{configure} file, it is assumed that it is a
5993 hand-made configure script that requires a different argument format than
5994 in the @code{gnu-build-system}. You can add more flags with the
5995 @code{#:configure-flags} key.
5997 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5998 @code{#t}), it will be used and more flags can be passed to the build and
5999 install phases with the @code{#:make-flags} key.
6001 Finally, some packages do not have these files and use a somewhat standard
6002 location for its build system. In that case, the build system will run
6003 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6004 providing the path to the required findlib module. Additional flags can
6005 be passed via the @code{#:build-flags} key. Install is taken care of by
6006 @command{opam-installer}. In this case, the @code{opam} package must
6007 be added to the @code{native-inputs} field of the package definition.
6009 Note that most OCaml packages assume they will be installed in the same
6010 directory as OCaml, which is not what we want in guix. In particular, they
6011 will install @file{.so} files in their module's directory, which is usually
6012 fine because it is in the OCaml compiler directory. In guix though, these
6013 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6014 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6015 @file{.so} libraries should be installed.
6018 @defvr {Scheme Variable} python-build-system
6019 This variable is exported by @code{(guix build-system python)}. It
6020 implements the more or less standard build procedure used by Python
6021 packages, which consists in running @code{python setup.py build} and
6022 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6024 For packages that install stand-alone Python programs under @code{bin/},
6025 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6026 environment variable points to all the Python libraries they depend on.
6028 Which Python package is used to perform the build can be specified with
6029 the @code{#:python} parameter. This is a useful way to force a package
6030 to be built for a specific version of the Python interpreter, which
6031 might be necessary if the package is only compatible with a single
6032 interpreter version.
6034 By default guix calls @code{setup.py} under control of
6035 @code{setuptools}, much like @command{pip} does. Some packages are not
6036 compatible with setuptools (and pip), thus you can disable this by
6037 setting the @code{#:use-setuptools} parameter to @code{#f}.
6040 @defvr {Scheme Variable} perl-build-system
6041 This variable is exported by @code{(guix build-system perl)}. It
6042 implements the standard build procedure for Perl packages, which either
6043 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6044 followed by @code{Build} and @code{Build install}; or in running
6045 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6046 @code{make} and @code{make install}, depending on which of
6047 @code{Build.PL} or @code{Makefile.PL} is present in the package
6048 distribution. Preference is given to the former if both @code{Build.PL}
6049 and @code{Makefile.PL} exist in the package distribution. This
6050 preference can be reversed by specifying @code{#t} for the
6051 @code{#:make-maker?} parameter.
6053 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6054 passes flags specified by the @code{#:make-maker-flags} or
6055 @code{#:module-build-flags} parameter, respectively.
6057 Which Perl package is used can be specified with @code{#:perl}.
6060 @defvr {Scheme Variable} r-build-system
6061 This variable is exported by @code{(guix build-system r)}. It
6062 implements the build procedure used by @uref{https://r-project.org, R}
6063 packages, which essentially is little more than running @code{R CMD
6064 INSTALL --library=/gnu/store/@dots{}} in an environment where
6065 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6066 are run after installation using the R function
6067 @code{tools::testInstalledPackage}.
6070 @defvr {Scheme Variable} rakudo-build-system
6071 This variable is exported by @code{(guix build-system rakudo)}. It
6072 implements the build procedure used by @uref{https://rakudo.org/,
6073 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6074 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6075 installs the binaries, library files and the resources, as well as wrap
6076 the files under the @code{bin/} directory. Tests can be skipped by
6077 passing @code{#f} to the @code{tests?} parameter.
6079 Which rakudo package is used can be specified with @code{rakudo}.
6080 Which perl6-tap-harness package used for the tests can be specified with
6081 @code{#:prove6} or removed by passing @code{#f} to the
6082 @code{with-prove6?} parameter.
6083 Which perl6-zef package used for tests and installing can be specified
6084 with @code{#:zef} or removed by passing @code{#f} to the
6085 @code{with-zef?} parameter.
6088 @defvr {Scheme Variable} texlive-build-system
6089 This variable is exported by @code{(guix build-system texlive)}. It is
6090 used to build TeX packages in batch mode with a specified engine. The
6091 build system sets the @code{TEXINPUTS} variable to find all TeX source
6092 files in the inputs.
6094 By default it runs @code{luatex} on all files ending on @code{ins}. A
6095 different engine and format can be specified with the
6096 @code{#:tex-format} argument. Different build targets can be specified
6097 with the @code{#:build-targets} argument, which expects a list of file
6098 names. The build system adds only @code{texlive-bin} and
6099 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6100 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6101 and @code{#:texlive-latex-base}, respectively.
6103 The @code{#:tex-directory} parameter tells the build system where to
6104 install the built files under the texmf tree.
6107 @defvr {Scheme Variable} ruby-build-system
6108 This variable is exported by @code{(guix build-system ruby)}. It
6109 implements the RubyGems build procedure used by Ruby packages, which
6110 involves running @code{gem build} followed by @code{gem install}.
6112 The @code{source} field of a package that uses this build system
6113 typically references a gem archive, since this is the format that Ruby
6114 developers use when releasing their software. The build system unpacks
6115 the gem archive, potentially patches the source, runs the test suite,
6116 repackages the gem, and installs it. Additionally, directories and
6117 tarballs may be referenced to allow building unreleased gems from Git or
6118 a traditional source release tarball.
6120 Which Ruby package is used can be specified with the @code{#:ruby}
6121 parameter. A list of additional flags to be passed to the @command{gem}
6122 command can be specified with the @code{#:gem-flags} parameter.
6125 @defvr {Scheme Variable} waf-build-system
6126 This variable is exported by @code{(guix build-system waf)}. It
6127 implements a build procedure around the @code{waf} script. The common
6128 phases---@code{configure}, @code{build}, and @code{install}---are
6129 implemented by passing their names as arguments to the @code{waf}
6132 The @code{waf} script is executed by the Python interpreter. Which
6133 Python package is used to run the script can be specified with the
6134 @code{#:python} parameter.
6137 @defvr {Scheme Variable} scons-build-system
6138 This variable is exported by @code{(guix build-system scons)}. It
6139 implements the build procedure used by the SCons software construction
6140 tool. This build system runs @code{scons} to build the package,
6141 @code{scons test} to run tests, and then @code{scons install} to install
6144 Additional flags to be passed to @code{scons} can be specified with the
6145 @code{#:scons-flags} parameter. The version of Python used to run SCons
6146 can be specified by selecting the appropriate SCons package with the
6147 @code{#:scons} parameter.
6150 @defvr {Scheme Variable} haskell-build-system
6151 This variable is exported by @code{(guix build-system haskell)}. It
6152 implements the Cabal build procedure used by Haskell packages, which
6153 involves running @code{runhaskell Setup.hs configure
6154 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6155 Instead of installing the package by running @code{runhaskell Setup.hs
6156 install}, to avoid trying to register libraries in the read-only
6157 compiler store directory, the build system uses @code{runhaskell
6158 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6159 addition, the build system generates the package documentation by
6160 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6161 is passed. Optional Haddock parameters can be passed with the help of
6162 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6163 not found, the build system looks for @code{Setup.lhs} instead.
6165 Which Haskell compiler is used can be specified with the @code{#:haskell}
6166 parameter which defaults to @code{ghc}.
6169 @defvr {Scheme Variable} dub-build-system
6170 This variable is exported by @code{(guix build-system dub)}. It
6171 implements the Dub build procedure used by D packages, which
6172 involves running @code{dub build} and @code{dub run}.
6173 Installation is done by copying the files manually.
6175 Which D compiler is used can be specified with the @code{#:ldc}
6176 parameter which defaults to @code{ldc}.
6179 @defvr {Scheme Variable} emacs-build-system
6180 This variable is exported by @code{(guix build-system emacs)}. It
6181 implements an installation procedure similar to the packaging system
6182 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6184 It first creates the @code{@var{package}-autoloads.el} file, then it
6185 byte compiles all Emacs Lisp files. Differently from the Emacs
6186 packaging system, the Info documentation files are moved to the standard
6187 documentation directory and the @file{dir} file is deleted. Each
6188 package is installed in its own directory under
6189 @file{share/emacs/site-lisp/guix.d}.
6192 @defvr {Scheme Variable} font-build-system
6193 This variable is exported by @code{(guix build-system font)}. It
6194 implements an installation procedure for font packages where upstream
6195 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6196 need to be copied into place. It copies font files to standard
6197 locations in the output directory.
6200 @defvr {Scheme Variable} meson-build-system
6201 This variable is exported by @code{(guix build-system meson)}. It
6202 implements the build procedure for packages that use
6203 @url{https://mesonbuild.com, Meson} as their build system.
6205 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6206 of inputs, and they can be changed with the parameters @code{#:meson}
6207 and @code{#:ninja} if needed. The default Meson is
6208 @code{meson-for-build}, which is special because it doesn't clear the
6209 @code{RUNPATH} of binaries and libraries when they are installed.
6211 This build system is an extension of @var{gnu-build-system}, but with the
6212 following phases changed to some specific for Meson:
6217 The phase runs @code{meson} with the flags specified in
6218 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6219 @code{plain} unless something else is specified in @code{#:build-type}.
6222 The phase runs @code{ninja} to build the package in parallel by default, but
6223 this can be changed with @code{#:parallel-build?}.
6226 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6227 which is @code{"test"} by default.
6230 The phase runs @code{ninja install} and can not be changed.
6233 Apart from that, the build system also adds the following phases:
6238 This phase ensures that all binaries can find the libraries they need.
6239 It searches for required libraries in subdirectories of the package being
6240 built, and adds those to @code{RUNPATH} where needed. It also removes
6241 references to libraries left over from the build phase by
6242 @code{meson-for-build}, such as test dependencies, that aren't actually
6243 required for the program to run.
6245 @item glib-or-gtk-wrap
6246 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6247 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6249 @item glib-or-gtk-compile-schemas
6250 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6251 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6255 @defvr {Scheme Variable} linux-module-build-system
6256 @var{linux-module-build-system} allows building Linux kernel modules.
6258 @cindex build phases
6259 This build system is an extension of @var{gnu-build-system}, but with the
6260 following phases changed:
6265 This phase configures the environment so that the Linux kernel's Makefile
6266 can be used to build the external kernel module.
6269 This phase uses the Linux kernel's Makefile in order to build the external
6273 This phase uses the Linux kernel's Makefile in order to install the external
6277 It is possible and useful to specify the Linux kernel to use for building
6278 the module (in the "arguments" form of a package using the
6279 linux-module-build-system, use the key #:linux to specify it).
6282 Lastly, for packages that do not need anything as sophisticated, a
6283 ``trivial'' build system is provided. It is trivial in the sense that
6284 it provides basically no support: it does not pull any implicit inputs,
6285 and does not have a notion of build phases.
6287 @defvr {Scheme Variable} trivial-build-system
6288 This variable is exported by @code{(guix build-system trivial)}.
6290 This build system requires a @code{#:builder} argument. This argument
6291 must be a Scheme expression that builds the package output(s)---as
6292 with @code{build-expression->derivation} (@pxref{Derivations,
6293 @code{build-expression->derivation}}).
6303 Conceptually, the @dfn{store} is the place where derivations that have
6304 been built successfully are stored---by default, @file{/gnu/store}.
6305 Sub-directories in the store are referred to as @dfn{store items} or
6306 sometimes @dfn{store paths}. The store has an associated database that
6307 contains information such as the store paths referred to by each store
6308 path, and the list of @emph{valid} store items---results of successful
6309 builds. This database resides in @file{@var{localstatedir}/guix/db},
6310 where @var{localstatedir} is the state directory specified @i{via}
6311 @option{--localstatedir} at configure time, usually @file{/var}.
6313 The store is @emph{always} accessed by the daemon on behalf of its clients
6314 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6315 connect to the daemon over a Unix-domain socket, send requests to it,
6316 and read the result---these are remote procedure calls, or RPCs.
6319 Users must @emph{never} modify files under @file{/gnu/store} directly.
6320 This would lead to inconsistencies and break the immutability
6321 assumptions of Guix's functional model (@pxref{Introduction}).
6323 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6324 how to check the integrity of the store and attempt recovery from
6325 accidental modifications.
6328 The @code{(guix store)} module provides procedures to connect to the
6329 daemon, and to perform RPCs. These are described below. By default,
6330 @code{open-connection}, and thus all the @command{guix} commands,
6331 connect to the local daemon or to the URI specified by the
6332 @code{GUIX_DAEMON_SOCKET} environment variable.
6334 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6335 When set, the value of this variable should be a file name or a URI
6336 designating the daemon endpoint. When it is a file name, it denotes a
6337 Unix-domain socket to connect to. In addition to file names, the
6338 supported URI schemes are:
6343 These are for Unix-domain sockets.
6344 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6345 @file{/var/guix/daemon-socket/socket}.
6348 @cindex daemon, remote access
6349 @cindex remote access to the daemon
6350 @cindex daemon, cluster setup
6351 @cindex clusters, daemon setup
6352 These URIs denote connections over TCP/IP, without encryption nor
6353 authentication of the remote host. The URI must specify the host name
6354 and optionally a port number (by default port 44146 is used):
6357 guix://master.guix.example.org:1234
6360 This setup is suitable on local networks, such as clusters, where only
6361 trusted nodes may connect to the build daemon at
6362 @code{master.guix.example.org}.
6364 The @code{--listen} option of @command{guix-daemon} can be used to
6365 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6369 @cindex SSH access to build daemons
6370 These URIs allow you to connect to a remote daemon over
6371 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6372 A typical URL might look like this:
6375 ssh://charlie@@guix.example.org:22
6378 As for @command{guix copy}, the usual OpenSSH client configuration files
6379 are honored (@pxref{Invoking guix copy}).
6382 Additional URI schemes may be supported in the future.
6384 @c XXX: Remove this note when the protocol incurs fewer round trips
6385 @c and when (guix derivations) no longer relies on file system access.
6387 The ability to connect to remote build daemons is considered
6388 experimental as of @value{VERSION}. Please get in touch with us to
6389 share any problems or suggestions you may have (@pxref{Contributing}).
6393 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6394 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6395 @var{reserve-space?} is true, instruct it to reserve a little bit of
6396 extra space on the file system so that the garbage collector can still
6397 operate should the disk become full. Return a server object.
6399 @var{file} defaults to @var{%default-socket-path}, which is the normal
6400 location given the options that were passed to @command{configure}.
6403 @deffn {Scheme Procedure} close-connection @var{server}
6404 Close the connection to @var{server}.
6407 @defvr {Scheme Variable} current-build-output-port
6408 This variable is bound to a SRFI-39 parameter, which refers to the port
6409 where build and error logs sent by the daemon should be written.
6412 Procedures that make RPCs all take a server object as their first
6415 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6416 @cindex invalid store items
6417 Return @code{#t} when @var{path} designates a valid store item and
6418 @code{#f} otherwise (an invalid item may exist on disk but still be
6419 invalid, for instance because it is the result of an aborted or failed
6422 A @code{&store-protocol-error} condition is raised if @var{path} is not
6423 prefixed by the store directory (@file{/gnu/store}).
6426 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6427 Add @var{text} under file @var{name} in the store, and return its store
6428 path. @var{references} is the list of store paths referred to by the
6429 resulting store path.
6432 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6433 Build @var{derivations} (a list of @code{<derivation>} objects or
6434 derivation paths), and return when the worker is done building them.
6435 Return @code{#t} on success.
6438 Note that the @code{(guix monads)} module provides a monad as well as
6439 monadic versions of the above procedures, with the goal of making it
6440 more convenient to work with code that accesses the store (@pxref{The
6444 @i{This section is currently incomplete.}
6447 @section Derivations
6450 Low-level build actions and the environment in which they are performed
6451 are represented by @dfn{derivations}. A derivation contains the
6452 following pieces of information:
6456 The outputs of the derivation---derivations produce at least one file or
6457 directory in the store, but may produce more.
6460 @cindex build-time dependencies
6461 @cindex dependencies, build-time
6462 The inputs of the derivations---i.e., its build-time dependencies---which may
6463 be other derivations or plain files in the store (patches, build scripts,
6467 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6470 The file name of a build script in the store, along with the arguments
6474 A list of environment variables to be defined.
6478 @cindex derivation path
6479 Derivations allow clients of the daemon to communicate build actions to
6480 the store. They exist in two forms: as an in-memory representation,
6481 both on the client- and daemon-side, and as files in the store whose
6482 name end in @code{.drv}---these files are referred to as @dfn{derivation
6483 paths}. Derivations paths can be passed to the @code{build-derivations}
6484 procedure to perform the build actions they prescribe (@pxref{The
6487 @cindex fixed-output derivations
6488 Operations such as file downloads and version-control checkouts for
6489 which the expected content hash is known in advance are modeled as
6490 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6491 of a fixed-output derivation are independent of its inputs---e.g., a
6492 source code download produces the same result regardless of the download
6493 method and tools being used.
6496 @cindex run-time dependencies
6497 @cindex dependencies, run-time
6498 The outputs of derivations---i.e., the build results---have a set of
6499 @dfn{references}, as reported by the @code{references} RPC or the
6500 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6501 are the set of run-time dependencies of the build results. References are a
6502 subset of the inputs of the derivation; this subset is automatically computed
6503 by the build daemon by scanning all the files in the outputs.
6505 The @code{(guix derivations)} module provides a representation of
6506 derivations as Scheme objects, along with procedures to create and
6507 otherwise manipulate derivations. The lowest-level primitive to create
6508 a derivation is the @code{derivation} procedure:
6510 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6511 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6512 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6513 [#:system (%current-system)] [#:references-graphs #f] @
6514 [#:allowed-references #f] [#:disallowed-references #f] @
6515 [#:leaked-env-vars #f] [#:local-build? #f] @
6516 [#:substitutable? #t] [#:properties '()]
6517 Build a derivation with the given arguments, and return the resulting
6518 @code{<derivation>} object.
6520 When @var{hash} and @var{hash-algo} are given, a
6521 @dfn{fixed-output derivation} is created---i.e., one whose result is
6522 known in advance, such as a file download. If, in addition,
6523 @var{recursive?} is true, then that fixed output may be an executable
6524 file or a directory and @var{hash} must be the hash of an archive
6525 containing this output.
6527 When @var{references-graphs} is true, it must be a list of file
6528 name/store path pairs. In that case, the reference graph of each store
6529 path is exported in the build environment in the corresponding file, in
6530 a simple text format.
6532 When @var{allowed-references} is true, it must be a list of store items
6533 or outputs that the derivation's output may refer to. Likewise,
6534 @var{disallowed-references}, if true, must be a list of things the
6535 outputs may @emph{not} refer to.
6537 When @var{leaked-env-vars} is true, it must be a list of strings
6538 denoting environment variables that are allowed to ``leak'' from the
6539 daemon's environment to the build environment. This is only applicable
6540 to fixed-output derivations---i.e., when @var{hash} is true. The main
6541 use is to allow variables such as @code{http_proxy} to be passed to
6542 derivations that download files.
6544 When @var{local-build?} is true, declare that the derivation is not a
6545 good candidate for offloading and should rather be built locally
6546 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6547 where the costs of data transfers would outweigh the benefits.
6549 When @var{substitutable?} is false, declare that substitutes of the
6550 derivation's output should not be used (@pxref{Substitutes}). This is
6551 useful, for instance, when building packages that capture details of the
6552 host CPU instruction set.
6554 @var{properties} must be an association list describing ``properties'' of the
6555 derivation. It is kept as-is, uninterpreted, in the derivation.
6559 Here's an example with a shell script as its builder, assuming
6560 @var{store} is an open connection to the daemon, and @var{bash} points
6561 to a Bash executable in the store:
6564 (use-modules (guix utils)
6568 (let ((builder ; add the Bash script to the store
6569 (add-text-to-store store "my-builder.sh"
6570 "echo hello world > $out\n" '())))
6571 (derivation store "foo"
6572 bash `("-e" ,builder)
6573 #:inputs `((,bash) (,builder))
6574 #:env-vars '(("HOME" . "/homeless"))))
6575 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6578 As can be guessed, this primitive is cumbersome to use directly. A
6579 better approach is to write build scripts in Scheme, of course! The
6580 best course of action for that is to write the build code as a
6581 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6582 information, @pxref{G-Expressions}.
6584 Once upon a time, @code{gexp->derivation} did not exist and constructing
6585 derivations with build code written in Scheme was achieved with
6586 @code{build-expression->derivation}, documented below. This procedure
6587 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6589 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6590 @var{name} @var{exp} @
6591 [#:system (%current-system)] [#:inputs '()] @
6592 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6593 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6594 [#:references-graphs #f] [#:allowed-references #f] @
6595 [#:disallowed-references #f] @
6596 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6597 Return a derivation that executes Scheme expression @var{exp} as a
6598 builder for derivation @var{name}. @var{inputs} must be a list of
6599 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6600 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6601 modules from the current search path to be copied in the store,
6602 compiled, and made available in the load path during the execution of
6603 @var{exp}---e.g., @code{((guix build utils) (guix build
6604 gnu-build-system))}.
6606 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6607 to a list of output/path pairs, and where @code{%build-inputs} is bound
6608 to a list of string/output-path pairs made from @var{inputs}.
6609 Optionally, @var{env-vars} is a list of string pairs specifying the name
6610 and value of environment variables visible to the builder. The builder
6611 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6612 @var{exp} returns @code{#f}, the build is considered to have failed.
6614 @var{exp} is built using @var{guile-for-build} (a derivation). When
6615 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6616 @code{%guile-for-build} fluid is used instead.
6618 See the @code{derivation} procedure for the meaning of
6619 @var{references-graphs}, @var{allowed-references},
6620 @var{disallowed-references}, @var{local-build?}, and
6621 @var{substitutable?}.
6625 Here's an example of a single-output derivation that creates a directory
6626 containing one file:
6629 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6630 (mkdir out) ; create /gnu/store/@dots{}-goo
6631 (call-with-output-file (string-append out "/test")
6633 (display '(hello guix) p))))))
6634 (build-expression->derivation store "goo" builder))
6636 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6640 @node The Store Monad
6641 @section The Store Monad
6645 The procedures that operate on the store described in the previous
6646 sections all take an open connection to the build daemon as their first
6647 argument. Although the underlying model is functional, they either have
6648 side effects or depend on the current state of the store.
6650 The former is inconvenient: the connection to the build daemon has to be
6651 carried around in all those functions, making it impossible to compose
6652 functions that do not take that parameter with functions that do. The
6653 latter can be problematic: since store operations have side effects
6654 and/or depend on external state, they have to be properly sequenced.
6656 @cindex monadic values
6657 @cindex monadic functions
6658 This is where the @code{(guix monads)} module comes in. This module
6659 provides a framework for working with @dfn{monads}, and a particularly
6660 useful monad for our uses, the @dfn{store monad}. Monads are a
6661 construct that allows two things: associating ``context'' with values
6662 (in our case, the context is the store), and building sequences of
6663 computations (here computations include accesses to the store). Values
6664 in a monad---values that carry this additional context---are called
6665 @dfn{monadic values}; procedures that return such values are called
6666 @dfn{monadic procedures}.
6668 Consider this ``normal'' procedure:
6671 (define (sh-symlink store)
6672 ;; Return a derivation that symlinks the 'bash' executable.
6673 (let* ((drv (package-derivation store bash))
6674 (out (derivation->output-path drv))
6675 (sh (string-append out "/bin/bash")))
6676 (build-expression->derivation store "sh"
6677 `(symlink ,sh %output))))
6680 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6681 as a monadic function:
6684 (define (sh-symlink)
6685 ;; Same, but return a monadic value.
6686 (mlet %store-monad ((drv (package->derivation bash)))
6687 (gexp->derivation "sh"
6688 #~(symlink (string-append #$drv "/bin/bash")
6692 There are several things to note in the second version: the @code{store}
6693 parameter is now implicit and is ``threaded'' in the calls to the
6694 @code{package->derivation} and @code{gexp->derivation} monadic
6695 procedures, and the monadic value returned by @code{package->derivation}
6696 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6698 As it turns out, the call to @code{package->derivation} can even be
6699 omitted since it will take place implicitly, as we will see later
6700 (@pxref{G-Expressions}):
6703 (define (sh-symlink)
6704 (gexp->derivation "sh"
6705 #~(symlink (string-append #$bash "/bin/bash")
6710 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6711 @c for the funny quote.
6712 Calling the monadic @code{sh-symlink} has no effect. As someone once
6713 said, ``you exit a monad like you exit a building on fire: by running''.
6714 So, to exit the monad and get the desired effect, one must use
6715 @code{run-with-store}:
6718 (run-with-store (open-connection) (sh-symlink))
6719 @result{} /gnu/store/...-sh-symlink
6722 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6723 new ``meta-commands'' to make it easier to deal with monadic procedures:
6724 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6725 to ``run'' a single monadic value through the store:
6728 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6729 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6732 The latter enters a recursive REPL, where all the return values are
6733 automatically run through the store:
6736 scheme@@(guile-user)> ,enter-store-monad
6737 store-monad@@(guile-user) [1]> (package->derivation hello)
6738 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6739 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6740 $3 = "/gnu/store/@dots{}-foo"
6741 store-monad@@(guile-user) [1]> ,q
6742 scheme@@(guile-user)>
6746 Note that non-monadic values cannot be returned in the
6747 @code{store-monad} REPL.
6749 The main syntactic forms to deal with monads in general are provided by
6750 the @code{(guix monads)} module and are described below.
6752 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6753 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6757 @deffn {Scheme Syntax} return @var{val}
6758 Return a monadic value that encapsulates @var{val}.
6761 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6762 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6763 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6764 referred to as ``bind'', but that name denotes an unrelated procedure in
6765 Guile. Thus we use this somewhat cryptic symbol inherited from the
6766 Haskell language.}. There can be one @var{mproc} or several of them, as
6771 (with-monad %state-monad
6773 (lambda (x) (return (+ 1 x)))
6774 (lambda (x) (return (* 2 x)))))
6778 @result{} some-state
6782 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6784 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6786 Bind the variables @var{var} to the monadic values @var{mval} in
6787 @var{body}, which is a sequence of expressions. As with the bind
6788 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6789 value ``contained'' in @var{mval} and making @var{var} refer to that
6790 raw, non-monadic value within the scope of the @var{body}. The form
6791 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6792 @var{val}, as per @code{let}. The binding operations occur in sequence
6793 from left to right. The last expression of @var{body} must be a monadic
6794 expression, and its result will become the result of the @code{mlet} or
6795 @code{mlet*} when run in the @var{monad}.
6797 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6798 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6801 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6802 Bind @var{mexp} and the following monadic expressions in sequence,
6803 returning the result of the last expression. Every expression in the
6804 sequence must be a monadic expression.
6806 This is akin to @code{mlet}, except that the return values of the
6807 monadic expressions are ignored. In that sense, it is analogous to
6808 @code{begin}, but applied to monadic expressions.
6811 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6812 When @var{condition} is true, evaluate the sequence of monadic
6813 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6814 @var{condition} is false, return @code{*unspecified*} in the current
6815 monad. Every expression in the sequence must be a monadic expression.
6818 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6819 When @var{condition} is false, evaluate the sequence of monadic
6820 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6821 @var{condition} is true, return @code{*unspecified*} in the current
6822 monad. Every expression in the sequence must be a monadic expression.
6826 The @code{(guix monads)} module provides the @dfn{state monad}, which
6827 allows an additional value---the state---to be @emph{threaded} through
6828 monadic procedure calls.
6830 @defvr {Scheme Variable} %state-monad
6831 The state monad. Procedures in the state monad can access and change
6832 the state that is threaded.
6834 Consider the example below. The @code{square} procedure returns a value
6835 in the state monad. It returns the square of its argument, but also
6836 increments the current state value:
6840 (mlet %state-monad ((count (current-state)))
6841 (mbegin %state-monad
6842 (set-current-state (+ 1 count))
6845 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6850 When ``run'' through @var{%state-monad}, we obtain that additional state
6851 value, which is the number of @code{square} calls.
6854 @deffn {Monadic Procedure} current-state
6855 Return the current state as a monadic value.
6858 @deffn {Monadic Procedure} set-current-state @var{value}
6859 Set the current state to @var{value} and return the previous state as a
6863 @deffn {Monadic Procedure} state-push @var{value}
6864 Push @var{value} to the current state, which is assumed to be a list,
6865 and return the previous state as a monadic value.
6868 @deffn {Monadic Procedure} state-pop
6869 Pop a value from the current state and return it as a monadic value.
6870 The state is assumed to be a list.
6873 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6874 Run monadic value @var{mval} starting with @var{state} as the initial
6875 state. Return two values: the resulting value, and the resulting state.
6878 The main interface to the store monad, provided by the @code{(guix
6879 store)} module, is as follows.
6881 @defvr {Scheme Variable} %store-monad
6882 The store monad---an alias for @var{%state-monad}.
6884 Values in the store monad encapsulate accesses to the store. When its
6885 effect is needed, a value of the store monad must be ``evaluated'' by
6886 passing it to the @code{run-with-store} procedure (see below.)
6889 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6890 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6891 open store connection.
6894 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6895 Return as a monadic value the absolute file name in the store of the file
6896 containing @var{text}, a string. @var{references} is a list of store items that the
6897 resulting text file refers to; it defaults to the empty list.
6900 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6901 Return as a monadic value the absolute file name in the store of the file
6902 containing @var{data}, a bytevector. @var{references} is a list of store
6903 items that the resulting binary file refers to; it defaults to the empty list.
6906 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6907 [#:recursive? #t] [#:select? (const #t)]
6908 Return the name of @var{file} once interned in the store. Use
6909 @var{name} as its store name, or the basename of @var{file} if
6910 @var{name} is omitted.
6912 When @var{recursive?} is true, the contents of @var{file} are added
6913 recursively; if @var{file} designates a flat file and @var{recursive?}
6914 is true, its contents are added, and its permission bits are kept.
6916 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6917 @var{stat})} for each directory entry, where @var{file} is the entry's
6918 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6919 entries for which @var{select?} does not return true.
6921 The example below adds a file to the store, under two different names:
6924 (run-with-store (open-connection)
6925 (mlet %store-monad ((a (interned-file "README"))
6926 (b (interned-file "README" "LEGU-MIN")))
6927 (return (list a b))))
6929 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6934 The @code{(guix packages)} module exports the following package-related
6937 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6938 [#:system (%current-system)] [#:target #f] @
6941 value in the absolute file name of @var{file} within the @var{output}
6942 directory of @var{package}. When @var{file} is omitted, return the name
6943 of the @var{output} directory of @var{package}. When @var{target} is
6944 true, use it as a cross-compilation target triplet.
6947 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6948 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6949 @var{target} [@var{system}]
6950 Monadic version of @code{package-derivation} and
6951 @code{package-cross-derivation} (@pxref{Defining Packages}).
6956 @section G-Expressions
6958 @cindex G-expression
6959 @cindex build code quoting
6960 So we have ``derivations'', which represent a sequence of build actions
6961 to be performed to produce an item in the store (@pxref{Derivations}).
6962 These build actions are performed when asking the daemon to actually
6963 build the derivations; they are run by the daemon in a container
6964 (@pxref{Invoking guix-daemon}).
6966 @cindex strata of code
6967 It should come as no surprise that we like to write these build actions
6968 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6969 code@footnote{The term @dfn{stratum} in this context was coined by
6970 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6971 Kiselyov, who has written insightful
6972 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6973 on this topic}, refers to this kind of code generation as
6974 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6975 to the daemon, etc.---and the ``build code''---code that actually
6976 performs build actions, such as making directories, invoking
6977 @command{make}, etc.
6979 To describe a derivation and its build actions, one typically needs to
6980 embed build code inside host code. It boils down to manipulating build
6981 code as data, and the homoiconicity of Scheme---code has a direct
6982 representation as data---comes in handy for that. But we need more than
6983 the normal @code{quasiquote} mechanism in Scheme to construct build
6986 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6987 S-expressions adapted to build expressions. G-expressions, or
6988 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6989 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6990 @code{#$}, and @code{#$@@}), which are comparable to
6991 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6992 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6993 GNU Guile Reference Manual}). However, there are major differences:
6997 Gexps are meant to be written to a file and run or manipulated by other
7001 When a high-level object such as a package or derivation is unquoted
7002 inside a gexp, the result is as if its output file name had been
7006 Gexps carry information about the packages or derivations they refer to,
7007 and these dependencies are automatically added as inputs to the build
7008 processes that use them.
7011 @cindex lowering, of high-level objects in gexps
7012 This mechanism is not limited to package and derivation
7013 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7014 derivations or files in the store can be defined,
7015 such that these objects can also be inserted
7016 into gexps. For example, a useful type of high-level objects that can be
7017 inserted in a gexp is ``file-like objects'', which make it easy to
7018 add files to the store and to refer to them in
7019 derivations and such (see @code{local-file} and @code{plain-file}
7022 To illustrate the idea, here is an example of a gexp:
7029 (symlink (string-append #$coreutils "/bin/ls")
7033 This gexp can be passed to @code{gexp->derivation}; we obtain a
7034 derivation that builds a directory containing exactly one symlink to
7035 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7038 (gexp->derivation "the-thing" build-exp)
7041 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7042 substituted to the reference to the @var{coreutils} package in the
7043 actual build code, and @var{coreutils} is automatically made an input to
7044 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7045 output)}) is replaced by a string containing the directory name of the
7046 output of the derivation.
7048 @cindex cross compilation
7049 In a cross-compilation context, it is useful to distinguish between
7050 references to the @emph{native} build of a package---that can run on the
7051 host---versus references to cross builds of a package. To that end, the
7052 @code{#+} plays the same role as @code{#$}, but is a reference to a
7053 native package build:
7056 (gexp->derivation "vi"
7059 (system* (string-append #+coreutils "/bin/ln")
7061 (string-append #$emacs "/bin/emacs")
7062 (string-append #$output "/bin/vi")))
7063 #:target "mips64el-linux-gnu")
7067 In the example above, the native build of @var{coreutils} is used, so
7068 that @command{ln} can actually run on the host; but then the
7069 cross-compiled build of @var{emacs} is referenced.
7071 @cindex imported modules, for gexps
7072 @findex with-imported-modules
7073 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7074 able to use certain Guile modules from the ``host environment'' in the
7075 gexp, so those modules should be imported in the ``build environment''.
7076 The @code{with-imported-modules} form allows you to express that:
7079 (let ((build (with-imported-modules '((guix build utils))
7081 (use-modules (guix build utils))
7082 (mkdir-p (string-append #$output "/bin"))))))
7083 (gexp->derivation "empty-dir"
7086 (display "success!\n")
7091 In this example, the @code{(guix build utils)} module is automatically
7092 pulled into the isolated build environment of our gexp, such that
7093 @code{(use-modules (guix build utils))} works as expected.
7095 @cindex module closure
7096 @findex source-module-closure
7097 Usually you want the @emph{closure} of the module to be imported---i.e.,
7098 the module itself and all the modules it depends on---rather than just
7099 the module; failing to do that, attempts to use the module will fail
7100 because of missing dependent modules. The @code{source-module-closure}
7101 procedure computes the closure of a module by looking at its source file
7102 headers, which comes in handy in this case:
7105 (use-modules (guix modules)) ;for 'source-module-closure'
7107 (with-imported-modules (source-module-closure
7108 '((guix build utils)
7110 (gexp->derivation "something-with-vms"
7112 (use-modules (guix build utils)
7117 @cindex extensions, for gexps
7118 @findex with-extensions
7119 In the same vein, sometimes you want to import not just pure-Scheme
7120 modules, but also ``extensions'' such as Guile bindings to C libraries
7121 or other ``full-blown'' packages. Say you need the @code{guile-json}
7122 package available on the build side, here's how you would do it:
7125 (use-modules (gnu packages guile)) ;for 'guile-json'
7127 (with-extensions (list guile-json)
7128 (gexp->derivation "something-with-json"
7130 (use-modules (json))
7134 The syntactic form to construct gexps is summarized below.
7136 @deffn {Scheme Syntax} #~@var{exp}
7137 @deffnx {Scheme Syntax} (gexp @var{exp})
7138 Return a G-expression containing @var{exp}. @var{exp} may contain one
7139 or more of the following forms:
7143 @itemx (ungexp @var{obj})
7144 Introduce a reference to @var{obj}. @var{obj} may have one of the
7145 supported types, for example a package or a
7146 derivation, in which case the @code{ungexp} form is replaced by its
7147 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7149 If @var{obj} is a list, it is traversed and references to supported
7150 objects are substituted similarly.
7152 If @var{obj} is another gexp, its contents are inserted and its
7153 dependencies are added to those of the containing gexp.
7155 If @var{obj} is another kind of object, it is inserted as is.
7157 @item #$@var{obj}:@var{output}
7158 @itemx (ungexp @var{obj} @var{output})
7159 This is like the form above, but referring explicitly to the
7160 @var{output} of @var{obj}---this is useful when @var{obj} produces
7161 multiple outputs (@pxref{Packages with Multiple Outputs}).
7164 @itemx #+@var{obj}:output
7165 @itemx (ungexp-native @var{obj})
7166 @itemx (ungexp-native @var{obj} @var{output})
7167 Same as @code{ungexp}, but produces a reference to the @emph{native}
7168 build of @var{obj} when used in a cross compilation context.
7170 @item #$output[:@var{output}]
7171 @itemx (ungexp output [@var{output}])
7172 Insert a reference to derivation output @var{output}, or to the main
7173 output when @var{output} is omitted.
7175 This only makes sense for gexps passed to @code{gexp->derivation}.
7178 @itemx (ungexp-splicing @var{lst})
7179 Like the above, but splices the contents of @var{lst} inside the
7183 @itemx (ungexp-native-splicing @var{lst})
7184 Like the above, but refers to native builds of the objects listed in
7189 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7190 of the @code{gexp?} type (see below.)
7193 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7194 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7195 in their execution environment.
7197 Each item in @var{modules} can be the name of a module, such as
7198 @code{(guix build utils)}, or it can be a module name, followed by an
7199 arrow, followed by a file-like object:
7202 `((guix build utils)
7204 ((guix config) => ,(scheme-file "config.scm"
7205 #~(define-module @dots{}))))
7209 In the example above, the first two modules are taken from the search
7210 path, and the last one is created from the given file-like object.
7212 This form has @emph{lexical} scope: it has an effect on the gexps
7213 directly defined in @var{body}@dots{}, but not on those defined, say, in
7214 procedures called from @var{body}@dots{}.
7217 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7218 Mark the gexps defined in @var{body}@dots{} as requiring
7219 @var{extensions} in their build and execution environment.
7220 @var{extensions} is typically a list of package objects such as those
7221 defined in the @code{(gnu packages guile)} module.
7223 Concretely, the packages listed in @var{extensions} are added to the
7224 load path while compiling imported modules in @var{body}@dots{}; they
7225 are also added to the load path of the gexp returned by
7229 @deffn {Scheme Procedure} gexp? @var{obj}
7230 Return @code{#t} if @var{obj} is a G-expression.
7233 G-expressions are meant to be written to disk, either as code building
7234 some derivation, or as plain files in the store. The monadic procedures
7235 below allow you to do that (@pxref{The Store Monad}, for more
7236 information about monads.)
7238 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7239 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7240 [#:hash #f] [#:hash-algo #f] @
7241 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7242 [#:module-path @var{%load-path}] @
7243 [#:effective-version "2.2"] @
7244 [#:references-graphs #f] [#:allowed-references #f] @
7245 [#:disallowed-references #f] @
7246 [#:leaked-env-vars #f] @
7247 [#:script-name (string-append @var{name} "-builder")] @
7248 [#:deprecation-warnings #f] @
7249 [#:local-build? #f] [#:substitutable? #t] @
7250 [#:properties '()] [#:guile-for-build #f]
7251 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7252 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7253 stored in a file called @var{script-name}. When @var{target} is true,
7254 it is used as the cross-compilation target triplet for packages referred
7257 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7259 make @var{modules} available in the evaluation context of @var{exp};
7260 @var{modules} is a list of names of Guile modules searched in
7261 @var{module-path} to be copied in the store, compiled, and made available in
7262 the load path during the execution of @var{exp}---e.g., @code{((guix
7263 build utils) (guix build gnu-build-system))}.
7265 @var{effective-version} determines the string to use when adding extensions of
7266 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7268 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7271 When @var{references-graphs} is true, it must be a list of tuples of one of the
7275 (@var{file-name} @var{package})
7276 (@var{file-name} @var{package} @var{output})
7277 (@var{file-name} @var{derivation})
7278 (@var{file-name} @var{derivation} @var{output})
7279 (@var{file-name} @var{store-item})
7282 The right-hand-side of each element of @var{references-graphs} is automatically made
7283 an input of the build process of @var{exp}. In the build environment, each
7284 @var{file-name} contains the reference graph of the corresponding item, in a simple
7287 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7288 In the latter case, the list denotes store items that the result is allowed to
7289 refer to. Any reference to another store item will lead to a build error.
7290 Similarly for @var{disallowed-references}, which can list items that must not be
7291 referenced by the outputs.
7293 @var{deprecation-warnings} determines whether to show deprecation warnings while
7294 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7296 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7299 @cindex file-like objects
7300 The @code{local-file}, @code{plain-file}, @code{computed-file},
7301 @code{program-file}, and @code{scheme-file} procedures below return
7302 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7303 these objects lead to a file in the store. Consider this G-expression:
7306 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7307 #$(local-file "/tmp/my-nscd.conf"))
7310 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7311 to the store. Once expanded, for instance @i{via}
7312 @code{gexp->derivation}, the G-expression refers to that copy under
7313 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7314 does not have any effect on what the G-expression does.
7315 @code{plain-file} can be used similarly; it differs in that the file
7316 content is directly passed as a string.
7318 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7319 [#:recursive? #f] [#:select? (const #t)]
7320 Return an object representing local file @var{file} to add to the store; this
7321 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7322 up relative to the source file where this form appears. @var{file} will be added to
7323 the store under @var{name}--by default the base name of @var{file}.
7325 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7326 designates a flat file and @var{recursive?} is true, its contents are added, and its
7327 permission bits are kept.
7329 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7330 @var{stat})} for each directory entry, where @var{file} is the entry's
7331 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7332 entries for which @var{select?} does not return true.
7334 This is the declarative counterpart of the @code{interned-file} monadic
7335 procedure (@pxref{The Store Monad, @code{interned-file}}).
7338 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7339 Return an object representing a text file called @var{name} with the given
7340 @var{content} (a string or a bytevector) to be added to the store.
7342 This is the declarative counterpart of @code{text-file}.
7345 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7346 [#:options '(#:local-build? #t)]
7347 Return an object representing the store item @var{name}, a file or
7348 directory computed by @var{gexp}. @var{options}
7349 is a list of additional arguments to pass to @code{gexp->derivation}.
7351 This is the declarative counterpart of @code{gexp->derivation}.
7354 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7355 [#:guile (default-guile)] [#:module-path %load-path]
7356 Return an executable script @var{name} that runs @var{exp} using
7357 @var{guile}, with @var{exp}'s imported modules in its search path.
7358 Look up @var{exp}'s modules in @var{module-path}.
7360 The example below builds a script that simply invokes the @command{ls}
7364 (use-modules (guix gexp) (gnu packages base))
7366 (gexp->script "list-files"
7367 #~(execl #$(file-append coreutils "/bin/ls")
7371 When ``running'' it through the store (@pxref{The Store Monad,
7372 @code{run-with-store}}), we obtain a derivation that produces an
7373 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7376 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7378 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7382 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7383 [#:guile #f] [#:module-path %load-path]
7384 Return an object representing the executable store item @var{name} that
7385 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7386 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7388 This is the declarative counterpart of @code{gexp->script}.
7391 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7392 [#:set-load-path? #t] [#:module-path %load-path] @
7394 [#:guile (default-guile)]
7395 Return a derivation that builds a file @var{name} containing @var{exp}.
7396 When @var{splice?} is true, @var{exp} is considered to be a list of
7397 expressions that will be spliced in the resulting file.
7399 When @var{set-load-path?} is true, emit code in the resulting file to
7400 set @code{%load-path} and @code{%load-compiled-path} to honor
7401 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7404 The resulting file holds references to all the dependencies of @var{exp}
7405 or a subset thereof.
7408 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7409 Return an object representing the Scheme file @var{name} that contains
7412 This is the declarative counterpart of @code{gexp->file}.
7415 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7416 Return as a monadic value a derivation that builds a text file
7417 containing all of @var{text}. @var{text} may list, in addition to
7418 strings, objects of any type that can be used in a gexp: packages,
7419 derivations, local file objects, etc. The resulting store file holds
7420 references to all these.
7422 This variant should be preferred over @code{text-file} anytime the file
7423 to create will reference items from the store. This is typically the
7424 case when building a configuration file that embeds store file names,
7428 (define (profile.sh)
7429 ;; Return the name of a shell script in the store that
7430 ;; initializes the 'PATH' environment variable.
7431 (text-file* "profile.sh"
7432 "export PATH=" coreutils "/bin:"
7433 grep "/bin:" sed "/bin\n"))
7436 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7437 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7438 preventing them from being garbage-collected during its lifetime.
7441 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7442 Return an object representing store file @var{name} containing
7443 @var{text}. @var{text} is a sequence of strings and file-like objects,
7447 (mixed-text-file "profile"
7448 "export PATH=" coreutils "/bin:" grep "/bin")
7451 This is the declarative counterpart of @code{text-file*}.
7454 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7455 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7456 Each item in @var{files} must be a two-element list where the first element is the
7457 file name to use in the new directory, and the second element is a gexp
7458 denoting the target file. Here's an example:
7462 `(("hosts" ,(plain-file "hosts"
7463 "127.0.0.1 localhost"))
7464 ("bashrc" ,(plain-file "bashrc"
7465 "alias ls='ls --color=auto'"))))
7468 This yields an @code{etc} directory containing these two files.
7471 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7472 Return a directory that is the union of @var{things}, where @var{things} is a list of
7473 file-like objects denoting directories. For example:
7476 (directory-union "guile+emacs" (list guile emacs))
7479 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7482 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7483 Return a file-like object that expands to the concatenation of @var{obj}
7484 and @var{suffix}, where @var{obj} is a lowerable object and each
7485 @var{suffix} is a string.
7487 As an example, consider this gexp:
7490 (gexp->script "run-uname"
7491 #~(system* #$(file-append coreutils
7495 The same effect could be achieved with:
7498 (gexp->script "run-uname"
7499 #~(system* (string-append #$coreutils
7503 There is one difference though: in the @code{file-append} case, the
7504 resulting script contains the absolute file name as a string, whereas in
7505 the second case, the resulting script contains a @code{(string-append
7506 @dots{})} expression to construct the file name @emph{at run time}.
7510 Of course, in addition to gexps embedded in ``host'' code, there are
7511 also modules containing build tools. To make it clear that they are
7512 meant to be used in the build stratum, these modules are kept in the
7513 @code{(guix build @dots{})} name space.
7515 @cindex lowering, of high-level objects in gexps
7516 Internally, high-level objects are @dfn{lowered}, using their compiler,
7517 to either derivations or store items. For instance, lowering a package
7518 yields a derivation, and lowering a @code{plain-file} yields a store
7519 item. This is achieved using the @code{lower-object} monadic procedure.
7521 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7523 Return as a value in @var{%store-monad} the derivation or store item
7524 corresponding to @var{obj} for @var{system}, cross-compiling for
7525 @var{target} if @var{target} is true. @var{obj} must be an object that
7526 has an associated gexp compiler, such as a @code{<package>}.
7529 @node Invoking guix repl
7530 @section Invoking @command{guix repl}
7532 @cindex REPL, read-eval-print loop
7533 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7534 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7535 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7536 command, @command{guix repl} guarantees that all the Guix modules and all its
7537 dependencies are available in the search path. You can use it this way:
7541 scheme@@(guile-user)> ,use (gnu packages base)
7542 scheme@@(guile-user)> coreutils
7543 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7547 In addition, @command{guix repl} implements a simple machine-readable REPL
7548 protocol for use by @code{(guix inferior)}, a facility to interact with
7549 @dfn{inferiors}, separate processes running a potentially different revision
7552 The available options are as follows:
7555 @item --type=@var{type}
7556 @itemx -t @var{type}
7557 Start a REPL of the given @var{TYPE}, which can be one of the following:
7561 This is default, and it spawns a standard full-featured Guile REPL.
7563 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7564 that the @code{(guix inferior)} module speaks.
7567 @item --listen=@var{endpoint}
7568 By default, @command{guix repl} reads from standard input and writes to
7569 standard output. When this option is passed, it will instead listen for
7570 connections on @var{endpoint}. Here are examples of valid options:
7573 @item --listen=tcp:37146
7574 Accept connections on localhost on port 37146.
7576 @item --listen=unix:/tmp/socket
7577 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7581 @c *********************************************************************
7585 This section describes Guix command-line utilities. Some of them are
7586 primarily targeted at developers and users who write new package
7587 definitions, while others are more generally useful. They complement
7588 the Scheme programming interface of Guix in a convenient way.
7591 * Invoking guix build:: Building packages from the command line.
7592 * Invoking guix edit:: Editing package definitions.
7593 * Invoking guix download:: Downloading a file and printing its hash.
7594 * Invoking guix hash:: Computing the cryptographic hash of a file.
7595 * Invoking guix import:: Importing package definitions.
7596 * Invoking guix refresh:: Updating package definitions.
7597 * Invoking guix lint:: Finding errors in package definitions.
7598 * Invoking guix size:: Profiling disk usage.
7599 * Invoking guix graph:: Visualizing the graph of packages.
7600 * Invoking guix publish:: Sharing substitutes.
7601 * Invoking guix challenge:: Challenging substitute servers.
7602 * Invoking guix copy:: Copying to and from a remote store.
7603 * Invoking guix container:: Process isolation.
7604 * Invoking guix weather:: Assessing substitute availability.
7605 * Invoking guix processes:: Listing client processes.
7608 @node Invoking guix build
7609 @section Invoking @command{guix build}
7611 @cindex package building
7612 @cindex @command{guix build}
7613 The @command{guix build} command builds packages or derivations and
7614 their dependencies, and prints the resulting store paths. Note that it
7615 does not modify the user's profile---this is the job of the
7616 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7617 it is mainly useful for distribution developers.
7619 The general syntax is:
7622 guix build @var{options} @var{package-or-derivation}@dots{}
7625 As an example, the following command builds the latest versions of Emacs
7626 and of Guile, displays their build logs, and finally displays the
7627 resulting directories:
7630 guix build emacs guile
7633 Similarly, the following command builds all the available packages:
7636 guix build --quiet --keep-going \
7637 `guix package -A | cut -f1,2 --output-delimiter=@@`
7640 @var{package-or-derivation} may be either the name of a package found in
7641 the software distribution such as @code{coreutils} or
7642 @code{coreutils@@8.20}, or a derivation such as
7643 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7644 package with the corresponding name (and optionally version) is searched
7645 for among the GNU distribution modules (@pxref{Package Modules}).
7647 Alternatively, the @code{--expression} option may be used to specify a
7648 Scheme expression that evaluates to a package; this is useful when
7649 disambiguating among several same-named packages or package variants is
7652 There may be zero or more @var{options}. The available options are
7653 described in the subsections below.
7656 * Common Build Options:: Build options for most commands.
7657 * Package Transformation Options:: Creating variants of packages.
7658 * Additional Build Options:: Options specific to 'guix build'.
7659 * Debugging Build Failures:: Real life packaging experience.
7662 @node Common Build Options
7663 @subsection Common Build Options
7665 A number of options that control the build process are common to
7666 @command{guix build} and other commands that can spawn builds, such as
7667 @command{guix package} or @command{guix archive}. These are the
7672 @item --load-path=@var{directory}
7673 @itemx -L @var{directory}
7674 Add @var{directory} to the front of the package module search path
7675 (@pxref{Package Modules}).
7677 This allows users to define their own packages and make them visible to
7678 the command-line tools.
7682 Keep the build tree of failed builds. Thus, if a build fails, its build
7683 tree is kept under @file{/tmp}, in a directory whose name is shown at
7684 the end of the build log. This is useful when debugging build issues.
7685 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7688 This option has no effect when connecting to a remote daemon with a
7689 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7694 Keep going when some of the derivations fail to build; return only once
7695 all the builds have either completed or failed.
7697 The default behavior is to stop as soon as one of the specified
7698 derivations has failed.
7702 Do not build the derivations.
7704 @anchor{fallback-option}
7706 When substituting a pre-built binary fails, fall back to building
7707 packages locally (@pxref{Substitution Failure}).
7709 @item --substitute-urls=@var{urls}
7710 @anchor{client-substitute-urls}
7711 Consider @var{urls} the whitespace-separated list of substitute source
7712 URLs, overriding the default list of URLs of @command{guix-daemon}
7713 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7715 This means that substitutes may be downloaded from @var{urls}, provided
7716 they are signed by a key authorized by the system administrator
7717 (@pxref{Substitutes}).
7719 When @var{urls} is the empty string, substitutes are effectively
7722 @item --no-substitutes
7723 Do not use substitutes for build products. That is, always build things
7724 locally instead of allowing downloads of pre-built binaries
7725 (@pxref{Substitutes}).
7728 Do not ``graft'' packages. In practice, this means that package updates
7729 available as grafts are not applied. @xref{Security Updates}, for more
7730 information on grafts.
7732 @item --rounds=@var{n}
7733 Build each derivation @var{n} times in a row, and raise an error if
7734 consecutive build results are not bit-for-bit identical.
7736 This is a useful way to detect non-deterministic builds processes.
7737 Non-deterministic build processes are a problem because they make it
7738 practically impossible for users to @emph{verify} whether third-party
7739 binaries are genuine. @xref{Invoking guix challenge}, for more.
7741 Note that, currently, the differing build results are not kept around,
7742 so you will have to manually investigate in case of an error---e.g., by
7743 stashing one of the build results with @code{guix archive --export}
7744 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7747 @item --no-build-hook
7748 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7749 (@pxref{Daemon Offload Setup}). That is, always build things locally
7750 instead of offloading builds to remote machines.
7752 @item --max-silent-time=@var{seconds}
7753 When the build or substitution process remains silent for more than
7754 @var{seconds}, terminate it and report a build failure.
7756 By default, the daemon's setting is honored (@pxref{Invoking
7757 guix-daemon, @code{--max-silent-time}}).
7759 @item --timeout=@var{seconds}
7760 Likewise, when the build or substitution process lasts for more than
7761 @var{seconds}, terminate it and report a build failure.
7763 By default, the daemon's setting is honored (@pxref{Invoking
7764 guix-daemon, @code{--timeout}}).
7766 @c Note: This option is actually not part of %standard-build-options but
7767 @c most programs honor it.
7768 @cindex verbosity, of the command-line tools
7769 @cindex build logs, verbosity
7770 @item -v @var{level}
7771 @itemx --verbosity=@var{level}
7772 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7773 output is produced, 1 is for quiet output, and 2 shows all the build log
7774 output on standard error.
7776 @item --cores=@var{n}
7778 Allow the use of up to @var{n} CPU cores for the build. The special
7779 value @code{0} means to use as many CPU cores as available.
7781 @item --max-jobs=@var{n}
7783 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7784 guix-daemon, @code{--max-jobs}}, for details about this option and the
7785 equivalent @command{guix-daemon} option.
7787 @item --debug=@var{level}
7788 Produce debugging output coming from the build daemon. @var{level} must be an
7789 integer between 0 and 5; higher means more verbose output. Setting a level of
7790 4 or more may be helpful when debugging setup issues with the build daemon.
7794 Behind the scenes, @command{guix build} is essentially an interface to
7795 the @code{package-derivation} procedure of the @code{(guix packages)}
7796 module, and to the @code{build-derivations} procedure of the @code{(guix
7797 derivations)} module.
7799 In addition to options explicitly passed on the command line,
7800 @command{guix build} and other @command{guix} commands that support
7801 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7803 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7804 Users can define this variable to a list of command line options that
7805 will automatically be used by @command{guix build} and other
7806 @command{guix} commands that can perform builds, as in the example
7810 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7813 These options are parsed independently, and the result is appended to
7814 the parsed command-line options.
7818 @node Package Transformation Options
7819 @subsection Package Transformation Options
7821 @cindex package variants
7822 Another set of command-line options supported by @command{guix build}
7823 and also @command{guix package} are @dfn{package transformation
7824 options}. These are options that make it possible to define @dfn{package
7825 variants}---for instance, packages built from different source code.
7826 This is a convenient way to create customized packages on the fly
7827 without having to type in the definitions of package variants
7828 (@pxref{Defining Packages}).
7832 @item --with-source=@var{source}
7833 @itemx --with-source=@var{package}=@var{source}
7834 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7835 Use @var{source} as the source of @var{package}, and @var{version} as
7837 @var{source} must be a file name or a URL, as for @command{guix
7838 download} (@pxref{Invoking guix download}).
7840 When @var{package} is omitted,
7841 it is taken to be the package name specified on the
7842 command line that matches the base of @var{source}---e.g.,
7843 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7844 package is @code{guile}.
7846 Likewise, when @var{version} is omitted, the version string is inferred from
7847 @var{source}; in the previous example, it is @code{2.0.10}.
7849 This option allows users to try out versions of packages other than the
7850 one provided by the distribution. The example below downloads
7851 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7852 the @code{ed} package:
7855 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7858 As a developer, @code{--with-source} makes it easy to test release
7862 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7865 @dots{} or to build from a checkout in a pristine environment:
7868 $ git clone git://git.sv.gnu.org/guix.git
7869 $ guix build guix --with-source=guix@@1.0=./guix
7872 @item --with-input=@var{package}=@var{replacement}
7873 Replace dependency on @var{package} by a dependency on
7874 @var{replacement}. @var{package} must be a package name, and
7875 @var{replacement} must be a package specification such as @code{guile}
7876 or @code{guile@@1.8}.
7878 For instance, the following command builds Guix, but replaces its
7879 dependency on the current stable version of Guile with a dependency on
7880 the legacy version of Guile, @code{guile@@2.0}:
7883 guix build --with-input=guile=guile@@2.0 guix
7886 This is a recursive, deep replacement. So in this example, both
7887 @code{guix} and its dependency @code{guile-json} (which also depends on
7888 @code{guile}) get rebuilt against @code{guile@@2.0}.
7890 This is implemented using the @code{package-input-rewriting} Scheme
7891 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7893 @item --with-graft=@var{package}=@var{replacement}
7894 This is similar to @code{--with-input} but with an important difference:
7895 instead of rebuilding the whole dependency chain, @var{replacement} is
7896 built and then @dfn{grafted} onto the binaries that were initially
7897 referring to @var{package}. @xref{Security Updates}, for more
7898 information on grafts.
7900 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7901 and all its dependencies, replacing references to the version of GnuTLS
7902 they currently refer to:
7905 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7908 This has the advantage of being much faster than rebuilding everything.
7909 But there is a caveat: it works if and only if @var{package} and
7910 @var{replacement} are strictly compatible---for example, if they provide
7911 a library, the application binary interface (ABI) of those libraries
7912 must be compatible. If @var{replacement} is somehow incompatible with
7913 @var{package}, then the resulting package may be unusable. Use with
7916 @item --with-git-url=@var{package}=@var{url}
7917 @cindex Git, using the latest commit
7918 @cindex latest commit, building
7919 Build @var{package} from the latest commit of the @code{master} branch of the
7920 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7923 For example, the following command builds the NumPy Python library against the
7924 latest commit of the master branch of Python itself:
7927 guix build python-numpy \
7928 --with-git-url=python=https://github.com/python/cpython
7931 This option can also be combined with @code{--with-branch} or
7932 @code{--with-commit} (see below).
7934 @cindex continuous integration
7935 Obviously, since it uses the latest commit of the given branch, the result of
7936 such a command varies over time. Nevertheless it is a convenient way to
7937 rebuild entire software stacks against the latest commit of one or more
7938 packages. This is particularly useful in the context of continuous
7941 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7942 consecutive accesses to the same repository. You may want to clean it up once
7943 in a while to save disk space.
7945 @item --with-branch=@var{package}=@var{branch}
7946 Build @var{package} from the latest commit of @var{branch}. If the
7947 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7948 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7949 repository URL is taken from that @code{source}. Otherwise you have to use
7950 @code{--with-git-url} to specify the URL of the Git repository.
7952 For instance, the following command builds @code{guile-sqlite3} from the
7953 latest commit of its @code{master} branch, and then builds @code{guix} (which
7954 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7955 specific @code{guile-sqlite3} build:
7958 guix build --with-branch=guile-sqlite3=master cuirass
7961 @item --with-commit=@var{package}=@var{commit}
7962 This is similar to @code{--with-branch}, except that it builds from
7963 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7964 Git commit SHA1 identifier.
7967 @node Additional Build Options
7968 @subsection Additional Build Options
7970 The command-line options presented below are specific to @command{guix
7977 Build quietly, without displaying the build log; this is equivalent to
7978 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7979 (or similar) and can always be retrieved using the @option{--log-file} option.
7981 @item --file=@var{file}
7982 @itemx -f @var{file}
7983 Build the package, derivation, or other file-like object that the code within
7984 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7986 As an example, @var{file} might contain a package definition like this
7987 (@pxref{Defining Packages}):
7990 @verbatiminclude package-hello.scm
7993 @item --expression=@var{expr}
7994 @itemx -e @var{expr}
7995 Build the package or derivation @var{expr} evaluates to.
7997 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7998 guile-1.8)}, which unambiguously designates this specific variant of
7999 version 1.8 of Guile.
8001 Alternatively, @var{expr} may be a G-expression, in which case it is used
8002 as a build program passed to @code{gexp->derivation}
8003 (@pxref{G-Expressions}).
8005 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8006 (@pxref{The Store Monad}). The procedure must return a derivation as a
8007 monadic value, which is then passed through @code{run-with-store}.
8011 Build the source derivations of the packages, rather than the packages
8014 For instance, @code{guix build -S gcc} returns something like
8015 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8018 The returned source tarball is the result of applying any patches and
8019 code snippets specified in the package @code{origin} (@pxref{Defining
8023 Fetch and return the source of @var{package-or-derivation} and all their
8024 dependencies, recursively. This is a handy way to obtain a local copy
8025 of all the source code needed to build @var{packages}, allowing you to
8026 eventually build them even without network access. It is an extension
8027 of the @code{--source} option and can accept one of the following
8028 optional argument values:
8032 This value causes the @code{--sources} option to behave in the same way
8033 as the @code{--source} option.
8036 Build the source derivations of all packages, including any source that
8037 might be listed as @code{inputs}. This is the default value.
8040 $ guix build --sources tzdata
8041 The following derivations will be built:
8042 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8043 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8047 Build the source derivations of all packages, as well of all transitive
8048 inputs to the packages. This can be used e.g.@: to
8049 prefetch package source for later offline building.
8052 $ guix build --sources=transitive tzdata
8053 The following derivations will be built:
8054 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8055 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8056 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8057 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8058 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8059 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8065 @item --system=@var{system}
8066 @itemx -s @var{system}
8067 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8068 the system type of the build host. The @command{guix build} command allows
8069 you to repeat this option several times, in which case it builds for all the
8070 specified systems; other commands ignore extraneous @option{-s} options.
8073 The @code{--system} flag is for @emph{native} compilation and must not
8074 be confused with cross-compilation. See @code{--target} below for
8075 information on cross-compilation.
8078 An example use of this is on Linux-based systems, which can emulate
8079 different personalities. For instance, passing
8080 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8081 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8082 to build packages in a complete 32-bit environment.
8085 Building for an @code{armhf-linux} system is unconditionally enabled on
8086 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8087 allow for this functionality, notably the ThunderX.
8090 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8091 is enabled (@pxref{Virtualization Services,
8092 @code{qemu-binfmt-service-type}}), you can build for any system for
8093 which a QEMU @code{binfmt_misc} handler is installed.
8095 Builds for a system other than that of the machine you are using can
8096 also be offloaded to a remote machine of the right architecture.
8097 @xref{Daemon Offload Setup}, for more information on offloading.
8099 @item --target=@var{triplet}
8100 @cindex cross-compilation
8101 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8102 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8103 configuration triplets,, autoconf, Autoconf}).
8105 @anchor{build-check}
8107 @cindex determinism, checking
8108 @cindex reproducibility, checking
8109 Rebuild @var{package-or-derivation}, which are already available in the
8110 store, and raise an error if the build results are not bit-for-bit
8113 This mechanism allows you to check whether previously installed
8114 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8115 of a package is deterministic. @xref{Invoking guix challenge}, for more
8116 background information and tools.
8118 When used in conjunction with @option{--keep-failed}, the differing
8119 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8120 This makes it easy to look for differences between the two results.
8123 @cindex repairing store items
8124 @cindex corruption, recovering from
8125 Attempt to repair the specified store items, if they are corrupt, by
8126 re-downloading or rebuilding them.
8128 This operation is not atomic and thus restricted to @code{root}.
8132 Return the derivation paths, not the output paths, of the given
8135 @item --root=@var{file}
8136 @itemx -r @var{file}
8137 @cindex GC roots, adding
8138 @cindex garbage collector roots, adding
8139 Make @var{file} a symlink to the result, and register it as a garbage
8142 Consequently, the results of this @command{guix build} invocation are
8143 protected from garbage collection until @var{file} is removed. When
8144 that option is omitted, build results are eligible for garbage
8145 collection as soon as the build completes. @xref{Invoking guix gc}, for
8149 @cindex build logs, access
8150 Return the build log file names or URLs for the given
8151 @var{package-or-derivation}, or raise an error if build logs are
8154 This works regardless of how packages or derivations are specified. For
8155 instance, the following invocations are equivalent:
8158 guix build --log-file `guix build -d guile`
8159 guix build --log-file `guix build guile`
8160 guix build --log-file guile
8161 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8164 If a log is unavailable locally, and unless @code{--no-substitutes} is
8165 passed, the command looks for a corresponding log on one of the
8166 substitute servers (as specified with @code{--substitute-urls}.)
8168 So for instance, imagine you want to see the build log of GDB on MIPS,
8169 but you are actually on an @code{x86_64} machine:
8172 $ guix build --log-file gdb -s mips64el-linux
8173 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8176 You can freely access a huge library of build logs!
8179 @node Debugging Build Failures
8180 @subsection Debugging Build Failures
8182 @cindex build failures, debugging
8183 When defining a new package (@pxref{Defining Packages}), you will
8184 probably find yourself spending some time debugging and tweaking the
8185 build until it succeeds. To do that, you need to operate the build
8186 commands yourself in an environment as close as possible to the one the
8189 To that end, the first thing to do is to use the @option{--keep-failed}
8190 or @option{-K} option of @command{guix build}, which will keep the
8191 failed build tree in @file{/tmp} or whatever directory you specified as
8192 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8194 From there on, you can @command{cd} to the failed build tree and source
8195 the @file{environment-variables} file, which contains all the
8196 environment variable definitions that were in place when the build
8197 failed. So let's say you're debugging a build failure in package
8198 @code{foo}; a typical session would look like this:
8202 @dots{} @i{build fails}
8203 $ cd /tmp/guix-build-foo.drv-0
8204 $ source ./environment-variables
8208 Now, you can invoke commands as if you were the daemon (almost) and
8209 troubleshoot your build process.
8211 Sometimes it happens that, for example, a package's tests pass when you
8212 run them manually but they fail when the daemon runs them. This can
8213 happen because the daemon runs builds in containers where, unlike in our
8214 environment above, network access is missing, @file{/bin/sh} does not
8215 exist, etc. (@pxref{Build Environment Setup}).
8217 In such cases, you may need to run inspect the build process from within
8218 a container similar to the one the build daemon creates:
8223 $ cd /tmp/guix-build-foo.drv-0
8224 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8225 [env]# source ./environment-variables
8229 Here, @command{guix environment -C} creates a container and spawns a new
8230 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8231 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8232 the container, which would may find handy while debugging. The
8233 @option{--no-grafts} option makes sure we get the exact same
8234 environment, with ungrafted packages (@pxref{Security Updates}, for more
8237 To get closer to a container like that used by the build daemon, we can
8238 remove @file{/bin/sh}:
8244 (Don't worry, this is harmless: this is all happening in the throw-away
8245 container created by @command{guix environment}.)
8247 The @command{strace} command is probably not in the search path, but we
8251 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8254 In this way, not only you will have reproduced the environment variables
8255 the daemon uses, you will also be running the build process in a container
8256 similar to the one the daemon uses.
8259 @node Invoking guix edit
8260 @section Invoking @command{guix edit}
8262 @cindex @command{guix edit}
8263 @cindex package definition, editing
8264 So many packages, so many source files! The @command{guix edit} command
8265 facilitates the life of users and packagers by pointing their editor at
8266 the source file containing the definition of the specified packages.
8270 guix edit gcc@@4.9 vim
8274 launches the program specified in the @code{VISUAL} or in the
8275 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8278 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8279 have created your own packages on @code{GUIX_PACKAGE_PATH}
8280 (@pxref{Package Modules}), you will be able to edit the package
8281 recipes. In other cases, you will be able to examine the read-only recipes
8282 for packages currently in the store.
8285 @node Invoking guix download
8286 @section Invoking @command{guix download}
8288 @cindex @command{guix download}
8289 @cindex downloading package sources
8290 When writing a package definition, developers typically need to download
8291 a source tarball, compute its SHA256 hash, and write that
8292 hash in the package definition (@pxref{Defining Packages}). The
8293 @command{guix download} tool helps with this task: it downloads a file
8294 from the given URI, adds it to the store, and prints both its file name
8295 in the store and its SHA256 hash.
8297 The fact that the downloaded file is added to the store saves bandwidth:
8298 when the developer eventually tries to build the newly defined package
8299 with @command{guix build}, the source tarball will not have to be
8300 downloaded again because it is already in the store. It is also a
8301 convenient way to temporarily stash files, which may be deleted
8302 eventually (@pxref{Invoking guix gc}).
8304 The @command{guix download} command supports the same URIs as used in
8305 package definitions. In particular, it supports @code{mirror://} URIs.
8306 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8307 Guile bindings for GnuTLS are available in the user's environment; when
8308 they are not available, an error is raised. @xref{Guile Preparations,
8309 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8310 GnuTLS-Guile}, for more information.
8312 @command{guix download} verifies HTTPS server certificates by loading
8313 the certificates of X.509 authorities from the directory pointed to by
8314 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8315 Certificates}), unless @option{--no-check-certificate} is used.
8317 The following options are available:
8320 @item --format=@var{fmt}
8322 Write the hash in the format specified by @var{fmt}. For more
8323 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8325 @item --no-check-certificate
8326 Do not validate the X.509 certificates of HTTPS servers.
8328 When using this option, you have @emph{absolutely no guarantee} that you
8329 are communicating with the authentic server responsible for the given
8330 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8332 @item --output=@var{file}
8333 @itemx -o @var{file}
8334 Save the downloaded file to @var{file} instead of adding it to the
8338 @node Invoking guix hash
8339 @section Invoking @command{guix hash}
8341 @cindex @command{guix hash}
8342 The @command{guix hash} command computes the SHA256 hash of a file.
8343 It is primarily a convenience tool for anyone contributing to the
8344 distribution: it computes the cryptographic hash of a file, which can be
8345 used in the definition of a package (@pxref{Defining Packages}).
8347 The general syntax is:
8350 guix hash @var{option} @var{file}
8353 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8354 hash of data read from standard input. @command{guix hash} has the
8359 @item --format=@var{fmt}
8361 Write the hash in the format specified by @var{fmt}.
8363 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8364 (@code{hex} and @code{hexadecimal} can be used as well).
8366 If the @option{--format} option is not specified, @command{guix hash}
8367 will output the hash in @code{nix-base32}. This representation is used
8368 in the definitions of packages.
8372 Compute the hash on @var{file} recursively.
8374 In this case, the hash is computed on an archive containing @var{file},
8375 including its children if it is a directory. Some of the metadata of
8376 @var{file} is part of the archive; for instance, when @var{file} is a
8377 regular file, the hash is different depending on whether @var{file} is
8378 executable or not. Metadata such as time stamps has no impact on the
8379 hash (@pxref{Invoking guix archive}).
8380 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8385 When combined with @option{--recursive}, exclude version control system
8386 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8389 As an example, here is how you would compute the hash of a Git checkout,
8390 which is useful when using the @code{git-fetch} method (@pxref{origin
8394 $ git clone http://example.org/foo.git
8400 @node Invoking guix import
8401 @section Invoking @command{guix import}
8403 @cindex importing packages
8404 @cindex package import
8405 @cindex package conversion
8406 @cindex Invoking @command{guix import}
8407 The @command{guix import} command is useful for people who would like to
8408 add a package to the distribution with as little work as
8409 possible---a legitimate demand. The command knows of a few
8410 repositories from which it can ``import'' package metadata. The result
8411 is a package definition, or a template thereof, in the format we know
8412 (@pxref{Defining Packages}).
8414 The general syntax is:
8417 guix import @var{importer} @var{options}@dots{}
8420 @var{importer} specifies the source from which to import package
8421 metadata, and @var{options} specifies a package identifier and other
8422 options specific to @var{importer}. Currently, the available
8427 Import metadata for the given GNU package. This provides a template
8428 for the latest version of that GNU package, including the hash of its
8429 source tarball, and its canonical synopsis and description.
8431 Additional information such as the package dependencies and its
8432 license needs to be figured out manually.
8434 For example, the following command returns a package definition for
8438 guix import gnu hello
8441 Specific command-line options are:
8444 @item --key-download=@var{policy}
8445 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8446 keys when verifying the package signature. @xref{Invoking guix
8447 refresh, @code{--key-download}}.
8452 Import metadata from the @uref{https://pypi.python.org/, Python Package
8453 Index}. Information is taken from the JSON-formatted description
8454 available at @code{pypi.python.org} and usually includes all the relevant
8455 information, including package dependencies. For maximum efficiency, it
8456 is recommended to install the @command{unzip} utility, so that the
8457 importer can unzip Python wheels and gather data from them.
8459 The command below imports metadata for the @code{itsdangerous} Python
8463 guix import pypi itsdangerous
8469 Traverse the dependency graph of the given upstream package recursively
8470 and generate package expressions for all those packages that are not yet
8476 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8477 is taken from the JSON-formatted description available at
8478 @code{rubygems.org} and includes most relevant information, including
8479 runtime dependencies. There are some caveats, however. The metadata
8480 doesn't distinguish between synopses and descriptions, so the same string
8481 is used for both fields. Additionally, the details of non-Ruby
8482 dependencies required to build native extensions is unavailable and left
8483 as an exercise to the packager.
8485 The command below imports metadata for the @code{rails} Ruby package:
8488 guix import gem rails
8494 Traverse the dependency graph of the given upstream package recursively
8495 and generate package expressions for all those packages that are not yet
8501 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8502 Information is taken from the JSON-formatted metadata provided through
8503 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8504 relevant information, such as module dependencies. License information
8505 should be checked closely. If Perl is available in the store, then the
8506 @code{corelist} utility will be used to filter core modules out of the
8507 list of dependencies.
8509 The command command below imports metadata for the @code{Acme::Boolean}
8513 guix import cpan Acme::Boolean
8518 @cindex Bioconductor
8519 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8520 central repository for the @uref{https://r-project.org, GNU@tie{}R
8521 statistical and graphical environment}.
8523 Information is extracted from the @code{DESCRIPTION} file of the package.
8525 The command command below imports metadata for the @code{Cairo}
8529 guix import cran Cairo
8532 When @code{--recursive} is added, the importer will traverse the
8533 dependency graph of the given upstream package recursively and generate
8534 package expressions for all those packages that are not yet in Guix.
8536 When @code{--archive=bioconductor} is added, metadata is imported from
8537 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8538 packages for for the analysis and comprehension of high-throughput
8539 genomic data in bioinformatics.
8541 Information is extracted from the @code{DESCRIPTION} file of a package
8542 published on the web interface of the Bioconductor SVN repository.
8544 The command below imports metadata for the @code{GenomicRanges}
8548 guix import cran --archive=bioconductor GenomicRanges
8554 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8555 comprehensive TeX archive network for TeX packages that are part of the
8556 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8558 Information about the package is obtained through the XML API provided
8559 by CTAN, while the source code is downloaded from the SVN repository of
8560 the Tex Live project. This is done because the CTAN does not keep
8563 The command command below imports metadata for the @code{fontspec}
8567 guix import texlive fontspec
8570 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8571 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8572 tree in the TeX Live SVN repository, but from the specified sibling
8573 directory under the same root.
8575 The command below imports metadata for the @code{ifxetex} package from
8576 CTAN while fetching the sources from the directory
8577 @file{texmf/source/generic}:
8580 guix import texlive --archive=generic ifxetex
8584 @cindex JSON, import
8585 Import package metadata from a local JSON file. Consider the following
8586 example package definition in JSON format:
8592 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8593 "build-system": "gnu",
8594 "home-page": "https://www.gnu.org/software/hello/",
8595 "synopsis": "Hello, GNU world: An example GNU package",
8596 "description": "GNU Hello prints a greeting.",
8597 "license": "GPL-3.0+",
8598 "native-inputs": ["gcc@@6"]
8602 The field names are the same as for the @code{<package>} record
8603 (@xref{Defining Packages}). References to other packages are provided
8604 as JSON lists of quoted package specification strings such as
8605 @code{guile} or @code{guile@@2.0}.
8607 The importer also supports a more explicit source definition using the
8608 common fields for @code{<origin>} records:
8614 "method": "url-fetch",
8615 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8617 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8624 The command below reads metadata from the JSON file @code{hello.json}
8625 and outputs a package expression:
8628 guix import json hello.json
8632 Import metadata from a local copy of the source of the
8633 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8634 relies on the @command{nix-instantiate} command of
8635 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8636 typically written in a mixture of Nix-language and Bash code. This
8637 command only imports the high-level package structure that is written in
8638 the Nix language. It normally includes all the basic fields of a
8641 When importing a GNU package, the synopsis and descriptions are replaced
8642 by their canonical upstream variant.
8644 Usually, you will first need to do:
8647 export NIX_REMOTE=daemon
8651 so that @command{nix-instantiate} does not try to open the Nix database.
8653 As an example, the command below imports the package definition of
8654 LibreOffice (more precisely, it imports the definition of the package
8655 bound to the @code{libreoffice} top-level attribute):
8658 guix import nix ~/path/to/nixpkgs libreoffice
8663 Import metadata from the Haskell community's central package archive
8664 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8665 Cabal files and includes all the relevant information, including package
8668 Specific command-line options are:
8673 Read a Cabal file from standard input.
8674 @item --no-test-dependencies
8676 Do not include dependencies required only by the test suites.
8677 @item --cabal-environment=@var{alist}
8678 @itemx -e @var{alist}
8679 @var{alist} is a Scheme alist defining the environment in which the
8680 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8681 @code{arch}, @code{impl} and a string representing the name of a flag.
8682 The value associated with a flag has to be either the symbol
8683 @code{true} or @code{false}. The value associated with other keys
8684 has to conform to the Cabal file format definition. The default value
8685 associated with the keys @code{os}, @code{arch} and @code{impl} is
8686 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8689 Traverse the dependency graph of the given upstream package recursively
8690 and generate package expressions for all those packages that are not yet
8694 The command below imports metadata for the latest version of the
8695 @code{HTTP} Haskell package without including test dependencies and
8696 specifying the value of the flag @samp{network-uri} as @code{false}:
8699 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8702 A specific package version may optionally be specified by following the
8703 package name by an at-sign and a version number as in the following example:
8706 guix import hackage mtl@@2.1.3.1
8711 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8712 It takes a package name, looks up the package version included in a
8713 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8714 release and uses the @code{hackage} importer to retrieve its metadata.
8715 Note that it is up to you to select an LTS release compatible with the
8716 GHC compiler used by Guix.
8718 Specific command-line options are:
8721 @item --no-test-dependencies
8723 Do not include dependencies required only by the test suites.
8724 @item --lts-version=@var{version}
8725 @itemx -l @var{version}
8726 @var{version} is the desired LTS release version. If omitted the latest
8730 Traverse the dependency graph of the given upstream package recursively
8731 and generate package expressions for all those packages that are not yet
8735 The command below imports metadata for the @code{HTTP} Haskell package
8736 included in the LTS Stackage release version 7.18:
8739 guix import stackage --lts-version=7.18 HTTP
8744 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8745 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8747 Specific command-line options are:
8750 @item --archive=@var{repo}
8751 @itemx -a @var{repo}
8752 @var{repo} identifies the archive repository from which to retrieve the
8753 information. Currently the supported repositories and their identifiers
8757 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8758 identifier. This is the default.
8760 Packages from @code{elpa.gnu.org} are signed with one of the keys
8761 contained in the GnuPG keyring at
8762 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8763 @code{emacs} package (@pxref{Package Installation, ELPA package
8764 signatures,, emacs, The GNU Emacs Manual}).
8767 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8768 @code{melpa-stable} identifier.
8771 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8777 Traverse the dependency graph of the given upstream package recursively
8778 and generate package expressions for all those packages that are not yet
8784 Import metadata from the crates.io Rust package repository
8785 @uref{https://crates.io, crates.io}.
8790 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8791 repository used by the OCaml community.
8794 The structure of the @command{guix import} code is modular. It would be
8795 useful to have more importers for other package formats, and your help
8796 is welcome here (@pxref{Contributing}).
8798 @node Invoking guix refresh
8799 @section Invoking @command{guix refresh}
8801 @cindex @command {guix refresh}
8802 The primary audience of the @command{guix refresh} command is developers
8803 of the GNU software distribution. By default, it reports any packages
8804 provided by the distribution that are outdated compared to the latest
8805 upstream version, like this:
8809 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8810 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8813 Alternately, one can specify packages to consider, in which case a
8814 warning is emitted for packages that lack an updater:
8817 $ guix refresh coreutils guile guile-ssh
8818 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8819 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8822 @command{guix refresh} browses the upstream repository of each package and determines
8823 the highest version number of the releases therein. The command
8824 knows how to update specific types of packages: GNU packages, ELPA
8825 packages, etc.---see the documentation for @option{--type} below. There
8826 are many packages, though, for which it lacks a method to determine
8827 whether a new upstream release is available. However, the mechanism is
8828 extensible, so feel free to get in touch with us to add a new method!
8833 Consider the packages specified, and all the packages upon which they depend.
8836 $ guix refresh --recursive coreutils
8837 gnu/packages/acl.scm:35:2: warning: no updater for acl
8838 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8839 gnu/packages/xml.scm:68:2: warning: no updater for expat
8840 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8846 Sometimes the upstream name differs from the package name used in Guix,
8847 and @command{guix refresh} needs a little help. Most updaters honor the
8848 @code{upstream-name} property in package definitions, which can be used
8852 (define-public network-manager
8854 (name "network-manager")
8856 (properties '((upstream-name . "NetworkManager")))))
8859 When passed @code{--update}, it modifies distribution source files to
8860 update the version numbers and source tarball hashes of those package
8861 recipes (@pxref{Defining Packages}). This is achieved by downloading
8862 each package's latest source tarball and its associated OpenPGP
8863 signature, authenticating the downloaded tarball against its signature
8864 using @command{gpg}, and finally computing its hash. When the public
8865 key used to sign the tarball is missing from the user's keyring, an
8866 attempt is made to automatically retrieve it from a public key server;
8867 when this is successful, the key is added to the user's keyring; otherwise,
8868 @command{guix refresh} reports an error.
8870 The following options are supported:
8874 @item --expression=@var{expr}
8875 @itemx -e @var{expr}
8876 Consider the package @var{expr} evaluates to.
8878 This is useful to precisely refer to a package, as in this example:
8881 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8884 This command lists the dependents of the ``final'' libc (essentially all
8889 Update distribution source files (package recipes) in place. This is
8890 usually run from a checkout of the Guix source tree (@pxref{Running
8891 Guix Before It Is Installed}):
8894 $ ./pre-inst-env guix refresh -s non-core -u
8897 @xref{Defining Packages}, for more information on package definitions.
8899 @item --select=[@var{subset}]
8900 @itemx -s @var{subset}
8901 Select all the packages in @var{subset}, one of @code{core} or
8904 The @code{core} subset refers to all the packages at the core of the
8905 distribution---i.e., packages that are used to build ``everything
8906 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8907 changing one of these packages in the distribution entails a rebuild of
8908 all the others. Thus, such updates are an inconvenience to users in
8909 terms of build time or bandwidth used to achieve the upgrade.
8911 The @code{non-core} subset refers to the remaining packages. It is
8912 typically useful in cases where an update of the core packages would be
8915 @item --manifest=@var{file}
8916 @itemx -m @var{file}
8917 Select all the packages from the manifest in @var{file}. This is useful to
8918 check if any packages of the user manifest can be updated.
8920 @item --type=@var{updater}
8921 @itemx -t @var{updater}
8922 Select only packages handled by @var{updater} (may be a comma-separated
8923 list of updaters). Currently, @var{updater} may be one of:
8927 the updater for GNU packages;
8929 the updater for GNOME packages;
8931 the updater for KDE packages;
8933 the updater for X.org packages;
8935 the updater for packages hosted on kernel.org;
8937 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
8939 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8941 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8943 the updater for @uref{https://www.cpan.org/, CPAN} packages;
8945 the updater for @uref{https://pypi.python.org, PyPI} packages.
8947 the updater for @uref{https://rubygems.org, RubyGems} packages.
8949 the updater for @uref{https://github.com, GitHub} packages.
8951 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8953 the updater for @uref{https://www.stackage.org, Stackage} packages.
8955 the updater for @uref{https://crates.io, Crates} packages.
8957 the updater for @uref{https://launchpad.net, Launchpad} packages.
8960 For instance, the following command only checks for updates of Emacs
8961 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8964 $ guix refresh --type=elpa,cran
8965 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8966 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8971 In addition, @command{guix refresh} can be passed one or more package
8972 names, as in this example:
8975 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8979 The command above specifically updates the @code{emacs} and
8980 @code{idutils} packages. The @code{--select} option would have no
8981 effect in this case.
8983 When considering whether to upgrade a package, it is sometimes
8984 convenient to know which packages would be affected by the upgrade and
8985 should be checked for compatibility. For this the following option may
8986 be used when passing @command{guix refresh} one or more package names:
8990 @item --list-updaters
8992 List available updaters and exit (see @option{--type} above.)
8994 For each updater, display the fraction of packages it covers; at the
8995 end, display the fraction of packages covered by all these updaters.
8997 @item --list-dependent
8999 List top-level dependent packages that would need to be rebuilt as a
9000 result of upgrading one or more packages.
9002 @xref{Invoking guix graph, the @code{reverse-package} type of
9003 @command{guix graph}}, for information on how to visualize the list of
9004 dependents of a package.
9008 Be aware that the @code{--list-dependent} option only
9009 @emph{approximates} the rebuilds that would be required as a result of
9010 an upgrade. More rebuilds might be required under some circumstances.
9013 $ guix refresh --list-dependent flex
9014 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9015 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9018 The command above lists a set of packages that could be built to check
9019 for compatibility with an upgraded @code{flex} package.
9023 @item --list-transitive
9024 List all the packages which one or more packages depend upon.
9027 $ guix refresh --list-transitive flex
9028 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9029 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{}
9034 The command above lists a set of packages which, when changed, would cause
9035 @code{flex} to be rebuilt.
9037 The following options can be used to customize GnuPG operation:
9041 @item --gpg=@var{command}
9042 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9043 for in @code{$PATH}.
9045 @item --keyring=@var{file}
9046 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9047 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9048 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9049 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9050 information on a tool to manipulate keybox files).
9052 When this option is omitted, @command{guix refresh} uses
9053 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9054 signing keys. OpenPGP signatures are checked against keys from this keyring;
9055 missing keys are downloaded to this keyring as well (see
9056 @option{--key-download} below.)
9058 You can export keys from your default GPG keyring into a keybox file using
9059 commands like this one:
9062 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9065 Likewise, you can fetch keys to a specific keybox file like this:
9068 gpg --no-default-keyring --keyring mykeyring.kbx \
9069 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9072 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9073 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9075 @item --key-download=@var{policy}
9076 Handle missing OpenPGP keys according to @var{policy}, which may be one
9081 Always download missing OpenPGP keys from the key server, and add them
9082 to the user's GnuPG keyring.
9085 Never try to download missing OpenPGP keys. Instead just bail out.
9088 When a package signed with an unknown OpenPGP key is encountered, ask
9089 the user whether to download it or not. This is the default behavior.
9092 @item --key-server=@var{host}
9093 Use @var{host} as the OpenPGP key server when importing a public key.
9097 The @code{github} updater uses the
9098 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9099 releases. When used repeatedly e.g.@: when refreshing all packages,
9100 GitHub will eventually refuse to answer any further API requests. By
9101 default 60 API requests per hour are allowed, and a full refresh on all
9102 GitHub packages in Guix requires more than this. Authentication with
9103 GitHub through the use of an API token alleviates these limits. To use
9104 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9105 token procured from @uref{https://github.com/settings/tokens} or
9109 @node Invoking guix lint
9110 @section Invoking @command{guix lint}
9112 @cindex @command{guix lint}
9113 @cindex package, checking for errors
9114 The @command{guix lint} command is meant to help package developers avoid
9115 common errors and use a consistent style. It runs a number of checks on
9116 a given set of packages in order to find common mistakes in their
9117 definitions. Available @dfn{checkers} include (see
9118 @code{--list-checkers} for a complete list):
9123 Validate certain typographical and stylistic rules about package
9124 descriptions and synopses.
9126 @item inputs-should-be-native
9127 Identify inputs that should most likely be native inputs.
9133 @itemx source-file-name
9134 Probe @code{home-page} and @code{source} URLs and report those that are
9135 invalid. Suggest a @code{mirror://} URL when applicable. If the
9136 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9137 URL. Check that the source file name is meaningful, e.g.@: is not just a
9138 version number or ``git-checkout'', without a declared @code{file-name}
9139 (@pxref{origin Reference}).
9141 @item source-unstable-tarball
9142 Parse the @code{source} URL to determine if a tarball from GitHub is
9143 autogenerated or if it is a release tarball. Unfortunately GitHub's
9144 autogenerated tarballs are sometimes regenerated.
9147 @cindex security vulnerabilities
9148 @cindex CVE, Common Vulnerabilities and Exposures
9149 Report known vulnerabilities found in the Common Vulnerabilities and
9150 Exposures (CVE) databases of the current and past year
9151 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9154 To view information about a particular vulnerability, visit pages such as:
9158 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9160 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9164 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9165 @code{CVE-2015-7554}.
9167 Package developers can specify in package recipes the
9168 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9169 name and version of the package when they differ from the name or version
9170 that Guix uses, as in this example:
9176 ;; CPE calls this package "grub2".
9177 (properties '((cpe-name . "grub2")
9178 (cpe-version . "2.3")))
9181 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9182 Some entries in the CVE database do not specify which version of a
9183 package they apply to, and would thus ``stick around'' forever. Package
9184 developers who found CVE alerts and verified they can be ignored can
9185 declare them as in this example:
9191 ;; These CVEs no longer apply and can be safely ignored.
9192 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9195 "CVE-2011-5244")))))
9199 Warn about obvious source code formatting issues: trailing white space,
9200 use of tabulations, etc.
9203 The general syntax is:
9206 guix lint @var{options} @var{package}@dots{}
9209 If no package is given on the command line, then all packages are checked.
9210 The @var{options} may be zero or more of the following:
9213 @item --list-checkers
9215 List and describe all the available checkers that will be run on packages
9220 Only enable the checkers specified in a comma-separated list using the
9221 names returned by @code{--list-checkers}.
9225 @node Invoking guix size
9226 @section Invoking @command{guix size}
9229 @cindex package size
9231 @cindex @command{guix size}
9232 The @command{guix size} command helps package developers profile the
9233 disk usage of packages. It is easy to overlook the impact of an
9234 additional dependency added to a package, or the impact of using a
9235 single output for a package that could easily be split (@pxref{Packages
9236 with Multiple Outputs}). Such are the typical issues that
9237 @command{guix size} can highlight.
9239 The command can be passed one or more package specifications
9240 such as @code{gcc@@4.8}
9241 or @code{guile:debug}, or a file name in the store. Consider this
9245 $ guix size coreutils
9246 store item total self
9247 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9248 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9249 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9250 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9251 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9252 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9253 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9254 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9259 The store items listed here constitute the @dfn{transitive closure} of
9260 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9261 would be returned by:
9264 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9267 Here the output shows three columns next to store items. The first column,
9268 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9269 the store item---that is, its own size plus the size of all its
9270 dependencies. The next column, labeled ``self'', shows the size of the
9271 item itself. The last column shows the ratio of the size of the item
9272 itself to the space occupied by all the items listed here.
9274 In this example, we see that the closure of Coreutils weighs in at
9275 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9276 libraries. (That libc and GCC's libraries represent a large fraction of
9277 the closure is not a problem @i{per se} because they are always available
9278 on the system anyway.)
9280 When the package(s) passed to @command{guix size} are available in the
9281 store@footnote{More precisely, @command{guix size} looks for the
9282 @emph{ungrafted} variant of the given package(s), as returned by
9283 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9284 for information on grafts.}, @command{guix size} queries the daemon to determine its
9285 dependencies, and measures its size in the store, similar to @command{du
9286 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9289 When the given packages are @emph{not} in the store, @command{guix size}
9290 reports information based on the available substitutes
9291 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9292 store items that are not even on disk, only available remotely.
9294 You can also specify several package names:
9297 $ guix size coreutils grep sed bash
9298 store item total self
9299 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9300 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9301 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9302 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9308 In this example we see that the combination of the four packages takes
9309 102.3@tie{}MiB in total, which is much less than the sum of each closure
9310 since they have a lot of dependencies in common.
9312 The available options are:
9316 @item --substitute-urls=@var{urls}
9317 Use substitute information from @var{urls}.
9318 @xref{client-substitute-urls, the same option for @code{guix build}}.
9320 @item --sort=@var{key}
9321 Sort lines according to @var{key}, one of the following options:
9325 the size of each item (the default);
9327 the total size of the item's closure.
9330 @item --map-file=@var{file}
9331 Write a graphical map of disk usage in PNG format to @var{file}.
9333 For the example above, the map looks like this:
9335 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9336 produced by @command{guix size}}
9338 This option requires that
9339 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9340 installed and visible in Guile's module search path. When that is not
9341 the case, @command{guix size} fails as it tries to load it.
9343 @item --system=@var{system}
9344 @itemx -s @var{system}
9345 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9349 @node Invoking guix graph
9350 @section Invoking @command{guix graph}
9353 @cindex @command{guix graph}
9354 @cindex package dependencies
9355 Packages and their dependencies form a @dfn{graph}, specifically a
9356 directed acyclic graph (DAG). It can quickly become difficult to have a
9357 mental model of the package DAG, so the @command{guix graph} command
9358 provides a visual representation of the DAG. By default,
9359 @command{guix graph} emits a DAG representation in the input format of
9360 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9361 directly to the @command{dot} command of Graphviz. It can also emit an
9362 HTML page with embedded JavaScript code to display a ``chord diagram''
9363 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9364 emit Cypher queries to construct a graph in a graph database supporting
9365 the @uref{https://www.opencypher.org/, openCypher} query language.
9366 The general syntax is:
9369 guix graph @var{options} @var{package}@dots{}
9372 For example, the following command generates a PDF file representing the
9373 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9377 guix graph coreutils | dot -Tpdf > dag.pdf
9380 The output looks like this:
9382 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9384 Nice little graph, no?
9386 But there is more than one graph! The one above is concise: it is the
9387 graph of package objects, omitting implicit inputs such as GCC, libc,
9388 grep, etc. It is often useful to have such a concise graph, but
9389 sometimes one may want to see more details. @command{guix graph} supports
9390 several types of graphs, allowing you to choose the level of detail:
9394 This is the default type used in the example above. It shows the DAG of
9395 package objects, excluding implicit dependencies. It is concise, but
9396 filters out many details.
9398 @item reverse-package
9399 This shows the @emph{reverse} DAG of packages. For example:
9402 guix graph --type=reverse-package ocaml
9405 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9406 you are also interested in cases where OCaml is an implicit dependency, see
9407 @code{reverse-bag} below.)
9409 Note that for core packages this can yield huge graphs. If all you want
9410 is to know the number of packages that depend on a given package, use
9411 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9412 @option{--list-dependent}}).
9415 This is the package DAG, @emph{including} implicit inputs.
9417 For instance, the following command:
9420 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9423 ...@: yields this bigger graph:
9425 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9427 At the bottom of the graph, we see all the implicit inputs of
9428 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9430 Now, note that the dependencies of these implicit inputs---that is, the
9431 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9432 here, for conciseness.
9435 Similar to @code{bag-emerged}, but this time including all the bootstrap
9438 @item bag-with-origins
9439 Similar to @code{bag}, but also showing origins and their dependencies.
9442 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9443 it also takes implicit dependencies into account. For example:
9446 guix graph -t reverse-bag dune
9450 ...@: yields the graph of all packages that depend on Dune, directly or
9451 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9452 @i{via} @code{dune-build-system}, this shows a large number of packages,
9453 whereas @code{reverse-package} would show very few if any.
9456 This is the most detailed representation: It shows the DAG of
9457 derivations (@pxref{Derivations}) and plain store items. Compared to
9458 the above representation, many additional nodes are visible, including
9459 build scripts, patches, Guile modules, etc.
9461 For this type of graph, it is also possible to pass a @file{.drv} file
9462 name instead of a package name, as in:
9465 guix graph -t derivation `guix system build -d my-config.scm`
9469 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9470 For example, the following command shows the graph for the package
9471 module that defines the @code{guile} package:
9474 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9478 All the types above correspond to @emph{build-time dependencies}. The
9479 following graph type represents the @emph{run-time dependencies}:
9483 This is the graph of @dfn{references} of a package output, as returned
9484 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9486 If the given package output is not available in the store, @command{guix
9487 graph} attempts to obtain dependency information from substitutes.
9489 Here you can also pass a store file name instead of a package name. For
9490 example, the command below produces the reference graph of your profile
9491 (which can be big!):
9494 guix graph -t references `readlink -f ~/.guix-profile`
9498 This is the graph of the @dfn{referrers} of a store item, as returned by
9499 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9501 This relies exclusively on local information from your store. For
9502 instance, let us suppose that the current Inkscape is available in 10
9503 profiles on your machine; @command{guix graph -t referrers inkscape}
9504 will show a graph rooted at Inkscape and with those 10 profiles linked
9507 It can help determine what is preventing a store item from being garbage
9512 The available options are the following:
9515 @item --type=@var{type}
9516 @itemx -t @var{type}
9517 Produce a graph output of @var{type}, where @var{type} must be one of
9518 the values listed above.
9521 List the supported graph types.
9523 @item --backend=@var{backend}
9524 @itemx -b @var{backend}
9525 Produce a graph using the selected @var{backend}.
9527 @item --list-backends
9528 List the supported graph backends.
9530 Currently, the available backends are Graphviz and d3.js.
9532 @item --expression=@var{expr}
9533 @itemx -e @var{expr}
9534 Consider the package @var{expr} evaluates to.
9536 This is useful to precisely refer to a package, as in this example:
9539 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9542 @item --system=@var{system}
9543 @itemx -s @var{system}
9544 Display the graph for @var{system}---e.g., @code{i686-linux}.
9546 The package dependency graph is largely architecture-independent, but there
9547 are some architecture-dependent bits that this option allows you to visualize.
9552 @node Invoking guix publish
9553 @section Invoking @command{guix publish}
9555 @cindex @command{guix publish}
9556 The purpose of @command{guix publish} is to enable users to easily share
9557 their store with others, who can then use it as a substitute server
9558 (@pxref{Substitutes}).
9560 When @command{guix publish} runs, it spawns an HTTP server which allows
9561 anyone with network access to obtain substitutes from it. This means
9562 that any machine running Guix can also act as if it were a build farm,
9563 since the HTTP interface is compatible with Hydra, the software behind
9564 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9566 For security, each substitute is signed, allowing recipients to check
9567 their authenticity and integrity (@pxref{Substitutes}). Because
9568 @command{guix publish} uses the signing key of the system, which is only
9569 readable by the system administrator, it must be started as root; the
9570 @code{--user} option makes it drop root privileges early on.
9572 The signing key pair must be generated before @command{guix publish} is
9573 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9576 The general syntax is:
9579 guix publish @var{options}@dots{}
9582 Running @command{guix publish} without any additional arguments will
9583 spawn an HTTP server on port 8080:
9589 Once a publishing server has been authorized (@pxref{Invoking guix
9590 archive}), the daemon may download substitutes from it:
9593 guix-daemon --substitute-urls=http://example.org:8080
9596 By default, @command{guix publish} compresses archives on the fly as it
9597 serves them. This ``on-the-fly'' mode is convenient in that it requires
9598 no setup and is immediately available. However, when serving lots of
9599 clients, we recommend using the @option{--cache} option, which enables
9600 caching of the archives before they are sent to clients---see below for
9601 details. The @command{guix weather} command provides a handy way to
9602 check what a server provides (@pxref{Invoking guix weather}).
9604 As a bonus, @command{guix publish} also serves as a content-addressed
9605 mirror for source files referenced in @code{origin} records
9606 (@pxref{origin Reference}). For instance, assuming @command{guix
9607 publish} is running on @code{example.org}, the following URL returns the
9608 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9609 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9612 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9615 Obviously, these URLs only work for files that are in the store; in
9616 other cases, they return 404 (``Not Found'').
9618 @cindex build logs, publication
9619 Build logs are available from @code{/log} URLs like:
9622 http://example.org/log/gwspk@dots{}-guile-2.2.3
9626 When @command{guix-daemon} is configured to save compressed build logs,
9627 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9628 URLs return the compressed log as-is, with an appropriate
9629 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9630 running @command{guix-daemon} with @code{--log-compression=gzip} since
9631 Web browsers can automatically decompress it, which is not the case with
9634 The following options are available:
9637 @item --port=@var{port}
9638 @itemx -p @var{port}
9639 Listen for HTTP requests on @var{port}.
9641 @item --listen=@var{host}
9642 Listen on the network interface for @var{host}. The default is to
9643 accept connections from any interface.
9645 @item --user=@var{user}
9646 @itemx -u @var{user}
9647 Change privileges to @var{user} as soon as possible---i.e., once the
9648 server socket is open and the signing key has been read.
9650 @item --compression[=@var{level}]
9651 @itemx -C [@var{level}]
9652 Compress data using the given @var{level}. When @var{level} is zero,
9653 disable compression. The range 1 to 9 corresponds to different gzip
9654 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9657 Unless @option{--cache} is used, compression occurs on the fly and
9658 the compressed streams are not
9659 cached. Thus, to reduce load on the machine that runs @command{guix
9660 publish}, it may be a good idea to choose a low compression level, to
9661 run @command{guix publish} behind a caching proxy, or to use
9662 @option{--cache}. Using @option{--cache} has the advantage that it
9663 allows @command{guix publish} to add @code{Content-Length} HTTP header
9666 @item --cache=@var{directory}
9667 @itemx -c @var{directory}
9668 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9669 and only serve archives that are in cache.
9671 When this option is omitted, archives and meta-data are created
9672 on-the-fly. This can reduce the available bandwidth, especially when
9673 compression is enabled, since this may become CPU-bound. Another
9674 drawback of the default mode is that the length of archives is not known
9675 in advance, so @command{guix publish} does not add a
9676 @code{Content-Length} HTTP header to its responses, which in turn
9677 prevents clients from knowing the amount of data being downloaded.
9679 Conversely, when @option{--cache} is used, the first request for a store
9680 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9681 background process to @dfn{bake} the archive---computing its
9682 @code{.narinfo} and compressing the archive, if needed. Once the
9683 archive is cached in @var{directory}, subsequent requests succeed and
9684 are served directly from the cache, which guarantees that clients get
9685 the best possible bandwidth.
9687 The ``baking'' process is performed by worker threads. By default, one
9688 thread per CPU core is created, but this can be customized. See
9689 @option{--workers} below.
9691 When @option{--ttl} is used, cached entries are automatically deleted
9692 when they have expired.
9694 @item --workers=@var{N}
9695 When @option{--cache} is used, request the allocation of @var{N} worker
9696 threads to ``bake'' archives.
9698 @item --ttl=@var{ttl}
9699 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9700 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9701 days, @code{1m} means 1 month, and so on.
9703 This allows the user's Guix to keep substitute information in cache for
9704 @var{ttl}. However, note that @code{guix publish} does not itself
9705 guarantee that the store items it provides will indeed remain available
9706 for as long as @var{ttl}.
9708 Additionally, when @option{--cache} is used, cached entries that have
9709 not been accessed for @var{ttl} and that no longer have a corresponding
9710 item in the store, may be deleted.
9712 @item --nar-path=@var{path}
9713 Use @var{path} as the prefix for the URLs of ``nar'' files
9714 (@pxref{Invoking guix archive, normalized archives}).
9716 By default, nars are served at a URL such as
9717 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9718 change the @code{/nar} part to @var{path}.
9720 @item --public-key=@var{file}
9721 @itemx --private-key=@var{file}
9722 Use the specific @var{file}s as the public/private key pair used to sign
9723 the store items being published.
9725 The files must correspond to the same key pair (the private key is used
9726 for signing and the public key is merely advertised in the signature
9727 metadata). They must contain keys in the canonical s-expression format
9728 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9729 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9730 @file{/etc/guix/signing-key.sec} are used.
9732 @item --repl[=@var{port}]
9733 @itemx -r [@var{port}]
9734 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9735 Reference Manual}) on @var{port} (37146 by default). This is used
9736 primarily for debugging a running @command{guix publish} server.
9739 Enabling @command{guix publish} on Guix System is a one-liner: just
9740 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9741 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9742 @code{guix-publish-service-type}}).
9744 If you are instead running Guix on a ``foreign distro'', follow these
9749 If your host distro uses the systemd init system:
9752 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9753 /etc/systemd/system/
9754 # systemctl start guix-publish && systemctl enable guix-publish
9758 If your host distro uses the Upstart init system:
9761 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9762 # start guix-publish
9766 Otherwise, proceed similarly with your distro's init system.
9769 @node Invoking guix challenge
9770 @section Invoking @command{guix challenge}
9772 @cindex reproducible builds
9773 @cindex verifiable builds
9774 @cindex @command{guix challenge}
9776 Do the binaries provided by this server really correspond to the source
9777 code it claims to build? Is a package build process deterministic?
9778 These are the questions the @command{guix challenge} command attempts to
9781 The former is obviously an important question: Before using a substitute
9782 server (@pxref{Substitutes}), one had better @emph{verify} that it
9783 provides the right binaries, and thus @emph{challenge} it. The latter
9784 is what enables the former: If package builds are deterministic, then
9785 independent builds of the package should yield the exact same result,
9786 bit for bit; if a server provides a binary different from the one
9787 obtained locally, it may be either corrupt or malicious.
9789 We know that the hash that shows up in @file{/gnu/store} file names is
9790 the hash of all the inputs of the process that built the file or
9791 directory---compilers, libraries, build scripts,
9792 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9793 one store file name should map to exactly one build output.
9794 @command{guix challenge} checks whether there is, indeed, a single
9795 mapping by comparing the build outputs of several independent builds of
9796 any given store item.
9798 The command output looks like this:
9801 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9802 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9803 updating list of substitutes from 'https://guix.example.org'... 100.0%
9804 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9805 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9806 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9807 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9808 /gnu/store/@dots{}-git-2.5.0 contents differ:
9809 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9810 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9811 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9812 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9813 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9814 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9815 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9819 6,406 store items were analyzed:
9820 - 4,749 (74.1%) were identical
9821 - 525 (8.2%) differed
9822 - 1,132 (17.7%) were inconclusive
9826 In this example, @command{guix challenge} first scans the store to
9827 determine the set of locally-built derivations---as opposed to store
9828 items that were downloaded from a substitute server---and then queries
9829 all the substitute servers. It then reports those store items for which
9830 the servers obtained a result different from the local build.
9832 @cindex non-determinism, in package builds
9833 As an example, @code{guix.example.org} always gets a different answer.
9834 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9835 case of Git. This might indicate that the build process of Git is
9836 non-deterministic, meaning that its output varies as a function of
9837 various things that Guix does not fully control, in spite of building
9838 packages in isolated environments (@pxref{Features}). Most common
9839 sources of non-determinism include the addition of timestamps in build
9840 results, the inclusion of random numbers, and directory listings sorted
9841 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9844 To find out what is wrong with this Git binary, we can do something along
9845 these lines (@pxref{Invoking guix archive}):
9848 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9849 | guix archive -x /tmp/git
9850 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9853 This command shows the difference between the files resulting from the
9854 local build, and the files resulting from the build on
9855 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9856 diffutils, Comparing and Merging Files}). The @command{diff} command
9857 works great for text files. When binary files differ, a better option
9858 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9859 visualize differences for all kinds of files.
9861 Once you have done that work, you can tell whether the differences are due
9862 to a non-deterministic build process or to a malicious server. We try
9863 hard to remove sources of non-determinism in packages to make it easier
9864 to verify substitutes, but of course, this is a process that
9865 involves not just Guix, but a large part of the free software community.
9866 In the meantime, @command{guix challenge} is one tool to help address
9869 If you are writing packages for Guix, you are encouraged to check
9870 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9871 same build result as you did with:
9874 $ guix challenge @var{package}
9878 where @var{package} is a package specification such as
9879 @code{guile@@2.0} or @code{glibc:debug}.
9881 The general syntax is:
9884 guix challenge @var{options} [@var{packages}@dots{}]
9887 When a difference is found between the hash of a locally-built item and
9888 that of a server-provided substitute, or among substitutes provided by
9889 different servers, the command displays it as in the example above and
9890 its exit code is 2 (other non-zero exit codes denote other kinds of
9893 The one option that matters is:
9897 @item --substitute-urls=@var{urls}
9898 Consider @var{urls} the whitespace-separated list of substitute source
9903 Show details about matches (identical contents) in addition to
9904 information about mismatches.
9908 @node Invoking guix copy
9909 @section Invoking @command{guix copy}
9911 @cindex copy, of store items, over SSH
9912 @cindex SSH, copy of store items
9913 @cindex sharing store items across machines
9914 @cindex transferring store items across machines
9915 The @command{guix copy} command copies items from the store of one
9916 machine to that of another machine over a secure shell (SSH)
9917 connection@footnote{This command is available only when Guile-SSH was
9918 found. @xref{Requirements}, for details.}. For example, the following
9919 command copies the @code{coreutils} package, the user's profile, and all
9920 their dependencies over to @var{host}, logged in as @var{user}:
9923 guix copy --to=@var{user}@@@var{host} \
9924 coreutils `readlink -f ~/.guix-profile`
9927 If some of the items to be copied are already present on @var{host},
9928 they are not actually sent.
9930 The command below retrieves @code{libreoffice} and @code{gimp} from
9931 @var{host}, assuming they are available there:
9934 guix copy --from=@var{host} libreoffice gimp
9937 The SSH connection is established using the Guile-SSH client, which is
9938 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9939 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9941 The key used to sign items that are sent must be accepted by the remote
9942 machine. Likewise, the key used by the remote machine to sign items you
9943 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9944 own daemon. @xref{Invoking guix archive}, for more information about
9945 store item authentication.
9947 The general syntax is:
9950 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9953 You must always specify one of the following options:
9956 @item --to=@var{spec}
9957 @itemx --from=@var{spec}
9958 Specify the host to send to or receive from. @var{spec} must be an SSH
9959 spec such as @code{example.org}, @code{charlie@@example.org}, or
9960 @code{charlie@@example.org:2222}.
9963 The @var{items} can be either package names, such as @code{gimp}, or
9964 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9966 When specifying the name of a package to send, it is first built if
9967 needed, unless @option{--dry-run} was specified. Common build options
9968 are supported (@pxref{Common Build Options}).
9971 @node Invoking guix container
9972 @section Invoking @command{guix container}
9974 @cindex @command{guix container}
9976 As of version @value{VERSION}, this tool is experimental. The interface
9977 is subject to radical change in the future.
9980 The purpose of @command{guix container} is to manipulate processes
9981 running within an isolated environment, commonly known as a
9982 ``container'', typically created by the @command{guix environment}
9983 (@pxref{Invoking guix environment}) and @command{guix system container}
9984 (@pxref{Invoking guix system}) commands.
9986 The general syntax is:
9989 guix container @var{action} @var{options}@dots{}
9992 @var{action} specifies the operation to perform with a container, and
9993 @var{options} specifies the context-specific arguments for the action.
9995 The following actions are available:
9999 Execute a command within the context of a running container.
10004 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10007 @var{pid} specifies the process ID of the running container.
10008 @var{program} specifies an executable file name within the root file
10009 system of the container. @var{arguments} are the additional options that
10010 will be passed to @var{program}.
10012 The following command launches an interactive login shell inside a
10013 Guix system container, started by @command{guix system container}, and whose
10014 process ID is 9001:
10017 guix container exec 9001 /run/current-system/profile/bin/bash --login
10020 Note that the @var{pid} cannot be the parent process of a container. It
10021 must be PID 1 of the container or one of its child processes.
10025 @node Invoking guix weather
10026 @section Invoking @command{guix weather}
10028 Occasionally you're grumpy because substitutes are lacking and you end
10029 up building packages by yourself (@pxref{Substitutes}). The
10030 @command{guix weather} command reports on substitute availability on the
10031 specified servers so you can have an idea of whether you'll be grumpy
10032 today. It can sometimes be useful info as a user, but it is primarily
10033 useful to people running @command{guix publish} (@pxref{Invoking guix
10036 @cindex statistics, for substitutes
10037 @cindex availability of substitutes
10038 @cindex substitute availability
10039 @cindex weather, substitute availability
10040 Here's a sample run:
10043 $ guix weather --substitute-urls=https://guix.example.org
10044 computing 5,872 package derivations for x86_64-linux...
10045 looking for 6,128 store items on https://guix.example.org..
10046 updating list of substitutes from 'https://guix.example.org'... 100.0%
10047 https://guix.example.org
10048 43.4% substitutes available (2,658 out of 6,128)
10049 7,032.5 MiB of nars (compressed)
10050 19,824.2 MiB on disk (uncompressed)
10051 0.030 seconds per request (182.9 seconds in total)
10052 33.5 requests per second
10054 9.8% (342 out of 3,470) of the missing items are queued
10056 x86_64-linux: 518 (59.7%)
10057 i686-linux: 221 (25.5%)
10058 aarch64-linux: 128 (14.8%)
10059 build rate: 23.41 builds per hour
10060 x86_64-linux: 11.16 builds per hour
10061 i686-linux: 6.03 builds per hour
10062 aarch64-linux: 6.41 builds per hour
10065 @cindex continuous integration, statistics
10066 As you can see, it reports the fraction of all the packages for which
10067 substitutes are available on the server---regardless of whether
10068 substitutes are enabled, and regardless of whether this server's signing
10069 key is authorized. It also reports the size of the compressed archives
10070 (``nars'') provided by the server, the size the corresponding store
10071 items occupy in the store (assuming deduplication is turned off), and
10072 the server's throughput. The second part gives continuous integration
10073 (CI) statistics, if the server supports it. In addition, using the
10074 @option{--coverage} option, @command{guix weather} can list ``important''
10075 package substitutes missing on the server (see below).
10077 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10078 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10079 challenge}, it ignores signatures on those substitutes, which is
10080 innocuous since the command only gathers statistics and cannot install
10083 Among other things, it is possible to query specific system types and
10084 specific package sets. The available options are listed below.
10087 @item --substitute-urls=@var{urls}
10088 @var{urls} is the space-separated list of substitute server URLs to
10089 query. When this option is omitted, the default set of substitute
10090 servers is queried.
10092 @item --system=@var{system}
10093 @itemx -s @var{system}
10094 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10095 option can be repeated, in which case @command{guix weather} will query
10096 substitutes for several system types.
10098 @item --manifest=@var{file}
10099 Instead of querying substitutes for all the packages, only ask for those
10100 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10101 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10104 @item --coverage[=@var{count}]
10105 @itemx -c [@var{count}]
10106 Report on substitute coverage for packages: list packages with at least
10107 @var{count} dependents (zero by default) for which substitutes are
10108 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10109 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10110 @var{b} usually lacks substitutes as well. The result looks like this:
10113 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10114 computing 8,983 package derivations for x86_64-linux...
10115 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10116 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10117 @value{SUBSTITUTE-URL}
10118 64.7% substitutes available (6,047 out of 9,343)
10120 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10121 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10122 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10123 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10127 What this example shows is that @code{kcoreaddons} and presumably the 58
10128 packages that depend on it have no substitutes at @code{ci.guix.info};
10129 likewise for @code{qgpgme} and the 46 packages that depend on it.
10131 If you are a Guix developer, or if you are taking care of this build farm,
10132 you'll probably want to have a closer look at these packages: they may simply
10136 @node Invoking guix processes
10137 @section Invoking @command{guix processes}
10139 The @command{guix processes} command can be useful to developers and system
10140 administrators, especially on multi-user machines and on build farms: it lists
10141 the current sessions (connections to the daemon), as well as information about
10142 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10143 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10144 listed.}. Here's an example of the information it returns:
10147 $ sudo guix processes
10150 ClientCommand: guix environment --ad-hoc python
10154 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10158 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10159 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10160 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10161 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10162 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10163 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10164 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10167 In this example we see that @command{guix-daemon} has three clients:
10168 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10169 integration tool; their process identifier (PID) is given by the
10170 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10171 @command{guix-daemon} sub-process of this particular session.
10173 The @code{LockHeld} fields show which store items are currently locked by this
10174 session, which corresponds to store items being built or substituted (the
10175 @code{LockHeld} field is not displayed when @command{guix processes} is not
10176 running as root.) Last, by looking at the @code{ChildProcess} field, we
10177 understand that these three builds are being offloaded (@pxref{Daemon Offload
10180 The output is in Recutils format so we can use the handy @command{recsel}
10181 command to select sessions of interest (@pxref{Selection Expressions,,,
10182 recutils, GNU recutils manual}). As an example, the command shows the command
10183 line and PID of the client that triggered the build of a Perl package:
10186 $ sudo guix processes | \
10187 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10189 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10193 @node System Configuration
10194 @chapter System Configuration
10196 @cindex system configuration
10197 Guix System supports a consistent whole-system configuration
10198 mechanism. By that we mean that all aspects of the global system
10199 configuration---such as the available system services, timezone and
10200 locale settings, user accounts---are declared in a single place. Such
10201 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10203 One of the advantages of putting all the system configuration under the
10204 control of Guix is that it supports transactional system upgrades, and
10205 makes it possible to roll back to a previous system instantiation,
10206 should something go wrong with the new one (@pxref{Features}). Another
10207 advantage is that it makes it easy to replicate the exact same configuration
10208 across different machines, or at different points in time, without
10209 having to resort to additional administration tools layered on top of
10210 the own tools of the system.
10211 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10213 This section describes this mechanism. First we focus on the system
10214 administrator's viewpoint---explaining how the system is configured and
10215 instantiated. Then we show how this mechanism can be extended, for
10216 instance to support new system services.
10219 * Using the Configuration System:: Customizing your GNU system.
10220 * operating-system Reference:: Detail of operating-system declarations.
10221 * File Systems:: Configuring file system mounts.
10222 * Mapped Devices:: Block device extra processing.
10223 * User Accounts:: Specifying user accounts.
10224 * Keyboard Layout:: How the system interprets key strokes.
10225 * Locales:: Language and cultural convention settings.
10226 * Services:: Specifying system services.
10227 * Setuid Programs:: Programs running with root privileges.
10228 * X.509 Certificates:: Authenticating HTTPS servers.
10229 * Name Service Switch:: Configuring libc's name service switch.
10230 * Initial RAM Disk:: Linux-Libre bootstrapping.
10231 * Bootloader Configuration:: Configuring the boot loader.
10232 * Invoking guix system:: Instantiating a system configuration.
10233 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10234 * Defining Services:: Adding new service definitions.
10237 @node Using the Configuration System
10238 @section Using the Configuration System
10240 The operating system is configured by providing an
10241 @code{operating-system} declaration in a file that can then be passed to
10242 the @command{guix system} command (@pxref{Invoking guix system}). A
10243 simple setup, with the default system services, the default Linux-Libre
10244 kernel, initial RAM disk, and boot loader looks like this:
10246 @findex operating-system
10248 @include os-config-bare-bones.texi
10251 This example should be self-describing. Some of the fields defined
10252 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10253 Others, such as @code{packages} and @code{services}, can be omitted, in
10254 which case they get a default value.
10256 Below we discuss the effect of some of the most important fields
10257 (@pxref{operating-system Reference}, for details about all the available
10258 fields), and how to @dfn{instantiate} the operating system using
10259 @command{guix system}.
10261 @unnumberedsubsec Bootloader
10263 @cindex legacy boot, on Intel machines
10264 @cindex BIOS boot, on Intel machines
10267 The @code{bootloader} field describes the method that will be used to boot
10268 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10269 mode, as in the example above. However, more recent machines rely instead on
10270 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10271 the @code{bootloader} field should contain something along these lines:
10274 (bootloader-configuration
10275 (bootloader grub-efi-bootloader)
10276 (target "/boot/efi"))
10279 @xref{Bootloader Configuration}, for more information on the available
10280 configuration options.
10282 @unnumberedsubsec Globally-Visible Packages
10284 @vindex %base-packages
10285 The @code{packages} field lists packages that will be globally visible
10286 on the system, for all user accounts---i.e., in every user's @code{PATH}
10287 environment variable---in addition to the per-user profiles
10288 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10289 provides all the tools one would expect for basic user and administrator
10290 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10291 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10292 etc. The example above adds GNU@tie{}Screen to those,
10293 taken from the @code{(gnu packages screen)}
10294 module (@pxref{Package Modules}). The
10295 @code{(list package output)} syntax can be used to add a specific output
10299 (use-modules (gnu packages))
10300 (use-modules (gnu packages dns))
10304 (packages (cons (list bind "utils")
10308 @findex specification->package
10309 Referring to packages by variable name, like @code{bind} above, has
10310 the advantage of being unambiguous; it also allows typos and such to be
10311 diagnosed right away as ``unbound variables''. The downside is that one
10312 needs to know which module defines which package, and to augment the
10313 @code{use-package-modules} line accordingly. To avoid that, one can use
10314 the @code{specification->package} procedure of the @code{(gnu packages)}
10315 module, which returns the best package for a given name or name and
10319 (use-modules (gnu packages))
10323 (packages (append (map specification->package
10324 '("tcpdump" "htop" "gnupg@@2.0"))
10328 @unnumberedsubsec System Services
10331 @vindex %base-services
10332 The @code{services} field lists @dfn{system services} to be made
10333 available when the system starts (@pxref{Services}).
10334 The @code{operating-system} declaration above specifies that, in
10335 addition to the basic services, we want the OpenSSH secure shell
10336 daemon listening on port 2222 (@pxref{Networking Services,
10337 @code{openssh-service-type}}). Under the hood,
10338 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10339 right command-line options, possibly with supporting configuration files
10340 generated as needed (@pxref{Defining Services}).
10342 @cindex customization, of services
10343 @findex modify-services
10344 Occasionally, instead of using the base services as is, you will want to
10345 customize them. To do this, use @code{modify-services} (@pxref{Service
10346 Reference, @code{modify-services}}) to modify the list.
10348 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10349 (the console log-in) in the @var{%base-services} list (@pxref{Base
10350 Services, @code{%base-services}}). To do that, you can write the
10351 following in your operating system declaration:
10354 (define %my-services
10355 ;; My very own list of services.
10356 (modify-services %base-services
10357 (guix-service-type config =>
10358 (guix-configuration
10360 (use-substitutes? #f)
10361 (extra-options '("--gc-keep-derivations"))))
10362 (mingetty-service-type config =>
10363 (mingetty-configuration
10364 (inherit config)))))
10368 (services %my-services))
10371 This changes the configuration---i.e., the service parameters---of the
10372 @code{guix-service-type} instance, and that of all the
10373 @code{mingetty-service-type} instances in the @var{%base-services} list.
10374 Observe how this is accomplished: first, we arrange for the original
10375 configuration to be bound to the identifier @code{config} in the
10376 @var{body}, and then we write the @var{body} so that it evaluates to the
10377 desired configuration. In particular, notice how we use @code{inherit}
10378 to create a new configuration which has the same values as the old
10379 configuration, but with a few modifications.
10381 @cindex encrypted disk
10382 The configuration for a typical ``desktop'' usage, with an encrypted
10383 root partition, the X11 display
10384 server, GNOME and Xfce (users can choose which of these desktop
10385 environments to use at the log-in screen by pressing @kbd{F1}), network
10386 management, power management, and more, would look like this:
10389 @include os-config-desktop.texi
10392 A graphical system with a choice of lightweight window managers
10393 instead of full-blown desktop environments would look like this:
10396 @include os-config-lightweight-desktop.texi
10399 This example refers to the @file{/boot/efi} file system by its UUID,
10400 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10401 as returned by the @command{blkid} command.
10403 @xref{Desktop Services}, for the exact list of services provided by
10404 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10405 information about the @code{nss-certs} package that is used here.
10407 Again, @var{%desktop-services} is just a list of service objects. If
10408 you want to remove services from there, you can do so using the
10409 procedures for list filtering (@pxref{SRFI-1 Filtering and
10410 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10411 following expression returns a list that contains all the services in
10412 @var{%desktop-services} minus the Avahi service:
10415 (remove (lambda (service)
10416 (eq? (service-kind service) avahi-service-type))
10420 @unnumberedsubsec Instantiating the System
10422 Assuming the @code{operating-system} declaration
10423 is stored in the @file{my-system-config.scm}
10424 file, the @command{guix system reconfigure my-system-config.scm} command
10425 instantiates that configuration, and makes it the default GRUB boot
10426 entry (@pxref{Invoking guix system}).
10428 The normal way to change the system configuration is by updating this
10429 file and re-running @command{guix system reconfigure}. One should never
10430 have to touch files in @file{/etc} or to run commands that modify the
10431 system state such as @command{useradd} or @command{grub-install}. In
10432 fact, you must avoid that since that would not only void your warranty
10433 but also prevent you from rolling back to previous versions of your
10434 system, should you ever need to.
10436 @cindex roll-back, of the operating system
10437 Speaking of roll-back, each time you run @command{guix system
10438 reconfigure}, a new @dfn{generation} of the system is created---without
10439 modifying or deleting previous generations. Old system generations get
10440 an entry in the bootloader boot menu, allowing you to boot them in case
10441 something went wrong with the latest generation. Reassuring, no? The
10442 @command{guix system list-generations} command lists the system
10443 generations available on disk. It is also possible to roll back the
10444 system via the commands @command{guix system roll-back} and
10445 @command{guix system switch-generation}.
10447 Although the @command{guix system reconfigure} command will not modify
10448 previous generations, you must take care when the current generation is not
10449 the latest (e.g., after invoking @command{guix system roll-back}), since
10450 the operation might overwrite a later generation (@pxref{Invoking guix
10453 @unnumberedsubsec The Programming Interface
10455 At the Scheme level, the bulk of an @code{operating-system} declaration
10456 is instantiated with the following monadic procedure (@pxref{The Store
10459 @deffn {Monadic Procedure} operating-system-derivation os
10460 Return a derivation that builds @var{os}, an @code{operating-system}
10461 object (@pxref{Derivations}).
10463 The output of the derivation is a single directory that refers to all
10464 the packages, configuration files, and other supporting files needed to
10465 instantiate @var{os}.
10468 This procedure is provided by the @code{(gnu system)} module. Along
10469 with @code{(gnu services)} (@pxref{Services}), this module contains the
10470 guts of Guix System. Make sure to visit it!
10473 @node operating-system Reference
10474 @section @code{operating-system} Reference
10476 This section summarizes all the options available in
10477 @code{operating-system} declarations (@pxref{Using the Configuration
10480 @deftp {Data Type} operating-system
10481 This is the data type representing an operating system configuration.
10482 By that, we mean all the global system configuration, not per-user
10483 configuration (@pxref{Using the Configuration System}).
10486 @item @code{kernel} (default: @var{linux-libre})
10487 The package object of the operating system kernel to use@footnote{Currently
10488 only the Linux-libre kernel is supported. In the future, it will be
10489 possible to use the GNU@tie{}Hurd.}.
10491 @item @code{kernel-arguments} (default: @code{'("quiet")})
10492 List of strings or gexps representing additional arguments to pass on
10493 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10495 @item @code{bootloader}
10496 The system bootloader configuration object. @xref{Bootloader Configuration}.
10499 This is the label (a string) as it appears in the bootloader's menu entry.
10500 The default label includes the kernel name and version.
10502 @item @code{keyboard-layout} (default: @code{#f})
10503 This field specifies the keyboard layout to use in the console. It can be
10504 either @code{#f}, in which case the default keyboard layout is used (usually
10505 US English), or a @code{<keyboard-layout>} record.
10507 This keyboard layout is in effect as soon as the kernel has booted. For
10508 instance, it is the keyboard layout in effect when you type a passphrase if
10509 your root file system is on a @code{luks-device-mapping} mapped device
10510 (@pxref{Mapped Devices}).
10513 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10514 that used by the graphical display server. @xref{Bootloader Configuration},
10515 for information on how to specify the bootloader's keyboard layout. @xref{X
10516 Window}, for information on how to specify the keyboard layout used by the X
10520 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10522 @cindex initial RAM disk
10523 The list of Linux kernel modules that need to be available in the
10524 initial RAM disk. @xref{Initial RAM Disk}.
10526 @item @code{initrd} (default: @code{base-initrd})
10527 A procedure that returns an initial RAM disk for the Linux
10528 kernel. This field is provided to support low-level customization and
10529 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10531 @item @code{firmware} (default: @var{%base-firmware})
10533 List of firmware packages loadable by the operating system kernel.
10535 The default includes firmware needed for Atheros- and Broadcom-based
10536 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10537 respectively). @xref{Hardware Considerations}, for more info on
10538 supported hardware.
10540 @item @code{host-name}
10543 @item @code{hosts-file}
10545 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10546 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10547 Reference Manual}). The default is a file with entries for
10548 @code{localhost} and @var{host-name}.
10550 @item @code{mapped-devices} (default: @code{'()})
10551 A list of mapped devices. @xref{Mapped Devices}.
10553 @item @code{file-systems}
10554 A list of file systems. @xref{File Systems}.
10556 @item @code{swap-devices} (default: @code{'()})
10557 @cindex swap devices
10558 A list of strings identifying devices or files to be used for ``swap
10559 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10560 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10561 It is possible to specify a swap file in a file system on a mapped
10562 device, provided that the necessary device mapping and file system are
10563 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10565 @item @code{users} (default: @code{%base-user-accounts})
10566 @itemx @code{groups} (default: @var{%base-groups})
10567 List of user accounts and groups. @xref{User Accounts}.
10569 If the @code{users} list lacks a user account with UID@tie{}0, a
10570 ``root'' account with UID@tie{}0 is automatically added.
10572 @item @code{skeletons} (default: @code{(default-skeletons)})
10573 A list target file name/file-like object tuples (@pxref{G-Expressions,
10574 file-like objects}). These are the skeleton files that will be added to
10575 the home directory of newly-created user accounts.
10577 For instance, a valid value may look like this:
10580 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10581 (".guile" ,(plain-file "guile"
10582 "(use-modules (ice-9 readline))
10583 (activate-readline)")))
10586 @item @code{issue} (default: @var{%default-issue})
10587 A string denoting the contents of the @file{/etc/issue} file, which is
10588 displayed when users log in on a text console.
10590 @item @code{packages} (default: @var{%base-packages})
10591 The set of packages installed in the global profile, which is accessible
10592 at @file{/run/current-system/profile}.
10594 The default set includes core utilities and it is good practice to
10595 install non-core utilities in user profiles (@pxref{Invoking guix
10598 @item @code{timezone}
10599 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10601 You can run the @command{tzselect} command to find out which timezone
10602 string corresponds to your region. Choosing an invalid timezone name
10603 causes @command{guix system} to fail.
10605 @item @code{locale} (default: @code{"en_US.utf8"})
10606 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10607 Library Reference Manual}). @xref{Locales}, for more information.
10609 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10610 The list of locale definitions to be compiled and that may be used at
10611 run time. @xref{Locales}.
10613 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10614 The list of GNU@tie{}libc packages whose locale data and tools are used
10615 to build the locale definitions. @xref{Locales}, for compatibility
10616 considerations that justify this option.
10618 @item @code{name-service-switch} (default: @var{%default-nss})
10619 Configuration of the libc name service switch (NSS)---a
10620 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10623 @item @code{services} (default: @var{%base-services})
10624 A list of service objects denoting system services. @xref{Services}.
10626 @cindex essential services
10627 @item @code{essential-services} (default: ...)
10628 The list of ``essential services''---i.e., things like instances of
10629 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10630 Reference}), which are derived from the operating system definition itself.
10631 As a user you should @emph{never} need to touch this field.
10633 @item @code{pam-services} (default: @code{(base-pam-services)})
10635 @cindex pluggable authentication modules
10636 Linux @dfn{pluggable authentication module} (PAM) services.
10637 @c FIXME: Add xref to PAM services section.
10639 @item @code{setuid-programs} (default: @var{%setuid-programs})
10640 List of string-valued G-expressions denoting setuid programs.
10641 @xref{Setuid Programs}.
10643 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10644 @cindex sudoers file
10645 The contents of the @file{/etc/sudoers} file as a file-like object
10646 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10648 This file specifies which users can use the @command{sudo} command, what
10649 they are allowed to do, and what privileges they may gain. The default
10650 is that only @code{root} and members of the @code{wheel} group may use
10655 @deffn {Scheme Syntax} this-operating-system
10656 When used in the @emph{lexical scope} of an operating system field definition,
10657 this identifier resolves to the operating system being defined.
10659 The example below shows how to refer to the operating system being defined in
10660 the definition of the @code{label} field:
10663 (use-modules (gnu) (guix))
10667 (label (package-full-name
10668 (operating-system-kernel this-operating-system))))
10671 It is an error to refer to @code{this-operating-system} outside an operating
10678 @section File Systems
10680 The list of file systems to be mounted is specified in the
10681 @code{file-systems} field of the operating system declaration
10682 (@pxref{Using the Configuration System}). Each file system is declared
10683 using the @code{file-system} form, like this:
10687 (mount-point "/home")
10688 (device "/dev/sda3")
10692 As usual, some of the fields are mandatory---those shown in the example
10693 above---while others can be omitted. These are described below.
10695 @deftp {Data Type} file-system
10696 Objects of this type represent file systems to be mounted. They
10697 contain the following members:
10701 This is a string specifying the type of the file system---e.g.,
10704 @item @code{mount-point}
10705 This designates the place where the file system is to be mounted.
10707 @item @code{device}
10708 This names the ``source'' of the file system. It can be one of three
10709 things: a file system label, a file system UUID, or the name of a
10710 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10711 systems without having to hard-code their actual device
10712 name@footnote{Note that, while it is tempting to use
10713 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10714 result, this is not recommended: These special device nodes are created
10715 by the udev daemon and may be unavailable at the time the device is
10718 @findex file-system-label
10719 File system labels are created using the @code{file-system-label}
10720 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10721 plain strings. Here's an example of a file system referred to by its
10722 label, as shown by the @command{e2label} command:
10726 (mount-point "/home")
10728 (device (file-system-label "my-home")))
10732 UUIDs are converted from their string representation (as shown by the
10733 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10734 @code{uuid} form expects 16-byte UUIDs as defined in
10735 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10736 form of UUID used by the ext2 family of file systems and others, but it
10737 is different from ``UUIDs'' found in FAT file systems, for instance.},
10742 (mount-point "/home")
10744 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10747 When the source of a file system is a mapped device (@pxref{Mapped
10748 Devices}), its @code{device} field @emph{must} refer to the mapped
10749 device name---e.g., @file{"/dev/mapper/root-partition"}.
10750 This is required so that
10751 the system knows that mounting the file system depends on having the
10752 corresponding device mapping established.
10754 @item @code{flags} (default: @code{'()})
10755 This is a list of symbols denoting mount flags. Recognized flags
10756 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10757 access to special files), @code{no-suid} (ignore setuid and setgid
10758 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10759 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10760 Library Reference Manual}, for more information on these flags.
10762 @item @code{options} (default: @code{#f})
10763 This is either @code{#f}, or a string denoting mount options passed to the
10764 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10765 Reference Manual}, for details and run @command{man 8 mount} for options for
10766 various file systems.
10768 @item @code{mount?} (default: @code{#t})
10769 This value indicates whether to automatically mount the file system when
10770 the system is brought up. When set to @code{#f}, the file system gets
10771 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10772 is not automatically mounted.
10774 @item @code{needed-for-boot?} (default: @code{#f})
10775 This Boolean value indicates whether the file system is needed when
10776 booting. If that is true, then the file system is mounted when the
10777 initial RAM disk (initrd) is loaded. This is always the case, for
10778 instance, for the root file system.
10780 @item @code{check?} (default: @code{#t})
10781 This Boolean indicates whether the file system needs to be checked for
10782 errors before being mounted.
10784 @item @code{create-mount-point?} (default: @code{#f})
10785 When true, the mount point is created if it does not exist yet.
10787 @item @code{dependencies} (default: @code{'()})
10788 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10789 representing file systems that must be mounted or mapped devices that
10790 must be opened before (and unmounted or closed after) this one.
10792 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10793 a dependency of @file{/sys/fs/cgroup/cpu} and
10794 @file{/sys/fs/cgroup/memory}.
10796 Another example is a file system that depends on a mapped device, for
10797 example for an encrypted partition (@pxref{Mapped Devices}).
10801 The @code{(gnu system file-systems)} exports the following useful
10804 @defvr {Scheme Variable} %base-file-systems
10805 These are essential file systems that are required on normal systems,
10806 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10807 below.) Operating system declarations should always contain at least
10811 @defvr {Scheme Variable} %pseudo-terminal-file-system
10812 This is the file system to be mounted as @file{/dev/pts}. It supports
10813 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10814 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10815 Manual}). Pseudo-terminals are used by terminal emulators such as
10819 @defvr {Scheme Variable} %shared-memory-file-system
10820 This file system is mounted as @file{/dev/shm} and is used to support
10821 memory sharing across processes (@pxref{Memory-mapped I/O,
10822 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10825 @defvr {Scheme Variable} %immutable-store
10826 This file system performs a read-only ``bind mount'' of
10827 @file{/gnu/store}, making it read-only for all the users including
10828 @code{root}. This prevents against accidental modification by software
10829 running as @code{root} or by system administrators.
10831 The daemon itself is still able to write to the store: it remounts it
10832 read-write in its own ``name space.''
10835 @defvr {Scheme Variable} %binary-format-file-system
10836 The @code{binfmt_misc} file system, which allows handling of arbitrary
10837 executable file types to be delegated to user space. This requires the
10838 @code{binfmt.ko} kernel module to be loaded.
10841 @defvr {Scheme Variable} %fuse-control-file-system
10842 The @code{fusectl} file system, which allows unprivileged users to mount
10843 and unmount user-space FUSE file systems. This requires the
10844 @code{fuse.ko} kernel module to be loaded.
10847 @node Mapped Devices
10848 @section Mapped Devices
10850 @cindex device mapping
10851 @cindex mapped devices
10852 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10853 such as a hard disk partition, can be @dfn{mapped} into another device,
10854 usually in @code{/dev/mapper/},
10855 with additional processing over the data that flows through
10856 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10857 concept of a ``mapped device'' and that of a file system: both boil down
10858 to @emph{translating} input/output operations made on a file to
10859 operations on its backing store. Thus, the Hurd implements mapped
10860 devices, like file systems, using the generic @dfn{translator} mechanism
10861 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10862 typical example is encryption device mapping: all writes to the mapped
10863 device are encrypted, and all reads are deciphered, transparently.
10864 Guix extends this notion by considering any device or set of devices that
10865 are @dfn{transformed} in some way to create a new device; for instance,
10866 RAID devices are obtained by @dfn{assembling} several other devices, such
10867 as hard disks or partitions, into a new one that behaves as one partition.
10868 Other examples, not yet implemented, are LVM logical volumes.
10870 Mapped devices are declared using the @code{mapped-device} form,
10871 defined as follows; for examples, see below.
10873 @deftp {Data Type} mapped-device
10874 Objects of this type represent device mappings that will be made when
10875 the system boots up.
10879 This is either a string specifying the name of the block device to be mapped,
10880 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10881 need to be assembled for creating a new one.
10884 This string specifies the name of the resulting mapped device. For
10885 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10886 specifying @code{"my-partition"} leads to the creation of
10887 the @code{"/dev/mapper/my-partition"} device.
10888 For RAID devices of type @code{raid-device-mapping}, the full device name
10889 such as @code{"/dev/md0"} needs to be given.
10892 This must be a @code{mapped-device-kind} object, which specifies how
10893 @var{source} is mapped to @var{target}.
10897 @defvr {Scheme Variable} luks-device-mapping
10898 This defines LUKS block device encryption using the @command{cryptsetup}
10899 command from the package with the same name. It relies on the
10900 @code{dm-crypt} Linux kernel module.
10903 @defvr {Scheme Variable} raid-device-mapping
10904 This defines a RAID device, which is assembled using the @code{mdadm}
10905 command from the package with the same name. It requires a Linux kernel
10906 module for the appropriate RAID level to be loaded, such as @code{raid456}
10907 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10910 @cindex disk encryption
10912 The following example specifies a mapping from @file{/dev/sda3} to
10913 @file{/dev/mapper/home} using LUKS---the
10914 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10915 standard mechanism for disk encryption.
10916 The @file{/dev/mapper/home}
10917 device can then be used as the @code{device} of a @code{file-system}
10918 declaration (@pxref{File Systems}).
10922 (source "/dev/sda3")
10924 (type luks-device-mapping))
10927 Alternatively, to become independent of device numbering, one may obtain
10928 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10932 cryptsetup luksUUID /dev/sda3
10935 and use it as follows:
10939 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10941 (type luks-device-mapping))
10944 @cindex swap encryption
10945 It is also desirable to encrypt swap space, since swap space may contain
10946 sensitive data. One way to accomplish that is to use a swap file in a
10947 file system on a device mapped via LUKS encryption. In this way, the
10948 swap file is encrypted because the entire device is encrypted.
10949 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10951 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10952 may be declared as follows:
10956 (source (list "/dev/sda1" "/dev/sdb1"))
10957 (target "/dev/md0")
10958 (type raid-device-mapping))
10961 The @file{/dev/md0} device can then be used as the @code{device} of a
10962 @code{file-system} declaration (@pxref{File Systems}).
10963 Note that the RAID level need not be given; it is chosen during the
10964 initial creation and formatting of the RAID device and is determined
10965 automatically later.
10968 @node User Accounts
10969 @section User Accounts
10973 @cindex user accounts
10974 User accounts and groups are entirely managed through the
10975 @code{operating-system} declaration. They are specified with the
10976 @code{user-account} and @code{user-group} forms:
10982 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10983 "audio" ;sound card
10984 "video" ;video devices such as webcams
10985 "cdrom")) ;the good ol' CD-ROM
10986 (comment "Bob's sister")
10987 (home-directory "/home/alice"))
10990 When booting or upon completion of @command{guix system reconfigure},
10991 the system ensures that only the user accounts and groups specified in
10992 the @code{operating-system} declaration exist, and with the specified
10993 properties. Thus, account or group creations or modifications made by
10994 directly invoking commands such as @command{useradd} are lost upon
10995 reconfiguration or reboot. This ensures that the system remains exactly
10998 @deftp {Data Type} user-account
10999 Objects of this type represent user accounts. The following members may
11004 The name of the user account.
11008 This is the name (a string) or identifier (a number) of the user group
11009 this account belongs to.
11011 @item @code{supplementary-groups} (default: @code{'()})
11012 Optionally, this can be defined as a list of group names that this
11013 account belongs to.
11015 @item @code{uid} (default: @code{#f})
11016 This is the user ID for this account (a number), or @code{#f}. In the
11017 latter case, a number is automatically chosen by the system when the
11018 account is created.
11020 @item @code{comment} (default: @code{""})
11021 A comment about the account, such as the account owner's full name.
11023 @item @code{home-directory}
11024 This is the name of the home directory for the account.
11026 @item @code{create-home-directory?} (default: @code{#t})
11027 Indicates whether the home directory of this account should be created
11028 if it does not exist yet.
11030 @item @code{shell} (default: Bash)
11031 This is a G-expression denoting the file name of a program to be used as
11032 the shell (@pxref{G-Expressions}).
11034 @item @code{system?} (default: @code{#f})
11035 This Boolean value indicates whether the account is a ``system''
11036 account. System accounts are sometimes treated specially; for instance,
11037 graphical login managers do not list them.
11039 @anchor{user-account-password}
11040 @cindex password, for user accounts
11041 @item @code{password} (default: @code{#f})
11042 You would normally leave this field to @code{#f}, initialize user
11043 passwords as @code{root} with the @command{passwd} command, and then let
11044 users change it with @command{passwd}. Passwords set with
11045 @command{passwd} are of course preserved across reboot and
11048 If you @emph{do} want to set an initial password for an account, then
11049 this field must contain the encrypted password, as a string. You can use the
11050 @code{crypt} procedure for this purpose:
11057 ;; Specify a SHA-512-hashed initial password.
11058 (password (crypt "InitialPassword!" "$6$abc")))
11062 The hash of this initial password will be available in a file in
11063 @file{/gnu/store}, readable by all the users, so this method must be used with
11067 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11068 more information on password encryption, and @ref{Encryption,,, guile, GNU
11069 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11075 User group declarations are even simpler:
11078 (user-group (name "students"))
11081 @deftp {Data Type} user-group
11082 This type is for, well, user groups. There are just a few fields:
11086 The name of the group.
11088 @item @code{id} (default: @code{#f})
11089 The group identifier (a number). If @code{#f}, a new number is
11090 automatically allocated when the group is created.
11092 @item @code{system?} (default: @code{#f})
11093 This Boolean value indicates whether the group is a ``system'' group.
11094 System groups have low numerical IDs.
11096 @item @code{password} (default: @code{#f})
11097 What, user groups can have a password? Well, apparently yes. Unless
11098 @code{#f}, this field specifies the password of the group.
11103 For convenience, a variable lists all the basic user groups one may
11106 @defvr {Scheme Variable} %base-groups
11107 This is the list of basic user groups that users and/or packages expect
11108 to be present on the system. This includes groups such as ``root'',
11109 ``wheel'', and ``users'', as well as groups used to control access to
11110 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11113 @defvr {Scheme Variable} %base-user-accounts
11114 This is the list of basic system accounts that programs may expect to
11115 find on a GNU/Linux system, such as the ``nobody'' account.
11117 Note that the ``root'' account is not included here. It is a
11118 special-case and is automatically added whether or not it is specified.
11121 @node Keyboard Layout
11122 @section Keyboard Layout
11124 @cindex keyboard layout
11126 To specify what each key of your keyboard does, you need to tell the operating
11127 system what @dfn{keyboard layout} you want to use. The default, when nothing
11128 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11129 However, German speakers will usually prefer the German QWERTZ layout, French
11130 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11131 or bépo, and they might even want to further customize the effect of some of
11132 the keys. This section explains how to get that done.
11134 @cindex keyboard layout, definition
11135 There are three components that will want to know about your keyboard layout:
11139 The @emph{bootloader} may want to know what keyboard layout you want to use
11140 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11141 you want, for instance, to make sure that you can type the passphrase of your
11142 encrypted root partition using the right layout.
11145 The @emph{operating system kernel}, Linux, will need that so that the console
11146 is properly configured (@pxref{operating-system Reference,
11147 @code{keyboard-layout}}).
11150 The @emph{graphical display server}, usually Xorg, also has its own idea of
11151 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11154 Guix allows you to configure all three separately but, fortunately, it allows
11155 you to share the same keyboard layout for all three components.
11157 @cindex XKB, keyboard layouts
11158 Keyboard layouts are represented by records created by the
11159 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11160 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11161 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11162 optional variant name, an optional keyboard model name, and a possibly empty
11163 list of additional options. In most cases the layout name is all you care
11164 about. Here are a few example:
11167 ;; The German QWERTZ layout. Here we assume a standard
11168 ;; "pc105" keyboard model.
11169 (keyboard-layout "de")
11171 ;; The bépo variant of the French layout.
11172 (keyboard-layout "fr" "bepo")
11174 ;; The Catalan layout.
11175 (keyboard-layout "es" "cat")
11177 ;; The Latin American Spanish layout. In addition, the
11178 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11179 ;; and the "Menu" key is used as a "Compose" key to enter
11180 ;; accented letters.
11181 (keyboard-layout "latam"
11182 #:options '("ctrl:nocaps" "compose:menu"))
11184 ;; The Russian layout for a ThinkPad keyboard.
11185 (keyboard-layout "ru" #:model "thinkpad")
11187 ;; The "US international" layout, which is the US layout plus
11188 ;; dead keys to enter accented characters. This is for an
11189 ;; Apple MacBook keyboard.
11190 (keyboard-layout "us" "intl" #:model "macbook78")
11193 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11194 for a complete list of supported layouts, variants, and models.
11196 @cindex keyboard layout, configuration
11197 Let's say you want your system to use the Turkish keyboard layout throughout
11198 your system---bootloader, console, and Xorg. Here's what your system
11199 configuration would look like:
11201 @findex set-xorg-configuration
11203 ;; Using the Turkish layout for the bootloader, the console,
11208 (keyboard-layout (keyboard-layout "tr")) ;for the console
11209 (bootloader (bootloader-configuration
11210 (bootloader grub-efi-bootloader)
11211 (target "/boot/efi")
11212 (keyboard-layout keyboard-layout))) ;for GRUB
11213 (services (cons (set-xorg-configuration
11214 (xorg-configuration ;for Xorg
11215 (keyboard-layout keyboard-layout)))
11216 %desktop-services)))
11219 In the example above, for GRUB and for Xorg, we just refer to the
11220 @code{keyboard-layout} field defined above, but we could just as well refer to
11221 a different layout. The @code{set-xorg-configuration} procedure communicates
11222 the desired Xorg configuration to the graphical log-in manager, by default
11225 We've discussed how to specify the @emph{default} keyboard layout of your
11226 system when it starts, but you can also adjust it at run time:
11230 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11231 where you can select one or more keyboard layouts.
11234 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11235 allows you to change the current layout. For example, this is how you would
11236 change the layout to US Dvorak:
11239 setxkbmap us dvorak
11243 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11244 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11245 keyboard layout categorization described above. The command below loads the
11246 French bépo layout:
11257 A @dfn{locale} defines cultural conventions for a particular language
11258 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11259 Reference Manual}). Each locale has a name that typically has the form
11260 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11261 @code{fr_LU.utf8} designates the locale for the French language, with
11262 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11264 @cindex locale definition
11265 Usually, you will want to specify the default locale for the machine
11266 using the @code{locale} field of the @code{operating-system} declaration
11267 (@pxref{operating-system Reference, @code{locale}}).
11269 The selected locale is automatically added to the @dfn{locale
11270 definitions} known to the system if needed, with its codeset inferred
11271 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11272 @code{UTF-8} codeset. Additional locale definitions can be specified in
11273 the @code{locale-definitions} slot of @code{operating-system}---this is
11274 useful, for instance, if the codeset could not be inferred from the
11275 locale name. The default set of locale definitions includes some widely
11276 used locales, but not all the available locales, in order to save space.
11278 For instance, to add the North Frisian locale for Germany, the value of
11282 (cons (locale-definition
11283 (name "fy_DE.utf8") (source "fy_DE"))
11284 %default-locale-definitions)
11287 Likewise, to save space, one might want @code{locale-definitions} to
11288 list only the locales that are actually used, as in:
11291 (list (locale-definition
11292 (name "ja_JP.eucjp") (source "ja_JP")
11293 (charset "EUC-JP")))
11297 The compiled locale definitions are available at
11298 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11299 version, which is the default location where the GNU@tie{}libc provided
11300 by Guix looks for locale data. This can be overridden using the
11301 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11302 @code{LOCPATH} and locale packages}).
11304 The @code{locale-definition} form is provided by the @code{(gnu system
11305 locale)} module. Details are given below.
11307 @deftp {Data Type} locale-definition
11308 This is the data type of a locale definition.
11313 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11314 Reference Manual}, for more information on locale names.
11316 @item @code{source}
11317 The name of the source for that locale. This is typically the
11318 @code{@var{language}_@var{territory}} part of the locale name.
11320 @item @code{charset} (default: @code{"UTF-8"})
11321 The ``character set'' or ``code set'' for that locale,
11322 @uref{https://www.iana.org/assignments/character-sets, as defined by
11328 @defvr {Scheme Variable} %default-locale-definitions
11329 A list of commonly used UTF-8 locales, used as the default
11330 value of the @code{locale-definitions} field of @code{operating-system}
11333 @cindex locale name
11334 @cindex normalized codeset in locale names
11335 These locale definitions use the @dfn{normalized codeset} for the part
11336 that follows the dot in the name (@pxref{Using gettextized software,
11337 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11338 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11339 @code{uk_UA.UTF-8}.
11342 @subsection Locale Data Compatibility Considerations
11344 @cindex incompatibility, of locale data
11345 @code{operating-system} declarations provide a @code{locale-libcs} field
11346 to specify the GNU@tie{}libc packages that are used to compile locale
11347 declarations (@pxref{operating-system Reference}). ``Why would I
11348 care?'', you may ask. Well, it turns out that the binary format of
11349 locale data is occasionally incompatible from one libc version to
11352 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11353 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11354 For instance, a program linked against libc version 2.21 is unable to
11355 read locale data produced with libc 2.22; worse, that program
11356 @emph{aborts} instead of simply ignoring the incompatible locale
11357 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11358 the incompatible locale data, which is already an improvement.}.
11359 Similarly, a program linked against libc 2.22 can read most, but not
11360 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11361 data is incompatible); thus calls to @code{setlocale} may fail, but
11362 programs will not abort.
11364 The ``problem'' with Guix is that users have a lot of freedom: They can
11365 choose whether and when to upgrade software in their profiles, and might
11366 be using a libc version different from the one the system administrator
11367 used to build the system-wide locale data.
11369 Fortunately, unprivileged users can also install their own locale data
11370 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11371 @code{GUIX_LOCPATH} and locale packages}).
11373 Still, it is best if the system-wide locale data at
11374 @file{/run/current-system/locale} is built for all the libc versions
11375 actually in use on the system, so that all the programs can access
11376 it---this is especially crucial on a multi-user system. To do that, the
11377 administrator can specify several libc packages in the
11378 @code{locale-libcs} field of @code{operating-system}:
11381 (use-package-modules base)
11385 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11388 This example would lead to a system containing locale definitions for
11389 both libc 2.21 and the current version of libc in
11390 @file{/run/current-system/locale}.
11396 @cindex system services
11397 An important part of preparing an @code{operating-system} declaration is
11398 listing @dfn{system services} and their configuration (@pxref{Using the
11399 Configuration System}). System services are typically daemons launched
11400 when the system boots, or other actions needed at that time---e.g.,
11401 configuring network access.
11403 Guix has a broad definition of ``service'' (@pxref{Service
11404 Composition}), but many services are managed by the GNU@tie{}Shepherd
11405 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11406 command allows you to list the available services, show their status,
11407 start and stop them, or do other specific operations (@pxref{Jump
11408 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11414 The above command, run as @code{root}, lists the currently defined
11415 services. The @command{herd doc} command shows a synopsis of the given
11416 service and its associated actions:
11420 Run libc's name service cache daemon (nscd).
11422 # herd doc nscd action invalidate
11423 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11426 The @command{start}, @command{stop}, and @command{restart} sub-commands
11427 have the effect you would expect. For instance, the commands below stop
11428 the nscd service and restart the Xorg display server:
11432 Service nscd has been stopped.
11433 # herd restart xorg-server
11434 Service xorg-server has been stopped.
11435 Service xorg-server has been started.
11438 The following sections document the available services, starting with
11439 the core services, that may be used in an @code{operating-system}
11443 * Base Services:: Essential system services.
11444 * Scheduled Job Execution:: The mcron service.
11445 * Log Rotation:: The rottlog service.
11446 * Networking Services:: Network setup, SSH daemon, etc.
11447 * X Window:: Graphical display.
11448 * Printing Services:: Local and remote printer support.
11449 * Desktop Services:: D-Bus and desktop services.
11450 * Sound Services:: ALSA and Pulseaudio services.
11451 * Database Services:: SQL databases, key-value stores, etc.
11452 * Mail Services:: IMAP, POP3, SMTP, and all that.
11453 * Messaging Services:: Messaging services.
11454 * Telephony Services:: Telephony services.
11455 * Monitoring Services:: Monitoring services.
11456 * Kerberos Services:: Kerberos services.
11457 * LDAP Services:: LDAP services.
11458 * Web Services:: Web servers.
11459 * Certificate Services:: TLS certificates via Let's Encrypt.
11460 * DNS Services:: DNS daemons.
11461 * VPN Services:: VPN daemons.
11462 * Network File System:: NFS related services.
11463 * Continuous Integration:: The Cuirass service.
11464 * Power Management Services:: Extending battery life.
11465 * Audio Services:: The MPD.
11466 * Virtualization Services:: Virtualization services.
11467 * Version Control Services:: Providing remote access to Git repositories.
11468 * Game Services:: Game servers.
11469 * Miscellaneous Services:: Other services.
11472 @node Base Services
11473 @subsection Base Services
11475 The @code{(gnu services base)} module provides definitions for the basic
11476 services that one expects from the system. The services exported by
11477 this module are listed below.
11479 @defvr {Scheme Variable} %base-services
11480 This variable contains a list of basic services (@pxref{Service Types
11481 and Services}, for more information on service objects) one would
11482 expect from the system: a login service (mingetty) on each tty, syslogd,
11483 the libc name service cache daemon (nscd), the udev device manager, and
11486 This is the default value of the @code{services} field of
11487 @code{operating-system} declarations. Usually, when customizing a
11488 system, you will want to append services to @var{%base-services}, like
11492 (append (list (service avahi-service-type)
11493 (service openssh-service-type))
11498 @defvr {Scheme Variable} special-files-service-type
11499 This is the service that sets up ``special files'' such as
11500 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11502 The value associated with @code{special-files-service-type} services
11503 must be a list of tuples where the first element is the ``special file''
11504 and the second element is its target. By default it is:
11506 @cindex @file{/bin/sh}
11507 @cindex @file{sh}, in @file{/bin}
11509 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11512 @cindex @file{/usr/bin/env}
11513 @cindex @file{env}, in @file{/usr/bin}
11514 If you want to add, say, @code{/usr/bin/env} to your system, you can
11518 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11519 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11522 Since this is part of @code{%base-services}, you can use
11523 @code{modify-services} to customize the set of special files
11524 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11525 to add a special file is @i{via} the @code{extra-special-file} procedure
11529 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11530 Use @var{target} as the ``special file'' @var{file}.
11532 For example, adding the following lines to the @code{services} field of
11533 your operating system declaration leads to a @file{/usr/bin/env}
11537 (extra-special-file "/usr/bin/env"
11538 (file-append coreutils "/bin/env"))
11542 @deffn {Scheme Procedure} host-name-service @var{name}
11543 Return a service that sets the host name to @var{name}.
11546 @deffn {Scheme Procedure} login-service @var{config}
11547 Return a service to run login according to @var{config}, a
11548 @code{<login-configuration>} object, which specifies the message of the day,
11549 among other things.
11552 @deftp {Data Type} login-configuration
11553 This is the data type representing the configuration of login.
11558 @cindex message of the day
11559 A file-like object containing the ``message of the day''.
11561 @item @code{allow-empty-passwords?} (default: @code{#t})
11562 Allow empty passwords by default so that first-time users can log in when
11563 the 'root' account has just been created.
11568 @deffn {Scheme Procedure} mingetty-service @var{config}
11569 Return a service to run mingetty according to @var{config}, a
11570 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11574 @deftp {Data Type} mingetty-configuration
11575 This is the data type representing the configuration of Mingetty, which
11576 provides the default implementation of virtual console log-in.
11581 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11583 @item @code{auto-login} (default: @code{#f})
11584 When true, this field must be a string denoting the user name under
11585 which the system automatically logs in. When it is @code{#f}, a
11586 user name and password must be entered to log in.
11588 @item @code{login-program} (default: @code{#f})
11589 This must be either @code{#f}, in which case the default log-in program
11590 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11591 the name of the log-in program.
11593 @item @code{login-pause?} (default: @code{#f})
11594 When set to @code{#t} in conjunction with @var{auto-login}, the user
11595 will have to press a key before the log-in shell is launched.
11597 @item @code{mingetty} (default: @var{mingetty})
11598 The Mingetty package to use.
11603 @deffn {Scheme Procedure} agetty-service @var{config}
11604 Return a service to run agetty according to @var{config}, an
11605 @code{<agetty-configuration>} object, which specifies the tty to run,
11606 among other things.
11609 @deftp {Data Type} agetty-configuration
11610 This is the data type representing the configuration of agetty, which
11611 implements virtual and serial console log-in. See the @code{agetty(8)}
11612 man page for more information.
11617 The name of the console this agetty runs on, as a string---e.g.,
11618 @code{"ttyS0"}. This argument is optional, it will default to
11619 a reasonable default serial port used by the kernel Linux.
11621 For this, if there is a value for an option @code{agetty.tty} in the kernel
11622 command line, agetty will extract the device name of the serial port
11623 from it and use that.
11625 If not and if there is a value for an option @code{console} with a tty in
11626 the Linux command line, agetty will extract the device name of the
11627 serial port from it and use that.
11629 In both cases, agetty will leave the other serial device settings
11630 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11633 @item @code{baud-rate} (default: @code{#f})
11634 A string containing a comma-separated list of one or more baud rates, in
11637 @item @code{term} (default: @code{#f})
11638 A string containing the value used for the @code{TERM} environment
11641 @item @code{eight-bits?} (default: @code{#f})
11642 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11645 @item @code{auto-login} (default: @code{#f})
11646 When passed a login name, as a string, the specified user will be logged
11647 in automatically without prompting for their login name or password.
11649 @item @code{no-reset?} (default: @code{#f})
11650 When @code{#t}, don't reset terminal cflags (control modes).
11652 @item @code{host} (default: @code{#f})
11653 This accepts a string containing the "login_host", which will be written
11654 into the @file{/var/run/utmpx} file.
11656 @item @code{remote?} (default: @code{#f})
11657 When set to @code{#t} in conjunction with @var{host}, this will add an
11658 @code{-r} fakehost option to the command line of the login program
11659 specified in @var{login-program}.
11661 @item @code{flow-control?} (default: @code{#f})
11662 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11664 @item @code{no-issue?} (default: @code{#f})
11665 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11666 not be displayed before presenting the login prompt.
11668 @item @code{init-string} (default: @code{#f})
11669 This accepts a string that will be sent to the tty or modem before
11670 sending anything else. It can be used to initialize a modem.
11672 @item @code{no-clear?} (default: @code{#f})
11673 When set to @code{#t}, agetty will not clear the screen before showing
11676 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11677 This must be either a gexp denoting the name of a log-in program, or
11678 unset, in which case the default value is the @command{login} from the
11681 @item @code{local-line} (default: @code{#f})
11682 Control the CLOCAL line flag. This accepts one of three symbols as
11683 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11684 the default value chosen by agetty is @code{'auto}.
11686 @item @code{extract-baud?} (default: @code{#f})
11687 When set to @code{#t}, instruct agetty to try to extract the baud rate
11688 from the status messages produced by certain types of modems.
11690 @item @code{skip-login?} (default: @code{#f})
11691 When set to @code{#t}, do not prompt the user for a login name. This
11692 can be used with @var{login-program} field to use non-standard login
11695 @item @code{no-newline?} (default: @code{#f})
11696 When set to @code{#t}, do not print a newline before printing the
11697 @file{/etc/issue} file.
11699 @c Is this dangerous only when used with login-program, or always?
11700 @item @code{login-options} (default: @code{#f})
11701 This option accepts a string containing options that are passed to the
11702 login program. When used with the @var{login-program}, be aware that a
11703 malicious user could try to enter a login name containing embedded
11704 options that could be parsed by the login program.
11706 @item @code{login-pause} (default: @code{#f})
11707 When set to @code{#t}, wait for any key before showing the login prompt.
11708 This can be used in conjunction with @var{auto-login} to save memory by
11709 lazily spawning shells.
11711 @item @code{chroot} (default: @code{#f})
11712 Change root to the specified directory. This option accepts a directory
11715 @item @code{hangup?} (default: @code{#f})
11716 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11717 specified terminal.
11719 @item @code{keep-baud?} (default: @code{#f})
11720 When set to @code{#t}, try to keep the existing baud rate. The baud
11721 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11724 @item @code{timeout} (default: @code{#f})
11725 When set to an integer value, terminate if no user name could be read
11726 within @var{timeout} seconds.
11728 @item @code{detect-case?} (default: @code{#f})
11729 When set to @code{#t}, turn on support for detecting an uppercase-only
11730 terminal. This setting will detect a login name containing only
11731 uppercase letters as indicating an uppercase-only terminal and turn on
11732 some upper-to-lower case conversions. Note that this will not support
11733 Unicode characters.
11735 @item @code{wait-cr?} (default: @code{#f})
11736 When set to @code{#t}, wait for the user or modem to send a
11737 carriage-return or linefeed character before displaying
11738 @file{/etc/issue} or login prompt. This is typically used with the
11739 @var{init-string} option.
11741 @item @code{no-hints?} (default: @code{#f})
11742 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11745 @item @code{no-hostname?} (default: @code{#f})
11746 By default, the hostname is printed. When this option is set to
11747 @code{#t}, no hostname will be shown at all.
11749 @item @code{long-hostname?} (default: @code{#f})
11750 By default, the hostname is only printed until the first dot. When this
11751 option is set to @code{#t}, the fully qualified hostname by
11752 @code{gethostname} or @code{getaddrinfo} is shown.
11754 @item @code{erase-characters} (default: @code{#f})
11755 This option accepts a string of additional characters that should be
11756 interpreted as backspace when the user types their login name.
11758 @item @code{kill-characters} (default: @code{#f})
11759 This option accepts a string that should be interpreted to mean "ignore
11760 all previous characters" (also called a "kill" character) when the user
11761 types their login name.
11763 @item @code{chdir} (default: @code{#f})
11764 This option accepts, as a string, a directory path that will be changed
11767 @item @code{delay} (default: @code{#f})
11768 This options accepts, as an integer, the number of seconds to sleep
11769 before opening the tty and displaying the login prompt.
11771 @item @code{nice} (default: @code{#f})
11772 This option accepts, as an integer, the nice value with which to run the
11773 @command{login} program.
11775 @item @code{extra-options} (default: @code{'()})
11776 This option provides an "escape hatch" for the user to provide arbitrary
11777 command-line arguments to @command{agetty} as a list of strings.
11782 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11783 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11784 according to @var{config}, a @code{<kmscon-configuration>} object, which
11785 specifies the tty to run, among other things.
11788 @deftp {Data Type} kmscon-configuration
11789 This is the data type representing the configuration of Kmscon, which
11790 implements virtual console log-in.
11794 @item @code{virtual-terminal}
11795 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11797 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11798 A gexp denoting the name of the log-in program. The default log-in program is
11799 @command{login} from the Shadow tool suite.
11801 @item @code{login-arguments} (default: @code{'("-p")})
11802 A list of arguments to pass to @command{login}.
11804 @item @code{auto-login} (default: @code{#f})
11805 When passed a login name, as a string, the specified user will be logged
11806 in automatically without prompting for their login name or password.
11808 @item @code{hardware-acceleration?} (default: #f)
11809 Whether to use hardware acceleration.
11811 @item @code{kmscon} (default: @var{kmscon})
11812 The Kmscon package to use.
11817 @cindex name service cache daemon
11819 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11820 [#:name-services '()]
11821 Return a service that runs the libc name service cache daemon (nscd) with the
11822 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11823 Service Switch}, for an example.
11825 For convenience, the Shepherd service for nscd provides the following actions:
11829 @cindex cache invalidation, nscd
11830 @cindex nscd, cache invalidation
11831 This invalidate the given cache. For instance, running:
11834 herd invalidate nscd hosts
11838 invalidates the host name lookup cache of nscd.
11841 Running @command{herd statistics nscd} displays information about nscd usage
11847 @defvr {Scheme Variable} %nscd-default-configuration
11848 This is the default @code{<nscd-configuration>} value (see below) used
11849 by @code{nscd-service}. It uses the caches defined by
11850 @var{%nscd-default-caches}; see below.
11853 @deftp {Data Type} nscd-configuration
11854 This is the data type representing the name service cache daemon (nscd)
11859 @item @code{name-services} (default: @code{'()})
11860 List of packages denoting @dfn{name services} that must be visible to
11861 the nscd---e.g., @code{(list @var{nss-mdns})}.
11863 @item @code{glibc} (default: @var{glibc})
11864 Package object denoting the GNU C Library providing the @command{nscd}
11867 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11868 Name of the nscd log file. This is where debugging output goes when
11869 @code{debug-level} is strictly positive.
11871 @item @code{debug-level} (default: @code{0})
11872 Integer denoting the debugging levels. Higher numbers mean that more
11873 debugging output is logged.
11875 @item @code{caches} (default: @var{%nscd-default-caches})
11876 List of @code{<nscd-cache>} objects denoting things to be cached; see
11882 @deftp {Data Type} nscd-cache
11883 Data type representing a cache database of nscd and its parameters.
11887 @item @code{database}
11888 This is a symbol representing the name of the database to be cached.
11889 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11890 @code{services}, which designate the corresponding NSS database
11891 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11893 @item @code{positive-time-to-live}
11894 @itemx @code{negative-time-to-live} (default: @code{20})
11895 A number representing the number of seconds during which a positive or
11896 negative lookup result remains in cache.
11898 @item @code{check-files?} (default: @code{#t})
11899 Whether to check for updates of the files corresponding to
11902 For instance, when @var{database} is @code{hosts}, setting this flag
11903 instructs nscd to check for updates in @file{/etc/hosts} and to take
11906 @item @code{persistent?} (default: @code{#t})
11907 Whether the cache should be stored persistently on disk.
11909 @item @code{shared?} (default: @code{#t})
11910 Whether the cache should be shared among users.
11912 @item @code{max-database-size} (default: 32@tie{}MiB)
11913 Maximum size in bytes of the database cache.
11915 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11916 @c settings, so leave them out.
11921 @defvr {Scheme Variable} %nscd-default-caches
11922 List of @code{<nscd-cache>} objects used by default by
11923 @code{nscd-configuration} (see above).
11925 It enables persistent and aggressive caching of service and host name
11926 lookups. The latter provides better host name lookup performance,
11927 resilience in the face of unreliable name servers, and also better
11928 privacy---often the result of host name lookups is in local cache, so
11929 external name servers do not even need to be queried.
11932 @anchor{syslog-configuration-type}
11935 @deftp {Data Type} syslog-configuration
11936 This data type represents the configuration of the syslog daemon.
11939 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11940 The syslog daemon to use.
11942 @item @code{config-file} (default: @code{%default-syslog.conf})
11943 The syslog configuration file to use.
11948 @anchor{syslog-service}
11950 @deffn {Scheme Procedure} syslog-service @var{config}
11951 Return a service that runs a syslog daemon according to @var{config}.
11953 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11954 information on the configuration file syntax.
11957 @defvr {Scheme Variable} guix-service-type
11958 This is the type of the service that runs the build daemon,
11959 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11960 @code{guix-configuration} record as described below.
11963 @anchor{guix-configuration-type}
11964 @deftp {Data Type} guix-configuration
11965 This data type represents the configuration of the Guix build daemon.
11966 @xref{Invoking guix-daemon}, for more information.
11969 @item @code{guix} (default: @var{guix})
11970 The Guix package to use.
11972 @item @code{build-group} (default: @code{"guixbuild"})
11973 Name of the group for build user accounts.
11975 @item @code{build-accounts} (default: @code{10})
11976 Number of build user accounts to create.
11978 @item @code{authorize-key?} (default: @code{#t})
11979 @cindex substitutes, authorization thereof
11980 Whether to authorize the substitute keys listed in
11981 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11982 (@pxref{Substitutes}).
11984 @vindex %default-authorized-guix-keys
11985 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11986 The list of authorized key files for archive imports, as a list of
11987 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11988 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11990 @item @code{use-substitutes?} (default: @code{#t})
11991 Whether to use substitutes.
11993 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11994 The list of URLs where to look for substitutes by default.
11996 @item @code{max-silent-time} (default: @code{0})
11997 @itemx @code{timeout} (default: @code{0})
11998 The number of seconds of silence and the number of seconds of activity,
11999 respectively, after which a build process times out. A value of zero
12000 disables the timeout.
12002 @item @code{log-compression} (default: @code{'bzip2})
12003 The type of compression used for build logs---one of @code{gzip},
12004 @code{bzip2}, or @code{none}.
12006 @item @code{extra-options} (default: @code{'()})
12007 List of extra command-line options for @command{guix-daemon}.
12009 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12010 File where @command{guix-daemon}'s standard output and standard error
12013 @item @code{http-proxy} (default: @code{#f})
12014 The HTTP proxy used for downloading fixed-output derivations and
12017 @item @code{tmpdir} (default: @code{#f})
12018 A directory path where the @command{guix-daemon} will perform builds.
12023 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12024 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12025 udev rules can be provided as a list of files through the @var{rules}
12026 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12027 @code{(gnu services base)} simplify the creation of such rule files.
12030 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12031 Return a udev-rule file named @var{file-name} containing the rules
12032 defined by the @var{contents} literal.
12034 In the following example, a rule for a USB device is defined to be
12035 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12036 upon detecting a USB device with a given product identifier.
12039 (define %example-udev-rule
12041 "90-usb-thing.rules"
12042 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12043 "ATTR@{product@}==\"Example\", "
12044 "RUN+=\"/path/to/script\"")))
12047 The @command{herd rules udev} command, as root, returns the name of the
12048 directory containing all the active udev rules.
12051 Here we show how the default @var{udev-service} can be extended with it.
12057 (modify-services %desktop-services
12058 (udev-service-type config =>
12059 (udev-configuration (inherit config)
12060 (rules (append (udev-configuration-rules config)
12061 (list %example-udev-rule))))))))
12064 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12065 Return a udev file named @var{file-name} containing the rules defined
12066 within @var{file}, a file-like object.
12068 The following example showcases how we can use an existing rule file.
12071 (use-modules (guix download) ;for url-fetch
12072 (guix packages) ;for origin
12075 (define %android-udev-rules
12077 "51-android-udev.rules"
12078 (let ((version "20170910"))
12081 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12082 "android-udev-rules/" version "/51-android.rules"))
12084 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12088 Additionally, Guix package definitions can be included in @var{rules} in
12089 order to extend the udev rules with the definitions found under their
12090 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12091 @var{file->udev-rule} example, we could have used the
12092 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12093 packages android)} module.
12095 The following example shows how to use the @var{android-udev-rules}
12096 package so that the Android tool @command{adb} can detect devices
12097 without root privileges. It also details how to create the
12098 @code{adbusers} group, which is required for the proper functioning of
12099 the rules defined within the @var{android-udev-rules} package. To
12100 create such a group, we must define it both as part of the
12101 @var{supplementary-groups} of our @var{user-account} declaration, as
12102 well as in the @var{groups} field of the @var{operating-system} record.
12105 (use-modules (gnu packages android) ;for android-udev-rules
12106 (gnu system shadow) ;for user-group
12111 (users (cons (user-acount
12113 (supplementary-groups
12114 '("adbusers" ;for adb
12115 "wheel" "netdev" "audio" "video"))
12118 (groups (cons (user-group (system? #t) (name "adbusers"))
12124 (modify-services %desktop-services
12127 (udev-configuration (inherit config)
12128 (rules (cons android-udev-rules
12129 (udev-configuration-rules config))))))))
12132 @defvr {Scheme Variable} urandom-seed-service-type
12133 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12134 when rebooting. It also tries to seed @file{/dev/urandom} from
12135 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12139 @defvr {Scheme Variable} %random-seed-file
12140 This is the name of the file where some random bytes are saved by
12141 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12142 It defaults to @file{/var/lib/random-seed}.
12147 @defvr {Scheme Variable} gpm-service-type
12148 This is the type of the service that runs GPM, the @dfn{general-purpose
12149 mouse daemon}, which provides mouse support to the Linux console. GPM
12150 allows users to use the mouse in the console, notably to select, copy,
12153 The value for services of this type must be a @code{gpm-configuration}
12154 (see below). This service is not part of @var{%base-services}.
12157 @deftp {Data Type} gpm-configuration
12158 Data type representing the configuration of GPM.
12161 @item @code{options} (default: @code{%default-gpm-options})
12162 Command-line options passed to @command{gpm}. The default set of
12163 options instruct @command{gpm} to listen to mouse events on
12164 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12167 @item @code{gpm} (default: @code{gpm})
12168 The GPM package to use.
12173 @anchor{guix-publish-service-type}
12174 @deffn {Scheme Variable} guix-publish-service-type
12175 This is the service type for @command{guix publish} (@pxref{Invoking
12176 guix publish}). Its value must be a @code{guix-configuration}
12177 object, as described below.
12179 This assumes that @file{/etc/guix} already contains a signing key pair as
12180 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12181 archive}). If that is not the case, the service will fail to start.
12184 @deftp {Data Type} guix-publish-configuration
12185 Data type representing the configuration of the @code{guix publish}
12189 @item @code{guix} (default: @code{guix})
12190 The Guix package to use.
12192 @item @code{port} (default: @code{80})
12193 The TCP port to listen for connections.
12195 @item @code{host} (default: @code{"localhost"})
12196 The host (and thus, network interface) to listen to. Use
12197 @code{"0.0.0.0"} to listen on all the network interfaces.
12199 @item @code{compression-level} (default: @code{3})
12200 The gzip compression level at which substitutes are compressed. Use
12201 @code{0} to disable compression altogether, and @code{9} to get the best
12202 compression ratio at the expense of increased CPU usage.
12204 @item @code{nar-path} (default: @code{"nar"})
12205 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12206 publish, @code{--nar-path}}, for details.
12208 @item @code{cache} (default: @code{#f})
12209 When it is @code{#f}, disable caching and instead generate archives on
12210 demand. Otherwise, this should be the name of a directory---e.g.,
12211 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12212 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12213 @option{--cache}}, for more information on the tradeoffs involved.
12215 @item @code{workers} (default: @code{#f})
12216 When it is an integer, this is the number of worker threads used for
12217 caching; when @code{#f}, the number of processors is used.
12218 @xref{Invoking guix publish, @option{--workers}}, for more information.
12220 @item @code{ttl} (default: @code{#f})
12221 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12222 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12223 for more information.
12227 @anchor{rngd-service}
12228 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12229 [#:device "/dev/hwrng"]
12230 Return a service that runs the @command{rngd} program from @var{rng-tools}
12231 to add @var{device} to the kernel's entropy pool. The service will fail if
12232 @var{device} does not exist.
12235 @anchor{pam-limits-service}
12236 @cindex session limits
12241 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12243 Return a service that installs a configuration file for the
12244 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12245 @code{pam_limits} module}. The procedure optionally takes a list of
12246 @code{pam-limits-entry} values, which can be used to specify
12247 @code{ulimit} limits and nice priority limits to user sessions.
12249 The following limits definition sets two hard and soft limits for all
12250 login sessions of users in the @code{realtime} group:
12253 (pam-limits-service
12255 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12256 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12259 The first entry increases the maximum realtime priority for
12260 non-privileged processes; the second entry lifts any restriction of the
12261 maximum address space that can be locked in memory. These settings are
12262 commonly used for real-time audio systems.
12265 @node Scheduled Job Execution
12266 @subsection Scheduled Job Execution
12270 @cindex scheduling jobs
12271 The @code{(gnu services mcron)} module provides an interface to
12272 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12273 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12274 Unix @command{cron} daemon; the main difference is that it is
12275 implemented in Guile Scheme, which provides a lot of flexibility when
12276 specifying the scheduling of jobs and their actions.
12278 The example below defines an operating system that runs the
12279 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12280 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12281 well as the @command{mkid} command on behalf of an unprivileged user
12282 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12283 gexps to introduce job definitions that are passed to mcron
12284 (@pxref{G-Expressions}).
12287 (use-modules (guix) (gnu) (gnu services mcron))
12288 (use-package-modules base idutils)
12290 (define updatedb-job
12291 ;; Run 'updatedb' at 3AM every day. Here we write the
12292 ;; job's action as a Scheme procedure.
12293 #~(job '(next-hour '(3))
12295 (execl (string-append #$findutils "/bin/updatedb")
12297 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12299 (define garbage-collector-job
12300 ;; Collect garbage 5 minutes after midnight every day.
12301 ;; The job's action is a shell command.
12302 #~(job "5 0 * * *" ;Vixie cron syntax
12305 (define idutils-job
12306 ;; Update the index database as user "charlie" at 12:15PM
12307 ;; and 19:15PM. This runs from the user's home directory.
12308 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12309 (string-append #$idutils "/bin/mkid src")
12314 (services (cons (service mcron-service-type
12315 (mcron-configuration
12316 (jobs (list garbage-collector-job
12322 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12323 for more information on mcron job specifications. Below is the
12324 reference of the mcron service.
12326 On a running system, you can use the @code{schedule} action of the service to
12327 visualize the mcron jobs that will be executed next:
12330 # herd schedule mcron
12334 The example above lists the next five tasks that will be executed, but you can
12335 also specify the number of tasks to display:
12338 # herd schedule mcron 10
12341 @defvr {Scheme Variable} mcron-service-type
12342 This is the type of the @code{mcron} service, whose value is an
12343 @code{mcron-configuration} object.
12345 This service type can be the target of a service extension that provides
12346 it additional job specifications (@pxref{Service Composition}). In
12347 other words, it is possible to define services that provide additional
12351 @deftp {Data Type} mcron-configuration
12352 Data type representing the configuration of mcron.
12355 @item @code{mcron} (default: @var{mcron})
12356 The mcron package to use.
12359 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12360 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12361 specifications,, mcron, GNU@tie{}mcron}).
12367 @subsection Log Rotation
12370 @cindex log rotation
12372 Log files such as those found in @file{/var/log} tend to grow endlessly,
12373 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12374 their contents in separate files, possibly compressed. The @code{(gnu
12375 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12376 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12378 The example below defines an operating system that provides log rotation
12379 with the default settings, for commonly encountered log files.
12382 (use-modules (guix) (gnu))
12383 (use-service-modules admin mcron)
12384 (use-package-modules base idutils)
12388 (services (cons (service rottlog-service-type)
12392 @defvr {Scheme Variable} rottlog-service-type
12393 This is the type of the Rottlog service, whose value is a
12394 @code{rottlog-configuration} object.
12396 Other services can extend this one with new @code{log-rotation} objects
12397 (see below), thereby augmenting the set of files to be rotated.
12399 This service type can define mcron jobs (@pxref{Scheduled Job
12400 Execution}) to run the rottlog service.
12403 @deftp {Data Type} rottlog-configuration
12404 Data type representing the configuration of rottlog.
12407 @item @code{rottlog} (default: @code{rottlog})
12408 The Rottlog package to use.
12410 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12411 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12412 rottlog, GNU Rot[t]log Manual}).
12414 @item @code{rotations} (default: @code{%default-rotations})
12415 A list of @code{log-rotation} objects as defined below.
12418 This is a list of gexps where each gexp corresponds to an mcron job
12419 specification (@pxref{Scheduled Job Execution}).
12423 @deftp {Data Type} log-rotation
12424 Data type representing the rotation of a group of log files.
12426 Taking an example from the Rottlog manual (@pxref{Period Related File
12427 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12433 (files '("/var/log/apache/*"))
12434 (options '("storedir apache-archives"
12440 The list of fields is as follows:
12443 @item @code{frequency} (default: @code{'weekly})
12444 The log rotation frequency, a symbol.
12447 The list of files or file glob patterns to rotate.
12449 @item @code{options} (default: @code{'()})
12450 The list of rottlog options for this rotation (@pxref{Configuration
12451 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12453 @item @code{post-rotate} (default: @code{#f})
12454 Either @code{#f} or a gexp to execute once the rotation has completed.
12458 @defvr {Scheme Variable} %default-rotations
12459 Specifies weekly rotation of @var{%rotated-files} and
12460 a couple of other files.
12463 @defvr {Scheme Variable} %rotated-files
12464 The list of syslog-controlled files to be rotated. By default it is:
12465 @code{'("/var/log/messages" "/var/log/secure")}.
12468 @node Networking Services
12469 @subsection Networking Services
12471 The @code{(gnu services networking)} module provides services to configure
12472 the network interface.
12474 @cindex DHCP, networking service
12475 @defvr {Scheme Variable} dhcp-client-service-type
12476 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12477 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12478 is the DHCP client package to use, @code{isc-dhcp} by default.
12481 @deffn {Scheme Procedure} dhcpd-service-type
12482 This type defines a service that runs a DHCP daemon. To create a
12483 service of this type, you must supply a @code{<dhcpd-configuration>}.
12487 (service dhcpd-service-type
12488 (dhcpd-configuration
12489 (config-file (local-file "my-dhcpd.conf"))
12490 (interfaces '("enp0s25"))))
12494 @deftp {Data Type} dhcpd-configuration
12496 @item @code{package} (default: @code{isc-dhcp})
12497 The package that provides the DHCP daemon. This package is expected to
12498 provide the daemon at @file{sbin/dhcpd} relative to its output
12499 directory. The default package is the
12500 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12501 @item @code{config-file} (default: @code{#f})
12502 The configuration file to use. This is required. It will be passed to
12503 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12504 object (@pxref{G-Expressions, file-like objects}). See @code{man
12505 dhcpd.conf} for details on the configuration file syntax.
12506 @item @code{version} (default: @code{"4"})
12507 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12508 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12509 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12511 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12512 The run directory to use. At service activation time, this directory
12513 will be created if it does not exist.
12514 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12515 The PID file to use. This corresponds to the @code{-pf} option of
12516 @code{dhcpd}. See @code{man dhcpd} for details.
12517 @item @code{interfaces} (default: @code{'()})
12518 The names of the network interfaces on which dhcpd should listen for
12519 broadcasts. If this list is not empty, then its elements (which must be
12520 strings) will be appended to the @code{dhcpd} invocation when starting
12521 the daemon. It may not be necessary to explicitly specify any
12522 interfaces here; see @code{man dhcpd} for details.
12526 @defvr {Scheme Variable} static-networking-service-type
12527 This is the type for statically-configured network interfaces.
12528 @c TODO Document <static-networking> data structures.
12531 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12532 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12533 [#:requirement @code{'(udev)}]
12534 Return a service that starts @var{interface} with address @var{ip}. If
12535 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12536 it must be a string specifying the default network gateway. @var{requirement}
12537 can be used to declare a dependency on another service before configuring the
12540 This procedure can be called several times, one for each network
12541 interface of interest. Behind the scenes what it does is extend
12542 @code{static-networking-service-type} with additional network interfaces
12548 (static-networking-service "eno1" "192.168.1.82"
12549 #:gateway "192.168.1.2"
12550 #:name-servers '("192.168.1.2"))
12557 @cindex network management
12558 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12559 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12560 management daemon that aims to simplify wired and wireless networking.
12562 This service adds the @var{wicd} package to the global profile, providing
12563 several commands to interact with the daemon and configure networking:
12564 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12565 and @command{wicd-curses} user interfaces.
12568 @cindex ModemManager
12570 @defvr {Scheme Variable} modem-manager-service-type
12571 This is the service type for the
12572 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12573 service. The value for this service type is a
12574 @code{modem-manager-configuration} record.
12576 This service is part of @code{%desktop-services} (@pxref{Desktop
12580 @deftp {Data Type} modem-manager-configuration
12581 Data type representing the configuration of ModemManager.
12584 @item @code{modem-manager} (default: @code{modem-manager})
12585 The ModemManager package to use.
12590 @cindex NetworkManager
12592 @defvr {Scheme Variable} network-manager-service-type
12593 This is the service type for the
12594 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12595 service. The value for this service type is a
12596 @code{network-manager-configuration} record.
12598 This service is part of @code{%desktop-services} (@pxref{Desktop
12602 @deftp {Data Type} network-manager-configuration
12603 Data type representing the configuration of NetworkManager.
12606 @item @code{network-manager} (default: @code{network-manager})
12607 The NetworkManager package to use.
12609 @item @code{dns} (default: @code{"default"})
12610 Processing mode for DNS, which affects how NetworkManager uses the
12611 @code{resolv.conf} configuration file.
12615 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12616 provided by currently active connections.
12619 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12620 using a "split DNS" configuration if you are connected to a VPN, and
12621 then update @code{resolv.conf} to point to the local nameserver.
12624 NetworkManager will not modify @code{resolv.conf}.
12627 @item @code{vpn-plugins} (default: @code{'()})
12628 This is the list of available plugins for virtual private networks
12629 (VPNs). An example of this is the @code{network-manager-openvpn}
12630 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12636 @deffn {Scheme Variable} connman-service-type
12637 This is the service type to run @url{https://01.org/connman,Connman},
12638 a network connection manager.
12640 Its value must be an
12641 @code{connman-configuration} record as in this example:
12644 (service connman-service-type
12645 (connman-configuration
12646 (disable-vpn? #t)))
12649 See below for details about @code{connman-configuration}.
12652 @deftp {Data Type} connman-configuration
12653 Data Type representing the configuration of connman.
12656 @item @code{connman} (default: @var{connman})
12657 The connman package to use.
12659 @item @code{disable-vpn?} (default: @code{#f})
12660 When true, disable connman's vpn plugin.
12664 @cindex WPA Supplicant
12665 @defvr {Scheme Variable} wpa-supplicant-service-type
12666 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12667 supplicant}, an authentication daemon required to authenticate against
12668 encrypted WiFi or ethernet networks.
12671 @deftp {Data Type} wpa-supplicant-configuration
12672 Data type representing the configuration of WPA Supplicant.
12674 It takes the following parameters:
12677 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12678 The WPA Supplicant package to use.
12680 @item @code{dbus?} (default: @code{#t})
12681 Whether to listen for requests on D-Bus.
12683 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12684 Where to store the PID file.
12686 @item @code{interface} (default: @code{#f})
12687 If this is set, it must specify the name of a network interface that
12688 WPA supplicant will control.
12690 @item @code{config-file} (default: @code{#f})
12691 Optional configuration file to use.
12693 @item @code{extra-options} (default: @code{'()})
12694 List of additional command-line arguments to pass to the daemon.
12699 @defvr {Scheme Variable} iptables-service-type
12700 This is the service type to set up an iptables configuration. iptables is a
12701 packet filtering framework supported by the Linux kernel. This service
12702 supports configuring iptables for both IPv4 and IPv6. A simple example
12703 configuration rejecting all incoming connections except those to the ssh port
12707 (service iptables-service-type
12708 (iptables-configuration
12709 (ipv4-rules (plain-file "iptables.rules" "*filter
12713 -A INPUT -p tcp --dport 22 -j ACCEPT
12714 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12717 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12721 -A INPUT -p tcp --dport 22 -j ACCEPT
12722 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12728 @deftp {Data Type} iptables-configuration
12729 The data type representing the configuration of iptables.
12732 @item @code{iptables} (default: @code{iptables})
12733 The iptables package that provides @code{iptables-restore} and
12734 @code{ip6tables-restore}.
12735 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12736 The iptables rules to use. It will be passed to @code{iptables-restore}.
12737 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12739 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12740 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12741 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12746 @cindex NTP (Network Time Protocol), service
12747 @cindex real time clock
12748 @defvr {Scheme Variable} ntp-service-type
12749 This is the type of the service running the @uref{http://www.ntp.org,
12750 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12751 system clock synchronized with that of the specified NTP servers.
12753 The value of this service is an @code{ntpd-configuration} object, as described
12757 @deftp {Data Type} ntp-configuration
12758 This is the data type for the NTP service configuration.
12761 @item @code{servers} (default: @code{%ntp-servers})
12762 This is the list of servers (host names) with which @command{ntpd} will be
12765 @item @code{allow-large-adjustment?} (default: @code{#f})
12766 This determines whether @command{ntpd} is allowed to make an initial
12767 adjustment of more than 1,000 seconds.
12769 @item @code{ntp} (default: @code{ntp})
12770 The NTP package to use.
12774 @defvr {Scheme Variable} %ntp-servers
12775 List of host names used as the default NTP servers. These are servers of the
12776 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12780 @deffn {Scheme Procedure} openntpd-service-type
12781 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12782 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12783 clock synchronized with that of the given servers.
12787 openntpd-service-type
12788 (openntpd-configuration
12789 (listen-on '("127.0.0.1" "::1"))
12790 (sensor '("udcf0 correction 70000"))
12791 (constraint-from '("www.gnu.org"))
12792 (constraints-from '("https://www.google.com/"))
12793 (allow-large-adjustment? #t)))
12798 @deftp {Data Type} openntpd-configuration
12800 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12801 The openntpd executable to use.
12802 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12803 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12804 @item @code{query-from} (default: @code{'()})
12805 A list of local IP address the ntpd daemon should use for outgoing queries.
12806 @item @code{sensor} (default: @code{'()})
12807 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12808 will listen to each sensor that actually exists and ignore non-existent ones.
12809 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12811 @item @code{server} (default: @var{%ntp-servers})
12812 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12813 @item @code{servers} (default: @code{'()})
12814 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12815 @item @code{constraint-from} (default: @code{'()})
12816 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12817 This time information is not used for precision but acts as an authenticated
12818 constraint, thereby reducing the impact of unauthenticated NTP
12819 man-in-the-middle attacks.
12820 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12822 @item @code{constraints-from} (default: @code{'()})
12823 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12824 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12825 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12826 @item @code{allow-large-adjustment?} (default: @code{#f})
12827 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12833 @deffn {Scheme variable} inetd-service-type
12834 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12835 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12836 connections on internet sockets, and lazily starts the specified server
12837 program when a connection is made on one of these sockets.
12839 The value of this service is an @code{inetd-configuration} object. The
12840 following example configures the @command{inetd} daemon to provide the
12841 built-in @command{echo} service, as well as an smtp service which
12842 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12843 gateway @code{hostname}:
12848 (inetd-configuration
12852 (socket-type 'stream)
12859 (socket-type 'stream)
12863 (program (file-append openssh "/bin/ssh"))
12865 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12866 "-W" "smtp-server:25" "user@@hostname")))))
12869 See below for more details about @code{inetd-configuration}.
12872 @deftp {Data Type} inetd-configuration
12873 Data type representing the configuration of @command{inetd}.
12876 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12877 The @command{inetd} executable to use.
12879 @item @code{entries} (default: @code{'()})
12880 A list of @command{inetd} service entries. Each entry should be created
12881 by the @code{inetd-entry} constructor.
12885 @deftp {Data Type} inetd-entry
12886 Data type representing an entry in the @command{inetd} configuration.
12887 Each entry corresponds to a socket where @command{inetd} will listen for
12891 @item @code{node} (default: @code{#f})
12892 Optional string, a comma-separated list of local addresses
12893 @command{inetd} should use when listening for this service.
12894 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12895 description of all options.
12897 A string, the name must correspond to an entry in @code{/etc/services}.
12898 @item @code{socket-type}
12899 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12901 @item @code{protocol}
12902 A string, must correspond to an entry in @code{/etc/protocols}.
12903 @item @code{wait?} (default: @code{#t})
12904 Whether @command{inetd} should wait for the server to exit before
12905 listening to new service requests.
12907 A string containing the user (and, optionally, group) name of the user
12908 as whom the server should run. The group name can be specified in a
12909 suffix, separated by a colon or period, i.e.@: @code{"user"},
12910 @code{"user:group"} or @code{"user.group"}.
12911 @item @code{program} (default: @code{"internal"})
12912 The server program which will serve the requests, or @code{"internal"}
12913 if @command{inetd} should use a built-in service.
12914 @item @code{arguments} (default: @code{'()})
12915 A list strings or file-like objects, which are the server program's
12916 arguments, starting with the zeroth argument, i.e.@: the name of the
12917 program itself. For @command{inetd}'s internal services, this entry
12918 must be @code{'()} or @code{'("internal")}.
12921 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12922 detailed discussion of each configuration field.
12926 @defvr {Scheme Variable} tor-service-type
12927 This is the type for a service that runs the @uref{https://torproject.org,
12928 Tor} anonymous networking daemon. The service is configured using a
12929 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12930 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12934 @deftp {Data Type} tor-configuration
12936 @item @code{tor} (default: @code{tor})
12937 The package that provides the Tor daemon. This package is expected to provide
12938 the daemon at @file{bin/tor} relative to its output directory. The default
12939 package is the @uref{https://www.torproject.org, Tor Project's}
12942 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12943 The configuration file to use. It will be appended to a default configuration
12944 file, and the final configuration file will be passed to @code{tor} via its
12945 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12946 file-like objects}). See @code{man tor} for details on the configuration file
12949 @item @code{hidden-services} (default: @code{'()})
12950 The list of @code{<hidden-service>} records to use. For any hidden service
12951 you include in this list, appropriate configuration to enable the hidden
12952 service will be automatically added to the default configuration file. You
12953 may conveniently create @code{<hidden-service>} records using the
12954 @code{tor-hidden-service} procedure described below.
12956 @item @code{socks-socket-type} (default: @code{'tcp})
12957 The default socket type that Tor should use for its SOCKS socket. This must
12958 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12959 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12960 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12961 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12964 If you want to customize the SOCKS socket in more detail, leave
12965 @code{socks-socket-type} at its default value of @code{'tcp} and use
12966 @code{config-file} to override the default by providing your own
12967 @code{SocksPort} option.
12971 @cindex hidden service
12972 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12973 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12974 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12977 '((22 "127.0.0.1:22")
12978 (80 "127.0.0.1:8080"))
12981 In this example, port 22 of the hidden service is mapped to local port 22, and
12982 port 80 is mapped to local port 8080.
12984 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12985 the @file{hostname} file contains the @code{.onion} host name for the hidden
12988 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12989 project's documentation} for more information.
12992 The @code{(gnu services rsync)} module provides the following services:
12994 You might want an rsync daemon if you have files that you want available
12995 so anyone (or just yourself) can download existing files or upload new
12998 @deffn {Scheme Variable} rsync-service-type
12999 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13000 The value for this service type is a
13001 @command{rsync-configuration} record as in this example:
13004 (service rsync-service-type)
13007 See below for details about @code{rsync-configuration}.
13010 @deftp {Data Type} rsync-configuration
13011 Data type representing the configuration for @code{rsync-service}.
13014 @item @code{package} (default: @var{rsync})
13015 @code{rsync} package to use.
13017 @item @code{port-number} (default: @code{873})
13018 TCP port on which @command{rsync} listens for incoming connections. If port
13019 is less than @code{1024} @command{rsync} needs to be started as the
13020 @code{root} user and group.
13022 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13023 Name of the file where @command{rsync} writes its PID.
13025 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13026 Name of the file where @command{rsync} writes its lock file.
13028 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13029 Name of the file where @command{rsync} writes its log file.
13031 @item @code{use-chroot?} (default: @var{#t})
13032 Whether to use chroot for @command{rsync} shared directory.
13034 @item @code{share-path} (default: @file{/srv/rsync})
13035 Location of the @command{rsync} shared directory.
13037 @item @code{share-comment} (default: @code{"Rsync share"})
13038 Comment of the @command{rsync} shared directory.
13040 @item @code{read-only?} (default: @var{#f})
13041 Read-write permissions to shared directory.
13043 @item @code{timeout} (default: @code{300})
13044 I/O timeout in seconds.
13046 @item @code{user} (default: @var{"root"})
13047 Owner of the @code{rsync} process.
13049 @item @code{group} (default: @var{"root"})
13050 Group of the @code{rsync} process.
13052 @item @code{uid} (default: @var{"rsyncd"})
13053 User name or user ID that file transfers to and from that module should take
13054 place as when the daemon was run as @code{root}.
13056 @item @code{gid} (default: @var{"rsyncd"})
13057 Group name or group ID that will be used when accessing the module.
13062 Furthermore, @code{(gnu services ssh)} provides the following services.
13066 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13067 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13068 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13069 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13070 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13071 [#:public-key-authentication? #t] [#:initialize? #t]
13072 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13073 @var{host-key} must designate a file containing the host key, and readable
13076 When @var{daemonic?} is true, @command{lshd} will detach from the
13077 controlling terminal and log its output to syslogd, unless one sets
13078 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13079 depend on existence of syslogd service. When @var{pid-file?} is true,
13080 @command{lshd} writes its PID to the file called @var{pid-file}.
13082 When @var{initialize?} is true, automatically create the seed and host key
13083 upon service activation if they do not exist yet. This may take long and
13084 require interaction.
13086 When @var{initialize?} is false, it is up to the user to initialize the
13087 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13088 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13089 basics,,, lsh, LSH Manual}).
13091 When @var{interfaces} is empty, lshd listens for connections on all the
13092 network interfaces; otherwise, @var{interfaces} must be a list of host names
13095 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13096 passwords, and @var{root-login?} specifies whether to accept log-ins as
13099 The other options should be self-descriptive.
13104 @deffn {Scheme Variable} openssh-service-type
13105 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13106 shell daemon, @command{sshd}. Its value must be an
13107 @code{openssh-configuration} record as in this example:
13110 (service openssh-service-type
13111 (openssh-configuration
13112 (x11-forwarding? #t)
13113 (permit-root-login 'without-password)
13115 `(("alice" ,(local-file "alice.pub"))
13116 ("bob" ,(local-file "bob.pub"))))))
13119 See below for details about @code{openssh-configuration}.
13121 This service can be extended with extra authorized keys, as in this
13125 (service-extension openssh-service-type
13126 (const `(("charlie"
13127 ,(local-file "charlie.pub")))))
13131 @deftp {Data Type} openssh-configuration
13132 This is the configuration record for OpenSSH's @command{sshd}.
13135 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13136 Name of the file where @command{sshd} writes its PID.
13138 @item @code{port-number} (default: @code{22})
13139 TCP port on which @command{sshd} listens for incoming connections.
13141 @item @code{permit-root-login} (default: @code{#f})
13142 This field determines whether and when to allow logins as root. If
13143 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13144 If it's the symbol @code{'without-password}, then root logins are
13145 permitted but not with password-based authentication.
13147 @item @code{allow-empty-passwords?} (default: @code{#f})
13148 When true, users with empty passwords may log in. When false, they may
13151 @item @code{password-authentication?} (default: @code{#t})
13152 When true, users may log in with their password. When false, they have
13153 other authentication methods.
13155 @item @code{public-key-authentication?} (default: @code{#t})
13156 When true, users may log in using public key authentication. When
13157 false, users have to use other authentication method.
13159 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13160 This is used only by protocol version 2.
13162 @item @code{x11-forwarding?} (default: @code{#f})
13163 When true, forwarding of X11 graphical client connections is
13164 enabled---in other words, @command{ssh} options @option{-X} and
13165 @option{-Y} will work.
13167 @item @code{allow-agent-forwarding?} (default: @code{#t})
13168 Whether to allow agent forwarding.
13170 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13171 Whether to allow TCP forwarding.
13173 @item @code{gateway-ports?} (default: @code{#f})
13174 Whether to allow gateway ports.
13176 @item @code{challenge-response-authentication?} (default: @code{#f})
13177 Specifies whether challenge response authentication is allowed (e.g.@: via
13180 @item @code{use-pam?} (default: @code{#t})
13181 Enables the Pluggable Authentication Module interface. If set to
13182 @code{#t}, this will enable PAM authentication using
13183 @code{challenge-response-authentication?} and
13184 @code{password-authentication?}, in addition to PAM account and session
13185 module processing for all authentication types.
13187 Because PAM challenge response authentication usually serves an
13188 equivalent role to password authentication, you should disable either
13189 @code{challenge-response-authentication?} or
13190 @code{password-authentication?}.
13192 @item @code{print-last-log?} (default: @code{#t})
13193 Specifies whether @command{sshd} should print the date and time of the
13194 last user login when a user logs in interactively.
13196 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13197 Configures external subsystems (e.g.@: file transfer daemon).
13199 This is a list of two-element lists, each of which containing the
13200 subsystem name and a command (with optional arguments) to execute upon
13203 The command @command{internal-sftp} implements an in-process SFTP
13204 server. Alternately, one can specify the @command{sftp-server} command:
13206 (service openssh-service-type
13207 (openssh-configuration
13209 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13212 @item @code{accepted-environment} (default: @code{'()})
13213 List of strings describing which environment variables may be exported.
13215 Each string gets on its own line. See the @code{AcceptEnv} option in
13216 @code{man sshd_config}.
13218 This example allows ssh-clients to export the @code{COLORTERM} variable.
13219 It is set by terminal emulators, which support colors. You can use it in
13220 your shell's ressource file to enable colors for the prompt and commands
13221 if this variable is set.
13224 (service openssh-service-type
13225 (openssh-configuration
13226 (accepted-environment '("COLORTERM"))))
13229 @item @code{authorized-keys} (default: @code{'()})
13230 @cindex authorized keys, SSH
13231 @cindex SSH authorized keys
13232 This is the list of authorized keys. Each element of the list is a user
13233 name followed by one or more file-like objects that represent SSH public
13237 (openssh-configuration
13239 `(("rekado" ,(local-file "rekado.pub"))
13240 ("chris" ,(local-file "chris.pub"))
13241 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13245 registers the specified public keys for user accounts @code{rekado},
13246 @code{chris}, and @code{root}.
13248 Additional authorized keys can be specified @i{via}
13249 @code{service-extension}.
13251 Note that this does @emph{not} interfere with the use of
13252 @file{~/.ssh/authorized_keys}.
13254 @item @code{log-level} (default: @code{'info})
13255 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13256 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13257 page for @file{sshd_config} for the full list of level names.
13259 @item @code{extra-content} (default: @code{""})
13260 This field can be used to append arbitrary text to the configuration file. It
13261 is especially useful for elaborate configurations that cannot be expressed
13262 otherwise. This configuration, for example, would generally disable root
13263 logins, but permit them from one specific IP address:
13266 (openssh-configuration
13268 Match Address 192.168.0.1
13269 PermitRootLogin yes"))
13275 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13276 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13277 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13280 For example, to specify a Dropbear service listening on port 1234, add
13281 this call to the operating system's @code{services} field:
13284 (dropbear-service (dropbear-configuration
13285 (port-number 1234)))
13289 @deftp {Data Type} dropbear-configuration
13290 This data type represents the configuration of a Dropbear SSH daemon.
13293 @item @code{dropbear} (default: @var{dropbear})
13294 The Dropbear package to use.
13296 @item @code{port-number} (default: 22)
13297 The TCP port where the daemon waits for incoming connections.
13299 @item @code{syslog-output?} (default: @code{#t})
13300 Whether to enable syslog output.
13302 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13303 File name of the daemon's PID file.
13305 @item @code{root-login?} (default: @code{#f})
13306 Whether to allow @code{root} logins.
13308 @item @code{allow-empty-passwords?} (default: @code{#f})
13309 Whether to allow empty passwords.
13311 @item @code{password-authentication?} (default: @code{#t})
13312 Whether to enable password-based authentication.
13316 @defvr {Scheme Variable} %facebook-host-aliases
13317 This variable contains a string for use in @file{/etc/hosts}
13318 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13319 line contains a entry that maps a known server name of the Facebook
13320 on-line service---e.g., @code{www.facebook.com}---to the local
13321 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13323 This variable is typically used in the @code{hosts-file} field of an
13324 @code{operating-system} declaration (@pxref{operating-system Reference,
13325 @file{/etc/hosts}}):
13328 (use-modules (gnu) (guix))
13331 (host-name "mymachine")
13334 ;; Create a /etc/hosts file with aliases for "localhost"
13335 ;; and "mymachine", as well as for Facebook servers.
13336 (plain-file "hosts"
13337 (string-append (local-host-aliases host-name)
13338 %facebook-host-aliases))))
13341 This mechanism can prevent programs running locally, such as Web
13342 browsers, from accessing Facebook.
13345 The @code{(gnu services avahi)} provides the following definition.
13347 @defvr {Scheme Variable} avahi-service-type
13348 This is the service that runs @command{avahi-daemon}, a system-wide
13349 mDNS/DNS-SD responder that allows for service discovery and
13350 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13351 Its value must be a @code{zero-configuration} record---see below.
13353 This service extends the name service cache daemon (nscd) so that it can
13354 resolve @code{.local} host names using
13355 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13356 Service Switch}, for information on host name resolution.
13358 Additionally, add the @var{avahi} package to the system profile so that
13359 commands such as @command{avahi-browse} are directly usable.
13362 @deftp {Data Type} avahi-configuration
13363 Data type representation the configuration for Avahi.
13367 @item @code{host-name} (default: @code{#f})
13368 If different from @code{#f}, use that as the host name to
13369 publish for this machine; otherwise, use the machine's actual host name.
13371 @item @code{publish?} (default: @code{#t})
13372 When true, allow host names and services to be published (broadcast) over the
13375 @item @code{publish-workstation?} (default: @code{#t})
13376 When true, @command{avahi-daemon} publishes the machine's host name and IP
13377 address via mDNS on the local network. To view the host names published on
13378 your local network, you can run:
13381 avahi-browse _workstation._tcp
13384 @item @code{wide-area?} (default: @code{#f})
13385 When true, DNS-SD over unicast DNS is enabled.
13387 @item @code{ipv4?} (default: @code{#t})
13388 @itemx @code{ipv6?} (default: @code{#t})
13389 These fields determine whether to use IPv4/IPv6 sockets.
13391 @item @code{domains-to-browse} (default: @code{'()})
13392 This is a list of domains to browse.
13396 @deffn {Scheme Variable} openvswitch-service-type
13397 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13398 service, whose value should be an @code{openvswitch-configuration}
13402 @deftp {Data Type} openvswitch-configuration
13403 Data type representing the configuration of Open vSwitch, a multilayer
13404 virtual switch which is designed to enable massive network automation
13405 through programmatic extension.
13408 @item @code{package} (default: @var{openvswitch})
13409 Package object of the Open vSwitch.
13415 @subsection X Window
13418 @cindex X Window System
13419 @cindex login manager
13420 Support for the X Window graphical display system---specifically
13421 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13422 there is no @code{xorg-service} procedure. Instead, the X server is
13423 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13426 @cindex GNOME, login manager
13427 GDM of course allows users to log in into window managers and desktop
13428 environments other than GNOME; for those using GNOME, GDM is required for
13429 features such as automatic screen locking.
13431 @cindex window manager
13432 To use X11, you must install at least one @dfn{window manager}---for
13433 example the @code{windowmaker} or @code{openbox} packages---preferably
13434 by adding it to the @code{packages} field of your operating system
13435 definition (@pxref{operating-system Reference, system-wide packages}).
13437 @defvr {Scheme Variable} gdm-service-type
13438 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13439 Desktop Manager} (GDM), a program that manages graphical display servers and
13440 handles graphical user logins. Its value must be a @code{gdm-configuration}
13443 @cindex session types (X11)
13444 @cindex X11 session types
13445 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13446 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13447 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13448 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13449 set of packages automatically makes them available at the log-in screen.
13451 In addition, @file{~/.xsession} files are honored. When available,
13452 @file{~/.xsession} must be an executable that starts a window manager
13453 and/or other X clients.
13456 @deftp {Data Type} gdm-configuration
13458 @item @code{auto-login?} (default: @code{#f})
13459 @itemx @code{default-user} (default: @code{#f})
13460 When @code{auto-login?} is false, GDM presents a log-in screen.
13462 When @code{auto-login?} is true, GDM logs in directly as
13463 @code{default-user}.
13465 @item @code{gnome-shell-assets} (default: ...)
13466 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13468 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13469 Configuration of the Xorg graphical server.
13471 @item @code{xsession} (default: @code{(xinitrc)})
13472 Script to run before starting a X session.
13474 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13475 File name of the @code{dbus-daemon} executable.
13477 @item @code{gdm} (default: @code{gdm})
13478 The GDM package to use.
13482 @defvr {Scheme Variable} slim-service-type
13483 This is the type for the SLiM graphical login manager for X11.
13485 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13486 allows users to choose a session from the log-in screen using @kbd{F1}. It
13487 also honors @file{~/.xsession} files.
13489 Unlike GDM, SLiM does not spawn the user session on a different VT after
13490 logging in, which means that you can only start one graphical session. If you
13491 want to be able to run multiple graphical sessions at the same time you have
13492 to add multiple SLiM services to your system services. The following example
13493 shows how to replace the default GDM service with two SLiM services on tty7
13497 (use-modules (gnu services)
13498 (gnu services desktop)
13499 (gnu services xorg)
13500 (srfi srfi-1)) ;for 'remove'
13504 (services (cons* (service slim-service-type (slim-configuration
13507 (service slim-service-type (slim-configuration
13510 (remove (lambda (service)
13511 (eq? (service-kind service) gdm-service-type))
13512 %desktop-services))))
13517 @deftp {Data Type} slim-configuration
13518 Data type representing the configuration of @code{slim-service-type}.
13521 @item @code{allow-empty-passwords?} (default: @code{#t})
13522 Whether to allow logins with empty passwords.
13524 @item @code{auto-login?} (default: @code{#f})
13525 @itemx @code{default-user} (default: @code{""})
13526 When @code{auto-login?} is false, SLiM presents a log-in screen.
13528 When @code{auto-login?} is true, SLiM logs in directly as
13529 @code{default-user}.
13531 @item @code{theme} (default: @code{%default-slim-theme})
13532 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13533 The graphical theme to use and its name.
13535 @item @code{auto-login-session} (default: @code{#f})
13536 If true, this must be the name of the executable to start as the default
13537 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13539 If false, a session described by one of the available @file{.desktop}
13540 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13544 You must install at least one window manager in the system profile or in
13545 your user profile. Failing to do that, if @code{auto-login-session} is
13546 false, you will be unable to log in.
13549 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13550 Configuration of the Xorg graphical server.
13552 @item @code{display} (default @code{":0"})
13553 The display on which to start the Xorg graphical server.
13555 @item @code{vt} (default @code{"vt7"})
13556 The VT on which to start the Xorg graphical server.
13558 @item @code{xauth} (default: @code{xauth})
13559 The XAuth package to use.
13561 @item @code{shepherd} (default: @code{shepherd})
13562 The Shepherd package used when invoking @command{halt} and
13565 @item @code{sessreg} (default: @code{sessreg})
13566 The sessreg package used in order to register the session.
13568 @item @code{slim} (default: @code{slim})
13569 The SLiM package to use.
13573 @defvr {Scheme Variable} %default-theme
13574 @defvrx {Scheme Variable} %default-theme-name
13575 The default SLiM theme and its name.
13579 @deftp {Data Type} sddm-configuration
13580 This is the data type representing the sddm service configuration.
13583 @item @code{display-server} (default: "x11")
13584 Select display server to use for the greeter. Valid values are "x11"
13587 @item @code{numlock} (default: "on")
13588 Valid values are "on", "off" or "none".
13590 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13591 Command to run when halting.
13593 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13594 Command to run when rebooting.
13596 @item @code{theme} (default "maldives")
13597 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13599 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13600 Directory to look for themes.
13602 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13603 Directory to look for faces.
13605 @item @code{default-path} (default "/run/current-system/profile/bin")
13606 Default PATH to use.
13608 @item @code{minimum-uid} (default 1000)
13609 Minimum UID to display in SDDM.
13611 @item @code{maximum-uid} (default 2000)
13612 Maximum UID to display in SDDM
13614 @item @code{remember-last-user?} (default #t)
13615 Remember last user.
13617 @item @code{remember-last-session?} (default #t)
13618 Remember last session.
13620 @item @code{hide-users} (default "")
13621 Usernames to hide from SDDM greeter.
13623 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13624 Users with shells listed will be hidden from the SDDM greeter.
13626 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13627 Script to run before starting a wayland session.
13629 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13630 Directory to look for desktop files starting wayland sessions.
13632 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13633 Configuration of the Xorg graphical server.
13635 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13638 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13641 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13642 Script to run after starting xorg-server.
13644 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13645 Script to run before stopping xorg-server.
13647 @item @code{xsession-command} (default: @code{xinitrc})
13648 Script to run before starting a X session.
13650 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13651 Directory to look for desktop files starting X sessions.
13653 @item @code{minimum-vt} (default: 7)
13656 @item @code{auto-login-user} (default "")
13657 User to use for auto-login.
13659 @item @code{auto-login-session} (default "")
13660 Desktop file to use for auto-login.
13662 @item @code{relogin?} (default #f)
13663 Relogin after logout.
13668 @cindex login manager
13670 @deffn {Scheme Procedure} sddm-service config
13671 Return a service that spawns the SDDM graphical login manager for config of
13672 type @code{<sddm-configuration>}.
13675 (sddm-service (sddm-configuration
13676 (auto-login-user "Alice")
13677 (auto-login-session "xfce.desktop")))
13681 @cindex Xorg, configuration
13682 @deftp {Data Type} xorg-configuration
13683 This data type represents the configuration of the Xorg graphical display
13684 server. Note that there is not Xorg service; instead, the X server is started
13685 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13686 of these display managers aggregates an @code{xorg-configuration} record.
13689 @item @code{modules} (default: @code{%default-xorg-modules})
13690 This is a list of @dfn{module packages} loaded by the Xorg
13691 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13693 @item @code{fonts} (default: @code{%default-xorg-fonts})
13694 This is a list of font directories to add to the server's @dfn{font path}.
13696 @item @code{drivers} (default: @code{'()})
13697 This must be either the empty list, in which case Xorg chooses a graphics
13698 driver automatically, or a list of driver names that will be tried in this
13699 order---e.g., @code{("modesetting" "vesa")}.
13701 @item @code{resolutions} (default: @code{'()})
13702 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13703 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13706 @cindex keyboard layout, for Xorg
13707 @cindex keymap, for Xorg
13708 @item @code{keyboard-layout} (default: @code{#f})
13709 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13710 English (``qwerty'') for a 105-key PC keyboard.
13712 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13713 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13714 information on how to specify the keyboard layout.
13716 @item @code{extra-config} (default: @code{'()})
13717 This is a list of strings or objects appended to the configuration file. It
13718 is used to pass extra text to be added verbatim to the configuration file.
13720 @item @code{server} (default: @code{xorg-server})
13721 This is the package providing the Xorg server.
13723 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13724 This is the list of command-line arguments to pass to the X server. The
13725 default is @code{-nolisten tcp}.
13729 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13730 [@var{login-manager-service-type}]
13731 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13732 @var{config}, an @code{<xorg-configuration>} record.
13734 Since the Xorg configuration is embedded in the log-in manager's
13735 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13736 shorthand to set the Xorg configuration.
13739 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13740 Return a @code{startx} script in which the modules, fonts, etc. specified
13741 in @var{config}, are available. The result should be used in place of
13744 Usually the X server is started by a login manager.
13748 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13749 Add @var{package}, a package for a screen locker or screen saver whose
13750 command is @var{program}, to the set of setuid programs and add a PAM entry
13751 for it. For example:
13754 (screen-locker-service xlockmore "xlock")
13757 makes the good ol' XlockMore usable.
13761 @node Printing Services
13762 @subsection Printing Services
13764 @cindex printer support with CUPS
13765 The @code{(gnu services cups)} module provides a Guix service definition
13766 for the CUPS printing service. To add printer support to a Guix
13767 system, add a @code{cups-service} to the operating system definition:
13769 @deffn {Scheme Variable} cups-service-type
13770 The service type for the CUPS print server. Its value should be a valid
13771 CUPS configuration (see below). To use the default settings, simply
13774 (service cups-service-type)
13778 The CUPS configuration controls the basic things about your CUPS
13779 installation: what interfaces it listens on, what to do if a print job
13780 fails, how much logging to do, and so on. To actually add a printer,
13781 you have to visit the @url{http://localhost:631} URL, or use a tool such
13782 as GNOME's printer configuration services. By default, configuring a
13783 CUPS service will generate a self-signed certificate if needed, for
13784 secure connections to the print server.
13786 Suppose you want to enable the Web interface of CUPS and also add
13787 support for Epson printers @i{via} the @code{escpr} package and for HP
13788 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13789 like this (you need to use the @code{(gnu packages cups)} module):
13792 (service cups-service-type
13793 (cups-configuration
13794 (web-interface? #t)
13796 (list cups-filters escpr hplip-minimal))))
13799 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13800 package then it is suggested that you install the @code{hplip} package,
13801 either in your OS configuration file or as your user.
13803 The available configuration parameters follow. Each parameter
13804 definition is preceded by its type; for example, @samp{string-list foo}
13805 indicates that the @code{foo} parameter should be specified as a list of
13806 strings. There is also a way to specify the configuration as a string,
13807 if you have an old @code{cupsd.conf} file that you want to port over
13808 from some other system; see the end for more details.
13810 @c The following documentation was initially generated by
13811 @c (generate-documentation) in (gnu services cups). Manually maintained
13812 @c documentation is better, so we shouldn't hesitate to edit below as
13813 @c needed. However if the change you want to make to this documentation
13814 @c can be done in an automated way, it's probably easier to change
13815 @c (generate-documentation) than to make it below and have to deal with
13816 @c the churn as CUPS updates.
13819 Available @code{cups-configuration} fields are:
13821 @deftypevr {@code{cups-configuration} parameter} package cups
13825 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13826 Drivers and other extensions to the CUPS package.
13829 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13830 Configuration of where to write logs, what directories to use for print
13831 spools, and related privileged configuration parameters.
13833 Available @code{files-configuration} fields are:
13835 @deftypevr {@code{files-configuration} parameter} log-location access-log
13836 Defines the access log filename. Specifying a blank filename disables
13837 access log generation. The value @code{stderr} causes log entries to be
13838 sent to the standard error file when the scheduler is running in the
13839 foreground, or to the system log daemon when run in the background. The
13840 value @code{syslog} causes log entries to be sent to the system log
13841 daemon. The server name may be included in filenames using the string
13842 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13844 Defaults to @samp{"/var/log/cups/access_log"}.
13847 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13848 Where CUPS should cache data.
13850 Defaults to @samp{"/var/cache/cups"}.
13853 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13854 Specifies the permissions for all configuration files that the scheduler
13857 Note that the permissions for the printers.conf file are currently
13858 masked to only allow access from the scheduler user (typically root).
13859 This is done because printer device URIs sometimes contain sensitive
13860 authentication information that should not be generally known on the
13861 system. There is no way to disable this security feature.
13863 Defaults to @samp{"0640"}.
13866 @deftypevr {@code{files-configuration} parameter} log-location error-log
13867 Defines the error log filename. Specifying a blank filename disables
13868 error log generation. The value @code{stderr} causes log entries to be
13869 sent to the standard error file when the scheduler is running in the
13870 foreground, or to the system log daemon when run in the background. The
13871 value @code{syslog} causes log entries to be sent to the system log
13872 daemon. The server name may be included in filenames using the string
13873 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13875 Defaults to @samp{"/var/log/cups/error_log"}.
13878 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13879 Specifies which errors are fatal, causing the scheduler to exit. The
13884 No errors are fatal.
13887 All of the errors below are fatal.
13890 Browsing initialization errors are fatal, for example failed connections
13891 to the DNS-SD daemon.
13894 Configuration file syntax errors are fatal.
13897 Listen or Port errors are fatal, except for IPv6 failures on the
13898 loopback or @code{any} addresses.
13901 Log file creation or write errors are fatal.
13904 Bad startup file permissions are fatal, for example shared TLS
13905 certificate and key files with world-read permissions.
13908 Defaults to @samp{"all -browse"}.
13911 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13912 Specifies whether the file pseudo-device can be used for new printer
13913 queues. The URI @uref{file:///dev/null} is always allowed.
13915 Defaults to @samp{#f}.
13918 @deftypevr {@code{files-configuration} parameter} string group
13919 Specifies the group name or ID that will be used when executing external
13922 Defaults to @samp{"lp"}.
13925 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13926 Specifies the permissions for all log files that the scheduler writes.
13928 Defaults to @samp{"0644"}.
13931 @deftypevr {@code{files-configuration} parameter} log-location page-log
13932 Defines the page log filename. Specifying a blank filename disables
13933 page log generation. The value @code{stderr} causes log entries to be
13934 sent to the standard error file when the scheduler is running in the
13935 foreground, or to the system log daemon when run in the background. The
13936 value @code{syslog} causes log entries to be sent to the system log
13937 daemon. The server name may be included in filenames using the string
13938 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13940 Defaults to @samp{"/var/log/cups/page_log"}.
13943 @deftypevr {@code{files-configuration} parameter} string remote-root
13944 Specifies the username that is associated with unauthenticated accesses
13945 by clients claiming to be the root user. The default is @code{remroot}.
13947 Defaults to @samp{"remroot"}.
13950 @deftypevr {@code{files-configuration} parameter} file-name request-root
13951 Specifies the directory that contains print jobs and other HTTP request
13954 Defaults to @samp{"/var/spool/cups"}.
13957 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13958 Specifies the level of security sandboxing that is applied to print
13959 filters, backends, and other child processes of the scheduler; either
13960 @code{relaxed} or @code{strict}. This directive is currently only
13961 used/supported on macOS.
13963 Defaults to @samp{strict}.
13966 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13967 Specifies the location of TLS certificates and private keys. CUPS will
13968 look for public and private keys in this directory: a @code{.crt} files
13969 for PEM-encoded certificates and corresponding @code{.key} files for
13970 PEM-encoded private keys.
13972 Defaults to @samp{"/etc/cups/ssl"}.
13975 @deftypevr {@code{files-configuration} parameter} file-name server-root
13976 Specifies the directory containing the server configuration files.
13978 Defaults to @samp{"/etc/cups"}.
13981 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13982 Specifies whether the scheduler calls fsync(2) after writing
13983 configuration or state files.
13985 Defaults to @samp{#f}.
13988 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13989 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13992 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13993 Specifies the directory where temporary files are stored.
13995 Defaults to @samp{"/var/spool/cups/tmp"}.
13998 @deftypevr {@code{files-configuration} parameter} string user
13999 Specifies the user name or ID that is used when running external
14002 Defaults to @samp{"lp"}.
14006 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14007 Specifies the logging level for the AccessLog file. The @code{config}
14008 level logs when printers and classes are added, deleted, or modified and
14009 when configuration files are accessed or updated. The @code{actions}
14010 level logs when print jobs are submitted, held, released, modified, or
14011 canceled, and any of the conditions for @code{config}. The @code{all}
14012 level logs all requests.
14014 Defaults to @samp{actions}.
14017 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14018 Specifies whether to purge job history data automatically when it is no
14019 longer required for quotas.
14021 Defaults to @samp{#f}.
14024 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14025 Specifies which protocols to use for local printer sharing.
14027 Defaults to @samp{dnssd}.
14030 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14031 Specifies whether the CUPS web interface is advertised.
14033 Defaults to @samp{#f}.
14036 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14037 Specifies whether shared printers are advertised.
14039 Defaults to @samp{#f}.
14042 @deftypevr {@code{cups-configuration} parameter} string classification
14043 Specifies the security classification of the server. Any valid banner
14044 name can be used, including "classified", "confidential", "secret",
14045 "topsecret", and "unclassified", or the banner can be omitted to disable
14046 secure printing functions.
14048 Defaults to @samp{""}.
14051 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14052 Specifies whether users may override the classification (cover page) of
14053 individual print jobs using the @code{job-sheets} option.
14055 Defaults to @samp{#f}.
14058 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14059 Specifies the default type of authentication to use.
14061 Defaults to @samp{Basic}.
14064 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14065 Specifies whether encryption will be used for authenticated requests.
14067 Defaults to @samp{Required}.
14070 @deftypevr {@code{cups-configuration} parameter} string default-language
14071 Specifies the default language to use for text and web content.
14073 Defaults to @samp{"en"}.
14076 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14077 Specifies the default paper size for new print queues. @samp{"Auto"}
14078 uses a locale-specific default, while @samp{"None"} specifies there is
14079 no default paper size. Specific size names are typically
14080 @samp{"Letter"} or @samp{"A4"}.
14082 Defaults to @samp{"Auto"}.
14085 @deftypevr {@code{cups-configuration} parameter} string default-policy
14086 Specifies the default access policy to use.
14088 Defaults to @samp{"default"}.
14091 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14092 Specifies whether local printers are shared by default.
14094 Defaults to @samp{#t}.
14097 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14098 Specifies the delay for updating of configuration and state files, in
14099 seconds. A value of 0 causes the update to happen as soon as possible,
14100 typically within a few milliseconds.
14102 Defaults to @samp{30}.
14105 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14106 Specifies what to do when an error occurs. Possible values are
14107 @code{abort-job}, which will discard the failed print job;
14108 @code{retry-job}, which will retry the job at a later time;
14109 @code{retry-this-job}, which retries the failed job immediately; and
14110 @code{stop-printer}, which stops the printer.
14112 Defaults to @samp{stop-printer}.
14115 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14116 Specifies the maximum cost of filters that are run concurrently, which
14117 can be used to minimize disk, memory, and CPU resource problems. A
14118 limit of 0 disables filter limiting. An average print to a
14119 non-PostScript printer needs a filter limit of about 200. A PostScript
14120 printer needs about half that (100). Setting the limit below these
14121 thresholds will effectively limit the scheduler to printing a single job
14124 Defaults to @samp{0}.
14127 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14128 Specifies the scheduling priority of filters that are run to print a
14129 job. The nice value ranges from 0, the highest priority, to 19, the
14132 Defaults to @samp{0}.
14135 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14136 Specifies whether to do reverse lookups on connecting clients. The
14137 @code{double} setting causes @code{cupsd} to verify that the hostname
14138 resolved from the address matches one of the addresses returned for that
14139 hostname. Double lookups also prevent clients with unregistered
14140 addresses from connecting to your server. Only set this option to
14141 @code{#t} or @code{double} if absolutely required.
14143 Defaults to @samp{#f}.
14146 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14147 Specifies the number of seconds to wait before killing the filters and
14148 backend associated with a canceled or held job.
14150 Defaults to @samp{30}.
14153 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14154 Specifies the interval between retries of jobs in seconds. This is
14155 typically used for fax queues but can also be used with normal print
14156 queues whose error policy is @code{retry-job} or
14157 @code{retry-current-job}.
14159 Defaults to @samp{30}.
14162 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14163 Specifies the number of retries that are done for jobs. This is
14164 typically used for fax queues but can also be used with normal print
14165 queues whose error policy is @code{retry-job} or
14166 @code{retry-current-job}.
14168 Defaults to @samp{5}.
14171 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14172 Specifies whether to support HTTP keep-alive connections.
14174 Defaults to @samp{#t}.
14177 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14178 Specifies how long an idle client connection remains open, in seconds.
14180 Defaults to @samp{30}.
14183 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14184 Specifies the maximum size of print files, IPP requests, and HTML form
14185 data. A limit of 0 disables the limit check.
14187 Defaults to @samp{0}.
14190 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14191 Listens on the specified interfaces for connections. Valid values are
14192 of the form @var{address}:@var{port}, where @var{address} is either an
14193 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14194 indicate all addresses. Values can also be file names of local UNIX
14195 domain sockets. The Listen directive is similar to the Port directive
14196 but allows you to restrict access to specific interfaces or networks.
14199 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14200 Specifies the number of pending connections that will be allowed. This
14201 normally only affects very busy servers that have reached the MaxClients
14202 limit, but can also be triggered by large numbers of simultaneous
14203 connections. When the limit is reached, the operating system will
14204 refuse additional connections until the scheduler can accept the pending
14207 Defaults to @samp{128}.
14210 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14211 Specifies a set of additional access controls.
14213 Available @code{location-access-controls} fields are:
14215 @deftypevr {@code{location-access-controls} parameter} file-name path
14216 Specifies the URI path to which the access control applies.
14219 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14220 Access controls for all access to this path, in the same format as the
14221 @code{access-controls} of @code{operation-access-control}.
14223 Defaults to @samp{()}.
14226 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14227 Access controls for method-specific access to this path.
14229 Defaults to @samp{()}.
14231 Available @code{method-access-controls} fields are:
14233 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14234 If @code{#t}, apply access controls to all methods except the listed
14235 methods. Otherwise apply to only the listed methods.
14237 Defaults to @samp{#f}.
14240 @deftypevr {@code{method-access-controls} parameter} method-list methods
14241 Methods to which this access control applies.
14243 Defaults to @samp{()}.
14246 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14247 Access control directives, as a list of strings. Each string should be
14248 one directive, such as "Order allow,deny".
14250 Defaults to @samp{()}.
14255 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14256 Specifies the number of debugging messages that are retained for logging
14257 if an error occurs in a print job. Debug messages are logged regardless
14258 of the LogLevel setting.
14260 Defaults to @samp{100}.
14263 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14264 Specifies the level of logging for the ErrorLog file. The value
14265 @code{none} stops all logging while @code{debug2} logs everything.
14267 Defaults to @samp{info}.
14270 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14271 Specifies the format of the date and time in the log files. The value
14272 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14274 Defaults to @samp{standard}.
14277 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14278 Specifies the maximum number of simultaneous clients that are allowed by
14281 Defaults to @samp{100}.
14284 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14285 Specifies the maximum number of simultaneous clients that are allowed
14286 from a single address.
14288 Defaults to @samp{100}.
14291 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14292 Specifies the maximum number of copies that a user can print of each
14295 Defaults to @samp{9999}.
14298 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14299 Specifies the maximum time a job may remain in the @code{indefinite}
14300 hold state before it is canceled. A value of 0 disables cancellation of
14303 Defaults to @samp{0}.
14306 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14307 Specifies the maximum number of simultaneous jobs that are allowed. Set
14308 to 0 to allow an unlimited number of jobs.
14310 Defaults to @samp{500}.
14313 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14314 Specifies the maximum number of simultaneous jobs that are allowed per
14315 printer. A value of 0 allows up to MaxJobs jobs per printer.
14317 Defaults to @samp{0}.
14320 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14321 Specifies the maximum number of simultaneous jobs that are allowed per
14322 user. A value of 0 allows up to MaxJobs jobs per user.
14324 Defaults to @samp{0}.
14327 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14328 Specifies the maximum time a job may take to print before it is
14329 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14331 Defaults to @samp{10800}.
14334 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14335 Specifies the maximum size of the log files before they are rotated, in
14336 bytes. The value 0 disables log rotation.
14338 Defaults to @samp{1048576}.
14341 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14342 Specifies the maximum amount of time to allow between files in a
14343 multiple file print job, in seconds.
14345 Defaults to @samp{300}.
14348 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14349 Specifies the format of PageLog lines. Sequences beginning with percent
14350 (@samp{%}) characters are replaced with the corresponding information,
14351 while all other characters are copied literally. The following percent
14352 sequences are recognized:
14356 insert a single percent character
14359 insert the value of the specified IPP attribute
14362 insert the number of copies for the current page
14365 insert the current page number
14368 insert the current date and time in common log format
14374 insert the printer name
14377 insert the username
14380 A value of the empty string disables page logging. The string @code{%p
14381 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14382 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14385 Defaults to @samp{""}.
14388 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14389 Passes the specified environment variable(s) to child processes; a list
14392 Defaults to @samp{()}.
14395 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14396 Specifies named access control policies.
14398 Available @code{policy-configuration} fields are:
14400 @deftypevr {@code{policy-configuration} parameter} string name
14401 Name of the policy.
14404 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14405 Specifies an access list for a job's private values. @code{@@ACL} maps
14406 to the printer's requesting-user-name-allowed or
14407 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14408 owner. @code{@@SYSTEM} maps to the groups listed for the
14409 @code{system-group} field of the @code{files-config} configuration,
14410 which is reified into the @code{cups-files.conf(5)} file. Other
14411 possible elements of the access list include specific user names, and
14412 @code{@@@var{group}} to indicate members of a specific group. The
14413 access list may also be simply @code{all} or @code{default}.
14415 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14418 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14419 Specifies the list of job values to make private, or @code{all},
14420 @code{default}, or @code{none}.
14422 Defaults to @samp{"job-name job-originating-host-name
14423 job-originating-user-name phone"}.
14426 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14427 Specifies an access list for a subscription's private values.
14428 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14429 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14430 owner. @code{@@SYSTEM} maps to the groups listed for the
14431 @code{system-group} field of the @code{files-config} configuration,
14432 which is reified into the @code{cups-files.conf(5)} file. Other
14433 possible elements of the access list include specific user names, and
14434 @code{@@@var{group}} to indicate members of a specific group. The
14435 access list may also be simply @code{all} or @code{default}.
14437 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14440 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14441 Specifies the list of job values to make private, or @code{all},
14442 @code{default}, or @code{none}.
14444 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14445 notify-subscriber-user-name notify-user-data"}.
14448 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14449 Access control by IPP operation.
14451 Defaults to @samp{()}.
14455 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14456 Specifies whether job files (documents) are preserved after a job is
14457 printed. If a numeric value is specified, job files are preserved for
14458 the indicated number of seconds after printing. Otherwise a boolean
14459 value applies indefinitely.
14461 Defaults to @samp{86400}.
14464 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14465 Specifies whether the job history is preserved after a job is printed.
14466 If a numeric value is specified, the job history is preserved for the
14467 indicated number of seconds after printing. If @code{#t}, the job
14468 history is preserved until the MaxJobs limit is reached.
14470 Defaults to @samp{#t}.
14473 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14474 Specifies the amount of time to wait for job completion before
14475 restarting the scheduler.
14477 Defaults to @samp{30}.
14480 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14481 Specifies the maximum amount of memory to use when converting documents
14482 into bitmaps for a printer.
14484 Defaults to @samp{"128m"}.
14487 @deftypevr {@code{cups-configuration} parameter} string server-admin
14488 Specifies the email address of the server administrator.
14490 Defaults to @samp{"root@@localhost.localdomain"}.
14493 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14494 The ServerAlias directive is used for HTTP Host header validation when
14495 clients connect to the scheduler from external interfaces. Using the
14496 special name @code{*} can expose your system to known browser-based DNS
14497 rebinding attacks, even when accessing sites through a firewall. If the
14498 auto-discovery of alternate names does not work, we recommend listing
14499 each alternate name with a ServerAlias directive instead of using
14502 Defaults to @samp{*}.
14505 @deftypevr {@code{cups-configuration} parameter} string server-name
14506 Specifies the fully-qualified host name of the server.
14508 Defaults to @samp{"localhost"}.
14511 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14512 Specifies what information is included in the Server header of HTTP
14513 responses. @code{None} disables the Server header. @code{ProductOnly}
14514 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14515 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14516 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14517 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14518 2.0.0 (@var{uname}) IPP/2.0}.
14520 Defaults to @samp{Minimal}.
14523 @deftypevr {@code{cups-configuration} parameter} string set-env
14524 Set the specified environment variable to be passed to child processes.
14526 Defaults to @samp{"variable value"}.
14529 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14530 Listens on the specified interfaces for encrypted connections. Valid
14531 values are of the form @var{address}:@var{port}, where @var{address} is
14532 either an IPv6 address enclosed in brackets, an IPv4 address, or
14533 @code{*} to indicate all addresses.
14535 Defaults to @samp{()}.
14538 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14539 Sets encryption options. By default, CUPS only supports encryption
14540 using TLS v1.0 or higher using known secure cipher suites. The
14541 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14542 required for some older clients that do not implement newer ones. The
14543 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14544 older clients that do not support TLS v1.0.
14546 Defaults to @samp{()}.
14549 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14550 Specifies whether the scheduler requires clients to strictly adhere to
14551 the IPP specifications.
14553 Defaults to @samp{#f}.
14556 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14557 Specifies the HTTP request timeout, in seconds.
14559 Defaults to @samp{300}.
14563 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14564 Specifies whether the web interface is enabled.
14566 Defaults to @samp{#f}.
14569 At this point you're probably thinking ``oh dear, Guix manual, I like
14570 you but you can stop already with the configuration options''. Indeed.
14571 However, one more point: it could be that you have an existing
14572 @code{cupsd.conf} that you want to use. In that case, you can pass an
14573 @code{opaque-cups-configuration} as the configuration of a
14574 @code{cups-service-type}.
14576 Available @code{opaque-cups-configuration} fields are:
14578 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14582 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14583 The contents of the @code{cupsd.conf}, as a string.
14586 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14587 The contents of the @code{cups-files.conf} file, as a string.
14590 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14591 strings of the same name, you could instantiate a CUPS service like
14595 (service cups-service-type
14596 (opaque-cups-configuration
14597 (cupsd.conf cupsd.conf)
14598 (cups-files.conf cups-files.conf)))
14602 @node Desktop Services
14603 @subsection Desktop Services
14605 The @code{(gnu services desktop)} module provides services that are
14606 usually useful in the context of a ``desktop'' setup---that is, on a
14607 machine running a graphical display server, possibly with graphical user
14608 interfaces, etc. It also defines services that provide specific desktop
14609 environments like GNOME, Xfce or MATE.
14611 To simplify things, the module defines a variable containing the set of
14612 services that users typically expect on a machine with a graphical
14613 environment and networking:
14615 @defvr {Scheme Variable} %desktop-services
14616 This is a list of services that builds upon @var{%base-services} and
14617 adds or adjusts services for a typical ``desktop'' setup.
14619 In particular, it adds a graphical login manager (@pxref{X Window,
14620 @code{gdm-service-type}}), screen lockers, a network management tool
14621 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14622 management services, the @code{elogind} login and seat manager, the
14623 Polkit privilege service, the GeoClue location service, the
14624 AccountsService daemon that allows authorized users change system
14625 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14626 daemon, and has the name service switch service configured to be able to
14627 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14630 The @var{%desktop-services} variable can be used as the @code{services}
14631 field of an @code{operating-system} declaration (@pxref{operating-system
14632 Reference, @code{services}}).
14634 Additionally, the @code{gnome-desktop-service-type},
14635 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14636 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14637 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14638 services like the backlight adjustment helpers and the power management
14639 utilities are added to the system, extending @code{polkit} and @code{dbus}
14640 appropriately, allowing GNOME to operate with elevated privileges on a
14641 limited number of special-purpose system interfaces. Additionally,
14642 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14643 metapackage to the system profile. Likewise, adding the Xfce service
14644 not only adds the @code{xfce} metapackage to the system profile, but it
14645 also gives the Thunar file manager the ability to open a ``root-mode''
14646 file management window, if the user authenticates using the
14647 administrator's password via the standard polkit graphical interface.
14648 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14649 appropriately, allowing MATE to operate with elevated privileges on a
14650 limited number of special-purpose system interfaces. Additionally,
14651 adding a service of type @code{mate-desktop-service-type} adds the MATE
14652 metapackage to the system profile. ``Adding Enlightenment'' means that
14653 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14654 are set as setuid, allowing Enlightenment's screen locker and other
14655 functionality to work as expetected.
14657 The desktop environments in Guix use the Xorg display server by
14658 default. If you'd like to use the newer display server protocol
14659 called Wayland, you need to use the @code{sddm-service} instead of
14660 GDM as the graphical login manager. You should then
14661 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14662 also try starting GNOME on Wayland manually from a TTY with the
14663 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14664 gnome-session``. Currently only GNOME has support for Wayland.
14666 @defvr {Scheme Variable} gnome-desktop-service-type
14667 This is the type of the service that adds the @uref{https://www.gnome.org,
14668 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14669 object (see below.)
14671 This service adds the @code{gnome} package to the system profile, and extends
14672 polkit with the actions from @code{gnome-settings-daemon}.
14675 @deftp {Data Type} gnome-desktop-configuration
14676 Configuration record for the GNOME desktop environment.
14679 @item @code{gnome} (default: @code{gnome})
14680 The GNOME package to use.
14684 @defvr {Scheme Variable} xfce-desktop-service-type
14685 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14686 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14689 This service adds the @code{xfce} package to the system profile, and
14690 extends polkit with the ability for @code{thunar} to manipulate the file
14691 system as root from within a user session, after the user has authenticated
14692 with the administrator's password.
14695 @deftp {Data Type} xfce-desktop-configuration
14696 Configuration record for the Xfce desktop environment.
14699 @item @code{xfce} (default: @code{xfce})
14700 The Xfce package to use.
14704 @deffn {Scheme Variable} mate-desktop-service-type
14705 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14706 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14707 object (see below.)
14709 This service adds the @code{mate} package to the system
14710 profile, and extends polkit with the actions from
14711 @code{mate-settings-daemon}.
14714 @deftp {Data Type} mate-desktop-configuration
14715 Configuration record for the MATE desktop environment.
14718 @item @code{mate} (default: @code{mate})
14719 The MATE package to use.
14723 @deffn {Scheme Variable} enlightenment-desktop-service-type
14724 Return a service that adds the @code{enlightenment} package to the system
14725 profile, and extends dbus with actions from @code{efl}.
14728 @deftp {Data Type} enlightenment-desktop-service-configuration
14730 @item @code{enlightenment} (default: @code{enlightenment})
14731 The enlightenment package to use.
14735 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14736 the default @code{%desktop-services} variable doesn't include any of
14737 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14738 @code{%desktop-services} in the @code{services} field of your
14739 @code{operating-system}:
14742 (use-modules (gnu))
14743 (use-service-modules desktop)
14746 ;; cons* adds items to the list given as its last argument.
14747 (services (cons* (service gnome-desktop-service-type)
14748 (service xfce-desktop-service)
14749 %desktop-services))
14753 These desktop environments will then be available as options in the
14754 graphical login window.
14756 The actual service definitions included in @code{%desktop-services} and
14757 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14758 are described below.
14760 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14761 Return a service that runs the ``system bus'', using @var{dbus}, with
14762 support for @var{services}.
14764 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14765 facility. Its system bus is used to allow system services to communicate
14766 and to be notified of system-wide events.
14768 @var{services} must be a list of packages that provide an
14769 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14770 and policy files. For example, to allow avahi-daemon to use the system bus,
14771 @var{services} must be equal to @code{(list avahi)}.
14774 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14775 Return a service that runs the @code{elogind} login and
14776 seat management daemon. @uref{https://github.com/elogind/elogind,
14777 Elogind} exposes a D-Bus interface that can be used to know which users
14778 are logged in, know what kind of sessions they have open, suspend the
14779 system, inhibit system suspend, reboot the system, and other tasks.
14781 Elogind handles most system-level power events for a computer, for
14782 example suspending the system when a lid is closed, or shutting it down
14783 when the power button is pressed.
14785 The @var{config} keyword argument specifies the configuration for
14786 elogind, and should be the result of an @code{(elogind-configuration
14787 (@var{parameter} @var{value})...)} invocation. Available parameters and
14788 their default values are:
14791 @item kill-user-processes?
14793 @item kill-only-users
14795 @item kill-exclude-users
14797 @item inhibit-delay-max-seconds
14799 @item handle-power-key
14801 @item handle-suspend-key
14803 @item handle-hibernate-key
14805 @item handle-lid-switch
14807 @item handle-lid-switch-docked
14809 @item power-key-ignore-inhibited?
14811 @item suspend-key-ignore-inhibited?
14813 @item hibernate-key-ignore-inhibited?
14815 @item lid-switch-ignore-inhibited?
14817 @item holdoff-timeout-seconds
14821 @item idle-action-seconds
14823 @item runtime-directory-size-percent
14825 @item runtime-directory-size
14829 @item suspend-state
14830 @code{("mem" "standby" "freeze")}
14833 @item hibernate-state
14835 @item hibernate-mode
14836 @code{("platform" "shutdown")}
14837 @item hybrid-sleep-state
14839 @item hybrid-sleep-mode
14840 @code{("suspend" "platform" "shutdown")}
14844 @deffn {Scheme Procedure} accountsservice-service @
14845 [#:accountsservice @var{accountsservice}]
14846 Return a service that runs AccountsService, a system service that can
14847 list available accounts, change their passwords, and so on.
14848 AccountsService integrates with PolicyKit to enable unprivileged users
14849 to acquire the capability to modify their system configuration.
14850 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14851 accountsservice web site} for more information.
14853 The @var{accountsservice} keyword argument is the @code{accountsservice}
14854 package to expose as a service.
14857 @deffn {Scheme Procedure} polkit-service @
14858 [#:polkit @var{polkit}]
14859 Return a service that runs the
14860 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14861 management service}, which allows system administrators to grant access to
14862 privileged operations in a structured way. By querying the Polkit service, a
14863 privileged system component can know when it should grant additional
14864 capabilities to ordinary users. For example, an ordinary user can be granted
14865 the capability to suspend the system if the user is logged in locally.
14868 @defvr {Scheme Variable} upower-service-type
14869 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
14870 system-wide monitor for power consumption and battery levels, with the given
14871 configuration settings.
14873 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14874 notably used by GNOME.
14877 @deftp {Data Type} upower-configuration
14878 Data type representation the configuration for UPower.
14882 @item @code{upower} (default: @var{upower})
14883 Package to use for @code{upower}.
14885 @item @code{watts-up-pro?} (default: @code{#f})
14886 Enable the Watts Up Pro device.
14888 @item @code{poll-batteries?} (default: @code{#t})
14889 Enable polling the kernel for battery level changes.
14891 @item @code{ignore-lid?} (default: @code{#f})
14892 Ignore the lid state, this can be useful if it's incorrect on a device.
14894 @item @code{use-percentage-for-policy?} (default: @code{#f})
14895 Whether battery percentage based policy should be used. The default is to use
14896 the time left, change to @code{#t} to use the percentage.
14898 @item @code{percentage-low} (default: @code{10})
14899 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14900 at which the battery is considered low.
14902 @item @code{percentage-critical} (default: @code{3})
14903 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14904 at which the battery is considered critical.
14906 @item @code{percentage-action} (default: @code{2})
14907 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14908 at which action will be taken.
14910 @item @code{time-low} (default: @code{1200})
14911 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14912 seconds at which the battery is considered low.
14914 @item @code{time-critical} (default: @code{300})
14915 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14916 seconds at which the battery is considered critical.
14918 @item @code{time-action} (default: @code{120})
14919 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14920 seconds at which action will be taken.
14922 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14923 The action taken when @code{percentage-action} or @code{time-action} is
14924 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14926 Possible values are:
14936 @code{'hybrid-sleep}.
14942 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14943 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
14944 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14945 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14946 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14949 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14950 Return a service that runs @command{colord}, a system service with a D-Bus
14951 interface to manage the color profiles of input and output devices such as
14952 screens and scanners. It is notably used by the GNOME Color Manager graphical
14953 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
14954 site} for more information.
14957 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14958 Return a configuration allowing an application to access GeoClue
14959 location data. @var{name} is the Desktop ID of the application, without
14960 the @code{.desktop} part. If @var{allowed?} is true, the application
14961 will have access to location information by default. The boolean
14962 @var{system?} value indicates whether an application is a system component
14963 or not. Finally @var{users} is a list of UIDs of all users for which
14964 this application is allowed location info access. An empty users list
14965 means that all users are allowed.
14968 @defvr {Scheme Variable} %standard-geoclue-applications
14969 The standard list of well-known GeoClue application configurations,
14970 granting authority to the GNOME date-and-time utility to ask for the
14971 current location in order to set the time zone, and allowing the
14972 IceCat and Epiphany web browsers to request location information.
14973 IceCat and Epiphany both query the user before allowing a web page to
14974 know the user's location.
14977 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14978 [#:whitelist '()] @
14979 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14980 [#:submit-data? #f]
14981 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14982 [#:submission-nick "geoclue"] @
14983 [#:applications %standard-geoclue-applications]
14984 Return a service that runs the GeoClue location service. This service
14985 provides a D-Bus interface to allow applications to request access to a
14986 user's physical location, and optionally to add information to online
14987 location databases. See
14988 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14989 web site} for more information.
14992 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14993 [@w{#:auto-enable? #f}]
14994 Return a service that runs the @command{bluetoothd} daemon, which
14995 manages all the Bluetooth devices and provides a number of D-Bus
14996 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14997 powered automatically at boot, which can be useful when using a
14998 bluetooth keyboard or mouse.
15000 Users need to be in the @code{lp} group to access the D-Bus service.
15003 @node Sound Services
15004 @subsection Sound Services
15006 @cindex sound support
15008 @cindex PulseAudio, sound support
15010 The @code{(gnu services sound)} module provides a service to configure the
15011 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15012 preferred ALSA output driver.
15014 @deffn {Scheme Variable} alsa-service-type
15015 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15016 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15017 configuration file. The value for this type is a @command{alsa-configuration}
15018 record as in this example:
15021 (service alsa-service-type)
15024 See below for details about @code{alsa-configuration}.
15027 @deftp {Data Type} alsa-configuration
15028 Data type representing the configuration for @code{alsa-service}.
15031 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15032 @code{alsa-plugins} package to use.
15034 @item @code{pulseaudio?} (default: @var{#t})
15035 Whether ALSA applications should transparently be made to use the
15036 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15038 Using PulseAudio allows you to run several sound-producing applications
15039 at the same time and to individual control them @i{via}
15040 @command{pavucontrol}, among other things.
15042 @item @code{extra-options} (default: @var{""})
15043 String to append to the @file{/etc/asound.conf} file.
15048 Individual users who want to override the system configuration of ALSA can do
15049 it with the @file{~/.asoundrc} file:
15052 # In guix, we have to specify the absolute path for plugins.
15054 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15057 # Routing ALSA to jack:
15058 # <http://jackaudio.org/faq/routing_alsa.html>.
15062 0 system:playback_1
15063 1 system:playback_2
15080 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15084 @node Database Services
15085 @subsection Database Services
15089 The @code{(gnu services databases)} module provides the following services.
15091 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15092 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15093 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15094 Return a service that runs @var{postgresql}, the PostgreSQL database
15097 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15098 creates a database cluster with @var{locale} as the default
15099 locale, stored in @var{data-directory}. It then listens on @var{port}.
15101 @cindex postgresql extension-packages
15102 Additional extensions are loaded from packages listed in
15103 @var{extension-packages}. Extensions are available at runtime. For instance,
15104 to create a geographic database using the @code{postgis} extension, a user can
15105 configure the postgresql-service as in this example:
15109 (use-package-modules databases geo)
15113 ;; postgresql is required to run `psql' but postgis is not required for
15114 ;; proper operation.
15115 (packages (cons* postgresql %base-packages))
15118 (postgresql-service #:extension-packages (list postgis))
15122 Then the extension becomes visible and you can initialise an empty geographic
15123 database in this way:
15127 > create database postgistest;
15128 > \connect postgistest;
15129 > create extension postgis;
15130 > create extension postgis_topology;
15133 There is no need to add this field for contrib extensions such as hstore or
15134 dblink as they are already loadable by postgresql. This field is only
15135 required to add extensions provided by other packages.
15138 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15139 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15142 The optional @var{config} argument specifies the configuration for
15143 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15146 @deftp {Data Type} mysql-configuration
15147 Data type representing the configuration of @var{mysql-service}.
15150 @item @code{mysql} (default: @var{mariadb})
15151 Package object of the MySQL database server, can be either @var{mariadb}
15154 For MySQL, a temporary root password will be displayed at activation time.
15155 For MariaDB, the root password is empty.
15157 @item @code{port} (default: @code{3306})
15158 TCP port on which the database server listens for incoming connections.
15162 @defvr {Scheme Variable} memcached-service-type
15163 This is the service type for the @uref{https://memcached.org/,
15164 Memcached} service, which provides a distributed in memory cache. The
15165 value for the service type is a @code{memcached-configuration} object.
15169 (service memcached-service-type)
15172 @deftp {Data Type} memcached-configuration
15173 Data type representing the configuration of memcached.
15176 @item @code{memcached} (default: @code{memcached})
15177 The Memcached package to use.
15179 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15180 Network interfaces on which to listen.
15182 @item @code{tcp-port} (default: @code{11211})
15183 Port on which to accept connections on,
15185 @item @code{udp-port} (default: @code{11211})
15186 Port on which to accept UDP connections on, a value of 0 will disable
15187 listening on a UDP socket.
15189 @item @code{additional-options} (default: @code{'()})
15190 Additional command line options to pass to @code{memcached}.
15194 @defvr {Scheme Variable} mongodb-service-type
15195 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15196 The value for the service type is a @code{mongodb-configuration} object.
15200 (service mongodb-service-type)
15203 @deftp {Data Type} mongodb-configuration
15204 Data type representing the configuration of mongodb.
15207 @item @code{mongodb} (default: @code{mongodb})
15208 The MongoDB package to use.
15210 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15211 The configuration file for MongoDB.
15213 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15214 This value is used to create the directory, so that it exists and is
15215 owned by the mongodb user. It should match the data-directory which
15216 MongoDB is configured to use through the configuration file.
15220 @defvr {Scheme Variable} redis-service-type
15221 This is the service type for the @uref{https://redis.io/, Redis}
15222 key/value store, whose value is a @code{redis-configuration} object.
15225 @deftp {Data Type} redis-configuration
15226 Data type representing the configuration of redis.
15229 @item @code{redis} (default: @code{redis})
15230 The Redis package to use.
15232 @item @code{bind} (default: @code{"127.0.0.1"})
15233 Network interface on which to listen.
15235 @item @code{port} (default: @code{6379})
15236 Port on which to accept connections on, a value of 0 will disable
15237 listening on a TCP socket.
15239 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15240 Directory in which to store the database and related files.
15244 @node Mail Services
15245 @subsection Mail Services
15249 The @code{(gnu services mail)} module provides Guix service definitions
15250 for email services: IMAP, POP3, and LMTP servers, as well as mail
15251 transport agents (MTAs). Lots of acronyms! These services are detailed
15252 in the subsections below.
15254 @subsubheading Dovecot Service
15256 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15257 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15260 By default, Dovecot does not need much configuration; the default
15261 configuration object created by @code{(dovecot-configuration)} will
15262 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15263 certificate will be generated for TLS-protected connections, though
15264 Dovecot will also listen on cleartext ports by default. There are a
15265 number of options, though, which mail administrators might need to change,
15266 and as is the case with other services, Guix allows the system
15267 administrator to specify these parameters via a uniform Scheme interface.
15269 For example, to specify that mail is located at @code{maildir~/.mail},
15270 one would instantiate the Dovecot service like this:
15273 (dovecot-service #:config
15274 (dovecot-configuration
15275 (mail-location "maildir:~/.mail")))
15278 The available configuration parameters follow. Each parameter
15279 definition is preceded by its type; for example, @samp{string-list foo}
15280 indicates that the @code{foo} parameter should be specified as a list of
15281 strings. There is also a way to specify the configuration as a string,
15282 if you have an old @code{dovecot.conf} file that you want to port over
15283 from some other system; see the end for more details.
15285 @c The following documentation was initially generated by
15286 @c (generate-documentation) in (gnu services mail). Manually maintained
15287 @c documentation is better, so we shouldn't hesitate to edit below as
15288 @c needed. However if the change you want to make to this documentation
15289 @c can be done in an automated way, it's probably easier to change
15290 @c (generate-documentation) than to make it below and have to deal with
15291 @c the churn as dovecot updates.
15293 Available @code{dovecot-configuration} fields are:
15295 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15296 The dovecot package.
15299 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15300 A list of IPs or hosts where to listen for connections. @samp{*}
15301 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15302 interfaces. If you want to specify non-default ports or anything more
15303 complex, customize the address and port fields of the
15304 @samp{inet-listener} of the specific services you are interested in.
15307 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15308 List of protocols we want to serve. Available protocols include
15309 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15311 Available @code{protocol-configuration} fields are:
15313 @deftypevr {@code{protocol-configuration} parameter} string name
15314 The name of the protocol.
15317 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15318 UNIX socket path to the master authentication server to find users.
15319 This is used by imap (for shared users) and lda.
15320 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15323 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15324 Space separated list of plugins to load.
15327 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15328 Maximum number of IMAP connections allowed for a user from each IP
15329 address. NOTE: The username is compared case-sensitively.
15330 Defaults to @samp{10}.
15335 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15336 List of services to enable. Available services include @samp{imap},
15337 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15340 Available @code{service-configuration} fields are:
15342 @deftypevr {@code{service-configuration} parameter} string kind
15343 The service kind. Valid values include @code{director},
15344 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15345 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15346 @code{tcpwrap}, @code{quota-warning}, or anything else.
15349 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15350 Listeners for the service. A listener is either a
15351 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15352 an @code{inet-listener-configuration}.
15353 Defaults to @samp{()}.
15355 Available @code{unix-listener-configuration} fields are:
15357 @deftypevr {@code{unix-listener-configuration} parameter} string path
15358 Path to the file, relative to @code{base-dir} field. This is also used as
15362 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15363 The access mode for the socket.
15364 Defaults to @samp{"0600"}.
15367 @deftypevr {@code{unix-listener-configuration} parameter} string user
15368 The user to own the socket.
15369 Defaults to @samp{""}.
15372 @deftypevr {@code{unix-listener-configuration} parameter} string group
15373 The group to own the socket.
15374 Defaults to @samp{""}.
15378 Available @code{fifo-listener-configuration} fields are:
15380 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15381 Path to the file, relative to @code{base-dir} field. This is also used as
15385 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15386 The access mode for the socket.
15387 Defaults to @samp{"0600"}.
15390 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15391 The user to own the socket.
15392 Defaults to @samp{""}.
15395 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15396 The group to own the socket.
15397 Defaults to @samp{""}.
15401 Available @code{inet-listener-configuration} fields are:
15403 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15404 The protocol to listen for.
15407 @deftypevr {@code{inet-listener-configuration} parameter} string address
15408 The address on which to listen, or empty for all addresses.
15409 Defaults to @samp{""}.
15412 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15413 The port on which to listen.
15416 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15417 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15419 Defaults to @samp{#t}.
15424 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15425 Maximum number of simultaneous client connections per process. Once
15426 this number of connections is received, the next incoming connection
15427 will prompt Dovecot to spawn another process. If set to 0,
15428 @code{default-client-limit} is used instead.
15430 Defaults to @samp{0}.
15434 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15435 Number of connections to handle before starting a new process.
15436 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15437 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15438 Defaults to @samp{1}.
15442 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15443 Maximum number of processes that can exist for this service. If set to
15444 0, @code{default-process-limit} is used instead.
15446 Defaults to @samp{0}.
15450 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15451 Number of processes to always keep waiting for more connections.
15452 Defaults to @samp{0}.
15455 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15456 If you set @samp{service-count 0}, you probably need to grow
15458 Defaults to @samp{256000000}.
15463 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15464 Dict configuration, as created by the @code{dict-configuration}
15467 Available @code{dict-configuration} fields are:
15469 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15470 A list of key-value pairs that this dict should hold.
15471 Defaults to @samp{()}.
15476 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15477 A list of passdb configurations, each one created by the
15478 @code{passdb-configuration} constructor.
15480 Available @code{passdb-configuration} fields are:
15482 @deftypevr {@code{passdb-configuration} parameter} string driver
15483 The driver that the passdb should use. Valid values include
15484 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15486 Defaults to @samp{"pam"}.
15489 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15490 Space separated list of arguments to the passdb driver.
15491 Defaults to @samp{""}.
15496 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15497 List of userdb configurations, each one created by the
15498 @code{userdb-configuration} constructor.
15500 Available @code{userdb-configuration} fields are:
15502 @deftypevr {@code{userdb-configuration} parameter} string driver
15503 The driver that the userdb should use. Valid values include
15504 @samp{passwd} and @samp{static}.
15505 Defaults to @samp{"passwd"}.
15508 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15509 Space separated list of arguments to the userdb driver.
15510 Defaults to @samp{""}.
15513 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15514 Override fields from passwd.
15515 Defaults to @samp{()}.
15520 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15521 Plug-in configuration, created by the @code{plugin-configuration}
15525 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15526 List of namespaces. Each item in the list is created by the
15527 @code{namespace-configuration} constructor.
15529 Available @code{namespace-configuration} fields are:
15531 @deftypevr {@code{namespace-configuration} parameter} string name
15532 Name for this namespace.
15535 @deftypevr {@code{namespace-configuration} parameter} string type
15536 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15537 Defaults to @samp{"private"}.
15540 @deftypevr {@code{namespace-configuration} parameter} string separator
15541 Hierarchy separator to use. You should use the same separator for
15542 all namespaces or some clients get confused. @samp{/} is usually a good
15543 one. The default however depends on the underlying mail storage
15545 Defaults to @samp{""}.
15548 @deftypevr {@code{namespace-configuration} parameter} string prefix
15549 Prefix required to access this namespace. This needs to be
15550 different for all namespaces. For example @samp{Public/}.
15551 Defaults to @samp{""}.
15554 @deftypevr {@code{namespace-configuration} parameter} string location
15555 Physical location of the mailbox. This is in the same format as
15556 mail_location, which is also the default for it.
15557 Defaults to @samp{""}.
15560 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15561 There can be only one INBOX, and this setting defines which
15563 Defaults to @samp{#f}.
15566 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15567 If namespace is hidden, it's not advertised to clients via NAMESPACE
15568 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15569 useful when converting from another server with different namespaces
15570 which you want to deprecate but still keep working. For example you can
15571 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15573 Defaults to @samp{#f}.
15576 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15577 Show the mailboxes under this namespace with the LIST command. This
15578 makes the namespace visible for clients that do not support the NAMESPACE
15579 extension. The special @code{children} value lists child mailboxes, but
15580 hides the namespace prefix.
15581 Defaults to @samp{#t}.
15584 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15585 Namespace handles its own subscriptions. If set to @code{#f}, the
15586 parent namespace handles them. The empty prefix should always have this
15588 Defaults to @samp{#t}.
15591 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15592 List of predefined mailboxes in this namespace.
15593 Defaults to @samp{()}.
15595 Available @code{mailbox-configuration} fields are:
15597 @deftypevr {@code{mailbox-configuration} parameter} string name
15598 Name for this mailbox.
15601 @deftypevr {@code{mailbox-configuration} parameter} string auto
15602 @samp{create} will automatically create this mailbox.
15603 @samp{subscribe} will both create and subscribe to the mailbox.
15604 Defaults to @samp{"no"}.
15607 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15608 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15609 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15610 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15611 Defaults to @samp{()}.
15618 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15619 Base directory where to store runtime data.
15620 Defaults to @samp{"/var/run/dovecot/"}.
15623 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15624 Greeting message for clients.
15625 Defaults to @samp{"Dovecot ready."}.
15628 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15629 List of trusted network ranges. Connections from these IPs are
15630 allowed to override their IP addresses and ports (for logging and for
15631 authentication checks). @samp{disable-plaintext-auth} is also ignored
15632 for these networks. Typically you would specify your IMAP proxy servers
15634 Defaults to @samp{()}.
15637 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15638 List of login access check sockets (e.g.@: tcpwrap).
15639 Defaults to @samp{()}.
15642 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15643 Show more verbose process titles (in ps). Currently shows user name
15644 and IP address. Useful for seeing who is actually using the IMAP
15645 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15647 Defaults to @samp{#f}.
15650 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15651 Should all processes be killed when Dovecot master process shuts down.
15652 Setting this to @code{#f} means that Dovecot can be upgraded without
15653 forcing existing client connections to close (although that could also
15654 be a problem if the upgrade is e.g.@: due to a security fix).
15655 Defaults to @samp{#t}.
15658 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15659 If non-zero, run mail commands via this many connections to doveadm
15660 server, instead of running them directly in the same process.
15661 Defaults to @samp{0}.
15664 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15665 UNIX socket or host:port used for connecting to doveadm server.
15666 Defaults to @samp{"doveadm-server"}.
15669 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15670 List of environment variables that are preserved on Dovecot startup
15671 and passed down to all of its child processes. You can also give
15672 key=value pairs to always set specific settings.
15675 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15676 Disable LOGIN command and all other plaintext authentications unless
15677 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15678 matches the local IP (i.e.@: you're connecting from the same computer),
15679 the connection is considered secure and plaintext authentication is
15680 allowed. See also ssl=required setting.
15681 Defaults to @samp{#t}.
15684 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15685 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15686 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15687 for caching to be used.
15688 Defaults to @samp{0}.
15691 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15692 Time to live for cached data. After TTL expires the cached record
15693 is no longer used, *except* if the main database lookup returns internal
15694 failure. We also try to handle password changes automatically: If
15695 user's previous authentication was successful, but this one wasn't, the
15696 cache isn't used. For now this works only with plaintext
15698 Defaults to @samp{"1 hour"}.
15701 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15702 TTL for negative hits (user not found, password mismatch).
15703 0 disables caching them completely.
15704 Defaults to @samp{"1 hour"}.
15707 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15708 List of realms for SASL authentication mechanisms that need them.
15709 You can leave it empty if you don't want to support multiple realms.
15710 Many clients simply use the first one listed here, so keep the default
15712 Defaults to @samp{()}.
15715 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15716 Default realm/domain to use if none was specified. This is used for
15717 both SASL realms and appending @@domain to username in plaintext
15719 Defaults to @samp{""}.
15722 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15723 List of allowed characters in username. If the user-given username
15724 contains a character not listed in here, the login automatically fails.
15725 This is just an extra check to make sure user can't exploit any
15726 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15727 you want to allow all characters, set this value to empty.
15728 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15731 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15732 Username character translations before it's looked up from
15733 databases. The value contains series of from -> to characters. For
15734 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15735 translated to @samp{@@}.
15736 Defaults to @samp{""}.
15739 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15740 Username formatting before it's looked up from databases. You can
15741 use the standard variables here, e.g.@: %Lu would lowercase the username,
15742 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15743 change the @samp{@@} into @samp{-AT-}. This translation is done after
15744 @samp{auth-username-translation} changes.
15745 Defaults to @samp{"%Lu"}.
15748 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15749 If you want to allow master users to log in by specifying the master
15750 username within the normal username string (i.e.@: not using SASL
15751 mechanism's support for it), you can specify the separator character
15752 here. The format is then <username><separator><master username>.
15753 UW-IMAP uses @samp{*} as the separator, so that could be a good
15755 Defaults to @samp{""}.
15758 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15759 Username to use for users logging in with ANONYMOUS SASL
15761 Defaults to @samp{"anonymous"}.
15764 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15765 Maximum number of dovecot-auth worker processes. They're used to
15766 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15767 They're automatically created and destroyed as needed.
15768 Defaults to @samp{30}.
15771 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15772 Host name to use in GSSAPI principal names. The default is to use
15773 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15774 allow all keytab entries.
15775 Defaults to @samp{""}.
15778 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15779 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15780 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15781 need to change the auth service to run as root to be able to read this
15783 Defaults to @samp{""}.
15786 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15787 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15788 and @samp{ntlm-auth} helper.
15789 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15790 Defaults to @samp{#f}.
15793 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15794 Path for Samba's @samp{ntlm-auth} helper binary.
15795 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15798 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15799 Time to delay before replying to failed authentications.
15800 Defaults to @samp{"2 secs"}.
15803 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15804 Require a valid SSL client certificate or the authentication
15806 Defaults to @samp{#f}.
15809 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15810 Take the username from client's SSL certificate, using
15811 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15813 Defaults to @samp{#f}.
15816 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15817 List of wanted authentication mechanisms. Supported mechanisms are:
15818 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15819 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15820 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15821 @samp{disable-plaintext-auth} setting.
15824 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15825 List of IPs or hostnames to all director servers, including ourself.
15826 Ports can be specified as ip:port. The default port is the same as what
15827 director service's @samp{inet-listener} is using.
15828 Defaults to @samp{()}.
15831 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15832 List of IPs or hostnames to all backend mail servers. Ranges are
15833 allowed too, like 10.0.0.10-10.0.0.30.
15834 Defaults to @samp{()}.
15837 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15838 How long to redirect users to a specific server after it no longer
15839 has any connections.
15840 Defaults to @samp{"15 min"}.
15843 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15844 How the username is translated before being hashed. Useful values
15845 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15846 are shared within domain.
15847 Defaults to @samp{"%Lu"}.
15850 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15851 Log file to use for error messages. @samp{syslog} logs to syslog,
15852 @samp{/dev/stderr} logs to stderr.
15853 Defaults to @samp{"syslog"}.
15856 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15857 Log file to use for informational messages. Defaults to
15859 Defaults to @samp{""}.
15862 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15863 Log file to use for debug messages. Defaults to
15864 @samp{info-log-path}.
15865 Defaults to @samp{""}.
15868 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15869 Syslog facility to use if you're logging to syslog. Usually if you
15870 don't want to use @samp{mail}, you'll use local0..local7. Also other
15871 standard facilities are supported.
15872 Defaults to @samp{"mail"}.
15875 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15876 Log unsuccessful authentication attempts and the reasons why they
15878 Defaults to @samp{#f}.
15881 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
15882 In case of password mismatches, log the attempted password. Valid
15883 values are no, plain and sha1. sha1 can be useful for detecting brute
15884 force password attempts vs. user simply trying the same password over
15885 and over again. You can also truncate the value to n chars by appending
15886 ":n" (e.g.@: sha1:6).
15887 Defaults to @samp{"no"}.
15890 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15891 Even more verbose logging for debugging purposes. Shows for example
15893 Defaults to @samp{#f}.
15896 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15897 In case of password mismatches, log the passwords and used scheme so
15898 the problem can be debugged. Enabling this also enables
15900 Defaults to @samp{#f}.
15903 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15904 Enable mail process debugging. This can help you figure out why
15905 Dovecot isn't finding your mails.
15906 Defaults to @samp{#f}.
15909 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15910 Show protocol level SSL errors.
15911 Defaults to @samp{#f}.
15914 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15915 Prefix for each line written to log file. % codes are in
15916 strftime(3) format.
15917 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15920 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15921 List of elements we want to log. The elements which have a
15922 non-empty variable value are joined together to form a comma-separated
15926 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15927 Login log format. %s contains @samp{login-log-format-elements}
15928 string, %$ contains the data we want to log.
15929 Defaults to @samp{"%$: %s"}.
15932 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15933 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15934 of possible variables you can use.
15935 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15938 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15939 Format to use for logging mail deliveries. You can use variables:
15942 Delivery status message (e.g.@: @samp{saved to INBOX})
15954 Defaults to @samp{"msgid=%m: %$"}.
15957 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15958 Location for users' mailboxes. The default is empty, which means
15959 that Dovecot tries to find the mailboxes automatically. This won't work
15960 if the user doesn't yet have any mail, so you should explicitly tell
15961 Dovecot the full location.
15963 If you're using mbox, giving a path to the INBOX
15964 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15965 where the other mailboxes are kept. This is called the "root mail
15966 directory", and it must be the first path given in the
15967 @samp{mail-location} setting.
15969 There are a few special variables you can use, eg.:
15975 user part in user@@domain, same as %u if there's no domain
15977 domain part in user@@domain, empty if there's no domain
15982 See doc/wiki/Variables.txt for full list. Some examples:
15984 @item maildir:~/Maildir
15985 @item mbox:~/mail:INBOX=/var/mail/%u
15986 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15988 Defaults to @samp{""}.
15991 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15992 System user and group used to access mails. If you use multiple,
15993 userdb can override these by returning uid or gid fields. You can use
15994 either numbers or names. <doc/wiki/UserIds.txt>.
15995 Defaults to @samp{""}.
15998 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16000 Defaults to @samp{""}.
16003 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16004 Group to enable temporarily for privileged operations. Currently
16005 this is used only with INBOX when either its initial creation or
16006 dotlocking fails. Typically this is set to "mail" to give access to
16008 Defaults to @samp{""}.
16011 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16012 Grant access to these supplementary groups for mail processes.
16013 Typically these are used to set up access to shared mailboxes. Note
16014 that it may be dangerous to set these if users can create
16015 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16016 could allow a user to delete others' mailboxes, or ln -s
16017 /secret/shared/box ~/mail/mybox would allow reading it).
16018 Defaults to @samp{""}.
16021 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16022 Allow full file system access to clients. There's no access checks
16023 other than what the operating system does for the active UID/GID. It
16024 works with both maildir and mboxes, allowing you to prefix mailboxes
16025 names with e.g.@: /path/ or ~user/.
16026 Defaults to @samp{#f}.
16029 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16030 Don't use mmap() at all. This is required if you store indexes to
16031 shared file systems (NFS or clustered file system).
16032 Defaults to @samp{#f}.
16035 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16036 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16037 supports @samp{O_EXCL} since version 3, so this should be safe to use
16038 nowadays by default.
16039 Defaults to @samp{#t}.
16042 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16043 When to use fsync() or fdatasync() calls:
16046 Whenever necessary to avoid losing important data
16048 Useful with e.g.@: NFS when write()s are delayed
16050 Never use it (best performance, but crashes can lose data).
16052 Defaults to @samp{"optimized"}.
16055 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16056 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16057 NFS caches whenever needed. If you're using only a single mail server
16059 Defaults to @samp{#f}.
16062 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16063 Mail index files also exist in NFS. Setting this to yes requires
16064 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16065 Defaults to @samp{#f}.
16068 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16069 Locking method for index files. Alternatives are fcntl, flock and
16070 dotlock. Dotlocking uses some tricks which may create more disk I/O
16071 than other locking methods. NFS users: flock doesn't work, remember to
16072 change @samp{mmap-disable}.
16073 Defaults to @samp{"fcntl"}.
16076 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16077 Directory in which LDA/LMTP temporarily stores incoming mails >128
16079 Defaults to @samp{"/tmp"}.
16082 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16083 Valid UID range for users. This is mostly to make sure that users can't
16084 log in as daemons or other system users. Note that denying root logins is
16085 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16087 Defaults to @samp{500}.
16090 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16092 Defaults to @samp{0}.
16095 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16096 Valid GID range for users. Users having non-valid GID as primary group ID
16097 aren't allowed to log in. If user belongs to supplementary groups with
16098 non-valid GIDs, those groups are not set.
16099 Defaults to @samp{1}.
16102 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16104 Defaults to @samp{0}.
16107 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16108 Maximum allowed length for mail keyword name. It's only forced when
16109 trying to create new keywords.
16110 Defaults to @samp{50}.
16113 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16114 List of directories under which chrooting is allowed for mail
16115 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16116 too). This setting doesn't affect @samp{login-chroot}
16117 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16118 "/./" in home dirs are ignored. WARNING: Never add directories here
16119 which local users can modify, that may lead to root exploit. Usually
16120 this should be done only if you don't allow shell access for users.
16121 <doc/wiki/Chrooting.txt>.
16122 Defaults to @samp{()}.
16125 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16126 Default chroot directory for mail processes. This can be overridden
16127 for specific users in user database by giving /./ in user's home
16128 directory (e.g.@: /home/./user chroots into /home). Note that usually
16129 there is no real need to do chrooting, Dovecot doesn't allow users to
16130 access files outside their mail directory anyway. If your home
16131 directories are prefixed with the chroot directory, append "/."@: to
16132 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16133 Defaults to @samp{""}.
16136 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16137 UNIX socket path to master authentication server to find users.
16138 This is used by imap (for shared users) and lda.
16139 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16142 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16143 Directory where to look up mail plugins.
16144 Defaults to @samp{"/usr/lib/dovecot"}.
16147 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16148 List of plugins to load for all services. Plugins specific to IMAP,
16149 LDA, etc.@: are added to this list in their own .conf files.
16150 Defaults to @samp{()}.
16153 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16154 The minimum number of mails in a mailbox before updates are done to
16155 cache file. This allows optimizing Dovecot's behavior to do less disk
16156 writes at the cost of more disk reads.
16157 Defaults to @samp{0}.
16160 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16161 When IDLE command is running, mailbox is checked once in a while to
16162 see if there are any new mails or other changes. This setting defines
16163 the minimum time to wait between those checks. Dovecot can also use
16164 dnotify, inotify and kqueue to find out immediately when changes
16166 Defaults to @samp{"30 secs"}.
16169 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16170 Save mails with CR+LF instead of plain LF. This makes sending those
16171 mails take less CPU, especially with sendfile() syscall with Linux and
16172 FreeBSD. But it also creates a bit more disk I/O which may just make it
16173 slower. Also note that if other software reads the mboxes/maildirs,
16174 they may handle the extra CRs wrong and cause problems.
16175 Defaults to @samp{#f}.
16178 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16179 By default LIST command returns all entries in maildir beginning
16180 with a dot. Enabling this option makes Dovecot return only entries
16181 which are directories. This is done by stat()ing each entry, so it
16182 causes more disk I/O.
16183 (For systems setting struct @samp{dirent->d_type} this check is free
16184 and it's done always regardless of this setting).
16185 Defaults to @samp{#f}.
16188 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16189 When copying a message, do it with hard links whenever possible.
16190 This makes the performance much better, and it's unlikely to have any
16192 Defaults to @samp{#t}.
16195 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16196 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16197 directory only when its mtime changes unexpectedly or when we can't find
16198 the mail otherwise.
16199 Defaults to @samp{#f}.
16202 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16203 Which locking methods to use for locking mbox. There are four
16208 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16209 solution. If you want to use /var/mail/ like directory, the users will
16210 need write access to that directory.
16212 Same as dotlock, but if it fails because of permissions or because there
16213 isn't enough disk space, just skip it.
16215 Use this if possible. Works with NFS too if lockd is used.
16217 May not exist in all systems. Doesn't work with NFS.
16219 May not exist in all systems. Doesn't work with NFS.
16222 You can use multiple locking methods; if you do the order they're declared
16223 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16224 locking methods as well. Some operating systems don't allow using some of
16225 them simultaneously.
16228 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16232 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16233 Maximum time to wait for lock (all of them) before aborting.
16234 Defaults to @samp{"5 mins"}.
16237 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16238 If dotlock exists but the mailbox isn't modified in any way,
16239 override the lock file after this much time.
16240 Defaults to @samp{"2 mins"}.
16243 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16244 When mbox changes unexpectedly we have to fully read it to find out
16245 what changed. If the mbox is large this can take a long time. Since
16246 the change is usually just a newly appended mail, it'd be faster to
16247 simply read the new mails. If this setting is enabled, Dovecot does
16248 this but still safely fallbacks to re-reading the whole mbox file
16249 whenever something in mbox isn't how it's expected to be. The only real
16250 downside to this setting is that if some other MUA changes message
16251 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16252 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16253 Defaults to @samp{#t}.
16256 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16257 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16258 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16259 @samp{mbox-dirty-syncs} is ignored.
16260 Defaults to @samp{#f}.
16263 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16264 Delay writing mbox headers until doing a full write sync (EXPUNGE
16265 and CHECK commands and when closing the mailbox). This is especially
16266 useful for POP3 where clients often delete all mails. The downside is
16267 that our changes aren't immediately visible to other MUAs.
16268 Defaults to @samp{#t}.
16271 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16272 If mbox size is smaller than this (e.g.@: 100k), don't write index
16273 files. If an index file already exists it's still read, just not
16275 Defaults to @samp{0}.
16278 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16279 Maximum dbox file size until it's rotated.
16280 Defaults to @samp{10000000}.
16283 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16284 Maximum dbox file age until it's rotated. Typically in days. Day
16285 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16287 Defaults to @samp{"1d"}.
16290 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16291 When creating new mdbox files, immediately preallocate their size to
16292 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16293 with some file systems (ext4, xfs).
16294 Defaults to @samp{#f}.
16297 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16298 sdbox and mdbox support saving mail attachments to external files,
16299 which also allows single instance storage for them. Other backends
16300 don't support this for now.
16302 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16304 Directory root where to store mail attachments. Disabled, if empty.
16305 Defaults to @samp{""}.
16308 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16309 Attachments smaller than this aren't saved externally. It's also
16310 possible to write a plugin to disable saving specific attachments
16312 Defaults to @samp{128000}.
16315 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16316 File system backend to use for saving attachments:
16319 No SiS done by Dovecot (but this might help FS's own deduplication)
16321 SiS with immediate byte-by-byte comparison during saving
16322 @item sis-queue posix
16323 SiS with delayed comparison and deduplication.
16325 Defaults to @samp{"sis posix"}.
16328 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16329 Hash format to use in attachment filenames. You can add any text and
16330 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16331 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16332 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16333 Defaults to @samp{"%@{sha1@}"}.
16336 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16338 Defaults to @samp{100}.
16341 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16343 Defaults to @samp{1000}.
16346 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16347 Default VSZ (virtual memory size) limit for service processes.
16348 This is mainly intended to catch and kill processes that leak memory
16349 before they eat up everything.
16350 Defaults to @samp{256000000}.
16353 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16354 Login user is internally used by login processes. This is the most
16355 untrusted user in Dovecot system. It shouldn't have access to anything
16357 Defaults to @samp{"dovenull"}.
16360 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16361 Internal user is used by unprivileged processes. It should be
16362 separate from login user, so that login processes can't disturb other
16364 Defaults to @samp{"dovecot"}.
16367 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16368 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16369 Defaults to @samp{"required"}.
16372 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16373 PEM encoded X.509 SSL/TLS certificate (public key).
16374 Defaults to @samp{"</etc/dovecot/default.pem"}.
16377 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16378 PEM encoded SSL/TLS private key. The key is opened before
16379 dropping root privileges, so keep the key file unreadable by anyone but
16381 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16384 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16385 If key file is password protected, give the password here.
16386 Alternatively give it when starting dovecot with -p parameter. Since
16387 this file is often world-readable, you may want to place this setting
16388 instead to a different.
16389 Defaults to @samp{""}.
16392 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16393 PEM encoded trusted certificate authority. Set this only if you
16394 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16395 contain the CA certificate(s) followed by the matching
16396 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16397 Defaults to @samp{""}.
16400 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16401 Require that CRL check succeeds for client certificates.
16402 Defaults to @samp{#t}.
16405 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16406 Request client to send a certificate. If you also want to require
16407 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16408 Defaults to @samp{#f}.
16411 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16412 Which field from certificate to use for username. commonName and
16413 x500UniqueIdentifier are the usual choices. You'll also need to set
16414 @samp{auth-ssl-username-from-cert? #t}.
16415 Defaults to @samp{"commonName"}.
16418 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16419 Minimum SSL protocol version to accept.
16420 Defaults to @samp{"TLSv1"}.
16423 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16424 SSL ciphers to use.
16425 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16428 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16429 SSL crypto device to use, for valid values run "openssl engine".
16430 Defaults to @samp{""}.
16433 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16434 Address to use when sending rejection mails.
16435 %d expands to recipient domain.
16436 Defaults to @samp{"postmaster@@%d"}.
16439 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16440 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16441 and in LMTP replies. Default is the system's real hostname@@domain.
16442 Defaults to @samp{""}.
16445 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16446 If user is over quota, return with temporary failure instead of
16448 Defaults to @samp{#f}.
16451 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16452 Binary to use for sending mails.
16453 Defaults to @samp{"/usr/sbin/sendmail"}.
16456 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16457 If non-empty, send mails via this SMTP host[:port] instead of
16459 Defaults to @samp{""}.
16462 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16463 Subject: header to use for rejection mails. You can use the same
16464 variables as for @samp{rejection-reason} below.
16465 Defaults to @samp{"Rejected: %s"}.
16468 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16469 Human readable error message for rejection mails. You can use
16482 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16485 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16486 Delimiter character between local-part and detail in email
16488 Defaults to @samp{"+"}.
16491 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16492 Header where the original recipient address (SMTP's RCPT TO:
16493 address) is taken from if not available elsewhere. With dovecot-lda -a
16494 parameter overrides this. A commonly used header for this is
16496 Defaults to @samp{""}.
16499 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16500 Should saving a mail to a nonexistent mailbox automatically create
16502 Defaults to @samp{#f}.
16505 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16506 Should automatically created mailboxes be also automatically
16508 Defaults to @samp{#f}.
16511 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16512 Maximum IMAP command line length. Some clients generate very long
16513 command lines with huge mailboxes, so you may need to raise this if you
16514 get "Too long argument" or "IMAP command line too large" errors
16516 Defaults to @samp{64000}.
16519 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16520 IMAP logout format string:
16523 total number of bytes read from client
16525 total number of bytes sent to client.
16527 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16528 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@}"}.
16531 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16532 Override the IMAP CAPABILITY response. If the value begins with '+',
16533 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16534 Defaults to @samp{""}.
16537 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16538 How long to wait between "OK Still here" notifications when client
16540 Defaults to @samp{"2 mins"}.
16543 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16544 ID field names and values to send to clients. Using * as the value
16545 makes Dovecot use the default value. The following fields have default
16546 values currently: name, version, os, os-version, support-url,
16548 Defaults to @samp{""}.
16551 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16552 ID fields sent by client to log. * means everything.
16553 Defaults to @samp{""}.
16556 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16557 Workarounds for various client bugs:
16560 @item delay-newmail
16561 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16562 CHECK commands. Some clients ignore them otherwise, for example OSX
16563 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16564 may show user "Message no longer in server" errors. Note that OE6
16565 still breaks even with this workaround if synchronization is set to
16568 @item tb-extra-mailbox-sep
16569 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16570 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16571 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16573 @item tb-lsub-flags
16574 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16575 This makes Thunderbird realize they aren't selectable and show them
16576 greyed out, instead of only later giving "not selectable" popup error.
16578 Defaults to @samp{()}.
16581 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16582 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16583 Defaults to @samp{""}.
16587 Whew! Lots of configuration options. The nice thing about it though is
16588 that Guix has a complete interface to Dovecot's configuration
16589 language. This allows not only a nice way to declare configurations,
16590 but also offers reflective capabilities as well: users can write code to
16591 inspect and transform configurations from within Scheme.
16593 However, it could be that you just want to get a @code{dovecot.conf} up
16594 and running. In that case, you can pass an
16595 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16596 @code{dovecot-service}. As its name indicates, an opaque configuration
16597 does not have easy reflective capabilities.
16599 Available @code{opaque-dovecot-configuration} fields are:
16601 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16602 The dovecot package.
16605 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16606 The contents of the @code{dovecot.conf}, as a string.
16609 For example, if your @code{dovecot.conf} is just the empty string, you
16610 could instantiate a dovecot service like this:
16613 (dovecot-service #:config
16614 (opaque-dovecot-configuration
16618 @subsubheading OpenSMTPD Service
16620 @deffn {Scheme Variable} opensmtpd-service-type
16621 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16622 service, whose value should be an @code{opensmtpd-configuration} object
16623 as in this example:
16626 (service opensmtpd-service-type
16627 (opensmtpd-configuration
16628 (config-file (local-file "./my-smtpd.conf"))))
16632 @deftp {Data Type} opensmtpd-configuration
16633 Data type representing the configuration of opensmtpd.
16636 @item @code{package} (default: @var{opensmtpd})
16637 Package object of the OpenSMTPD SMTP server.
16639 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16640 File-like object of the OpenSMTPD configuration file to use. By default
16641 it listens on the loopback network interface, and allows for mail from
16642 users and daemons on the local machine, as well as permitting email to
16643 remote servers. Run @command{man smtpd.conf} for more information.
16648 @subsubheading Exim Service
16650 @cindex mail transfer agent (MTA)
16651 @cindex MTA (mail transfer agent)
16654 @deffn {Scheme Variable} exim-service-type
16655 This is the type of the @uref{https://exim.org, Exim} mail transfer
16656 agent (MTA), whose value should be an @code{exim-configuration} object
16657 as in this example:
16660 (service exim-service-type
16661 (exim-configuration
16662 (config-file (local-file "./my-exim.conf"))))
16666 In order to use an @code{exim-service-type} service you must also have a
16667 @code{mail-aliases-service-type} service present in your
16668 @code{operating-system} (even if it has no aliases).
16670 @deftp {Data Type} exim-configuration
16671 Data type representing the configuration of exim.
16674 @item @code{package} (default: @var{exim})
16675 Package object of the Exim server.
16677 @item @code{config-file} (default: @code{#f})
16678 File-like object of the Exim configuration file to use. If its value is
16679 @code{#f} then use the default configuration file from the package
16680 provided in @code{package}. The resulting configuration file is loaded
16681 after setting the @code{exim_user} and @code{exim_group} configuration
16687 @subsubheading Mail Aliases Service
16689 @cindex email aliases
16690 @cindex aliases, for email addresses
16692 @deffn {Scheme Variable} mail-aliases-service-type
16693 This is the type of the service which provides @code{/etc/aliases},
16694 specifying how to deliver mail to users on this system.
16697 (service mail-aliases-service-type
16698 '(("postmaster" "bob")
16699 ("bob" "bob@@example.com" "bob@@example2.com")))
16703 The configuration for a @code{mail-aliases-service-type} service is an
16704 association list denoting how to deliver mail that comes to this
16705 system. Each entry is of the form @code{(alias addresses ...)}, with
16706 @code{alias} specifying the local alias and @code{addresses} specifying
16707 where to deliver this user's mail.
16709 The aliases aren't required to exist as users on the local system. In
16710 the above example, there doesn't need to be a @code{postmaster} entry in
16711 the @code{operating-system}'s @code{user-accounts} in order to deliver
16712 the @code{postmaster} mail to @code{bob} (which subsequently would
16713 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16715 @subsubheading GNU Mailutils IMAP4 Daemon
16716 @cindex GNU Mailutils IMAP4 Daemon
16718 @deffn {Scheme Variable} imap4d-service-type
16719 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16720 mailutils, GNU Mailutils Manual}), whose value should be an
16721 @code{imap4d-configuration} object as in this example:
16724 (service imap4d-service-type
16725 (imap4d-configuration
16726 (config-file (local-file "imap4d.conf"))))
16730 @deftp {Data Type} imap4d-configuration
16731 Data type representing the configuration of @command{imap4d}.
16734 @item @code{package} (default: @code{mailutils})
16735 The package that provides @command{imap4d}.
16737 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16738 File-like object of the configuration file to use, by default it will listen
16739 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16740 Mailutils Manual}, for details.
16745 @node Messaging Services
16746 @subsection Messaging Services
16751 The @code{(gnu services messaging)} module provides Guix service
16752 definitions for messaging services: currently only Prosody is supported.
16754 @subsubheading Prosody Service
16756 @deffn {Scheme Variable} prosody-service-type
16757 This is the type for the @uref{https://prosody.im, Prosody XMPP
16758 communication server}. Its value must be a @code{prosody-configuration}
16759 record as in this example:
16762 (service prosody-service-type
16763 (prosody-configuration
16764 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16767 (int-component-configuration
16768 (hostname "conference.example.net")
16770 (mod-muc (mod-muc-configuration)))))
16773 (virtualhost-configuration
16774 (domain "example.net"))))))
16777 See below for details about @code{prosody-configuration}.
16781 By default, Prosody does not need much configuration. Only one
16782 @code{virtualhosts} field is needed: it specifies the domain you wish
16785 You can perform various sanity checks on the generated configuration
16786 with the @code{prosodyctl check} command.
16788 Prosodyctl will also help you to import certificates from the
16789 @code{letsencrypt} directory so that the @code{prosody} user can access
16790 them. See @url{https://prosody.im/doc/letsencrypt}.
16793 prosodyctl --root cert import /etc/letsencrypt/live
16796 The available configuration parameters follow. Each parameter
16797 definition is preceded by its type; for example, @samp{string-list foo}
16798 indicates that the @code{foo} parameter should be specified as a list of
16799 strings. Types starting with @code{maybe-} denote parameters that won't
16800 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16802 There is also a way to specify the configuration as a string, if you
16803 have an old @code{prosody.cfg.lua} file that you want to port over from
16804 some other system; see the end for more details.
16806 The @code{file-object} type designates either a file-like object
16807 (@pxref{G-Expressions, file-like objects}) or a file name.
16809 @c The following documentation was initially generated by
16810 @c (generate-documentation) in (gnu services messaging). Manually maintained
16811 @c documentation is better, so we shouldn't hesitate to edit below as
16812 @c needed. However if the change you want to make to this documentation
16813 @c can be done in an automated way, it's probably easier to change
16814 @c (generate-documentation) than to make it below and have to deal with
16815 @c the churn as Prosody updates.
16817 Available @code{prosody-configuration} fields are:
16819 @deftypevr {@code{prosody-configuration} parameter} package prosody
16820 The Prosody package.
16823 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16824 Location of the Prosody data storage directory. See
16825 @url{https://prosody.im/doc/configure}.
16826 Defaults to @samp{"/var/lib/prosody"}.
16829 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16830 Additional plugin directories. They are searched in all the specified
16831 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16832 Defaults to @samp{()}.
16835 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16836 Every virtual host and component needs a certificate so that clients and
16837 servers can securely verify its identity. Prosody will automatically load
16838 certificates/keys from the directory specified here.
16839 Defaults to @samp{"/etc/prosody/certs"}.
16842 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16843 This is a list of accounts that are admins for the server. Note that you
16844 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16845 @url{https://prosody.im/doc/creating_accounts}.
16846 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16847 Defaults to @samp{()}.
16850 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16851 Enable use of libevent for better performance under high load. See
16852 @url{https://prosody.im/doc/libevent}.
16853 Defaults to @samp{#f}.
16856 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16857 This is the list of modules Prosody will load on startup. It looks for
16858 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16859 Documentation on modules can be found at:
16860 @url{https://prosody.im/doc/modules}.
16861 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16864 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16865 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16866 should you want to disable them then add them to this list.
16867 Defaults to @samp{()}.
16870 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16871 Path to a text file where the shared groups are defined. If this path is
16872 empty then @samp{mod_groups} does nothing. See
16873 @url{https://prosody.im/doc/modules/mod_groups}.
16874 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16877 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16878 Disable account creation by default, for security. See
16879 @url{https://prosody.im/doc/creating_accounts}.
16880 Defaults to @samp{#f}.
16883 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16884 These are the SSL/TLS-related settings. Most of them are disabled so to
16885 use Prosody's defaults. If you do not completely understand these options, do
16886 not add them to your config, it is easy to lower the security of your server
16887 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16889 Available @code{ssl-configuration} fields are:
16891 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16892 This determines what handshake to use.
16895 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16896 Path to your private key file.
16899 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16900 Path to your certificate file.
16903 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16904 Path to directory containing root certificates that you wish Prosody to
16905 trust when verifying the certificates of remote servers.
16906 Defaults to @samp{"/etc/ssl/certs"}.
16909 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16910 Path to a file containing root certificates that you wish Prosody to trust.
16911 Similar to @code{capath} but with all certificates concatenated together.
16914 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16915 A list of verification options (these mostly map to OpenSSL's
16916 @code{set_verify()} flags).
16919 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16920 A list of general options relating to SSL/TLS. These map to OpenSSL's
16921 @code{set_options()}. For a full list of options available in LuaSec, see the
16925 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16926 How long a chain of certificate authorities to check when looking for a
16927 trusted root certificate.
16930 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16931 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16932 clients, and in what order.
16935 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16936 A path to a file containing parameters for Diffie-Hellman key exchange. You
16937 can create such a file with:
16938 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16941 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16942 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16943 @samp{"secp384r1"}.
16946 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16947 A list of "extra" verification options.
16950 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16951 Password for encrypted private keys.
16956 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16957 Whether to force all client-to-server connections to be encrypted or not.
16958 See @url{https://prosody.im/doc/modules/mod_tls}.
16959 Defaults to @samp{#f}.
16962 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16963 Set of mechanisms that will never be offered. See
16964 @url{https://prosody.im/doc/modules/mod_saslauth}.
16965 Defaults to @samp{("DIGEST-MD5")}.
16968 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16969 Whether to force all server-to-server connections to be encrypted or not.
16970 See @url{https://prosody.im/doc/modules/mod_tls}.
16971 Defaults to @samp{#f}.
16974 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16975 Whether to require encryption and certificate authentication. This
16976 provides ideal security, but requires servers you communicate with to support
16977 encryption AND present valid, trusted certificates. See
16978 @url{https://prosody.im/doc/s2s#security}.
16979 Defaults to @samp{#f}.
16982 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16983 Many servers don't support encryption or have invalid or self-signed
16984 certificates. You can list domains here that will not be required to
16985 authenticate using certificates. They will be authenticated using DNS. See
16986 @url{https://prosody.im/doc/s2s#security}.
16987 Defaults to @samp{()}.
16990 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16991 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16992 valid certificates for some domains by specifying a list here. See
16993 @url{https://prosody.im/doc/s2s#security}.
16994 Defaults to @samp{()}.
16997 @deftypevr {@code{prosody-configuration} parameter} string authentication
16998 Select the authentication backend to use. The default provider stores
16999 passwords in plaintext and uses Prosody's configured data storage to store the
17000 authentication data. If you do not trust your server please see
17001 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17002 about using the hashed backend. See also
17003 @url{https://prosody.im/doc/authentication}
17004 Defaults to @samp{"internal_plain"}.
17007 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17008 Set logging options. Advanced logging configuration is not yet supported
17009 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17010 Defaults to @samp{"*syslog"}.
17013 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17014 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17015 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17018 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17019 Maximum allowed size of the HTTP body (in bytes).
17022 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17023 Some modules expose their own URL in various ways. This URL is built
17024 from the protocol, host and port used. If Prosody sits behind a proxy, the
17025 public URL will be @code{http-external-url} instead. See
17026 @url{https://prosody.im/doc/http#external_url}.
17029 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17030 A host in Prosody is a domain on which user accounts can be created. For
17031 example if you want your users to have addresses like
17032 @samp{"john.smith@@example.com"} then you need to add a host
17033 @samp{"example.com"}. All options in this list will apply only to this host.
17035 Note: the name "virtual" host is used in configuration to avoid confusion with
17036 the actual physical host that Prosody is installed on. A single Prosody
17037 instance can serve many domains, each one defined as a VirtualHost entry in
17038 Prosody's configuration. Conversely a server that hosts a single domain would
17039 have just one VirtualHost entry.
17041 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17043 Available @code{virtualhost-configuration} fields are:
17045 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:
17046 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17047 Domain you wish Prosody to serve.
17052 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17053 Components are extra services on a server which are available to clients,
17054 usually on a subdomain of the main server (such as
17055 @samp{"mycomponent.example.com"}). Example components might be chatroom
17056 servers, user directories, or gateways to other protocols.
17058 Internal components are implemented with Prosody-specific plugins. To add an
17059 internal component, you simply fill the hostname field, and the plugin you wish
17060 to use for the component.
17062 See @url{https://prosody.im/doc/components}.
17063 Defaults to @samp{()}.
17065 Available @code{int-component-configuration} fields are:
17067 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:
17068 @deftypevr {@code{int-component-configuration} parameter} string hostname
17069 Hostname of the component.
17072 @deftypevr {@code{int-component-configuration} parameter} string plugin
17073 Plugin you wish to use for the component.
17076 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17077 Multi-user chat (MUC) is Prosody's module for allowing you to create
17078 hosted chatrooms/conferences for XMPP users.
17080 General information on setting up and using multi-user chatrooms can be found
17081 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17082 which you should read if you are new to XMPP chatrooms.
17084 See also @url{https://prosody.im/doc/modules/mod_muc}.
17086 Available @code{mod-muc-configuration} fields are:
17088 @deftypevr {@code{mod-muc-configuration} parameter} string name
17089 The name to return in service discovery responses.
17090 Defaults to @samp{"Prosody Chatrooms"}.
17093 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17094 If @samp{#t}, this will only allow admins to create new chatrooms.
17095 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17096 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17097 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17098 restricts to service administrators only.
17099 Defaults to @samp{#f}.
17102 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17103 Maximum number of history messages that will be sent to the member that has
17104 just joined the room.
17105 Defaults to @samp{20}.
17112 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17113 External components use XEP-0114, which most standalone components
17114 support. To add an external component, you simply fill the hostname field. See
17115 @url{https://prosody.im/doc/components}.
17116 Defaults to @samp{()}.
17118 Available @code{ext-component-configuration} fields are:
17120 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:
17121 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17122 Password which the component will use to log in.
17125 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17126 Hostname of the component.
17131 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17132 Port(s) Prosody listens on for component connections.
17133 Defaults to @samp{(5347)}.
17136 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17137 Interface Prosody listens on for component connections.
17138 Defaults to @samp{"127.0.0.1"}.
17141 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17142 Raw content that will be added to the configuration file.
17145 It could be that you just want to get a @code{prosody.cfg.lua}
17146 up and running. In that case, you can pass an
17147 @code{opaque-prosody-configuration} record as the value of
17148 @code{prosody-service-type}. As its name indicates, an opaque configuration
17149 does not have easy reflective capabilities.
17150 Available @code{opaque-prosody-configuration} fields are:
17152 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17153 The prosody package.
17156 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17157 The contents of the @code{prosody.cfg.lua} to use.
17160 For example, if your @code{prosody.cfg.lua} is just the empty
17161 string, you could instantiate a prosody service like this:
17164 (service prosody-service-type
17165 (opaque-prosody-configuration
17166 (prosody.cfg.lua "")))
17169 @c end of Prosody auto-generated documentation
17171 @subsubheading BitlBee Service
17173 @cindex IRC (Internet Relay Chat)
17174 @cindex IRC gateway
17175 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17176 interface to a variety of messaging protocols such as XMPP.
17178 @defvr {Scheme Variable} bitlbee-service-type
17179 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17180 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17183 To have BitlBee listen on port 6667 on localhost, add this line to your
17187 (service bitlbee-service-type)
17191 @deftp {Data Type} bitlbee-configuration
17192 This is the configuration for BitlBee, with the following fields:
17195 @item @code{interface} (default: @code{"127.0.0.1"})
17196 @itemx @code{port} (default: @code{6667})
17197 Listen on the network interface corresponding to the IP address
17198 specified in @var{interface}, on @var{port}.
17200 When @var{interface} is @code{127.0.0.1}, only local clients can
17201 connect; when it is @code{0.0.0.0}, connections can come from any
17202 networking interface.
17204 @item @code{package} (default: @code{bitlbee})
17205 The BitlBee package to use.
17207 @item @code{plugins} (default: @code{'()})
17208 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17210 @item @code{extra-settings} (default: @code{""})
17211 Configuration snippet added as-is to the BitlBee configuration file.
17215 @subsubheading Quassel Service
17217 @cindex IRC (Internet Relay Chat)
17218 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17219 meaning that one or more clients can attach to and detach from the
17222 @defvr {Scheme Variable} quassel-service-type
17223 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17224 IRC backend daemon. Its value is a @code{quassel-configuration}
17228 @deftp {Data Type} quassel-configuration
17229 This is the configuration for Quassel, with the following fields:
17232 @item @code{quassel} (default: @code{quassel})
17233 The Quassel package to use.
17235 @item @code{interface} (default: @code{"::,0.0.0.0"})
17236 @item @code{port} (default: @code{4242})
17237 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17238 interfaces specified in the comma delimited @var{interface}, on
17241 @item @code{loglevel} (default: @code{"Info"})
17242 The level of logging desired. Accepted values are Debug, Info, Warning
17247 @node Telephony Services
17248 @subsection Telephony Services
17250 @cindex Murmur (VoIP server)
17251 @cindex VoIP server
17252 This section describes how to set up and run a Murmur server. Murmur is
17253 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17256 @deftp {Data Type} murmur-configuration
17257 The service type for the Murmur server. An example configuration can
17261 (service murmur-service-type
17262 (murmur-configuration
17264 "Welcome to this Mumble server running on Guix!")
17265 (cert-required? #t) ;disallow text password logins
17266 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17267 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17270 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17271 password with the command that is printed during the activation phase.
17273 It is recommended to register a normal Mumble user account
17274 and grant it admin or moderator rights.
17275 You can use the @code{mumble} client to
17276 login as new normal user, register yourself, and log out.
17277 For the next step login with the name @code{SuperUser} use
17278 the @code{SuperUser} password that you set previously,
17279 and grant your newly registered mumble user administrator or moderator
17280 rights and create some channels.
17282 Available @code{murmur-configuration} fields are:
17285 @item @code{package} (default: @code{mumble})
17286 Package that contains @code{bin/murmurd}.
17288 @item @code{user} (default: @code{"murmur"})
17289 User who will run the Murmur server.
17291 @item @code{group} (default: @code{"murmur"})
17292 Group of the user who will run the murmur server.
17294 @item @code{port} (default: @code{64738})
17295 Port on which the server will listen.
17297 @item @code{welcome-text} (default: @code{""})
17298 Welcome text sent to clients when they connect.
17300 @item @code{server-password} (default: @code{""})
17301 Password the clients have to enter in order to connect.
17303 @item @code{max-users} (default: @code{100})
17304 Maximum of users that can be connected to the server at once.
17306 @item @code{max-user-bandwidth} (default: @code{#f})
17307 Maximum voice traffic a user can send per second.
17309 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17310 File name of the sqlite database.
17311 The service's user will become the owner of the directory.
17313 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17314 File name of the log file.
17315 The service's user will become the owner of the directory.
17317 @item @code{autoban-attempts} (default: @code{10})
17318 Maximum number of logins a user can make in @code{autoban-timeframe}
17319 without getting auto banned for @code{autoban-time}.
17321 @item @code{autoban-timeframe} (default: @code{120})
17322 Timeframe for autoban in seconds.
17324 @item @code{autoban-time} (default: @code{300})
17325 Amount of time in seconds for which a client gets banned
17326 when violating the autoban limits.
17328 @item @code{opus-threshold} (default: @code{100})
17329 Percentage of clients that need to support opus
17330 before switching over to opus audio codec.
17332 @item @code{channel-nesting-limit} (default: @code{10})
17333 How deep channels can be nested at maximum.
17335 @item @code{channelname-regex} (default: @code{#f})
17336 A string in form of a Qt regular expression that channel names must conform to.
17338 @item @code{username-regex} (default: @code{#f})
17339 A string in form of a Qt regular expression that user names must conform to.
17341 @item @code{text-message-length} (default: @code{5000})
17342 Maximum size in bytes that a user can send in one text chat message.
17344 @item @code{image-message-length} (default: @code{(* 128 1024)})
17345 Maximum size in bytes that a user can send in one image message.
17347 @item @code{cert-required?} (default: @code{#f})
17348 If it is set to @code{#t} clients that use weak password authentification
17349 will not be accepted. Users must have completed the certificate wizard to join.
17351 @item @code{remember-channel?} (default: @code{#f})
17352 Should murmur remember the last channel each user was in when they disconnected
17353 and put them into the remembered channel when they rejoin.
17355 @item @code{allow-html?} (default: @code{#f})
17356 Should html be allowed in text messages, user comments, and channel descriptions.
17358 @item @code{allow-ping?} (default: @code{#f})
17359 Setting to true exposes the current user count, the maximum user count, and
17360 the server's maximum bandwidth per client to unauthenticated users. In the
17361 Mumble client, this information is shown in the Connect dialog.
17363 Disabling this setting will prevent public listing of the server.
17365 @item @code{bonjour?} (default: @code{#f})
17366 Should the server advertise itself in the local network through the bonjour protocol.
17368 @item @code{send-version?} (default: @code{#f})
17369 Should the murmur server version be exposed in ping requests.
17371 @item @code{log-days} (default: @code{31})
17372 Murmur also stores logs in the database, which are accessible via RPC.
17373 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17374 or -1 to disable logging to the database.
17376 @item @code{obfuscate-ips?} (default: @code{#t})
17377 Should logged ips be obfuscated to protect the privacy of users.
17379 @item @code{ssl-cert} (default: @code{#f})
17380 File name of the SSL/TLS certificate used for encrypted connections.
17383 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17385 @item @code{ssl-key} (default: @code{#f})
17386 Filepath to the ssl private key used for encrypted connections.
17388 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17391 @item @code{ssl-dh-params} (default: @code{#f})
17392 File name of a PEM-encoded file with Diffie-Hellman parameters
17393 for the SSL/TLS encryption. Alternatively you set it to
17394 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17395 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17397 @item @code{ssl-ciphers} (default: @code{#f})
17398 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17401 This option is specified using
17402 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17403 OpenSSL cipher list notation}.
17405 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17406 before setting it here, to get a feel for which cipher suites you will get.
17407 After setting this option, it is recommend that you inspect your Murmur log
17408 to ensure that Murmur is using the cipher suites that you expected it to.
17410 Note: Changing this option may impact the backwards compatibility of your
17411 Murmur server, and can remove the ability for older Mumble clients to be able
17414 @item @code{public-registration} (default: @code{#f})
17415 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17417 You can optionally register your server in the public server list that the
17418 @code{mumble} client shows on startup.
17419 You cannot register your server if you have set a @code{server-password},
17420 or set @code{allow-ping} to @code{#f}.
17422 It might take a few hours until it shows up in the public list.
17424 @item @code{file} (default: @code{#f})
17425 Optional alternative override for this configuration.
17429 @deftp {Data Type} murmur-public-registration-configuration
17430 Configuration for public registration of a murmur service.
17434 This is a display name for your server. Not to be confused with the hostname.
17436 @item @code{password}
17437 A password to identify your registration.
17438 Subsequent updates will need the same password. Don't lose your password.
17441 This should be a @code{http://} or @code{https://} link to your web
17444 @item @code{hostname} (default: @code{#f})
17445 By default your server will be listed by its IP address.
17446 If it is set your server will be linked by this host name instead.
17452 @node Monitoring Services
17453 @subsection Monitoring Services
17455 @subsubheading Tailon Service
17457 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17458 viewing and searching log files.
17460 The following example will configure the service with default values.
17461 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17464 (service tailon-service-type)
17467 The following example customises more of the Tailon configuration,
17468 adding @command{sed} to the list of allowed commands.
17471 (service tailon-service-type
17472 (tailon-configuration
17474 (tailon-configuration-file
17475 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17479 @deftp {Data Type} tailon-configuration
17480 Data type representing the configuration of Tailon.
17481 This type has the following parameters:
17484 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17485 The configuration file to use for Tailon. This can be set to a
17486 @dfn{tailon-configuration-file} record value, or any gexp
17487 (@pxref{G-Expressions}).
17489 For example, to instead use a local file, the @code{local-file} function
17493 (service tailon-service-type
17494 (tailon-configuration
17495 (config-file (local-file "./my-tailon.conf"))))
17498 @item @code{package} (default: @code{tailon})
17499 The tailon package to use.
17504 @deftp {Data Type} tailon-configuration-file
17505 Data type representing the configuration options for Tailon.
17506 This type has the following parameters:
17509 @item @code{files} (default: @code{(list "/var/log")})
17510 List of files to display. The list can include strings for a single file
17511 or directory, or a list, where the first item is the name of a
17512 subsection, and the remaining items are the files or directories in that
17515 @item @code{bind} (default: @code{"localhost:8080"})
17516 Address and port to which Tailon should bind on.
17518 @item @code{relative-root} (default: @code{#f})
17519 URL path to use for Tailon, set to @code{#f} to not use a path.
17521 @item @code{allow-transfers?} (default: @code{#t})
17522 Allow downloading the log files in the web interface.
17524 @item @code{follow-names?} (default: @code{#t})
17525 Allow tailing of not-yet existent files.
17527 @item @code{tail-lines} (default: @code{200})
17528 Number of lines to read initially from each file.
17530 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17531 Commands to allow running. By default, @code{sed} is disabled.
17533 @item @code{debug?} (default: @code{#f})
17534 Set @code{debug?} to @code{#t} to show debug messages.
17536 @item @code{wrap-lines} (default: @code{#t})
17537 Initial line wrapping state in the web interface. Set to @code{#t} to
17538 initially wrap lines (the default), or to @code{#f} to initially not
17541 @item @code{http-auth} (default: @code{#f})
17542 HTTP authentication type to use. Set to @code{#f} to disable
17543 authentication (the default). Supported values are @code{"digest"} or
17546 @item @code{users} (default: @code{#f})
17547 If HTTP authentication is enabled (see @code{http-auth}), access will be
17548 restricted to the credentials provided here. To configure users, use a
17549 list of pairs, where the first element of the pair is the username, and
17550 the 2nd element of the pair is the password.
17553 (tailon-configuration-file
17554 (http-auth "basic")
17555 (users '(("user1" . "password1")
17556 ("user2" . "password2"))))
17563 @subsubheading Darkstat Service
17565 Darkstat is a packet sniffer that captures network traffic, calculates
17566 statistics about usage, and serves reports over HTTP.
17568 @defvar {Scheme Variable} darkstat-service-type
17569 This is the service type for the
17570 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17571 service, its value must be a @code{darkstat-configuration} record as in
17575 (service darkstat-service-type
17576 (darkstat-configuration
17577 (interface "eno1")))
17581 @deftp {Data Type} darkstat-configuration
17582 Data type representing the configuration of @command{darkstat}.
17585 @item @code{package} (default: @code{darkstat})
17586 The darkstat package to use.
17588 @item @code{interface}
17589 Capture traffic on the specified network interface.
17591 @item @code{port} (default: @code{"667"})
17592 Bind the web interface to the specified port.
17594 @item @code{bind-address} (default: @code{"127.0.0.1"})
17595 Bind the web interface to the specified address.
17597 @item @code{base} (default: @code{"/"})
17598 Specify the path of the base URL. This can be useful if
17599 @command{darkstat} is accessed via a reverse proxy.
17604 @subsubheading Prometheus Node Exporter Service
17606 @cindex prometheus-node-exporter
17607 The Prometheus ``node exporter'' makes hardware and operating system statistics
17608 provided by the Linux kernel available for the Prometheus monitoring system.
17609 This service should be deployed on all physical nodes and virtual machines,
17610 where monitoring these statistics is desirable.
17612 @defvar {Scheme variable} prometheus-node-exporter-service-type
17613 This is the service type for the
17614 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17615 service, its value must be a @code{prometheus-node-exporter-configuration}
17616 record as in this example:
17619 (service prometheus-node-exporter-service-type
17620 (prometheus-node-exporter-configuration
17621 (web-listen-address ":9100")))
17625 @deftp {Data Type} prometheus-node-exporter-configuration
17626 Data type representing the configuration of @command{node_exporter}.
17629 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17630 The prometheus-node-exporter package to use.
17632 @item @code{web-listen-address} (default: @code{":9100"})
17633 Bind the web interface to the specified address.
17638 @subsubheading Zabbix server
17639 @cindex zabbix zabbix-server
17640 Zabbix provides monitoring metrics, among others network utilization, CPU load
17641 and disk space consumption:
17644 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17645 @item Auto-discovery of servers and network devices and interfaces.
17646 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17647 @item Distributed monitoring with centralized web administration.
17648 @item Native high performance agents.
17649 @item SLA, and ITIL KPI metrics on reporting.
17650 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17651 @item Remote command execution through Zabbix proxies.
17654 @c %start of fragment
17656 Available @code{zabbix-server-configuration} fields are:
17658 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17659 The zabbix-server package.
17663 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17664 User who will run the Zabbix server.
17666 Defaults to @samp{"zabbix"}.
17670 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17671 Group who will run the Zabbix server.
17673 Defaults to @samp{"zabbix"}.
17677 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17678 Database host name.
17680 Defaults to @samp{"127.0.0.1"}.
17684 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17687 Defaults to @samp{"zabbix"}.
17691 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17694 Defaults to @samp{"zabbix"}.
17698 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17699 Database password. Please, use @code{include-files} with
17700 @code{DBPassword=SECRET} inside a specified file instead.
17702 Defaults to @samp{""}.
17706 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17709 Defaults to @samp{5432}.
17713 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17714 Specifies where log messages are written to:
17718 @code{system} - syslog.
17721 @code{file} - file specified with @code{log-file} parameter.
17724 @code{console} - standard output.
17728 Defaults to @samp{""}.
17732 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17733 Log file name for @code{log-type} @code{file} parameter.
17735 Defaults to @samp{"/var/log/zabbix/server.log"}.
17739 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17742 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17746 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17747 The location of certificate authority (CA) files for SSL server
17748 certificate verification.
17750 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17754 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17755 Location of SSL client certificates.
17757 Defaults to @samp{"/etc/ssl/certs"}.
17761 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17762 Extra options will be appended to Zabbix server configuration file.
17764 Defaults to @samp{""}.
17768 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17769 You may include individual files or all files in a directory in the
17770 configuration file.
17772 Defaults to @samp{()}.
17776 @c %end of fragment
17778 @subsubheading Zabbix agent
17779 @cindex zabbix zabbix-agent
17781 Zabbix agent gathers information for Zabbix server.
17783 @c %start of fragment
17785 Available @code{zabbix-agent-configuration} fields are:
17787 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17788 The zabbix-agent package.
17792 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17793 User who will run the Zabbix agent.
17795 Defaults to @samp{"zabbix"}.
17799 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17800 Group who will run the Zabbix agent.
17802 Defaults to @samp{"zabbix"}.
17806 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17807 Unique, case sensitive hostname which is required for active checks and
17808 must match hostname as configured on the server.
17810 Defaults to @samp{"Zabbix server"}.
17814 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17815 Specifies where log messages are written to:
17819 @code{system} - syslog.
17822 @code{file} - file specified with @code{log-file} parameter.
17825 @code{console} - standard output.
17829 Defaults to @samp{""}.
17833 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17834 Log file name for @code{log-type} @code{file} parameter.
17836 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17840 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17843 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17847 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17848 List of IP addresses, optionally in CIDR notation, or hostnames of
17849 Zabbix servers and Zabbix proxies. Incoming connections will be
17850 accepted only from the hosts listed here.
17852 Defaults to @samp{("127.0.0.1")}.
17856 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17857 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17858 proxies for active checks. If port is not specified, default port is
17859 used. If this parameter is not specified, active checks are disabled.
17861 Defaults to @samp{("127.0.0.1")}.
17865 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17866 Extra options will be appended to Zabbix server configuration file.
17868 Defaults to @samp{""}.
17872 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17873 You may include individual files or all files in a directory in the
17874 configuration file.
17876 Defaults to @samp{()}.
17880 @c %end of fragment
17882 @subsubheading Zabbix front-end
17883 @cindex zabbix zabbix-front-end
17885 This service provides a WEB interface to Zabbix server.
17887 @c %start of fragment
17889 Available @code{zabbix-front-end-configuration} fields are:
17891 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17892 NGINX configuration.
17896 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17897 Database host name.
17899 Defaults to @samp{"localhost"}.
17903 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17906 Defaults to @samp{5432}.
17910 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17913 Defaults to @samp{"zabbix"}.
17917 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17920 Defaults to @samp{"zabbix"}.
17924 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17925 Database password. Please, use @code{db-secret-file} instead.
17927 Defaults to @samp{""}.
17931 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17932 Secret file which will be appended to @file{zabbix.conf.php} file. This
17933 file contains credentials for use by Zabbix front-end. You are expected
17934 to create it manually.
17936 Defaults to @samp{""}.
17940 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17941 Zabbix server hostname.
17943 Defaults to @samp{"localhost"}.
17947 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17948 Zabbix server port.
17950 Defaults to @samp{10051}.
17955 @c %end of fragment
17957 @node Kerberos Services
17958 @subsection Kerberos Services
17961 The @code{(gnu services kerberos)} module provides services relating to
17962 the authentication protocol @dfn{Kerberos}.
17964 @subsubheading Krb5 Service
17966 Programs using a Kerberos client library normally
17967 expect a configuration file in @file{/etc/krb5.conf}.
17968 This service generates such a file from a definition provided in the
17969 operating system declaration.
17970 It does not cause any daemon to be started.
17972 No ``keytab'' files are provided by this service---you must explicitly create them.
17973 This service is known to work with the MIT client library, @code{mit-krb5}.
17974 Other implementations have not been tested.
17976 @defvr {Scheme Variable} krb5-service-type
17977 A service type for Kerberos 5 clients.
17981 Here is an example of its use:
17983 (service krb5-service-type
17984 (krb5-configuration
17985 (default-realm "EXAMPLE.COM")
17986 (allow-weak-crypto? #t)
17989 (name "EXAMPLE.COM")
17990 (admin-server "groucho.example.com")
17991 (kdc "karl.example.com"))
17994 (admin-server "kerb-admin.argrx.edu")
17995 (kdc "keys.argrx.edu"))))))
17999 This example provides a Kerberos@tie{}5 client configuration which:
18001 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18002 of which have distinct administration servers and key distribution centers;
18003 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18004 specified by clients;
18005 @item Accepts services which only support encryption types known to be weak.
18008 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18009 Only the most commonly used ones are described here.
18010 For a full list, and more detailed explanation of each, see the MIT
18011 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18015 @deftp {Data Type} krb5-realm
18016 @cindex realm, kerberos
18019 This field is a string identifying the name of the realm.
18020 A common convention is to use the fully qualified DNS name of your organization,
18021 converted to upper case.
18023 @item @code{admin-server}
18024 This field is a string identifying the host where the administration server is
18028 This field is a string identifying the key distribution center
18033 @deftp {Data Type} krb5-configuration
18036 @item @code{allow-weak-crypto?} (default: @code{#f})
18037 If this flag is @code{#t} then services which only offer encryption algorithms
18038 known to be weak will be accepted.
18040 @item @code{default-realm} (default: @code{#f})
18041 This field should be a string identifying the default Kerberos
18042 realm for the client.
18043 You should set this field to the name of your Kerberos realm.
18044 If this value is @code{#f}
18045 then a realm must be specified with every Kerberos principal when invoking programs
18046 such as @command{kinit}.
18048 @item @code{realms}
18049 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18051 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18057 @subsubheading PAM krb5 Service
18060 The @code{pam-krb5} service allows for login authentication and password
18061 management via Kerberos.
18062 You will need this service if you want PAM enabled applications to authenticate
18063 users using Kerberos.
18065 @defvr {Scheme Variable} pam-krb5-service-type
18066 A service type for the Kerberos 5 PAM module.
18069 @deftp {Data Type} pam-krb5-configuration
18070 Data type representing the configuration of the Kerberos 5 PAM module.
18071 This type has the following parameters:
18073 @item @code{pam-krb5} (default: @code{pam-krb5})
18074 The pam-krb5 package to use.
18076 @item @code{minimum-uid} (default: @code{1000})
18077 The smallest user ID for which Kerberos authentications should be attempted.
18078 Local accounts with lower values will silently fail to authenticate.
18083 @node LDAP Services
18084 @subsection LDAP Services
18086 @cindex nslcd, LDAP service
18088 The @code{(gnu services authentication)} module provides the
18089 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18090 server. In addition to configuring the service itself, you may want to add
18091 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18092 Switch} for detailed information.
18094 Here is a simple operating system declaration with a default configuration of
18095 the @code{nslcd-service-type} and a Name Service Switch configuration that
18096 consults the @code{ldap} name service last:
18099 (use-service-modules authentication)
18100 (use-modules (gnu system nss))
18106 (service nslcd-service-type)
18107 (service dhcp-client-service-type)
18109 (name-service-switch
18110 (let ((services (list (name-service (name "db"))
18111 (name-service (name "files"))
18112 (name-service (name "ldap")))))
18113 (name-service-switch
18114 (inherit %mdns-host-lookup-nss)
18115 (password services)
18118 (netgroup services)
18119 (gshadow services)))))
18122 @c %start of generated documentation for nslcd-configuration
18124 Available @code{nslcd-configuration} fields are:
18126 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18127 The @code{nss-pam-ldapd} package to use.
18131 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18132 The number of threads to start that can handle requests and perform LDAP
18133 queries. Each thread opens a separate connection to the LDAP server.
18134 The default is to start 5 threads.
18136 Defaults to @samp{disabled}.
18140 @deftypevr {@code{nslcd-configuration} parameter} string uid
18141 This specifies the user id with which the daemon should be run.
18143 Defaults to @samp{"nslcd"}.
18147 @deftypevr {@code{nslcd-configuration} parameter} string gid
18148 This specifies the group id with which the daemon should be run.
18150 Defaults to @samp{"nslcd"}.
18154 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18155 This option controls the way logging is done via a list containing
18156 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18157 or "syslog", or an absolute file name. The LEVEL argument is optional
18158 and specifies the log level. The log level may be one of the following
18159 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18160 messages with the specified log level or higher are logged.
18162 Defaults to @samp{("/var/log/nslcd" info)}.
18166 @deftypevr {@code{nslcd-configuration} parameter} list uri
18167 The list of LDAP server URIs. Normally, only the first server will be
18168 used with the following servers as fall-back.
18170 Defaults to @samp{("ldap://localhost:389/")}.
18174 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18175 The version of the LDAP protocol to use. The default is to use the
18176 maximum version supported by the LDAP library.
18178 Defaults to @samp{disabled}.
18182 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18183 Specifies the distinguished name with which to bind to the directory
18184 server for lookups. The default is to bind anonymously.
18186 Defaults to @samp{disabled}.
18190 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18191 Specifies the credentials with which to bind. This option is only
18192 applicable when used with binddn.
18194 Defaults to @samp{disabled}.
18198 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18199 Specifies the distinguished name to use when the root user tries to
18200 modify a user's password using the PAM module.
18202 Defaults to @samp{disabled}.
18206 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18207 Specifies the credentials with which to bind if the root user tries to
18208 change a user's password. This option is only applicable when used with
18211 Defaults to @samp{disabled}.
18215 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18216 Specifies the SASL mechanism to be used when performing SASL
18219 Defaults to @samp{disabled}.
18223 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18224 Specifies the SASL realm to be used when performing SASL authentication.
18226 Defaults to @samp{disabled}.
18230 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18231 Specifies the authentication identity to be used when performing SASL
18234 Defaults to @samp{disabled}.
18238 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18239 Specifies the authorization identity to be used when performing SASL
18242 Defaults to @samp{disabled}.
18246 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18247 Determines whether the LDAP server host name should be canonicalised. If
18248 this is enabled the LDAP library will do a reverse host name lookup. By
18249 default, it is left up to the LDAP library whether this check is
18252 Defaults to @samp{disabled}.
18256 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18257 Set the name for the GSS-API Kerberos credentials cache.
18259 Defaults to @samp{disabled}.
18263 @deftypevr {@code{nslcd-configuration} parameter} string base
18264 The directory search base.
18266 Defaults to @samp{"dc=example,dc=com"}.
18270 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18271 Specifies the search scope (subtree, onelevel, base or children). The
18272 default scope is subtree; base scope is almost never useful for name
18273 service lookups; children scope is not supported on all servers.
18275 Defaults to @samp{(subtree)}.
18279 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18280 Specifies the policy for dereferencing aliases. The default policy is
18281 to never dereference aliases.
18283 Defaults to @samp{disabled}.
18287 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18288 Specifies whether automatic referral chasing should be enabled. The
18289 default behaviour is to chase referrals.
18291 Defaults to @samp{disabled}.
18295 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18296 This option allows for custom attributes to be looked up instead of the
18297 default RFC 2307 attributes. It is a list of maps, each consisting of
18298 the name of a map, the RFC 2307 attribute to match and the query
18299 expression for the attribute as it is available in the directory.
18301 Defaults to @samp{()}.
18305 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18306 A list of filters consisting of the name of a map to which the filter
18307 applies and an LDAP search filter expression.
18309 Defaults to @samp{()}.
18313 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18314 Specifies the time limit in seconds to use when connecting to the
18315 directory server. The default value is 10 seconds.
18317 Defaults to @samp{disabled}.
18321 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18322 Specifies the time limit (in seconds) to wait for a response from the
18323 LDAP server. A value of zero, which is the default, is to wait
18324 indefinitely for searches to be completed.
18326 Defaults to @samp{disabled}.
18330 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18331 Specifies the period if inactivity (in seconds) after which the con‐
18332 nection to the LDAP server will be closed. The default is not to time
18335 Defaults to @samp{disabled}.
18339 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18340 Specifies the number of seconds to sleep when connecting to all LDAP
18341 servers fails. By default one second is waited between the first
18342 failure and the first retry.
18344 Defaults to @samp{disabled}.
18348 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18349 Specifies the time after which the LDAP server is considered to be
18350 permanently unavailable. Once this time is reached retries will be done
18351 only once per this time period. The default value is 10 seconds.
18353 Defaults to @samp{disabled}.
18357 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18358 Specifies whether to use SSL/TLS or not (the default is not to). If
18359 'start-tls is specified then StartTLS is used rather than raw LDAP over
18362 Defaults to @samp{disabled}.
18366 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18367 Specifies what checks to perform on a server-supplied certificate. The
18368 meaning of the values is described in the ldap.conf(5) manual page.
18370 Defaults to @samp{disabled}.
18374 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18375 Specifies the directory containing X.509 certificates for peer authen‐
18376 tication. This parameter is ignored when using GnuTLS.
18378 Defaults to @samp{disabled}.
18382 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18383 Specifies the path to the X.509 certificate for peer authentication.
18385 Defaults to @samp{disabled}.
18389 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18390 Specifies the path to an entropy source. This parameter is ignored when
18393 Defaults to @samp{disabled}.
18397 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18398 Specifies the ciphers to use for TLS as a string.
18400 Defaults to @samp{disabled}.
18404 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18405 Specifies the path to the file containing the local certificate for
18406 client TLS authentication.
18408 Defaults to @samp{disabled}.
18412 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18413 Specifies the path to the file containing the private key for client TLS
18416 Defaults to @samp{disabled}.
18420 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18421 Set this to a number greater than 0 to request paged results from the
18422 LDAP server in accordance with RFC2696. The default (0) is to not
18423 request paged results.
18425 Defaults to @samp{disabled}.
18429 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18430 This option prevents group membership lookups through LDAP for the
18431 specified users. Alternatively, the value 'all-local may be used. With
18432 that value nslcd builds a full list of non-LDAP users on startup.
18434 Defaults to @samp{disabled}.
18438 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18439 This option ensures that LDAP users with a numeric user id lower than
18440 the specified value are ignored.
18442 Defaults to @samp{disabled}.
18446 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18447 This option specifies an offset that is added to all LDAP numeric user
18448 ids. This can be used to avoid user id collisions with local users.
18450 Defaults to @samp{disabled}.
18454 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18455 This option specifies an offset that is added to all LDAP numeric group
18456 ids. This can be used to avoid user id collisions with local groups.
18458 Defaults to @samp{disabled}.
18462 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18463 If this option is set, the member attribute of a group may point to
18464 another group. Members of nested groups are also returned in the higher
18465 level group and parent groups are returned when finding groups for a
18466 specific user. The default is not to perform extra searches for nested
18469 Defaults to @samp{disabled}.
18473 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18474 If this option is set, the group member list is not retrieved when
18475 looking up groups. Lookups for finding which groups a user belongs to
18476 will remain functional so the user will likely still get the correct
18477 groups assigned on login.
18479 Defaults to @samp{disabled}.
18483 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18484 If this option is set, functions which cause all user/group entries to
18485 be loaded from the directory will not succeed in doing so. This can
18486 dramatically reduce LDAP server load in situations where there are a
18487 great number of users and/or groups. This option is not recommended for
18488 most configurations.
18490 Defaults to @samp{disabled}.
18494 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18495 This option can be used to specify how user and group names are verified
18496 within the system. This pattern is used to check all user and group
18497 names that are requested and returned from LDAP.
18499 Defaults to @samp{disabled}.
18503 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18504 This specifies whether or not to perform searches using case-insensitive
18505 matching. Enabling this could open up the system to authorization
18506 bypass vulnerabilities and introduce nscd cache poisoning
18507 vulnerabilities which allow denial of service.
18509 Defaults to @samp{disabled}.
18513 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18514 This option specifies whether password policy controls are requested and
18515 handled from the LDAP server when performing user authentication.
18517 Defaults to @samp{disabled}.
18521 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18522 By default nslcd performs an LDAP search with the user's credentials
18523 after BIND (authentication) to ensure that the BIND operation was
18524 successful. The default search is a simple check to see if the user's
18525 DN exists. A search filter can be specified that will be used instead.
18526 It should return at least one entry.
18528 Defaults to @samp{disabled}.
18532 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18533 This option allows flexible fine tuning of the authorisation check that
18534 should be performed. The search filter specified is executed and if any
18535 entries match, access is granted, otherwise access is denied.
18537 Defaults to @samp{disabled}.
18541 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18542 If this option is set password modification using pam_ldap will be
18543 denied and the specified message will be presented to the user instead.
18544 The message can be used to direct the user to an alternative means of
18545 changing their password.
18547 Defaults to @samp{disabled}.
18551 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18552 List of pam service names for which LDAP authentication should suffice.
18554 Defaults to @samp{()}.
18558 @c %end of generated documentation for nslcd-configuration
18562 @subsection Web Services
18567 The @code{(gnu services web)} module provides the Apache HTTP Server,
18568 the nginx web server, and also a fastcgi wrapper daemon.
18570 @subsubheading Apache HTTP Server
18572 @deffn {Scheme Variable} httpd-service-type
18573 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18574 (@dfn{httpd}). The value for this service type is a
18575 @code{httpd-configuration} record.
18577 A simple example configuration is given below.
18580 (service httpd-service-type
18581 (httpd-configuration
18584 (server-name "www.example.com")
18585 (document-root "/srv/http/www.example.com")))))
18588 Other services can also extend the @code{httpd-service-type} to add to
18592 (simple-service 'my-extra-server httpd-service-type
18596 (list (string-append
18597 "ServerName "www.example.com
18598 DocumentRoot \"/srv/http/www.example.com\"")))))
18602 The details for the @code{httpd-configuration}, @code{httpd-module},
18603 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18606 @deffn {Data Type} httpd-configuration
18607 This data type represents the configuration for the httpd service.
18610 @item @code{package} (default: @code{httpd})
18611 The httpd package to use.
18613 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18614 The pid file used by the shepherd-service.
18616 @item @code{config} (default: @code{(httpd-config-file)})
18617 The configuration file to use with the httpd service. The default value
18618 is a @code{httpd-config-file} record, but this can also be a different
18619 G-expression that generates a file, for example a @code{plain-file}. A
18620 file outside of the store can also be specified through a string.
18625 @deffn {Data Type} httpd-module
18626 This data type represents a module for the httpd service.
18630 The name of the module.
18633 The file for the module. This can be relative to the httpd package being
18634 used, the absolute location of a file, or a G-expression for a file
18635 within the store, for example @code{(file-append mod-wsgi
18636 "/modules/mod_wsgi.so")}.
18641 @defvr {Scheme Variable} %default-httpd-modules
18642 A default list of @code{httpd-module} objects.
18645 @deffn {Data Type} httpd-config-file
18646 This data type represents a configuration file for the httpd service.
18649 @item @code{modules} (default: @code{%default-httpd-modules})
18650 The modules to load. Additional modules can be added here, or loaded by
18651 additional configuration.
18653 For example, in order to handle requests for PHP files, you can use Apache’s
18654 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18657 (service httpd-service-type
18658 (httpd-configuration
18663 (name "proxy_module")
18664 (file "modules/mod_proxy.so"))
18666 (name "proxy_fcgi_module")
18667 (file "modules/mod_proxy_fcgi.so"))
18668 %default-httpd-modules))
18669 (extra-config (list "\
18670 <FilesMatch \\.php$>
18671 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18672 </FilesMatch>"))))))
18673 (service php-fpm-service-type
18674 (php-fpm-configuration
18675 (socket "/var/run/php-fpm.sock")
18676 (socket-group "httpd")))
18679 @item @code{server-root} (default: @code{httpd})
18680 The @code{ServerRoot} in the configuration file, defaults to the httpd
18681 package. Directives including @code{Include} and @code{LoadModule} are
18682 taken as relative to the server root.
18684 @item @code{server-name} (default: @code{#f})
18685 The @code{ServerName} in the configuration file, used to specify the
18686 request scheme, hostname and port that the server uses to identify
18689 This doesn't need to be set in the server config, and can be specifyed
18690 in virtual hosts. The default is @code{#f} to not specify a
18693 @item @code{document-root} (default: @code{"/srv/http"})
18694 The @code{DocumentRoot} from which files will be served.
18696 @item @code{listen} (default: @code{'("80")})
18697 The list of values for the @code{Listen} directives in the config
18698 file. The value should be a list of strings, when each string can
18699 specify the port number to listen on, and optionally the IP address and
18702 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18703 The @code{PidFile} to use. This should match the @code{pid-file} set in
18704 the @code{httpd-configuration} so that the Shepherd service is
18705 configured correctly.
18707 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18708 The @code{ErrorLog} to which the server will log errors.
18710 @item @code{user} (default: @code{"httpd"})
18711 The @code{User} which the server will answer requests as.
18713 @item @code{group} (default: @code{"httpd"})
18714 The @code{Group} which the server will answer requests as.
18716 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18717 A flat list of strings and G-expressions which will be added to the end
18718 of the configuration file.
18720 Any values which the service is extended with will be appended to this
18726 @deffn {Data Type} httpd-virtualhost
18727 This data type represents a virtualhost configuration block for the httpd service.
18729 These should be added to the extra-config for the httpd-service.
18732 (simple-service 'my-extra-server httpd-service-type
18736 (list (string-append
18737 "ServerName "www.example.com
18738 DocumentRoot \"/srv/http/www.example.com\"")))))
18742 @item @code{addresses-and-ports}
18743 The addresses and ports for the @code{VirtualHost} directive.
18745 @item @code{contents}
18746 The contents of the @code{VirtualHost} directive, this should be a list
18747 of strings and G-expressions.
18752 @subsubheading NGINX
18754 @deffn {Scheme Variable} nginx-service-type
18755 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18756 value for this service type is a @code{<nginx-configuration>} record.
18758 A simple example configuration is given below.
18761 (service nginx-service-type
18762 (nginx-configuration
18764 (list (nginx-server-configuration
18765 (server-name '("www.example.com"))
18766 (root "/srv/http/www.example.com"))))))
18769 In addition to adding server blocks to the service configuration
18770 directly, this service can be extended by other services to add server
18771 blocks, as in this example:
18774 (simple-service 'my-extra-server nginx-service-type
18775 (list (nginx-server-configuration
18776 (root "/srv/http/extra-website")
18777 (try-files (list "$uri" "$uri/index.html")))))
18781 At startup, @command{nginx} has not yet read its configuration file, so
18782 it uses a default file to log error messages. If it fails to load its
18783 configuration file, that is where error messages are logged. After the
18784 configuration file is loaded, the default error log file changes as per
18785 configuration. In our case, startup error messages can be found in
18786 @file{/var/run/nginx/logs/error.log}, and after configuration in
18787 @file{/var/log/nginx/error.log}. The second location can be changed
18788 with the @var{log-directory} configuration option.
18790 @deffn {Data Type} nginx-configuration
18791 This data type represents the configuration for NGinx. Some
18792 configuration can be done through this and the other provided record
18793 types, or alternatively, a config file can be provided.
18796 @item @code{nginx} (default: @code{nginx})
18797 The nginx package to use.
18799 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18800 The directory to which NGinx will write log files.
18802 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18803 The directory in which NGinx will create a pid file, and write temporary
18806 @item @code{server-blocks} (default: @code{'()})
18807 A list of @dfn{server blocks} to create in the generated configuration
18808 file, the elements should be of type
18809 @code{<nginx-server-configuration>}.
18811 The following example would setup NGinx to serve @code{www.example.com}
18812 from the @code{/srv/http/www.example.com} directory, without using
18815 (service nginx-service-type
18816 (nginx-configuration
18818 (list (nginx-server-configuration
18819 (server-name '("www.example.com"))
18820 (root "/srv/http/www.example.com"))))))
18823 @item @code{upstream-blocks} (default: @code{'()})
18824 A list of @dfn{upstream blocks} to create in the generated configuration
18825 file, the elements should be of type
18826 @code{<nginx-upstream-configuration>}.
18828 Configuring upstreams through the @code{upstream-blocks} can be useful
18829 when combined with @code{locations} in the
18830 @code{<nginx-server-configuration>} records. The following example
18831 creates a server configuration with one location configuration, that
18832 will proxy requests to a upstream configuration, which will handle
18833 requests with two servers.
18838 (nginx-configuration
18840 (list (nginx-server-configuration
18841 (server-name '("www.example.com"))
18842 (root "/srv/http/www.example.com")
18845 (nginx-location-configuration
18847 (body '("proxy_pass http://server-proxy;"))))))))
18849 (list (nginx-upstream-configuration
18850 (name "server-proxy")
18851 (servers (list "server1.example.com"
18852 "server2.example.com")))))))
18855 @item @code{file} (default: @code{#f})
18856 If a configuration @var{file} is provided, this will be used, rather than
18857 generating a configuration file from the provided @code{log-directory},
18858 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18859 proper operation, these arguments should match what is in @var{file} to ensure
18860 that the directories are created when the service is activated.
18862 This can be useful if you have an existing configuration file, or it's
18863 not possible to do what is required through the other parts of the
18864 nginx-configuration record.
18866 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18867 Bucket size for the server names hash tables, defaults to @code{#f} to
18868 use the size of the processors cache line.
18870 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18871 Maximum bucket size for the server names hash tables.
18873 @item @code{extra-content} (default: @code{""})
18874 Extra content for the @code{http} block. Should be string or a string
18875 valued G-expression.
18880 @deftp {Data Type} nginx-server-configuration
18881 Data type representing the configuration of an nginx server block.
18882 This type has the following parameters:
18885 @item @code{listen} (default: @code{'("80" "443 ssl")})
18886 Each @code{listen} directive sets the address and port for IP, or the
18887 path for a UNIX-domain socket on which the server will accept requests.
18888 Both address and port, or only address or only port can be specified.
18889 An address may also be a hostname, for example:
18892 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18895 @item @code{server-name} (default: @code{(list 'default)})
18896 A list of server names this server represents. @code{'default} represents the
18897 default server for connections matching no other server.
18899 @item @code{root} (default: @code{"/srv/http"})
18900 Root of the website nginx will serve.
18902 @item @code{locations} (default: @code{'()})
18903 A list of @dfn{nginx-location-configuration} or
18904 @dfn{nginx-named-location-configuration} records to use within this
18907 @item @code{index} (default: @code{(list "index.html")})
18908 Index files to look for when clients ask for a directory. If it cannot be found,
18909 Nginx will send the list of files in the directory.
18911 @item @code{try-files} (default: @code{'()})
18912 A list of files whose existence is checked in the specified order.
18913 @code{nginx} will use the first file it finds to process the request.
18915 @item @code{ssl-certificate} (default: @code{#f})
18916 Where to find the certificate for secure connections. Set it to @code{#f} if
18917 you don't have a certificate or you don't want to use HTTPS.
18919 @item @code{ssl-certificate-key} (default: @code{#f})
18920 Where to find the private key for secure connections. Set it to @code{#f} if
18921 you don't have a key or you don't want to use HTTPS.
18923 @item @code{server-tokens?} (default: @code{#f})
18924 Whether the server should add its configuration to response.
18926 @item @code{raw-content} (default: @code{'()})
18927 A list of raw lines added to the server block.
18932 @deftp {Data Type} nginx-upstream-configuration
18933 Data type representing the configuration of an nginx @code{upstream}
18934 block. This type has the following parameters:
18938 Name for this group of servers.
18940 @item @code{servers}
18941 Specify the addresses of the servers in the group. The address can be
18942 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18943 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18944 prefix @samp{unix:}. For addresses using an IP address or domain name,
18945 the default port is 80, and a different port can be specified
18951 @deftp {Data Type} nginx-location-configuration
18952 Data type representing the configuration of an nginx @code{location}
18953 block. This type has the following parameters:
18957 URI which this location block matches.
18959 @anchor{nginx-location-configuration body}
18961 Body of the location block, specified as a list of strings. This can contain
18963 configuration directives. For example, to pass requests to a upstream
18964 server group defined using an @code{nginx-upstream-configuration} block,
18965 the following directive would be specified in the body @samp{(list "proxy_pass
18966 http://upstream-name;")}.
18971 @deftp {Data Type} nginx-named-location-configuration
18972 Data type representing the configuration of an nginx named location
18973 block. Named location blocks are used for request redirection, and not
18974 used for regular request processing. This type has the following
18979 Name to identify this location block.
18982 @xref{nginx-location-configuration body}, as the body for named location
18983 blocks can be used in a similar way to the
18984 @code{nginx-location-configuration body}. One restriction is that the
18985 body of a named location block cannot contain location blocks.
18990 @subsubheading Varnish Cache
18992 Varnish is a fast cache server that sits in between web applications
18993 and end users. It proxies requests from clients and caches the
18994 accessed URLs such that multiple requests for the same resource only
18995 creates one request to the back-end.
18997 @defvr {Scheme Variable} varnish-service-type
18998 Service type for the Varnish daemon.
19001 @deftp {Data Type} varnish-configuration
19002 Data type representing the @code{varnish} service configuration.
19003 This type has the following parameters:
19006 @item @code{package} (default: @code{varnish})
19007 The Varnish package to use.
19009 @item @code{name} (default: @code{"default"})
19010 A name for this Varnish instance. Varnish will create a directory in
19011 @file{/var/varnish/} with this name and keep temporary files there. If
19012 the name starts with a forward slash, it is interpreted as an absolute
19015 Pass the @code{-n} argument to other Varnish programs to connect to the
19016 named instance, e.g.@: @command{varnishncsa -n default}.
19018 @item @code{backend} (default: @code{"localhost:8080"})
19019 The backend to use. This option has no effect if @code{vcl} is set.
19021 @item @code{vcl} (default: #f)
19022 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19023 is @code{#f}, Varnish will proxy @code{backend} using the default
19024 configuration. Otherwise this must be a file-like object with valid
19027 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19028 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19029 can do something along these lines:
19032 (define %gnu-mirror
19036 backend gnu @{ .host = "www.gnu.org"; @}"))
19040 (services (cons (service varnish-service-type
19041 (varnish-configuration
19043 (vcl %gnu-mirror)))
19047 The configuration of an already running Varnish instance can be inspected
19048 and changed using the @command{varnishadm} program.
19050 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19051 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19052 comprehensive documentation on Varnish and its configuration language.
19054 @item @code{listen} (default: @code{'("localhost:80")})
19055 List of addresses Varnish will listen on.
19057 @item @code{storage} (default: @code{'("malloc,128m")})
19058 List of storage backends that will be available in VCL.
19060 @item @code{parameters} (default: @code{'()})
19061 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19063 @item @code{extra-options} (default: @code{'()})
19064 Additional arguments to pass to the @command{varnishd} process.
19069 @subsubheading FastCGI
19072 FastCGI is an interface between the front-end and the back-end of a web
19073 service. It is a somewhat legacy facility; new web services should
19074 generally just talk HTTP between the front-end and the back-end.
19075 However there are a number of back-end services such as PHP or the
19076 optimized HTTP Git repository access that use FastCGI, so we have
19077 support for it in Guix.
19079 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19080 dispatch some subset of its requests to the fastcgi backend, which
19081 listens on a local TCP or UNIX socket. There is an intermediary
19082 @code{fcgiwrap} program that sits between the actual backend process and
19083 the web server. The front-end indicates which backend program to run,
19084 passing that information to the @code{fcgiwrap} process.
19086 @defvr {Scheme Variable} fcgiwrap-service-type
19087 A service type for the @code{fcgiwrap} FastCGI proxy.
19090 @deftp {Data Type} fcgiwrap-configuration
19091 Data type representing the configuration of the @code{fcgiwrap} service.
19092 This type has the following parameters:
19094 @item @code{package} (default: @code{fcgiwrap})
19095 The fcgiwrap package to use.
19097 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19098 The socket on which the @code{fcgiwrap} process should listen, as a
19099 string. Valid @var{socket} values include
19100 @code{unix:@var{/path/to/unix/socket}},
19101 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19102 @code{tcp6:[@var{ipv6_addr}]:port}.
19104 @item @code{user} (default: @code{fcgiwrap})
19105 @itemx @code{group} (default: @code{fcgiwrap})
19106 The user and group names, as strings, under which to run the
19107 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19108 the user asks for the specific user or group names @code{fcgiwrap} that
19109 the corresponding user and/or group is present on the system.
19111 It is possible to configure a FastCGI-backed web service to pass HTTP
19112 authentication information from the front-end to the back-end, and to
19113 allow @code{fcgiwrap} to run the back-end process as a corresponding
19114 local user. To enable this capability on the back-end., run
19115 @code{fcgiwrap} as the @code{root} user and group. Note that this
19116 capability also has to be configured on the front-end as well.
19121 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19122 with some additional features useful for sites of any size.
19124 These features include:
19126 @item Adaptive process spawning
19127 @item Basic statistics (similar to Apache's mod_status)
19128 @item Advanced process management with graceful stop/start
19129 @item Ability to start workers with different uid/gid/chroot/environment
19130 and different php.ini (replaces safe_mode)
19131 @item Stdout & stderr logging
19132 @item Emergency restart in case of accidental opcode cache destruction
19133 @item Accelerated upload support
19134 @item Support for a "slowlog"
19135 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19136 a special function to finish request & flush all data while continuing to do
19137 something time-consuming (video converting, stats processing, etc.)
19139 ...@: and much more.
19141 @defvr {Scheme Variable} php-fpm-service-type
19142 A Service type for @code{php-fpm}.
19145 @deftp {Data Type} php-fpm-configuration
19146 Data Type for php-fpm service configuration.
19148 @item @code{php} (default: @code{php})
19149 The php package to use.
19150 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19151 The address on which to accept FastCGI requests. Valid syntaxes are:
19153 @item @code{"ip.add.re.ss:port"}
19154 Listen on a TCP socket to a specific address on a specific port.
19155 @item @code{"port"}
19156 Listen on a TCP socket to all addresses on a specific port.
19157 @item @code{"/path/to/unix/socket"}
19158 Listen on a unix socket.
19161 @item @code{user} (default: @code{php-fpm})
19162 User who will own the php worker processes.
19163 @item @code{group} (default: @code{php-fpm})
19164 Group of the worker processes.
19165 @item @code{socket-user} (default: @code{php-fpm})
19166 User who can speak to the php-fpm socket.
19167 @item @code{socket-group} (default: @code{php-fpm})
19168 Group that can speak to the php-fpm socket.
19169 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19170 The process id of the php-fpm process is written to this file
19171 once the service has started.
19172 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19173 Log for the php-fpm master process.
19174 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19175 Detailed settings for the php-fpm process manager.
19178 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19179 @item @code{<php-fpm-static-process-manager-configuration>}
19180 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19182 @item @code{display-errors} (default @code{#f})
19183 Determines whether php errors and warning should be sent to clients
19184 and displayed in their browsers.
19185 This is useful for local php development, but a security risk for public sites,
19186 as error messages can reveal passwords and personal data.
19187 @item @code{timezone} (default @code{#f})
19188 Specifies @code{php_admin_value[date.timezone]} parameter.
19189 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19190 This file will log the @code{stderr} outputs of php worker processes.
19191 Can be set to @code{#f} to disable logging.
19192 @item @code{file} (default @code{#f})
19193 An optional override of the whole configuration.
19194 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19198 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19199 Data Type for the @code{dynamic} php-fpm process manager. With the
19200 @code{dynamic} process manager, spare worker processes are kept around
19201 based on it's configured limits.
19203 @item @code{max-children} (default: @code{5})
19204 Maximum of worker processes.
19205 @item @code{start-servers} (default: @code{2})
19206 How many worker processes should be started on start-up.
19207 @item @code{min-spare-servers} (default: @code{1})
19208 How many spare worker processes should be kept around at minimum.
19209 @item @code{max-spare-servers} (default: @code{3})
19210 How many spare worker processes should be kept around at maximum.
19214 @deftp {Data type} php-fpm-static-process-manager-configuration
19215 Data Type for the @code{static} php-fpm process manager. With the
19216 @code{static} process manager, an unchanging number of worker processes
19219 @item @code{max-children} (default: @code{5})
19220 Maximum of worker processes.
19224 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19225 Data Type for the @code{on-demand} php-fpm process manager. With the
19226 @code{on-demand} process manager, worker processes are only created as
19229 @item @code{max-children} (default: @code{5})
19230 Maximum of worker processes.
19231 @item @code{process-idle-timeout} (default: @code{10})
19232 The time in seconds after which a process with no requests is killed.
19237 @deffn {Scheme Procedure} nginx-php-fpm-location @
19238 [#:nginx-package nginx] @
19239 [socket (string-append "/var/run/php" @
19240 (version-major (package-version php)) @
19242 A helper function to quickly add php to an @code{nginx-server-configuration}.
19245 A simple services setup for nginx with php can look like this:
19247 (services (cons* (service dhcp-client-service-type)
19248 (service php-fpm-service-type)
19249 (service nginx-service-type
19250 (nginx-server-configuration
19251 (server-name '("example.com"))
19252 (root "/srv/http/")
19254 (list (nginx-php-location)))
19256 (ssl-certificate #f)
19257 (ssl-certificate-key #f)))
19261 @cindex cat-avatar-generator
19262 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19263 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19264 the hash of a user's email address.
19266 @deffn {Scheme Procedure} cat-avatar-generator-service @
19267 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19268 [#:package cat-avatar-generator] @
19269 [#:configuration (nginx-server-configuration)]
19270 Returns an nginx-server-configuration that inherits @code{configuration}. It
19271 extends the nginx configuration to add a server block that serves @code{package},
19272 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19273 be able to use @code{cache-dir} as its cache directory.
19276 A simple setup for cat-avatar-generator can look like this:
19278 (services (cons* (cat-avatar-generator-service
19280 (nginx-server-configuration
19281 (server-name '("example.com"))))
19286 @subsubheading Hpcguix-web
19288 @cindex hpcguix-web
19289 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19290 program is a customizable web interface to browse Guix packages,
19291 initially designed for users of high-performance computing (HPC)
19294 @defvr {Scheme Variable} hpcguix-web-service-type
19295 The service type for @code{hpcguix-web}.
19298 @deftp {Data Type} hpcguix-web-configuration
19299 Data type for the hpcguix-web service configuration.
19303 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19304 configuration. The main items available in this spec are:
19307 @item @code{title-prefix} (default: @code{"hpcguix | "})
19308 The page title prefix.
19310 @item @code{guix-command} (default: @code{"guix"})
19311 The @command{guix} command.
19313 @item @code{package-filter-proc} (default: @code{(const #t)})
19314 A procedure specifying how to filter packages that are displayed.
19316 @item @code{package-page-extension-proc} (default: @code{(const '())})
19317 Extension package for @code{hpcguix-web}.
19319 @item @code{menu} (default: @code{'()})
19320 Additional entry in page @code{menu}.
19322 @item @code{channels} (default: @code{%default-channels})
19323 List of channels from which the package list is built (@pxref{Channels}).
19325 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19326 The expiration time, in seconds, after which the package list is rebuilt from
19327 the latest instances of the given channels.
19330 See the hpcguix-web repository for a
19331 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19334 @item @code{package} (default: @code{hpcguix-web})
19335 The hpcguix-web package to use.
19339 A typical hpcguix-web service declaration looks like this:
19342 (service hpcguix-web-service-type
19343 (hpcguix-web-configuration
19345 #~(define site-config
19346 (hpcweb-configuration
19347 (title-prefix "Guix-HPC - ")
19348 (menu '(("/about" "ABOUT"))))))))
19352 The hpcguix-web service periodically updates the package list it publishes by
19353 pulling channels from Git. To that end, it needs to access X.509 certificates
19354 so that it can authenticate Git servers when communicating over HTTPS, and it
19355 assumes that @file{/etc/ssl/certs} contains those certificates.
19357 Thus, make sure to add @code{nss-certs} or another certificate package to the
19358 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19359 more information on X.509 certificates.
19362 @node Certificate Services
19363 @subsection Certificate Services
19366 @cindex HTTP, HTTPS
19367 @cindex Let's Encrypt
19368 @cindex TLS certificates
19369 The @code{(gnu services certbot)} module provides a service to
19370 automatically obtain a valid TLS certificate from the Let's Encrypt
19371 certificate authority. These certificates can then be used to serve
19372 content securely over HTTPS or other TLS-based protocols, with the
19373 knowledge that the client will be able to verify the server's
19376 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19377 @code{certbot} tool to automate the certification process. This tool
19378 first securely generates a key on the server. It then makes a request
19379 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19380 checks that the request originates from the host in question by using a
19381 challenge-response protocol, requiring the server to provide its
19382 response over HTTP. If that protocol completes successfully, the CA
19383 signs the key, resulting in a certificate. That certificate is valid
19384 for a limited period of time, and therefore to continue to provide TLS
19385 services, the server needs to periodically ask the CA to renew its
19388 The certbot service automates this process: the initial key
19389 generation, the initial certification request to the Let's Encrypt
19390 service, the web server challenge/response integration, writing the
19391 certificate to disk, the automated periodic renewals, and the deployment
19392 tasks associated with the renewal (e.g.@: reloading services, copying keys
19393 with different permissions).
19395 Certbot is run twice a day, at a random minute within the hour. It
19396 won't do anything until your certificates are due for renewal or
19397 revoked, but running it regularly would give your service a chance of
19398 staying online in case a Let's Encrypt-initiated revocation happened for
19401 By using this service, you agree to the ACME Subscriber Agreement, which
19402 can be found there:
19403 @url{https://acme-v01.api.letsencrypt.org/directory}.
19405 @defvr {Scheme Variable} certbot-service-type
19406 A service type for the @code{certbot} Let's Encrypt client. Its value
19407 must be a @code{certbot-configuration} record as in this example:
19410 (define %nginx-deploy-hook
19412 "nginx-deploy-hook"
19413 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19414 (kill pid SIGHUP))))
19416 (service certbot-service-type
19417 (certbot-configuration
19418 (email "foo@@example.net")
19421 (certificate-configuration
19422 (domains '("example.net" "www.example.net"))
19423 (deploy-hook %nginx-deploy-hook))
19424 (certificate-configuration
19425 (domains '("bar.example.net")))))))
19428 See below for details about @code{certbot-configuration}.
19431 @deftp {Data Type} certbot-configuration
19432 Data type representing the configuration of the @code{certbot} service.
19433 This type has the following parameters:
19436 @item @code{package} (default: @code{certbot})
19437 The certbot package to use.
19439 @item @code{webroot} (default: @code{/var/www})
19440 The directory from which to serve the Let's Encrypt challenge/response
19443 @item @code{certificates} (default: @code{()})
19444 A list of @code{certificates-configuration}s for which to generate
19445 certificates and request signatures. Each certificate has a @code{name}
19446 and several @code{domains}.
19449 Mandatory email used for registration, recovery contact, and important
19450 account notifications.
19452 @item @code{rsa-key-size} (default: @code{2048})
19453 Size of the RSA key.
19455 @item @code{default-location} (default: @i{see below})
19456 The default @code{nginx-location-configuration}. Because @code{certbot}
19457 needs to be able to serve challenges and responses, it needs to be able
19458 to run a web server. It does so by extending the @code{nginx} web
19459 service with an @code{nginx-server-configuration} listening on the
19460 @var{domains} on port 80, and which has a
19461 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19462 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19463 these nginx configuration data types.
19465 Requests to other URL paths will be matched by the
19466 @code{default-location}, which if present is added to all
19467 @code{nginx-server-configuration}s.
19469 By default, the @code{default-location} will issue a redirect from
19470 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19471 you to define what to serve on your site via @code{https}.
19473 Pass @code{#f} to not issue a default location.
19477 @deftp {Data Type} certificate-configuration
19478 Data type representing the configuration of a certificate.
19479 This type has the following parameters:
19482 @item @code{name} (default: @i{see below})
19483 This name is used by Certbot for housekeeping and in file paths; it
19484 doesn't affect the content of the certificate itself. To see
19485 certificate names, run @code{certbot certificates}.
19487 Its default is the first provided domain.
19489 @item @code{domains} (default: @code{()})
19490 The first domain provided will be the subject CN of the certificate, and
19491 all domains will be Subject Alternative Names on the certificate.
19493 @item @code{challenge} (default: @code{#f})
19494 The challenge type that has to be run by certbot. If @code{#f} is specified,
19495 default to the HTTP challenge. If a value is specified, defaults to the
19496 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
19497 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
19499 @item @code{authentication-hook} (default: @code{#f})
19500 Command to be run in a shell once for each certificate challenge to be
19501 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
19502 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
19503 contains the validation string and @code{$CERTBOT_TOKEN} contains the
19504 file name of the resource requested when performing an HTTP-01 challenge.
19506 @item @code{cleanup-hook} (default: @code{#f})
19507 Command to be run in a shell once for each certificate challenge that
19508 have been answered by the @code{auth-hook}. For this command, the shell
19509 variables available in the @code{auth-hook} script are still available, and
19510 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
19511 of the @code{auth-hook} script.
19513 @item @code{deploy-hook} (default: @code{#f})
19514 Command to be run in a shell once for each successfully issued
19515 certificate. For this command, the shell variable
19516 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19517 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19518 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19519 contain a space-delimited list of renewed certificate domains (for
19520 example, @samp{"example.com www.example.com"}.
19525 For each @code{certificate-configuration}, the certificate is saved to
19526 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19527 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19529 @subsection DNS Services
19530 @cindex DNS (domain name system)
19531 @cindex domain name system (DNS)
19533 The @code{(gnu services dns)} module provides services related to the
19534 @dfn{domain name system} (DNS). It provides a server service for hosting
19535 an @emph{authoritative} DNS server for multiple zones, slave or master.
19536 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19537 caching and forwarding DNS server for the LAN, which uses
19538 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19540 @subsubheading Knot Service
19542 An example configuration of an authoritative server for two zones, one master
19546 (define-zone-entries example.org.zone
19547 ;; Name TTL Class Type Data
19548 ("@@" "" "IN" "A" "127.0.0.1")
19549 ("@@" "" "IN" "NS" "ns")
19550 ("ns" "" "IN" "A" "127.0.0.1"))
19552 (define master-zone
19553 (knot-zone-configuration
19554 (domain "example.org")
19556 (origin "example.org")
19557 (entries example.org.zone)))))
19560 (knot-zone-configuration
19561 (domain "plop.org")
19562 (dnssec-policy "default")
19563 (master (list "plop-master"))))
19565 (define plop-master
19566 (knot-remote-configuration
19568 (address (list "208.76.58.171"))))
19572 (services (cons* (service knot-service-type
19573 (knot-configuration
19574 (remotes (list plop-master))
19575 (zones (list master-zone slave-zone))))
19580 @deffn {Scheme Variable} knot-service-type
19581 This is the type for the Knot DNS server.
19583 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19584 zones, that is to say domain names you would buy from a registrar. This server
19585 is not a resolver, meaning that it can only resolve names for which it is
19586 authoritative. This server can be configured to serve zones as a master server
19587 or a slave server as a per-zone basis. Slave zones will get their data from
19588 masters, and will serve it as an authoritative server. From the point of view
19589 of a resolver, there is no difference between master and slave.
19591 The following data types are used to configure the Knot DNS server:
19594 @deftp {Data Type} knot-key-configuration
19595 Data type representing a key.
19596 This type has the following parameters:
19599 @item @code{id} (default: @code{""})
19600 An identifier for other configuration fields to refer to this key. IDs must
19601 be unique and must not be empty.
19603 @item @code{algorithm} (default: @code{#f})
19604 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19605 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19606 and @code{'hmac-sha512}.
19608 @item @code{secret} (default: @code{""})
19609 The secret key itself.
19614 @deftp {Data Type} knot-acl-configuration
19615 Data type representing an Access Control List (ACL) configuration.
19616 This type has the following parameters:
19619 @item @code{id} (default: @code{""})
19620 An identifier for ether configuration fields to refer to this key. IDs must be
19621 unique and must not be empty.
19623 @item @code{address} (default: @code{'()})
19624 An ordered list of IP addresses, network subnets, or network ranges represented
19625 with strings. The query must match one of them. Empty value means that
19626 address match is not required.
19628 @item @code{key} (default: @code{'()})
19629 An ordered list of references to keys represented with strings. The string
19630 must match a key ID defined in a @code{knot-key-configuration}. No key means
19631 that a key is not require to match that ACL.
19633 @item @code{action} (default: @code{'()})
19634 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19635 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19636 and @code{'update}.
19638 @item @code{deny?} (default: @code{#f})
19639 When true, the ACL defines restrictions. Listed actions are forbidden. When
19640 false, listed actions are allowed.
19645 @deftp {Data Type} zone-entry
19646 Data type represnting a record entry in a zone file.
19647 This type has the following parameters:
19650 @item @code{name} (default: @code{"@@"})
19651 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19652 are relative to the origin of the zone. For example, in the @code{example.org}
19653 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19654 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19655 refers to @code{ns.example.org}.
19657 @item @code{ttl} (default: @code{""})
19658 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19660 @item @code{class} (default: @code{"IN"})
19661 The class of the record. Knot currently supports only @code{"IN"} and
19662 partially @code{"CH"}.
19664 @item @code{type} (default: @code{"A"})
19665 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19666 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19669 @item @code{data} (default: @code{""})
19670 The data contained in the record. For instance an IP address associated with
19671 an A record, or a domain name associated with an NS record. Remember that
19672 domain names are relative to the origin unless they end with a dot.
19677 @deftp {Data Type} zone-file
19678 Data type representing the content of a zone file.
19679 This type has the following parameters:
19682 @item @code{entries} (default: @code{'()})
19683 The list of entries. The SOA record is taken care of, so you don't need to
19684 put it in the list of entries. This list should probably contain an entry
19685 for your primary authoritative DNS server. Other than using a list of entries
19686 directly, you can use @code{define-zone-entries} to define a object containing
19687 the list of entries more easily, that you can later pass to the @code{entries}
19688 field of the @code{zone-file}.
19690 @item @code{origin} (default: @code{""})
19691 The name of your zone. This parameter cannot be empty.
19693 @item @code{ns} (default: @code{"ns"})
19694 The domain of your primary authoritative DNS server. The name is relative to
19695 the origin, unless it ends with a dot. It is mandatory that this primary
19696 DNS server corresponds to an NS record in the zone and that it is associated
19697 to an IP address in the list of entries.
19699 @item @code{mail} (default: @code{"hostmaster"})
19700 An email address people can contact you at, as the owner of the zone. This
19701 is translated as @code{<mail>@@<origin>}.
19703 @item @code{serial} (default: @code{1})
19704 The serial number of the zone. As this is used to keep track of changes by
19705 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19706 Always increment it when you make a change in your zone.
19708 @item @code{refresh} (default: @code{(* 2 24 3600)})
19709 The frequency at which slaves will do a zone transfer. This value is a number
19710 of seconds. It can be computed by multiplications or with
19711 @code{(string->duration)}.
19713 @item @code{retry} (default: @code{(* 15 60)})
19714 The period after which a slave will retry to contact its master when it fails
19715 to do so a first time.
19717 @item @code{expiry} (default: @code{(* 14 24 3600)})
19718 Default TTL of records. Existing records are considered correct for at most
19719 this amount of time. After this period, resolvers will invalidate their cache
19720 and check again that it still exists.
19722 @item @code{nx} (default: @code{3600})
19723 Default TTL of inexistant records. This delay is usually short because you want
19724 your new domains to reach everyone quickly.
19729 @deftp {Data Type} knot-remote-configuration
19730 Data type representing a remote configuration.
19731 This type has the following parameters:
19734 @item @code{id} (default: @code{""})
19735 An identifier for other configuration fields to refer to this remote. IDs must
19736 be unique and must not be empty.
19738 @item @code{address} (default: @code{'()})
19739 An ordered list of destination IP addresses. Addresses are tried in sequence.
19740 An optional port can be given with the @@ separator. For instance:
19741 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19743 @item @code{via} (default: @code{'()})
19744 An ordered list of source IP addresses. An empty list will have Knot choose
19745 an appropriate source IP. An optional port can be given with the @@ separator.
19746 The default is to choose at random.
19748 @item @code{key} (default: @code{#f})
19749 A reference to a key, that is a string containing the identifier of a key
19750 defined in a @code{knot-key-configuration} field.
19755 @deftp {Data Type} knot-keystore-configuration
19756 Data type representing a keystore to hold dnssec keys.
19757 This type has the following parameters:
19760 @item @code{id} (default: @code{""})
19761 The id of the keystore. It must not be empty.
19763 @item @code{backend} (default: @code{'pem})
19764 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19766 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19767 The configuration string of the backend. An example for the PKCS#11 is:
19768 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19769 For the pem backend, the string reprensents a path in the file system.
19774 @deftp {Data Type} knot-policy-configuration
19775 Data type representing a dnssec policy. Knot DNS is able to automatically
19776 sign your zones. It can either generate and manage your keys automatically or
19777 use keys that you generate.
19779 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19780 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19781 zone. In order to be trusted, the KSK needs to be present in the parent zone
19782 (usually a top-level domain). If your registrar supports dnssec, you will
19783 have to send them your KSK's hash so they can add a DS record in their zone.
19784 This is not automated and need to be done each time you change your KSK.
19786 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19787 easily and use weaker cryptographic functions (they use lower parameters) in
19788 order to sign records quickly, so they are changed often. The KSK however
19789 requires manual interaction with the registrar, so they are changed less often
19790 and use stronger parameters because they sign only one record.
19792 This type has the following parameters:
19795 @item @code{id} (default: @code{""})
19796 The id of the policy. It must not be empty.
19798 @item @code{keystore} (default: @code{"default"})
19799 A reference to a keystore, that is a string containing the identifier of a
19800 keystore defined in a @code{knot-keystore-configuration} field. The
19801 @code{"default"} identifier means the default keystore (a kasp database that
19802 was setup by this service).
19804 @item @code{manual?} (default: @code{#f})
19805 Whether the key management is manual or automatic.
19807 @item @code{single-type-signing?} (default: @code{#f})
19808 When @code{#t}, use the Single-Type Signing Scheme.
19810 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19811 An algorithm of signing keys and issued signatures.
19813 @item @code{ksk-size} (default: @code{256})
19814 The length of the KSK. Note that this value is correct for the default
19815 algorithm, but would be unsecure for other algorithms.
19817 @item @code{zsk-size} (default: @code{256})
19818 The length of the ZSK. Note that this value is correct for the default
19819 algorithm, but would be unsecure for other algorithms.
19821 @item @code{dnskey-ttl} (default: @code{'default})
19822 The TTL value for DNSKEY records added into zone apex. The special
19823 @code{'default} value means same as the zone SOA TTL.
19825 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19826 The period between ZSK publication and the next rollover initiation.
19828 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19829 An extra delay added for each key rollover step. This value should be high
19830 enough to cover propagation of data from the master server to all slaves.
19832 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19833 A validity period of newly issued signatures.
19835 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19836 A period how long before a signature expiration the signature will be refreshed.
19838 @item @code{nsec3?} (default: @code{#f})
19839 When @code{#t}, NSEC3 will be used instead of NSEC.
19841 @item @code{nsec3-iterations} (default: @code{5})
19842 The number of additional times the hashing is performed.
19844 @item @code{nsec3-salt-length} (default: @code{8})
19845 The length of a salt field in octets, which is appended to the original owner
19846 name before hashing.
19848 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19849 The validity period of newly issued salt field.
19854 @deftp {Data Type} knot-zone-configuration
19855 Data type representing a zone served by Knot.
19856 This type has the following parameters:
19859 @item @code{domain} (default: @code{""})
19860 The domain served by this configuration. It must not be empty.
19862 @item @code{file} (default: @code{""})
19863 The file where this zone is saved. This parameter is ignored by master zones.
19864 Empty means default location that depends on the domain name.
19866 @item @code{zone} (default: @code{(zone-file)})
19867 The content of the zone file. This parameter is ignored by slave zones. It
19868 must contain a zone-file record.
19870 @item @code{master} (default: @code{'()})
19871 A list of master remotes. When empty, this zone is a master. When set, this
19872 zone is a slave. This is a list of remotes identifiers.
19874 @item @code{ddns-master} (default: @code{#f})
19875 The main master. When empty, it defaults to the first master in the list of
19878 @item @code{notify} (default: @code{'()})
19879 A list of slave remote identifiers.
19881 @item @code{acl} (default: @code{'()})
19882 A list of acl identifiers.
19884 @item @code{semantic-checks?} (default: @code{#f})
19885 When set, this adds more semantic checks to the zone.
19887 @item @code{disable-any?} (default: @code{#f})
19888 When set, this forbids queries of the ANY type.
19890 @item @code{zonefile-sync} (default: @code{0})
19891 The delay between a modification in memory and on disk. 0 means immediate
19894 @item @code{zonefile-load} (default: @code{#f})
19895 The way the zone file contents are applied during zone load. Possible values
19899 @item @code{#f} for using the default value from Knot,
19900 @item @code{'none} for not using the zone file at all,
19901 @item @code{'difference} for computing the difference between already available
19902 contents and zone contents and applying it to the current zone contents,
19903 @item @code{'difference-no-serial} for the same as @code{'difference}, but
19904 ignoring the SOA serial in the zone file, while the server takes care of it
19906 @item @code{'whole} for loading zone contents from the zone file.
19909 @item @code{journal-content} (default: @code{#f})
19910 The way the journal is used to store zone and its changes. Possible values
19911 are @code{'none} to not use it at all, @code{'changes} to store changes and
19912 @code{'all} to store contents. @code{#f} does not set this option, so the
19913 default value from Knot is used.
19915 @item @code{max-journal-usage} (default: @code{#f})
19916 The maximum size for the journal on disk. @code{#f} does not set this option,
19917 so the default value from Knot is used.
19919 @item @code{max-journal-depth} (default: @code{#f})
19920 The maximum size of the history. @code{#f} does not set this option, so the
19921 default value from Knot is used.
19923 @item @code{max-zone-size} (default: @code{#f})
19924 The maximum size of the zone file. This limit is enforced for incoming
19925 transfer and updates. @code{#f} does not set this option, so the default
19926 value from Knot is used.
19928 @item @code{dnssec-policy} (default: @code{#f})
19929 A reference to a @code{knot-policy-configuration} record, or the special
19930 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
19933 @item @code{serial-policy} (default: @code{'increment})
19934 A policy between @code{'increment} and @code{'unixtime}.
19939 @deftp {Data Type} knot-configuration
19940 Data type representing the Knot configuration.
19941 This type has the following parameters:
19944 @item @code{knot} (default: @code{knot})
19947 @item @code{run-directory} (default: @code{"/var/run/knot"})
19948 The run directory. This directory will be used for pid file and sockets.
19950 @item @code{includes} (default: @code{'()})
19951 A list of strings or file-like objects denoting other files that must be
19952 included at the top of the configuration file.
19954 @cindex secrets, Knot service
19955 This can be used to manage secrets out-of-band. For example, secret
19956 keys may be stored in an out-of-band file not managed by Guix, and
19957 thus not visible in @file{/gnu/store}---e.g., you could store secret
19958 key configuration in @file{/etc/knot/secrets.conf} and add this file
19959 to the @code{includes} list.
19961 It can also be used to add configuration not supported by this interface.
19963 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19964 An ip address on which to listen.
19966 @item @code{listen-v6} (default: @code{"::"})
19967 An ip address on which to listen.
19969 @item @code{listen-port} (default: @code{53})
19970 A port on which to listen.
19972 @item @code{keys} (default: @code{'()})
19973 The list of knot-key-configuration used by this configuration.
19975 @item @code{acls} (default: @code{'()})
19976 The list of knot-acl-configuration used by this configuration.
19978 @item @code{remotes} (default: @code{'()})
19979 The list of knot-remote-configuration used by this configuration.
19981 @item @code{zones} (default: @code{'()})
19982 The list of knot-zone-configuration used by this configuration.
19987 @subsubheading Dnsmasq Service
19989 @deffn {Scheme Variable} dnsmasq-service-type
19990 This is the type of the dnsmasq service, whose value should be an
19991 @code{dnsmasq-configuration} object as in this example:
19994 (service dnsmasq-service-type
19995 (dnsmasq-configuration
19997 (servers '("192.168.1.1"))))
20001 @deftp {Data Type} dnsmasq-configuration
20002 Data type representing the configuration of dnsmasq.
20005 @item @code{package} (default: @var{dnsmasq})
20006 Package object of the dnsmasq server.
20008 @item @code{no-hosts?} (default: @code{#f})
20009 When true, don't read the hostnames in /etc/hosts.
20011 @item @code{port} (default: @code{53})
20012 The port to listen on. Setting this to zero completely disables DNS
20013 responses, leaving only DHCP and/or TFTP functions.
20015 @item @code{local-service?} (default: @code{#t})
20016 Accept DNS queries only from hosts whose address is on a local subnet,
20017 ie a subnet for which an interface exists on the server.
20019 @item @code{listen-addresses} (default: @code{'()})
20020 Listen on the given IP addresses.
20022 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20023 The file to read the IP address of the upstream nameservers from.
20025 @item @code{no-resolv?} (default: @code{#f})
20026 When true, don't read @var{resolv-file}.
20028 @item @code{servers} (default: @code{'()})
20029 Specify IP address of upstream servers directly.
20031 @item @code{cache-size} (default: @code{150})
20032 Set the size of dnsmasq's cache. Setting the cache size to zero
20035 @item @code{negative-cache?} (default: @code{#t})
20036 When false, disable negative caching.
20041 @subsubheading ddclient Service
20044 The ddclient service described below runs the ddclient daemon, which takes
20045 care of automatically updating DNS entries for service providers such as
20046 @uref{https://dyn.com/dns/, Dyn}.
20048 The following example show instantiates the service with its default
20052 (service ddclient-service-type)
20055 Note that ddclient needs to access credentials that are stored in a
20056 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20057 @code{secret-file} below.) You are expected to create this file manually, in
20058 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20059 service configuration, for instance by using @code{plain-file}, but it will be
20060 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20061 @file{share/ddclient} directory of the @code{ddclient} package.
20063 @c %start of fragment
20065 Available @code{ddclient-configuration} fields are:
20067 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20068 The ddclient package.
20072 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20073 The period after which ddclient will retry to check IP and domain name.
20075 Defaults to @samp{300}.
20079 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20080 Use syslog for the output.
20082 Defaults to @samp{#t}.
20086 @deftypevr {@code{ddclient-configuration} parameter} string mail
20089 Defaults to @samp{"root"}.
20093 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20094 Mail failed update to user.
20096 Defaults to @samp{"root"}.
20100 @deftypevr {@code{ddclient-configuration} parameter} string pid
20101 The ddclient PID file.
20103 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20107 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20108 Enable SSL support.
20110 Defaults to @samp{#t}.
20114 @deftypevr {@code{ddclient-configuration} parameter} string user
20115 Specifies the user name or ID that is used when running ddclient
20118 Defaults to @samp{"ddclient"}.
20122 @deftypevr {@code{ddclient-configuration} parameter} string group
20123 Group of the user who will run the ddclient program.
20125 Defaults to @samp{"ddclient"}.
20129 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20130 Secret file which will be appended to @file{ddclient.conf} file. This
20131 file contains credentials for use by ddclient. You are expected to
20132 create it manually.
20134 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20138 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20139 Extra options will be appended to @file{ddclient.conf} file.
20141 Defaults to @samp{()}.
20146 @c %end of fragment
20150 @subsection VPN Services
20151 @cindex VPN (virtual private network)
20152 @cindex virtual private network (VPN)
20154 The @code{(gnu services vpn)} module provides services related to
20155 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20156 your machine to connect to a VPN, and a @emph{server} service for your machine
20157 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20159 @deffn {Scheme Procedure} openvpn-client-service @
20160 [#:config (openvpn-client-configuration)]
20162 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20165 @deffn {Scheme Procedure} openvpn-server-service @
20166 [#:config (openvpn-server-configuration)]
20168 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20170 Both can be run simultaneously.
20173 @c %automatically generated documentation
20175 Available @code{openvpn-client-configuration} fields are:
20177 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20178 The OpenVPN package.
20182 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20183 The OpenVPN pid file.
20185 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20189 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20190 The protocol (UDP or TCP) used to open a channel between clients and
20193 Defaults to @samp{udp}.
20197 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20198 The device type used to represent the VPN connection.
20200 Defaults to @samp{tun}.
20204 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20205 The certificate authority to check connections against.
20207 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20211 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20212 The certificate of the machine the daemon is running on. It should be
20213 signed by the authority given in @code{ca}.
20215 Defaults to @samp{"/etc/openvpn/client.crt"}.
20219 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20220 The key of the machine the daemon is running on. It must be the key whose
20221 certificate is @code{cert}.
20223 Defaults to @samp{"/etc/openvpn/client.key"}.
20227 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20228 Whether to use the lzo compression algorithm.
20230 Defaults to @samp{#t}.
20234 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20235 Don't re-read key files across SIGUSR1 or --ping-restart.
20237 Defaults to @samp{#t}.
20241 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20242 Don't close and reopen TUN/TAP device or run up/down scripts across
20243 SIGUSR1 or --ping-restart restarts.
20245 Defaults to @samp{#t}.
20249 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20252 Defaults to @samp{3}.
20256 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20257 Add an additional layer of HMAC authentication on top of the TLS control
20258 channel to protect against DoS attacks.
20260 Defaults to @samp{#f}.
20264 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20265 Whether to check the server certificate has server usage extension.
20267 Defaults to @samp{#t}.
20271 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20272 Bind to a specific local port number.
20274 Defaults to @samp{#f}.
20278 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20279 Retry resolving server address.
20281 Defaults to @samp{#t}.
20285 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20286 A list of remote servers to connect to.
20288 Defaults to @samp{()}.
20290 Available @code{openvpn-remote-configuration} fields are:
20292 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20295 Defaults to @samp{"my-server"}.
20299 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20300 Port number the server listens to.
20302 Defaults to @samp{1194}.
20307 @c %end of automatic openvpn-client documentation
20309 @c %automatically generated documentation
20311 Available @code{openvpn-server-configuration} fields are:
20313 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20314 The OpenVPN package.
20318 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20319 The OpenVPN pid file.
20321 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20325 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20326 The protocol (UDP or TCP) used to open a channel between clients and
20329 Defaults to @samp{udp}.
20333 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20334 The device type used to represent the VPN connection.
20336 Defaults to @samp{tun}.
20340 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20341 The certificate authority to check connections against.
20343 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20347 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20348 The certificate of the machine the daemon is running on. It should be
20349 signed by the authority given in @code{ca}.
20351 Defaults to @samp{"/etc/openvpn/client.crt"}.
20355 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20356 The key of the machine the daemon is running on. It must be the key whose
20357 certificate is @code{cert}.
20359 Defaults to @samp{"/etc/openvpn/client.key"}.
20363 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20364 Whether to use the lzo compression algorithm.
20366 Defaults to @samp{#t}.
20370 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20371 Don't re-read key files across SIGUSR1 or --ping-restart.
20373 Defaults to @samp{#t}.
20377 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20378 Don't close and reopen TUN/TAP device or run up/down scripts across
20379 SIGUSR1 or --ping-restart restarts.
20381 Defaults to @samp{#t}.
20385 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20388 Defaults to @samp{3}.
20392 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20393 Add an additional layer of HMAC authentication on top of the TLS control
20394 channel to protect against DoS attacks.
20396 Defaults to @samp{#f}.
20400 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20401 Specifies the port number on which the server listens.
20403 Defaults to @samp{1194}.
20407 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20408 An ip and mask specifying the subnet inside the virtual network.
20410 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20414 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20415 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20417 Defaults to @samp{#f}.
20421 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20422 The Diffie-Hellman parameters file.
20424 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20428 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20429 The file that records client IPs.
20431 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20435 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20436 When true, the server will act as a gateway for its clients.
20438 Defaults to @samp{#f}.
20442 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20443 When true, clients are allowed to talk to each other inside the VPN.
20445 Defaults to @samp{#f}.
20449 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20450 Causes ping-like messages to be sent back and forth over the link so
20451 that each side knows when the other side has gone down. @code{keepalive}
20452 requires a pair. The first element is the period of the ping sending,
20453 and the second element is the timeout before considering the other side
20458 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20459 The maximum number of clients.
20461 Defaults to @samp{100}.
20465 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20466 The status file. This file shows a small report on current connection.
20467 It is truncated and rewritten every minute.
20469 Defaults to @samp{"/var/run/openvpn/status"}.
20473 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20474 The list of configuration for some clients.
20476 Defaults to @samp{()}.
20478 Available @code{openvpn-ccd-configuration} fields are:
20480 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20483 Defaults to @samp{"client"}.
20487 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20490 Defaults to @samp{#f}.
20494 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20497 Defaults to @samp{#f}.
20504 @c %end of automatic openvpn-server documentation
20507 @node Network File System
20508 @subsection Network File System
20511 The @code{(gnu services nfs)} module provides the following services,
20512 which are most commonly used in relation to mounting or exporting
20513 directory trees as @dfn{network file systems} (NFS).
20515 @subsubheading RPC Bind Service
20518 The RPC Bind service provides a facility to map program numbers into
20519 universal addresses.
20520 Many NFS related services use this facility. Hence it is automatically
20521 started when a dependent service starts.
20523 @defvr {Scheme Variable} rpcbind-service-type
20524 A service type for the RPC portmapper daemon.
20528 @deftp {Data Type} rpcbind-configuration
20529 Data type representing the configuration of the RPC Bind Service.
20530 This type has the following parameters:
20532 @item @code{rpcbind} (default: @code{rpcbind})
20533 The rpcbind package to use.
20535 @item @code{warm-start?} (default: @code{#t})
20536 If this parameter is @code{#t}, then the daemon will read a
20537 state file on startup thus reloading state information saved by a previous
20543 @subsubheading Pipefs Pseudo File System
20547 The pipefs file system is used to transfer NFS related data
20548 between the kernel and user space programs.
20550 @defvr {Scheme Variable} pipefs-service-type
20551 A service type for the pipefs pseudo file system.
20554 @deftp {Data Type} pipefs-configuration
20555 Data type representing the configuration of the pipefs pseudo file system service.
20556 This type has the following parameters:
20558 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20559 The directory to which the file system is to be attached.
20564 @subsubheading GSS Daemon Service
20567 @cindex global security system
20569 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20571 Before exchanging RPC requests an RPC client must establish a security
20572 context. Typically this is done using the Kerberos command @command{kinit}
20573 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20575 @defvr {Scheme Variable} gss-service-type
20576 A service type for the Global Security System (GSS) daemon.
20579 @deftp {Data Type} gss-configuration
20580 Data type representing the configuration of the GSS daemon service.
20581 This type has the following parameters:
20583 @item @code{nfs-utils} (default: @code{nfs-utils})
20584 The package in which the @command{rpc.gssd} command is to be found.
20586 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20587 The directory where the pipefs file system is mounted.
20593 @subsubheading IDMAP Daemon Service
20595 @cindex name mapper
20597 The idmap daemon service provides mapping between user IDs and user names.
20598 Typically it is required in order to access file systems mounted via NFSv4.
20600 @defvr {Scheme Variable} idmap-service-type
20601 A service type for the Identity Mapper (IDMAP) daemon.
20604 @deftp {Data Type} idmap-configuration
20605 Data type representing the configuration of the IDMAP daemon service.
20606 This type has the following parameters:
20608 @item @code{nfs-utils} (default: @code{nfs-utils})
20609 The package in which the @command{rpc.idmapd} command is to be found.
20611 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20612 The directory where the pipefs file system is mounted.
20614 @item @code{domain} (default: @code{#f})
20615 The local NFSv4 domain name.
20616 This must be a string or @code{#f}.
20617 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20622 @node Continuous Integration
20623 @subsection Continuous Integration
20625 @cindex continuous integration
20626 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20627 continuous integration tool for Guix. It can be used both for development and
20628 for providing substitutes to others (@pxref{Substitutes}).
20630 The @code{(gnu services cuirass)} module provides the following service.
20632 @defvr {Scheme Procedure} cuirass-service-type
20633 The type of the Cuirass service. Its value must be a
20634 @code{cuirass-configuration} object, as described below.
20637 To add build jobs, you have to set the @code{specifications} field of the
20638 configuration. Here is an example of a service that polls the Guix repository
20639 and builds the packages from a manifest. Some of the packages are defined in
20640 the @code{"custom-packages"} input, which is the equivalent of
20641 @code{GUIX_PACKAGE_PATH}.
20644 (define %cuirass-specs
20646 '((#:name . "my-manifest")
20647 (#:load-path-inputs . ("guix"))
20648 (#:package-path-inputs . ("custom-packages"))
20649 (#:proc-input . "guix")
20650 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20651 (#:proc . cuirass-jobs)
20652 (#:proc-args . ((subset . "manifests")
20653 (systems . ("x86_64-linux"))
20654 (manifests . (("config" . "guix/manifest.scm")))))
20655 (#:inputs . (((#:name . "guix")
20656 (#:url . "git://git.savannah.gnu.org/guix.git")
20657 (#:load-path . ".")
20658 (#:branch . "master")
20659 (#:no-compile? . #t))
20660 ((#:name . "config")
20661 (#:url . "git://git.example.org/config.git")
20662 (#:load-path . ".")
20663 (#:branch . "master")
20664 (#:no-compile? . #t))
20665 ((#:name . "custom-packages")
20666 (#:url . "git://git.example.org/custom-packages.git")
20667 (#:load-path . ".")
20668 (#:branch . "master")
20669 (#:no-compile? . #t)))))))
20671 (service cuirass-service-type
20672 (cuirass-configuration
20673 (specifications %cuirass-specs)))
20676 While information related to build jobs is located directly in the
20677 specifications, global settings for the @command{cuirass} process are
20678 accessible in other @code{cuirass-configuration} fields.
20680 @deftp {Data Type} cuirass-configuration
20681 Data type representing the configuration of Cuirass.
20684 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20685 Location of the log file.
20687 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20688 Location of the repository cache.
20690 @item @code{user} (default: @code{"cuirass"})
20691 Owner of the @code{cuirass} process.
20693 @item @code{group} (default: @code{"cuirass"})
20694 Owner's group of the @code{cuirass} process.
20696 @item @code{interval} (default: @code{60})
20697 Number of seconds between the poll of the repositories followed by the
20700 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20701 Location of sqlite database which contains the build results and previously
20702 added specifications.
20704 @item @code{ttl} (default: @code{(* 30 24 3600)})
20705 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20706 are registered for build results. This means that build results are protected
20707 from garbage collection for at least @var{ttl} seconds.
20709 @item @code{port} (default: @code{8081})
20710 Port number used by the HTTP server.
20712 @item --listen=@var{host}
20713 Listen on the network interface for @var{host}. The default is to
20714 accept connections from localhost.
20716 @item @code{specifications} (default: @code{#~'()})
20717 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20718 where a specification is an association list
20719 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20720 keys are keywords (@code{#:keyword-example}) as shown in the example
20723 @item @code{use-substitutes?} (default: @code{#f})
20724 This allows using substitutes to avoid building every dependencies of a job
20727 @item @code{one-shot?} (default: @code{#f})
20728 Only evaluate specifications and build derivations once.
20730 @item @code{fallback?} (default: @code{#f})
20731 When substituting a pre-built binary fails, fall back to building
20734 @item @code{cuirass} (default: @code{cuirass})
20735 The Cuirass package to use.
20739 @node Power Management Services
20740 @subsection Power Management Services
20743 @cindex power management with TLP
20744 @subsubheading TLP daemon
20746 The @code{(gnu services pm)} module provides a Guix service definition
20747 for the Linux power management tool TLP.
20749 TLP enables various powersaving modes in userspace and kernel.
20750 Contrary to @code{upower-service}, it is not a passive,
20751 monitoring tool, as it will apply custom settings each time a new power
20752 source is detected. More information can be found at
20753 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
20755 @deffn {Scheme Variable} tlp-service-type
20756 The service type for the TLP tool. Its value should be a valid
20757 TLP configuration (see below). To use the default settings, simply
20760 (service tlp-service-type)
20764 By default TLP does not need much configuration but most TLP parameters
20765 can be tweaked using @code{tlp-configuration}.
20767 Each parameter definition is preceded by its type; for example,
20768 @samp{boolean foo} indicates that the @code{foo} parameter
20769 should be specified as a boolean. Types starting with
20770 @code{maybe-} denote parameters that won't show up in TLP config file
20771 when their value is @code{'disabled}.
20773 @c The following documentation was initially generated by
20774 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20775 @c documentation is better, so we shouldn't hesitate to edit below as
20776 @c needed. However if the change you want to make to this documentation
20777 @c can be done in an automated way, it's probably easier to change
20778 @c (generate-documentation) than to make it below and have to deal with
20779 @c the churn as TLP updates.
20781 Available @code{tlp-configuration} fields are:
20783 @deftypevr {@code{tlp-configuration} parameter} package tlp
20788 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20789 Set to true if you wish to enable TLP.
20791 Defaults to @samp{#t}.
20795 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20796 Default mode when no power supply can be detected. Alternatives are AC
20799 Defaults to @samp{"AC"}.
20803 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20804 Number of seconds Linux kernel has to wait after the disk goes idle,
20805 before syncing on AC.
20807 Defaults to @samp{0}.
20811 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20812 Same as @code{disk-idle-ac} but on BAT mode.
20814 Defaults to @samp{2}.
20818 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20819 Dirty pages flushing periodicity, expressed in seconds.
20821 Defaults to @samp{15}.
20825 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20826 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20828 Defaults to @samp{60}.
20832 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20833 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20834 alternatives are powersave and performance. With acpi-cpufreq driver,
20835 alternatives are ondemand, powersave, performance and conservative.
20837 Defaults to @samp{disabled}.
20841 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20842 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20844 Defaults to @samp{disabled}.
20848 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20849 Set the min available frequency for the scaling governor on AC.
20851 Defaults to @samp{disabled}.
20855 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20856 Set the max available frequency for the scaling governor on AC.
20858 Defaults to @samp{disabled}.
20862 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20863 Set the min available frequency for the scaling governor on BAT.
20865 Defaults to @samp{disabled}.
20869 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20870 Set the max available frequency for the scaling governor on BAT.
20872 Defaults to @samp{disabled}.
20876 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20877 Limit the min P-state to control the power dissipation of the CPU, in AC
20878 mode. Values are stated as a percentage of the available performance.
20880 Defaults to @samp{disabled}.
20884 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20885 Limit the max P-state to control the power dissipation of the CPU, in AC
20886 mode. Values are stated as a percentage of the available performance.
20888 Defaults to @samp{disabled}.
20892 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20893 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20895 Defaults to @samp{disabled}.
20899 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20900 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20902 Defaults to @samp{disabled}.
20906 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20907 Enable CPU turbo boost feature on AC mode.
20909 Defaults to @samp{disabled}.
20913 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20914 Same as @code{cpu-boost-on-ac?} on BAT mode.
20916 Defaults to @samp{disabled}.
20920 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20921 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20922 used under light load conditions.
20924 Defaults to @samp{#f}.
20928 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20929 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20931 Defaults to @samp{#t}.
20935 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20936 Enable Linux kernel NMI watchdog.
20938 Defaults to @samp{#f}.
20942 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20943 For Linux kernels with PHC patch applied, change CPU voltages. An
20944 example value would be @samp{"F:V F:V F:V F:V"}.
20946 Defaults to @samp{disabled}.
20950 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20951 Set CPU performance versus energy saving policy on AC. Alternatives are
20952 performance, normal, powersave.
20954 Defaults to @samp{"performance"}.
20958 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20959 Same as @code{energy-perf-policy-ac} but on BAT mode.
20961 Defaults to @samp{"powersave"}.
20965 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20970 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20971 Hard disk advanced power management level.
20975 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20976 Same as @code{disk-apm-bat} but on BAT mode.
20980 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20981 Hard disk spin down timeout. One value has to be specified for each
20982 declared hard disk.
20984 Defaults to @samp{disabled}.
20988 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20989 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20991 Defaults to @samp{disabled}.
20995 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20996 Select IO scheduler for disk devices. One value has to be specified for
20997 each declared hard disk. Example alternatives are cfq, deadline and
21000 Defaults to @samp{disabled}.
21004 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21005 SATA aggressive link power management (ALPM) level. Alternatives are
21006 min_power, medium_power, max_performance.
21008 Defaults to @samp{"max_performance"}.
21012 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21013 Same as @code{sata-linkpwr-ac} but on BAT mode.
21015 Defaults to @samp{"min_power"}.
21019 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21020 Exclude specified SATA host devices for link power management.
21022 Defaults to @samp{disabled}.
21026 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21027 Enable Runtime Power Management for AHCI controller and disks on AC
21030 Defaults to @samp{disabled}.
21034 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21035 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21037 Defaults to @samp{disabled}.
21041 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21042 Seconds of inactivity before disk is suspended.
21044 Defaults to @samp{15}.
21048 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21049 PCI Express Active State Power Management level. Alternatives are
21050 default, performance, powersave.
21052 Defaults to @samp{"performance"}.
21056 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21057 Same as @code{pcie-aspm-ac} but on BAT mode.
21059 Defaults to @samp{"powersave"}.
21063 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21064 Radeon graphics clock speed level. Alternatives are low, mid, high,
21067 Defaults to @samp{"high"}.
21071 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21072 Same as @code{radeon-power-ac} but on BAT mode.
21074 Defaults to @samp{"low"}.
21078 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21079 Radeon dynamic power management method (DPM). Alternatives are battery,
21082 Defaults to @samp{"performance"}.
21086 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21087 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21089 Defaults to @samp{"battery"}.
21093 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21094 Radeon DPM performance level. Alternatives are auto, low, high.
21096 Defaults to @samp{"auto"}.
21100 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21101 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21103 Defaults to @samp{"auto"}.
21107 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21108 Wifi power saving mode.
21110 Defaults to @samp{#f}.
21114 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21115 Same as @code{wifi-power-ac?} but on BAT mode.
21117 Defaults to @samp{#t}.
21121 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21122 Disable wake on LAN.
21124 Defaults to @samp{#t}.
21128 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21129 Timeout duration in seconds before activating audio power saving on
21130 Intel HDA and AC97 devices. A value of 0 disables power saving.
21132 Defaults to @samp{0}.
21136 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21137 Same as @code{sound-powersave-ac} but on BAT mode.
21139 Defaults to @samp{1}.
21143 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21144 Disable controller in powersaving mode on Intel HDA devices.
21146 Defaults to @samp{#t}.
21150 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21151 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21152 powered on again by releasing (and reinserting) the eject lever or by
21153 pressing the disc eject button on newer models.
21155 Defaults to @samp{#f}.
21159 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21160 Name of the optical drive device to power off.
21162 Defaults to @samp{"sr0"}.
21166 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21167 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21170 Defaults to @samp{"on"}.
21174 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21175 Same as @code{runtime-pm-ac} but on BAT mode.
21177 Defaults to @samp{"auto"}.
21181 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21182 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21185 Defaults to @samp{#t}.
21189 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21190 Exclude specified PCI(e) device addresses from Runtime Power Management.
21192 Defaults to @samp{disabled}.
21196 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21197 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21202 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21203 Enable USB autosuspend feature.
21205 Defaults to @samp{#t}.
21209 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21210 Exclude specified devices from USB autosuspend.
21212 Defaults to @samp{disabled}.
21216 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21217 Exclude WWAN devices from USB autosuspend.
21219 Defaults to @samp{#t}.
21223 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21224 Include specified devices into USB autosuspend, even if they are already
21225 excluded by the driver or via @code{usb-blacklist-wwan?}.
21227 Defaults to @samp{disabled}.
21231 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21232 Enable USB autosuspend before shutdown.
21234 Defaults to @samp{disabled}.
21238 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21239 Restore radio device state (bluetooth, wifi, wwan) from previous
21240 shutdown on system startup.
21242 Defaults to @samp{#f}.
21247 @cindex CPU frequency scaling with thermald
21248 @subsubheading Thermald daemon
21250 The @code{(gnu services pm)} module provides an interface to
21251 thermald, a CPU frequency scaling service which helps prevent overheating.
21253 @defvr {Scheme Variable} thermald-service-type
21254 This is the service type for
21255 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21256 Thermal Daemon, which is responsible for controlling the thermal state
21257 of processors and preventing overheating.
21260 @deftp {Data Type} thermald-configuration
21261 Data type representing the configuration of @code{thermald-service-type}.
21264 @item @code{ignore-cpuid-check?} (default: @code{#f})
21265 Ignore cpuid check for supported CPU models.
21267 @item @code{thermald} (default: @var{thermald})
21268 Package object of thermald.
21273 @node Audio Services
21274 @subsection Audio Services
21276 The @code{(gnu services audio)} module provides a service to start MPD
21277 (the Music Player Daemon).
21280 @subsubheading Music Player Daemon
21282 The Music Player Daemon (MPD) is a service that can play music while
21283 being controlled from the local machine or over the network by a variety
21286 The following example shows how one might run @code{mpd} as user
21287 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21290 (service mpd-service-type
21296 @defvr {Scheme Variable} mpd-service-type
21297 The service type for @command{mpd}
21300 @deftp {Data Type} mpd-configuration
21301 Data type representing the configuration of @command{mpd}.
21304 @item @code{user} (default: @code{"mpd"})
21305 The user to run mpd as.
21307 @item @code{music-dir} (default: @code{"~/Music"})
21308 The directory to scan for music files.
21310 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21311 The directory to store playlists.
21313 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21314 The location of the music database.
21316 @item @code{state-file} (default: @code{"~/.mpd/state"})
21317 The location of the file that stores current MPD's state.
21319 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21320 The location of the sticker database.
21322 @item @code{port} (default: @code{"6600"})
21323 The port to run mpd on.
21325 @item @code{address} (default: @code{"any"})
21326 The address that mpd will bind to. To use a Unix domain socket,
21327 an absolute path can be specified here.
21332 @node Virtualization Services
21333 @subsection Virtualization services
21335 The @code{(gnu services virtualization)} module provides services for
21336 the libvirt and virtlog daemons, as well as other virtualization-related
21339 @subsubheading Libvirt daemon
21340 @code{libvirtd} is the server side daemon component of the libvirt
21341 virtualization management system. This daemon runs on host servers
21342 and performs required management tasks for virtualized guests.
21344 @deffn {Scheme Variable} libvirt-service-type
21345 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21346 Its value must be a @code{libvirt-configuration}.
21349 (service libvirt-service-type
21350 (libvirt-configuration
21351 (unix-sock-group "libvirt")
21352 (tls-port "16555")))
21356 @c Auto-generated with (generate-libvirt-documentation)
21357 Available @code{libvirt-configuration} fields are:
21359 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21364 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21365 Flag listening for secure TLS connections on the public TCP/IP port.
21366 must set @code{listen} for this to have any effect.
21368 It is necessary to setup a CA and issue server certificates before using
21371 Defaults to @samp{#t}.
21375 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21376 Listen for unencrypted TCP connections on the public TCP/IP port. must
21377 set @code{listen} for this to have any effect.
21379 Using the TCP socket requires SASL authentication by default. Only SASL
21380 mechanisms which support data encryption are allowed. This is
21381 DIGEST_MD5 and GSSAPI (Kerberos5)
21383 Defaults to @samp{#f}.
21387 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21388 Port for accepting secure TLS connections This can be a port number, or
21391 Defaults to @samp{"16514"}.
21395 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21396 Port for accepting insecure TCP connections This can be a port number,
21399 Defaults to @samp{"16509"}.
21403 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21404 IP address or hostname used for client connections.
21406 Defaults to @samp{"0.0.0.0"}.
21410 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21411 Flag toggling mDNS advertisement of the libvirt service.
21413 Alternatively can disable for all services on a host by stopping the
21416 Defaults to @samp{#f}.
21420 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21421 Default mDNS advertisement name. This must be unique on the immediate
21424 Defaults to @samp{"Virtualization Host <hostname>"}.
21428 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21429 UNIX domain socket group ownership. This can be used to allow a
21430 'trusted' set of users access to management capabilities without
21433 Defaults to @samp{"root"}.
21437 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21438 UNIX socket permissions for the R/O socket. This is used for monitoring
21441 Defaults to @samp{"0777"}.
21445 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21446 UNIX socket permissions for the R/W socket. Default allows only root.
21447 If PolicyKit is enabled on the socket, the default will change to allow
21448 everyone (eg, 0777)
21450 Defaults to @samp{"0770"}.
21454 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21455 UNIX socket permissions for the admin socket. Default allows only owner
21456 (root), do not change it unless you are sure to whom you are exposing
21459 Defaults to @samp{"0777"}.
21463 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21464 The directory in which sockets will be found/created.
21466 Defaults to @samp{"/var/run/libvirt"}.
21470 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21471 Authentication scheme for UNIX read-only sockets. By default socket
21472 permissions allow anyone to connect
21474 Defaults to @samp{"polkit"}.
21478 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21479 Authentication scheme for UNIX read-write sockets. By default socket
21480 permissions only allow root. If PolicyKit support was compiled into
21481 libvirt, the default will be to use 'polkit' auth.
21483 Defaults to @samp{"polkit"}.
21487 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21488 Authentication scheme for TCP sockets. If you don't enable SASL, then
21489 all TCP traffic is cleartext. Don't do this outside of a dev/test
21492 Defaults to @samp{"sasl"}.
21496 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21497 Authentication scheme for TLS sockets. TLS sockets already have
21498 encryption provided by the TLS layer, and limited authentication is done
21501 It is possible to make use of any SASL authentication mechanism as well,
21502 by using 'sasl' for this option
21504 Defaults to @samp{"none"}.
21508 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21509 API access control scheme.
21511 By default an authenticated user is allowed access to all APIs. Access
21512 drivers can place restrictions on this.
21514 Defaults to @samp{()}.
21518 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21519 Server key file path. If set to an empty string, then no private key is
21522 Defaults to @samp{""}.
21526 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21527 Server key file path. If set to an empty string, then no certificate is
21530 Defaults to @samp{""}.
21534 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21535 Server key file path. If set to an empty string, then no CA certificate
21538 Defaults to @samp{""}.
21542 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21543 Certificate revocation list path. If set to an empty string, then no
21546 Defaults to @samp{""}.
21550 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21551 Disable verification of our own server certificates.
21553 When libvirtd starts it performs some sanity checks against its own
21556 Defaults to @samp{#f}.
21560 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21561 Disable verification of client certificates.
21563 Client certificate verification is the primary authentication mechanism.
21564 Any client which does not present a certificate signed by the CA will be
21567 Defaults to @samp{#f}.
21571 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21572 Whitelist of allowed x509 Distinguished Name.
21574 Defaults to @samp{()}.
21578 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21579 Whitelist of allowed SASL usernames. The format for username depends on
21580 the SASL authentication mechanism.
21582 Defaults to @samp{()}.
21586 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21587 Override the compile time default TLS priority string. The default is
21588 usually "NORMAL" unless overridden at build time. Only set this is it
21589 is desired for libvirt to deviate from the global default settings.
21591 Defaults to @samp{"NORMAL"}.
21595 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21596 Maximum number of concurrent client connections to allow over all
21599 Defaults to @samp{5000}.
21603 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21604 Maximum length of queue of connections waiting to be accepted by the
21605 daemon. Note, that some protocols supporting retransmission may obey
21606 this so that a later reattempt at connection succeeds.
21608 Defaults to @samp{1000}.
21612 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21613 Maximum length of queue of accepted but not yet authenticated clients.
21614 Set this to zero to turn this feature off
21616 Defaults to @samp{20}.
21620 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21621 Number of workers to start up initially.
21623 Defaults to @samp{5}.
21627 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21628 Maximum number of worker threads.
21630 If the number of active clients exceeds @code{min-workers}, then more
21631 threads are spawned, up to max_workers limit. Typically you'd want
21632 max_workers to equal maximum number of clients allowed.
21634 Defaults to @samp{20}.
21638 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21639 Number of priority workers. If all workers from above pool are stuck,
21640 some calls marked as high priority (notably domainDestroy) can be
21641 executed in this pool.
21643 Defaults to @samp{5}.
21647 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21648 Total global limit on concurrent RPC calls.
21650 Defaults to @samp{20}.
21654 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21655 Limit on concurrent requests from a single client connection. To avoid
21656 one client monopolizing the server this should be a small fraction of
21657 the global max_requests and max_workers parameter.
21659 Defaults to @samp{5}.
21663 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21664 Same as @code{min-workers} but for the admin interface.
21666 Defaults to @samp{1}.
21670 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21671 Same as @code{max-workers} but for the admin interface.
21673 Defaults to @samp{5}.
21677 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21678 Same as @code{max-clients} but for the admin interface.
21680 Defaults to @samp{5}.
21684 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21685 Same as @code{max-queued-clients} but for the admin interface.
21687 Defaults to @samp{5}.
21691 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21692 Same as @code{max-client-requests} but for the admin interface.
21694 Defaults to @samp{5}.
21698 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21699 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21701 Defaults to @samp{3}.
21705 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21708 A filter allows to select a different logging level for a given category
21709 of logs The format for a filter is one of:
21720 where @code{name} is a string which is matched against the category
21721 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21722 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21723 be a substring of the full category name, in order to match multiple
21724 similar categories), the optional "+" prefix tells libvirt to log stack
21725 trace for each message matching name, and @code{x} is the minimal level
21726 where matching messages should be logged:
21743 Multiple filters can be defined in a single filters statement, they just
21744 need to be separated by spaces.
21746 Defaults to @samp{"3:remote 4:event"}.
21750 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21753 An output is one of the places to save logging information. The format
21754 for an output can be:
21758 output goes to stderr
21760 @item x:syslog:name
21761 use syslog for the output and use the given name as the ident
21763 @item x:file:file_path
21764 output to a file, with the given filepath
21767 output to journald logging system
21771 In all case the x prefix is the minimal level, acting as a filter
21788 Multiple outputs can be defined, they just need to be separated by
21791 Defaults to @samp{"3:stderr"}.
21795 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21796 Allows usage of the auditing subsystem to be altered
21800 0: disable all auditing
21803 1: enable auditing, only if enabled on host
21806 2: enable auditing, and exit if disabled on host.
21810 Defaults to @samp{1}.
21814 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21815 Send audit messages via libvirt logging infrastructure.
21817 Defaults to @samp{#f}.
21821 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21822 Host UUID. UUID must not have all digits be the same.
21824 Defaults to @samp{""}.
21828 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21829 Source to read host UUID.
21833 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21836 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21840 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21843 Defaults to @samp{"smbios"}.
21847 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21848 A keepalive message is sent to a client after @code{keepalive_interval}
21849 seconds of inactivity to check if the client is still responding. If
21850 set to -1, libvirtd will never send keepalive requests; however clients
21851 can still send them and the daemon will send responses.
21853 Defaults to @samp{5}.
21857 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21858 Maximum number of keepalive messages that are allowed to be sent to the
21859 client without getting any response before the connection is considered
21862 In other words, the connection is automatically closed approximately
21863 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21864 the last message received from the client. When @code{keepalive-count}
21865 is set to 0, connections will be automatically closed after
21866 @code{keepalive-interval} seconds of inactivity without sending any
21867 keepalive messages.
21869 Defaults to @samp{5}.
21873 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21874 Same as above but for admin interface.
21876 Defaults to @samp{5}.
21880 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21881 Same as above but for admin interface.
21883 Defaults to @samp{5}.
21887 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21888 Timeout for Open vSwitch calls.
21890 The @code{ovs-vsctl} utility is used for the configuration and its
21891 timeout option is set by default to 5 seconds to avoid potential
21892 infinite waits blocking libvirt.
21894 Defaults to @samp{5}.
21898 @c %end of autogenerated docs
21900 @subsubheading Virtlog daemon
21901 The virtlogd service is a server side daemon component of libvirt that is
21902 used to manage logs from virtual machine consoles.
21904 This daemon is not used directly by libvirt client applications, rather it
21905 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21906 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21907 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21908 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21910 @deffn {Scheme Variable} virtlog-service-type
21911 This is the type of the virtlog daemon.
21912 Its value must be a @code{virtlog-configuration}.
21915 (service virtlog-service-type
21916 (virtlog-configuration
21917 (max-clients 1000)))
21921 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21922 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21924 Defaults to @samp{3}.
21928 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21931 A filter allows to select a different logging level for a given category
21932 of logs The format for a filter is one of:
21943 where @code{name} is a string which is matched against the category
21944 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21945 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21946 be a substring of the full category name, in order to match multiple
21947 similar categories), the optional "+" prefix tells libvirt to log stack
21948 trace for each message matching name, and @code{x} is the minimal level
21949 where matching messages should be logged:
21966 Multiple filters can be defined in a single filters statement, they just
21967 need to be separated by spaces.
21969 Defaults to @samp{"3:remote 4:event"}.
21973 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21976 An output is one of the places to save logging information The format
21977 for an output can be:
21981 output goes to stderr
21983 @item x:syslog:name
21984 use syslog for the output and use the given name as the ident
21986 @item x:file:file_path
21987 output to a file, with the given filepath
21990 output to journald logging system
21994 In all case the x prefix is the minimal level, acting as a filter
22011 Multiple outputs can be defined, they just need to be separated by
22014 Defaults to @samp{"3:stderr"}.
22018 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22019 Maximum number of concurrent client connections to allow over all
22022 Defaults to @samp{1024}.
22026 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22027 Maximum file size before rolling over.
22029 Defaults to @samp{2MB}
22033 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22034 Maximum number of backup files to keep.
22036 Defaults to @samp{3}
22040 @subsubheading Transparent Emulation with QEMU
22043 @cindex @code{binfmt_misc}
22044 @code{qemu-binfmt-service-type} provides support for transparent
22045 emulation of program binaries built for different architectures---e.g.,
22046 it allows you to transparently execute an ARMv7 program on an x86_64
22047 machine. It achieves this by combining the @uref{https://www.qemu.org,
22048 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22050 @defvr {Scheme Variable} qemu-binfmt-service-type
22051 This is the type of the QEMU/binfmt service for transparent emulation.
22052 Its value must be a @code{qemu-binfmt-configuration} object, which
22053 specifies the QEMU package to use as well as the architecture we want to
22057 (service qemu-binfmt-service-type
22058 (qemu-binfmt-configuration
22059 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22062 In this example, we enable transparent emulation for the ARM and aarch64
22063 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22064 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22065 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22068 @deftp {Data Type} qemu-binfmt-configuration
22069 This is the configuration for the @code{qemu-binfmt} service.
22072 @item @code{platforms} (default: @code{'()})
22073 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22074 object} as returned by @code{lookup-qemu-platforms} (see below).
22076 @item @code{guix-support?} (default: @code{#f})
22077 When it is true, QEMU and all its dependencies are added to the build
22078 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22079 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22080 handlers to be used within the build environment, which in turn means
22081 that you can transparently build programs for another architecture.
22083 For example, let's suppose you're on an x86_64 machine and you have this
22087 (service qemu-binfmt-service-type
22088 (qemu-binfmt-configuration
22089 (platforms (lookup-qemu-platforms "arm"))
22090 (guix-support? #t)))
22096 guix build -s armhf-linux inkscape
22100 and it will build Inkscape for ARMv7 @emph{as if it were a native
22101 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22102 if you'd like to test a package build for an architecture you don't have
22105 @item @code{qemu} (default: @code{qemu})
22106 The QEMU package to use.
22110 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22111 Return the list of QEMU platform objects corresponding to
22112 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22113 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22114 @code{"mips64el"}, and so on.
22117 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22118 Return true if @var{obj} is a platform object.
22121 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22122 Return the name of @var{platform}---a string such as @code{"arm"}.
22125 @node Version Control Services
22126 @subsection Version Control Services
22128 The @code{(gnu services version-control)} module provides a service to
22129 allow remote access to local Git repositories. There are three options:
22130 the @code{git-daemon-service}, which provides access to repositories via
22131 the @code{git://} unsecured TCP-based protocol, extending the
22132 @code{nginx} web server to proxy some requests to
22133 @code{git-http-backend}, or providing a web interface with
22134 @code{cgit-service-type}.
22136 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22138 Return a service that runs @command{git daemon}, a simple TCP server to
22139 expose repositories over the Git protocol for anonymous access.
22141 The optional @var{config} argument should be a
22142 @code{<git-daemon-configuration>} object, by default it allows read-only
22143 access to exported@footnote{By creating the magic file
22144 "git-daemon-export-ok" in the repository directory.} repositories under
22149 @deftp {Data Type} git-daemon-configuration
22150 Data type representing the configuration for @code{git-daemon-service}.
22153 @item @code{package} (default: @var{git})
22154 Package object of the Git distributed version control system.
22156 @item @code{export-all?} (default: @var{#f})
22157 Whether to allow access for all Git repositories, even if they do not
22158 have the @file{git-daemon-export-ok} file.
22160 @item @code{base-path} (default: @file{/srv/git})
22161 Whether to remap all the path requests as relative to the given path.
22162 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22163 then if you later try to pull @code{git://example.com/hello.git}, git
22164 daemon will interpret the path as @code{/srv/git/hello.git}.
22166 @item @code{user-path} (default: @var{#f})
22167 Whether to allow @code{~user} notation to be used in requests. When
22168 specified with empty string, requests to @code{git://host/~alice/foo} is
22169 taken as a request to access @code{foo} repository in the home directory
22170 of user @code{alice}. If @var{(user-path "path")} is specified, the
22171 same request is taken as a request to access @code{path/foo} repository
22172 in the home directory of user @code{alice}.
22174 @item @code{listen} (default: @var{'()})
22175 Whether to listen on specific IP addresses or hostnames, defaults to
22178 @item @code{port} (default: @var{#f})
22179 Whether to listen on an alternative port, which defaults to 9418.
22181 @item @code{whitelist} (default: @var{'()})
22182 If not empty, only allow access to this list of directories.
22184 @item @code{extra-options} (default: @var{'()})
22185 Extra options will be passed to @code{git daemon}, please run
22186 @command{man git-daemon} for more information.
22191 The @code{git://} protocol lacks authentication. When you pull from a
22192 repository fetched via @code{git://}, you don't know that the data you
22193 receive was modified is really coming from the specified host, and you
22194 have your connection is subject to eavesdropping. It's better to use an
22195 authenticated and encrypted transport, such as @code{https}. Although Git allows you
22196 to serve repositories using unsophisticated file-based web servers,
22197 there is a faster protocol implemented by the @code{git-http-backend}
22198 program. This program is the back-end of a proper Git web service. It
22199 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22200 on running the necessary @code{fcgiwrap} daemon.
22202 Guix has a separate configuration data type for serving Git repositories
22205 @deftp {Data Type} git-http-configuration
22206 Data type representing the configuration for @code{git-http-service}.
22209 @item @code{package} (default: @var{git})
22210 Package object of the Git distributed version control system.
22212 @item @code{git-root} (default: @file{/srv/git})
22213 Directory containing the Git repositories to expose to the world.
22215 @item @code{export-all?} (default: @var{#f})
22216 Whether to expose access for all Git repositories in @var{git-root},
22217 even if they do not have the @file{git-daemon-export-ok} file.
22219 @item @code{uri-path} (default: @file{/git/})
22220 Path prefix for Git access. With the default @code{/git/} prefix, this
22221 will map @code{http://@var{server}/git/@var{repo}.git} to
22222 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22223 with this prefix are not passed on to this Git instance.
22225 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22226 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22231 There is no @code{git-http-service-type}, currently; instead you can
22232 create an @code{nginx-location-configuration} from a
22233 @code{git-http-configuration} and then add that location to a web
22236 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22237 [config=(git-http-configuration)]
22238 Compute an @code{nginx-location-configuration} that corresponds to the
22239 given Git http configuration. An example nginx service definition to
22240 serve the default @file{/srv/git} over HTTPS might be:
22243 (service nginx-service-type
22244 (nginx-configuration
22247 (nginx-server-configuration
22248 (listen '("443 ssl"))
22249 (server-name "git.my-host.org")
22251 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22252 (ssl-certificate-key
22253 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22256 (git-http-nginx-location-configuration
22257 (git-http-configuration (uri-path "/"))))))))))
22260 This example assumes that you are using Let's Encrypt to get your TLS
22261 certificate. @xref{Certificate Services}. The default @code{certbot}
22262 service will redirect all HTTP traffic on @code{git.my-host.org} to
22263 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22264 system services. @xref{Web Services}.
22267 @subsubheading Cgit Service
22269 @cindex Cgit service
22270 @cindex Git, web interface
22271 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22272 repositories written in C.
22274 The following example will configure the service with default values.
22275 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22278 (service cgit-service-type)
22281 The @code{file-object} type designates either a file-like object
22282 (@pxref{G-Expressions, file-like objects}) or a string.
22284 @c %start of fragment
22286 Available @code{cgit-configuration} fields are:
22288 @deftypevr {@code{cgit-configuration} parameter} package package
22293 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22294 NGINX configuration.
22298 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22299 Specifies a command which will be invoked to format the content of about
22300 pages (both top-level and for each repository).
22302 Defaults to @samp{""}.
22306 @deftypevr {@code{cgit-configuration} parameter} string agefile
22307 Specifies a path, relative to each repository path, which can be used to
22308 specify the date and time of the youngest commit in the repository.
22310 Defaults to @samp{""}.
22314 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22315 Specifies a command that will be invoked for authenticating repository
22318 Defaults to @samp{""}.
22322 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22323 Flag which, when set to @samp{age}, enables date ordering in the branch
22324 ref list, and when set @samp{name} enables ordering by branch name.
22326 Defaults to @samp{"name"}.
22330 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22331 Path used to store the cgit cache entries.
22333 Defaults to @samp{"/var/cache/cgit"}.
22337 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22338 Number which specifies the time-to-live, in minutes, for the cached
22339 version of repository pages accessed with a fixed SHA1.
22341 Defaults to @samp{-1}.
22345 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22346 Number which specifies the time-to-live, in minutes, for the cached
22347 version of repository pages accessed without a fixed SHA1.
22349 Defaults to @samp{5}.
22353 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22354 Number which specifies the time-to-live, in minutes, for the cached
22355 version of the repository summary page.
22357 Defaults to @samp{5}.
22361 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22362 Number which specifies the time-to-live, in minutes, for the cached
22363 version of the repository index page.
22365 Defaults to @samp{5}.
22369 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22370 Number which specifies the time-to-live, in minutes, for the result of
22371 scanning a path for Git repositories.
22373 Defaults to @samp{15}.
22377 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22378 Number which specifies the time-to-live, in minutes, for the cached
22379 version of the repository about page.
22381 Defaults to @samp{15}.
22385 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22386 Number which specifies the time-to-live, in minutes, for the cached
22387 version of snapshots.
22389 Defaults to @samp{5}.
22393 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22394 The maximum number of entries in the cgit cache. When set to @samp{0},
22395 caching is disabled.
22397 Defaults to @samp{0}.
22401 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22402 Sort items in the repo list case sensitively.
22404 Defaults to @samp{#t}.
22408 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22409 List of common prefixes which, when combined with a repository URL,
22410 generates valid clone URLs for the repository.
22412 Defaults to @samp{()}.
22416 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22417 List of @code{clone-url} templates.
22419 Defaults to @samp{()}.
22423 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22424 Command which will be invoked to format commit messages.
22426 Defaults to @samp{""}.
22430 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22431 Flag which, when set to @samp{date}, enables strict date ordering in the
22432 commit log, and when set to @samp{topo} enables strict topological
22435 Defaults to @samp{"git log"}.
22439 @deftypevr {@code{cgit-configuration} parameter} file-object css
22440 URL which specifies the css document to include in all cgit pages.
22442 Defaults to @samp{"/share/cgit/cgit.css"}.
22446 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22447 Specifies a command which will be invoked to format names and email
22448 address of committers, authors, and taggers, as represented in various
22449 places throughout the cgit interface.
22451 Defaults to @samp{""}.
22455 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22456 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22457 fragment suitable for embedding in other HTML pages.
22459 Defaults to @samp{#f}.
22463 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22464 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22465 commit history graph to the left of the commit messages in the
22466 repository log page.
22468 Defaults to @samp{#f}.
22472 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22473 Flag which, when set to @samp{#t}, allows all filter settings to be
22474 overridden in repository-specific cgitrc files.
22476 Defaults to @samp{#f}.
22480 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22481 Flag which, when set to @samp{#t}, allows users to follow a file in the
22484 Defaults to @samp{#f}.
22488 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22489 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22492 Defaults to @samp{#t}.
22496 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22497 Flag which, when set to @samp{#t}, will make cgit generate extra links
22498 "summary", "commit", "tree" for each repo in the repository index.
22500 Defaults to @samp{#f}.
22504 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22505 Flag which, when set to @samp{#t}, will make cgit display the owner of
22506 each repo in the repository index.
22508 Defaults to @samp{#t}.
22512 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22513 Flag which, when set to @samp{#t}, will make cgit print the number of
22514 modified files for each commit on the repository log page.
22516 Defaults to @samp{#f}.
22520 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22521 Flag which, when set to @samp{#t}, will make cgit print the number of
22522 added and removed lines for each commit on the repository log page.
22524 Defaults to @samp{#f}.
22528 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22529 Flag which, when set to @code{#t}, will make cgit display remote
22530 branches in the summary and refs views.
22532 Defaults to @samp{#f}.
22536 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22537 Flag which, when set to @code{1}, will make cgit use the subject of the
22538 parent commit as link text when generating links to parent commits in
22541 Defaults to @samp{#f}.
22545 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22546 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22547 parent commit as link text when generating links to parent commits in
22550 Defaults to @samp{#f}.
22554 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22555 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22556 links for plaintext blobs printed in the tree view.
22558 Defaults to @samp{#t}.
22562 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22563 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22564 set any repo specific settings.
22566 Defaults to @samp{#f}.
22570 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22571 URL used as link to a shortcut icon for cgit.
22573 Defaults to @samp{"/favicon.ico"}.
22577 @deftypevr {@code{cgit-configuration} parameter} string footer
22578 The content of the file specified with this option will be included
22579 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22580 "generated by..."@: message).
22582 Defaults to @samp{""}.
22586 @deftypevr {@code{cgit-configuration} parameter} string head-include
22587 The content of the file specified with this option will be included
22588 verbatim in the HTML HEAD section on all pages.
22590 Defaults to @samp{""}.
22594 @deftypevr {@code{cgit-configuration} parameter} string header
22595 The content of the file specified with this option will be included
22596 verbatim at the top of all pages.
22598 Defaults to @samp{""}.
22602 @deftypevr {@code{cgit-configuration} parameter} file-object include
22603 Name of a configfile to include before the rest of the current config-
22606 Defaults to @samp{""}.
22610 @deftypevr {@code{cgit-configuration} parameter} string index-header
22611 The content of the file specified with this option will be included
22612 verbatim above the repository index.
22614 Defaults to @samp{""}.
22618 @deftypevr {@code{cgit-configuration} parameter} string index-info
22619 The content of the file specified with this option will be included
22620 verbatim below the heading on the repository index page.
22622 Defaults to @samp{""}.
22626 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22627 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22628 in the servers timezone.
22630 Defaults to @samp{#f}.
22634 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22635 URL which specifies the source of an image which will be used as a logo
22638 Defaults to @samp{"/share/cgit/cgit.png"}.
22642 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22643 URL loaded when clicking on the cgit logo image.
22645 Defaults to @samp{""}.
22649 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22650 Command which will be invoked to format the Owner column of the main
22653 Defaults to @samp{""}.
22657 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22658 Number of items to display in atom feeds view.
22660 Defaults to @samp{10}.
22664 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22665 Number of entries to list per page in "log" view.
22667 Defaults to @samp{50}.
22671 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22672 Number of commit message characters to display in "log" view.
22674 Defaults to @samp{80}.
22678 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22679 Specifies the number of entries to list per page on the repository index
22682 Defaults to @samp{50}.
22686 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22687 Specifies the maximum number of repo description characters to display
22688 on the repository index page.
22690 Defaults to @samp{80}.
22694 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22695 Specifies the maximum size of a blob to display HTML for in KBytes.
22697 Defaults to @samp{0}.
22701 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22702 Maximum statistics period. Valid values are @samp{week},@samp{month},
22703 @samp{quarter} and @samp{year}.
22705 Defaults to @samp{""}.
22709 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22710 Mimetype for the specified filename extension.
22712 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22713 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22714 "image/png") (svg "image/svg+xml"))}.
22718 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22719 Specifies the file to use for automatic mimetype lookup.
22721 Defaults to @samp{""}.
22725 @deftypevr {@code{cgit-configuration} parameter} string module-link
22726 Text which will be used as the formatstring for a hyperlink when a
22727 submodule is printed in a directory listing.
22729 Defaults to @samp{""}.
22733 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22734 If set to the value @samp{#t} caching will be disabled.
22736 Defaults to @samp{#f}.
22740 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22741 If set to @samp{#t} showing full author email addresses will be
22744 Defaults to @samp{#f}.
22748 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22749 Flag which, when set to @samp{#t}, will make cgit omit the standard
22750 header on all pages.
22752 Defaults to @samp{#f}.
22756 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22757 A list of subdirectories inside of @code{repository-directory}, relative
22758 to it, that should loaded as Git repositories. An empty list means that
22759 all subdirectories will be loaded.
22761 Defaults to @samp{()}.
22765 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22766 Text which will be used as default value for @code{cgit-repo-readme}.
22768 Defaults to @samp{""}.
22772 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22773 If set to @code{#t} and @code{repository-directory} is enabled, if any
22774 repositories are found with a suffix of @code{.git}, this suffix will be
22775 removed for the URL and name.
22777 Defaults to @samp{#f}.
22781 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22782 Maximum number of files to consider when detecting renames.
22784 Defaults to @samp{-1}.
22788 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22789 The way in which repositories in each section are sorted.
22791 Defaults to @samp{""}.
22795 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22796 Text used as content for the @code{robots} meta-tag.
22798 Defaults to @samp{("noindex" "nofollow")}.
22802 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22803 Text printed below the heading on the repository index page.
22805 Defaults to @samp{"a fast webinterface for the git dscm"}.
22809 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22810 The content of the file specified with this option will be included
22811 verbatim below thef "about" link on the repository index page.
22813 Defaults to @samp{""}.
22817 @deftypevr {@code{cgit-configuration} parameter} string root-title
22818 Text printed as heading on the repository index page.
22820 Defaults to @samp{""}.
22824 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22825 If set to @samp{#t} and repository-directory is enabled,
22826 repository-directory will recurse into directories whose name starts
22827 with a period. Otherwise, repository-directory will stay away from such
22828 directories, considered as "hidden". Note that this does not apply to
22829 the ".git" directory in non-bare repos.
22831 Defaults to @samp{#f}.
22835 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22836 Text which specifies the default set of snapshot formats that cgit
22837 generates links for.
22839 Defaults to @samp{()}.
22843 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22844 Name of the directory to scan for repositories (represents
22847 Defaults to @samp{"/srv/git"}.
22851 @deftypevr {@code{cgit-configuration} parameter} string section
22852 The name of the current repository section - all repositories defined
22853 after this option will inherit the current section name.
22855 Defaults to @samp{""}.
22859 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22860 Flag which, when set to @samp{1}, will sort the sections on the
22861 repository listing by name.
22863 Defaults to @samp{""}.
22867 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22868 A number which, if defined prior to repository-directory, specifies how
22869 many path elements from each repo path to use as a default section name.
22871 Defaults to @samp{0}.
22875 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22876 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22879 Defaults to @samp{#f}.
22883 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22884 Specifies a command which will be invoked to format plaintext blobs in
22887 Defaults to @samp{""}.
22891 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22892 Specifies the number of branches to display in the repository "summary"
22895 Defaults to @samp{10}.
22899 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22900 Specifies the number of log entries to display in the repository
22903 Defaults to @samp{10}.
22907 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22908 Specifies the number of tags to display in the repository "summary"
22911 Defaults to @samp{10}.
22915 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22916 Filename which, if specified, needs to be present within the repository
22917 for cgit to allow access to that repository.
22919 Defaults to @samp{""}.
22923 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22924 URL which, if specified, will be used as root for all cgit links.
22926 Defaults to @samp{"/"}.
22930 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22931 A list of @dfn{cgit-repo} records to use with config.
22933 Defaults to @samp{()}.
22935 Available @code{repository-cgit-configuration} fields are:
22937 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22938 A mask of snapshot formats for this repo that cgit generates links for,
22939 restricted by the global @code{snapshots} setting.
22941 Defaults to @samp{()}.
22945 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22946 Override the default @code{source-filter}.
22948 Defaults to @samp{""}.
22952 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22953 The relative URL used to access the repository.
22955 Defaults to @samp{""}.
22959 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22960 Override the default @code{about-filter}.
22962 Defaults to @samp{""}.
22966 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22967 Flag which, when set to @samp{age}, enables date ordering in the branch
22968 ref list, and when set to @samp{name} enables ordering by branch name.
22970 Defaults to @samp{""}.
22974 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22975 A list of URLs which can be used to clone repo.
22977 Defaults to @samp{()}.
22981 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22982 Override the default @code{commit-filter}.
22984 Defaults to @samp{""}.
22988 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22989 Flag which, when set to @samp{date}, enables strict date ordering in the
22990 commit log, and when set to @samp{topo} enables strict topological
22993 Defaults to @samp{""}.
22997 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22998 The name of the default branch for this repository. If no such branch
22999 exists in the repository, the first branch name (when sorted) is used as
23000 default instead. By default branch pointed to by HEAD, or "master" if
23001 there is no suitable HEAD.
23003 Defaults to @samp{""}.
23007 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23008 The value to show as repository description.
23010 Defaults to @samp{""}.
23014 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23015 The value to show as repository homepage.
23017 Defaults to @samp{""}.
23021 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23022 Override the default @code{email-filter}.
23024 Defaults to @samp{""}.
23028 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23029 A flag which can be used to disable the global setting
23030 @code{enable-commit-graph?}.
23032 Defaults to @samp{disabled}.
23036 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23037 A flag which can be used to disable the global setting
23038 @code{enable-log-filecount?}.
23040 Defaults to @samp{disabled}.
23044 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23045 A flag which can be used to disable the global setting
23046 @code{enable-log-linecount?}.
23048 Defaults to @samp{disabled}.
23052 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23053 Flag which, when set to @code{#t}, will make cgit display remote
23054 branches in the summary and refs views.
23056 Defaults to @samp{disabled}.
23060 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23061 A flag which can be used to override the global setting
23062 @code{enable-subject-links?}.
23064 Defaults to @samp{disabled}.
23068 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23069 A flag which can be used to override the global setting
23070 @code{enable-html-serving?}.
23072 Defaults to @samp{disabled}.
23076 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23077 Flag which, when set to @code{#t}, hides the repository from the
23080 Defaults to @samp{#f}.
23084 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23085 Flag which, when set to @samp{#t}, ignores the repository.
23087 Defaults to @samp{#f}.
23091 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23092 URL which specifies the source of an image which will be used as a logo
23093 on this repo’s pages.
23095 Defaults to @samp{""}.
23099 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23100 URL loaded when clicking on the cgit logo image.
23102 Defaults to @samp{""}.
23106 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23107 Override the default @code{owner-filter}.
23109 Defaults to @samp{""}.
23113 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23114 Text which will be used as the formatstring for a hyperlink when a
23115 submodule is printed in a directory listing. The arguments for the
23116 formatstring are the path and SHA1 of the submodule commit.
23118 Defaults to @samp{""}.
23122 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23123 Text which will be used as the formatstring for a hyperlink when a
23124 submodule with the specified subdirectory path is printed in a directory
23127 Defaults to @samp{()}.
23131 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23132 Override the default maximum statistics period.
23134 Defaults to @samp{""}.
23138 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23139 The value to show as repository name.
23141 Defaults to @samp{""}.
23145 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23146 A value used to identify the owner of the repository.
23148 Defaults to @samp{""}.
23152 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23153 An absolute path to the repository directory.
23155 Defaults to @samp{""}.
23159 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23160 A path (relative to repo) which specifies a file to include verbatim as
23161 the "About" page for this repo.
23163 Defaults to @samp{""}.
23167 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23168 The name of the current repository section - all repositories defined
23169 after this option will inherit the current section name.
23171 Defaults to @samp{""}.
23175 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23176 Extra options will be appended to cgitrc file.
23178 Defaults to @samp{()}.
23184 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23185 Extra options will be appended to cgitrc file.
23187 Defaults to @samp{()}.
23192 @c %end of fragment
23194 However, it could be that you just want to get a @code{cgitrc} up and
23195 running. In that case, you can pass an @code{opaque-cgit-configuration}
23196 as a record to @code{cgit-service-type}. As its name indicates, an
23197 opaque configuration does not have easy reflective capabilities.
23199 Available @code{opaque-cgit-configuration} fields are:
23201 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23205 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23206 The contents of the @code{cgitrc}, as a string.
23209 For example, if your @code{cgitrc} is just the empty string, you
23210 could instantiate a cgit service like this:
23213 (service cgit-service-type
23214 (opaque-cgit-configuration
23218 @subsubheading Gitolite Service
23220 @cindex Gitolite service
23221 @cindex Git, hosting
23222 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23223 repositories on a central server.
23225 Gitolite can handle multiple repositories and users, and supports flexible
23226 configuration of the permissions for the users on the repositories.
23228 The following example will configure Gitolite using the default @code{git}
23229 user, and the provided SSH public key.
23232 (service gitolite-service-type
23233 (gitolite-configuration
23234 (admin-pubkey (plain-file
23236 "ssh-rsa AAAA... guix@@example.com"))))
23239 Gitolite is configured through a special admin repository which you can clone,
23240 for example, if you setup Gitolite on @code{example.com}, you would run the
23241 following command to clone the admin repository.
23244 git clone git@@example.com:gitolite-admin
23247 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23248 be inserted in to the @file{keydir} directory in the gitolite-admin
23249 repository. If this results in a change in the repository, it will be
23250 committed using the message ``gitolite setup by GNU Guix''.
23252 @deftp {Data Type} gitolite-configuration
23253 Data type representing the configuration for @code{gitolite-service-type}.
23256 @item @code{package} (default: @var{gitolite})
23257 Gitolite package to use.
23259 @item @code{user} (default: @var{git})
23260 User to use for Gitolite. This will be user that you use when accessing
23263 @item @code{group} (default: @var{git})
23264 Group to use for Gitolite.
23266 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23267 Directory in which to store the Gitolite configuration and repositories.
23269 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23270 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23271 representing the configuration for Gitolite.
23273 @item @code{admin-pubkey} (default: @var{#f})
23274 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23275 setup Gitolite. This will be inserted in to the @file{keydir} directory
23276 within the gitolite-admin repository.
23278 To specify the SSH key as a string, use the @code{plain-file} function.
23281 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23287 @deftp {Data Type} gitolite-rc-file
23288 Data type representing the Gitolite RC file.
23291 @item @code{umask} (default: @code{#o0077})
23292 This controls the permissions Gitolite sets on the repositories and their
23295 A value like @code{#o0027} will give read access to the group used by Gitolite
23296 (by default: @code{git}). This is necessary when using Gitolite with software
23297 like cgit or gitweb.
23299 @item @code{git-config-keys} (default: @code{""})
23300 Gitolite allows you to set git config values using the "config" keyword. This
23301 setting allows control over the config keys to accept.
23303 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23304 Set the role names allowed to be used by users running the perms command.
23306 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23307 This setting controls the commands and features to enable within Gitolite.
23313 @node Game Services
23314 @subsection Game Services
23316 @subsubheading The Battle for Wesnoth Service
23318 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23319 based tactical strategy game, with several single player campaigns, and
23320 multiplayer games (both networked and local).
23322 @defvar {Scheme Variable} wesnothd-service-type
23323 Service type for the wesnothd service. Its value must be a
23324 @code{wesnothd-configuration} object. To run wesnothd in the default
23325 configuration, instantiate it as:
23328 (service wesnothd-service-type)
23332 @deftp {Data Type} wesnothd-configuration
23333 Data type representing the configuration of @command{wesnothd}.
23336 @item @code{package} (default: @code{wesnoth-server})
23337 The wesnoth server package to use.
23339 @item @code{port} (default: @code{15000})
23340 The port to bind the server to.
23344 @node Miscellaneous Services
23345 @subsection Miscellaneous Services
23347 @cindex fingerprint
23348 @subsubheading Fingerprint Service
23350 The @code{(gnu services authentication)} module provides a DBus service to
23351 read and identify fingerprints via a fingerprint sensor.
23353 @defvr {Scheme Variable} fprintd-service-type
23354 The service type for @command{fprintd}, which provides the fingerprint
23355 reading capability.
23358 (service fprintd-service-type)
23363 @subsubheading System Control Service
23365 The @code{(gnu services sysctl)} provides a service to configure kernel
23366 parameters at boot.
23368 @defvr {Scheme Variable} sysctl-service-type
23369 The service type for @command{sysctl}, which modifies kernel parameters
23370 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23374 (service sysctl-service-type
23375 (sysctl-configuration
23376 (settings '(("net.ipv4.ip_forward" . "1")))))
23380 @deftp {Data Type} sysctl-configuration
23381 The data type representing the configuration of @command{sysctl}.
23384 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23385 The @command{sysctl} executable to use.
23387 @item @code{settings} (default: @code{'()})
23388 An association list specifies kernel parameters and their values.
23393 @subsubheading PC/SC Smart Card Daemon Service
23395 The @code{(gnu services security-token)} module provides the following service
23396 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23397 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23398 manager that coordinates communications with smart card readers, smart cards
23399 and cryptographic tokens that are connected to the system.
23401 @defvr {Scheme Variable} pcscd-service-type
23402 Service type for the @command{pcscd} service. Its value must be a
23403 @code{pcscd-configuration} object. To run pcscd in the default
23404 configuration, instantiate it as:
23407 (service pcscd-service-type)
23411 @deftp {Data Type} pcscd-configuration
23412 The data type representing the configuration of @command{pcscd}.
23415 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23416 The pcsc-lite package that provides pcscd.
23417 @item @code{usb-drivers} (default: @code{(list ccid)})
23418 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23419 under @file{pcsc/drivers} in the store directory of the package.
23424 @subsubheading Lirc Service
23426 The @code{(gnu services lirc)} module provides the following service.
23428 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23429 [#:device #f] [#:driver #f] [#:config-file #f] @
23430 [#:extra-options '()]
23431 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23432 decodes infrared signals from remote controls.
23434 Optionally, @var{device}, @var{driver} and @var{config-file}
23435 (configuration file name) may be specified. See @command{lircd} manual
23438 Finally, @var{extra-options} is a list of additional command-line options
23439 passed to @command{lircd}.
23443 @subsubheading Spice Service
23445 The @code{(gnu services spice)} module provides the following service.
23447 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23448 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
23449 that enables sharing the clipboard with a vm and setting the guest display
23450 resolution when the graphical console window resizes.
23453 @cindex inputattach
23454 @subsubheading inputattach Service
23456 @cindex tablet input, for Xorg
23457 @cindex touchscreen input, for Xorg
23458 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23459 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23460 Xorg display server.
23462 @deffn {Scheme Variable} inputattach-service-type
23463 Type of a service that runs @command{inputattach} on a device and
23464 dispatches events from it.
23467 @deftp {Data Type} inputattach-configuration
23469 @item @code{device-type} (default: @code{"wacom"})
23470 The type of device to connect to. Run @command{inputattach --help}, from the
23471 @code{inputattach} package, to see the list of supported device types.
23473 @item @code{device} (default: @code{"/dev/ttyS0"})
23474 The device file to connect to the device.
23476 @item @code{log-file} (default: @code{#f})
23477 If true, this must be the name of a file to log messages to.
23481 @subsection Dictionary Services
23483 The @code{(gnu services dict)} module provides the following service:
23485 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23486 Return a service that runs the @command{dicod} daemon, an implementation
23487 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23489 The optional @var{config} argument specifies the configuration for
23490 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23491 default it serves the GNU Collaborative International Dictonary of English.
23493 You can add @command{open localhost} to your @file{~/.dico} file to make
23494 @code{localhost} the default server for @command{dico} client
23495 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23498 @deftp {Data Type} dicod-configuration
23499 Data type representing the configuration of dicod.
23502 @item @code{dico} (default: @var{dico})
23503 Package object of the GNU Dico dictionary server.
23505 @item @code{interfaces} (default: @var{'("localhost")})
23506 This is the list of IP addresses and ports and possibly socket file
23507 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23508 dico, GNU Dico Manual}).
23510 @item @code{handlers} (default: @var{'()})
23511 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23513 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23514 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23518 @deftp {Data Type} dicod-handler
23519 Data type representing a dictionary handler (module instance).
23523 Name of the handler (module instance).
23525 @item @code{module} (default: @var{#f})
23526 Name of the dicod module of the handler (instance). If it is @code{#f},
23527 the module has the same name as the handler.
23528 (@pxref{Modules,,, dico, GNU Dico Manual}).
23530 @item @code{options}
23531 List of strings or gexps representing the arguments for the module handler
23535 @deftp {Data Type} dicod-database
23536 Data type representing a dictionary database.
23540 Name of the database, will be used in DICT commands.
23542 @item @code{handler}
23543 Name of the dicod handler (module instance) used by this database
23544 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23546 @item @code{complex?} (default: @var{#f})
23547 Whether the database configuration complex. The complex configuration
23548 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23550 @item @code{options}
23551 List of strings or gexps representing the arguments for the database
23552 (@pxref{Databases,,, dico, GNU Dico Manual}).
23556 @defvr {Scheme Variable} %dicod-database:gcide
23557 A @code{<dicod-database>} object serving the GNU Collaborative International
23558 Dictionary of English using the @code{gcide} package.
23561 The following is an example @code{dicod-service} configuration.
23564 (dicod-service #:config
23565 (dicod-configuration
23566 (handlers (list (dicod-handler
23570 (list #~(string-append "dbdir=" #$wordnet))))))
23571 (databases (list (dicod-database
23574 (handler "wordnet")
23575 (options '("database=wn")))
23576 %dicod-database:gcide))))
23580 @subsubheading Docker Service
23582 The @code{(gnu services docker)} module provides the following service.
23584 @defvr {Scheme Variable} docker-service-type
23586 This is the type of the service that runs @url{https://www.docker.com,Docker},
23587 a daemon that can execute application bundles (sometimes referred to as
23588 ``containers'') in isolated environments.
23592 @deftp {Data Type} docker-configuration
23593 This is the data type representing the configuration of Docker and Containerd.
23597 @item @code{package} (default: @code{docker})
23598 The Docker package to use.
23600 @item @code{containerd} (default: @var{containerd})
23601 The Containerd package to use.
23606 @node Setuid Programs
23607 @section Setuid Programs
23609 @cindex setuid programs
23610 Some programs need to run with ``root'' privileges, even when they are
23611 launched by unprivileged users. A notorious example is the
23612 @command{passwd} program, which users can run to change their
23613 password, and which needs to access the @file{/etc/passwd} and
23614 @file{/etc/shadow} files---something normally restricted to root, for
23615 obvious security reasons. To address that, these executables are
23616 @dfn{setuid-root}, meaning that they always run with root privileges
23617 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23618 for more info about the setuid mechanism.)
23620 The store itself @emph{cannot} contain setuid programs: that would be a
23621 security issue since any user on the system can write derivations that
23622 populate the store (@pxref{The Store}). Thus, a different mechanism is
23623 used: instead of changing the setuid bit directly on files that are in
23624 the store, we let the system administrator @emph{declare} which programs
23625 should be setuid root.
23627 The @code{setuid-programs} field of an @code{operating-system}
23628 declaration contains a list of G-expressions denoting the names of
23629 programs to be setuid-root (@pxref{Using the Configuration System}).
23630 For instance, the @command{passwd} program, which is part of the Shadow
23631 package, can be designated by this G-expression (@pxref{G-Expressions}):
23634 #~(string-append #$shadow "/bin/passwd")
23637 A default set of setuid programs is defined by the
23638 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23640 @defvr {Scheme Variable} %setuid-programs
23641 A list of G-expressions denoting common programs that are setuid-root.
23643 The list includes commands such as @command{passwd}, @command{ping},
23644 @command{su}, and @command{sudo}.
23647 Under the hood, the actual setuid programs are created in the
23648 @file{/run/setuid-programs} directory at system activation time. The
23649 files in this directory refer to the ``real'' binaries, which are in the
23652 @node X.509 Certificates
23653 @section X.509 Certificates
23655 @cindex HTTPS, certificates
23656 @cindex X.509 certificates
23658 Web servers available over HTTPS (that is, HTTP over the transport-layer
23659 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23660 that the client can then use to @emph{authenticate} the server. To do
23661 that, clients verify that the server's certificate is signed by a
23662 so-called @dfn{certificate authority} (CA). But to verify the CA's
23663 signature, clients must have first acquired the CA's certificate.
23665 Web browsers such as GNU@tie{}IceCat include their own set of CA
23666 certificates, such that they are able to verify CA signatures
23669 However, most other programs that can talk HTTPS---@command{wget},
23670 @command{git}, @command{w3m}, etc.---need to be told where CA
23671 certificates can be found.
23673 @cindex @code{nss-certs}
23674 In Guix, this is done by adding a package that provides certificates
23675 to the @code{packages} field of the @code{operating-system} declaration
23676 (@pxref{operating-system Reference}). Guix includes one such package,
23677 @code{nss-certs}, which is a set of CA certificates provided as part of
23678 Mozilla's Network Security Services.
23680 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23681 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23682 most applications and libraries look for certificates by default, points
23683 to the certificates installed globally.
23685 Unprivileged users, including users of Guix on a foreign distro,
23686 can also install their own certificate package in
23687 their profile. A number of environment variables need to be defined so
23688 that applications and libraries know where to find them. Namely, the
23689 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23690 variables. Some applications add their own environment variables; for
23691 instance, the Git version control system honors the certificate bundle
23692 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23693 would typically run something like:
23696 $ guix install nss-certs
23697 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23698 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23699 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23702 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23703 variable to point to a certificate bundle, so you would have to run
23704 something like this:
23707 $ guix install nss-certs
23708 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23711 For other applications you may want to look up the required environment
23712 variable in the relevant documentation.
23715 @node Name Service Switch
23716 @section Name Service Switch
23718 @cindex name service switch
23720 The @code{(gnu system nss)} module provides bindings to the
23721 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23722 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23723 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23724 extended with new ``name'' lookup methods for system databases, which
23725 includes host names, service names, user accounts, and more (@pxref{Name
23726 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23727 C Library Reference Manual}).
23729 The NSS configuration specifies, for each system database, which lookup
23730 method is to be used, and how the various methods are chained
23731 together---for instance, under which circumstances NSS should try the
23732 next method in the list. The NSS configuration is given in the
23733 @code{name-service-switch} field of @code{operating-system} declarations
23734 (@pxref{operating-system Reference, @code{name-service-switch}}).
23737 @cindex .local, host name lookup
23738 As an example, the declaration below configures the NSS to use the
23739 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23740 back-end}, which supports host name lookups over multicast DNS (mDNS)
23741 for host names ending in @code{.local}:
23744 (name-service-switch
23745 (hosts (list %files ;first, check /etc/hosts
23747 ;; If the above did not succeed, try
23748 ;; with 'mdns_minimal'.
23750 (name "mdns_minimal")
23752 ;; 'mdns_minimal' is authoritative for
23753 ;; '.local'. When it returns "not found",
23754 ;; no need to try the next methods.
23755 (reaction (lookup-specification
23756 (not-found => return))))
23758 ;; Then fall back to DNS.
23762 ;; Finally, try with the "full" 'mdns'.
23767 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23768 contains this configuration, so you will not have to type it if all you
23769 want is to have @code{.local} host lookup working.
23771 Note that, in this case, in addition to setting the
23772 @code{name-service-switch} of the @code{operating-system} declaration,
23773 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23774 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23775 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23776 to the name service cache daemon (@pxref{Base Services,
23777 @code{nscd-service}}).
23779 For convenience, the following variables provide typical NSS
23782 @defvr {Scheme Variable} %default-nss
23783 This is the default name service switch configuration, a
23784 @code{name-service-switch} object.
23787 @defvr {Scheme Variable} %mdns-host-lookup-nss
23788 This is the name service switch configuration with support for host name
23789 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23792 The reference for name service switch configuration is given below. It
23793 is a direct mapping of the configuration file format of the C library , so
23794 please refer to the C library manual for more information (@pxref{NSS
23795 Configuration File,,, libc, The GNU C Library Reference Manual}).
23796 Compared to the configuration file format of libc NSS, it has the advantage
23797 not only of adding this warm parenthetic feel that we like, but also
23798 static checks: you will know about syntax errors and typos as soon as you
23799 run @command{guix system}.
23801 @deftp {Data Type} name-service-switch
23803 This is the data type representation the configuration of libc's name
23804 service switch (NSS). Each field below represents one of the supported
23821 The system databases handled by the NSS. Each of these fields must be a
23822 list of @code{<name-service>} objects (see below).
23826 @deftp {Data Type} name-service
23828 This is the data type representing an actual name service and the
23829 associated lookup action.
23833 A string denoting the name service (@pxref{Services in the NSS
23834 configuration,,, libc, The GNU C Library Reference Manual}).
23836 Note that name services listed here must be visible to nscd. This is
23837 achieved by passing the @code{#:name-services} argument to
23838 @code{nscd-service} the list of packages providing the needed name
23839 services (@pxref{Base Services, @code{nscd-service}}).
23842 An action specified using the @code{lookup-specification} macro
23843 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23844 Reference Manual}). For example:
23847 (lookup-specification (unavailable => continue)
23848 (success => return))
23853 @node Initial RAM Disk
23854 @section Initial RAM Disk
23857 @cindex initial RAM disk
23858 For bootstrapping purposes, the Linux-Libre kernel is passed an
23859 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23860 root file system as well as an initialization script. The latter is
23861 responsible for mounting the real root file system, and for loading any
23862 kernel modules that may be needed to achieve that.
23864 The @code{initrd-modules} field of an @code{operating-system}
23865 declaration allows you to specify Linux-libre kernel modules that must
23866 be available in the initrd. In particular, this is where you would list
23867 modules needed to actually drive the hard disk where your root partition
23868 is---although the default value of @code{initrd-modules} should cover
23869 most use cases. For example, assuming you need the @code{megaraid_sas}
23870 module in addition to the default modules to be able to access your root
23871 file system, you would write:
23876 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23879 @defvr {Scheme Variable} %base-initrd-modules
23880 This is the list of kernel modules included in the initrd by default.
23883 Furthermore, if you need lower-level customization, the @code{initrd}
23884 field of an @code{operating-system} declaration allows
23885 you to specify which initrd you would like to use. The @code{(gnu
23886 system linux-initrd)} module provides three ways to build an initrd: the
23887 high-level @code{base-initrd} procedure and the low-level
23888 @code{raw-initrd} and @code{expression->initrd} procedures.
23890 The @code{base-initrd} procedure is intended to cover most common uses.
23891 For example, if you want to add a bunch of kernel modules to be loaded
23892 at boot time, you can define the @code{initrd} field of the operating
23893 system declaration like this:
23896 (initrd (lambda (file-systems . rest)
23897 ;; Create a standard initrd but set up networking
23898 ;; with the parameters QEMU expects by default.
23899 (apply base-initrd file-systems
23900 #:qemu-networking? #t
23904 The @code{base-initrd} procedure also handles common use cases that
23905 involves using the system as a QEMU guest, or as a ``live'' system with
23906 volatile root file system.
23908 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23909 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23910 such as trying to guess which kernel modules and packages should be included
23911 to the initrd. An example use of @code{raw-initrd} is when a user has
23912 a custom Linux kernel configuration and default kernel modules included by
23913 @code{base-initrd} are not available.
23915 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23916 honors several options passed on the Linux kernel command line
23917 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23918 @code{-append} option of QEMU), notably:
23921 @item --load=@var{boot}
23922 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23923 program, once it has mounted the root file system.
23925 Guix uses this option to yield control to a boot program that runs the
23926 service activation programs and then spawns the GNU@tie{}Shepherd, the
23927 initialization system.
23929 @item --root=@var{root}
23930 Mount @var{root} as the root file system. @var{root} can be a
23931 device name like @code{/dev/sda1}, a file system label, or a file system
23934 @item --system=@var{system}
23935 Have @file{/run/booted-system} and @file{/run/current-system} point to
23938 @item modprobe.blacklist=@var{modules}@dots{}
23939 @cindex module, black-listing
23940 @cindex black list, of kernel modules
23941 Instruct the initial RAM disk as well as the @command{modprobe} command
23942 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23943 must be a comma-separated list of module names---e.g.,
23944 @code{usbkbd,9pnet}.
23947 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23948 tries to load kernel modules and to mount the root file system. Our
23949 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23950 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23951 Manual}, for more information on Guile's REPL.
23955 Now that you know all the features that initial RAM disks produced by
23956 @code{base-initrd} and @code{raw-initrd} provide,
23957 here is how to use it and customize it further.
23960 @cindex initial RAM disk
23961 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23962 [#:linux-modules '()] [#:mapped-devices '()] @
23963 [#:keyboard-layout #f] @
23964 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23965 Return a derivation that builds a raw initrd. @var{file-systems} is
23966 a list of file systems to be mounted by the initrd, possibly in addition to
23967 the root file system specified on the kernel command line via @code{--root}.
23968 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23969 @var{mapped-devices} is a list of device mappings to realize before
23970 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23971 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23972 include @code{e2fsck/static} or other packages needed by the initrd to check
23973 the root file system.
23975 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23976 the desired console keyboard layout. This is done before @var{mapped-devices}
23977 are set up and before @var{file-systems} are mounted such that, should the
23978 user need to enter a passphrase or use the REPL, this happens using the
23979 intended keyboard layout.
23981 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23982 parameters. When @var{virtio?} is true, load additional modules so that the
23983 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23985 When @var{volatile-root?} is true, the root file system is writable but any changes
23989 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23990 [#:mapped-devices '()] [#:keyboard-layout #f] @
23991 [#:qemu-networking? #f] [#:volatile-root? #f] @
23992 [#:linux-modules '()]
23993 Return as a file-like object a generic initrd, with kernel
23994 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23995 mounted by the initrd, possibly in addition to the root file system specified
23996 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23997 mappings to realize before @var{file-systems} are mounted.
23999 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24000 the desired console keyboard layout. This is done before @var{mapped-devices}
24001 are set up and before @var{file-systems} are mounted such that, should the
24002 user need to enter a passphrase or use the REPL, this happens using the
24003 intended keyboard layout.
24005 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24007 The initrd is automatically populated with all the kernel modules necessary
24008 for @var{file-systems} and for the given options. Additional kernel
24009 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24010 loaded at boot time in the order in which they appear.
24013 Needless to say, the initrds we produce and use embed a
24014 statically-linked Guile, and the initialization program is a Guile
24015 program. That gives a lot of flexibility. The
24016 @code{expression->initrd} procedure builds such an initrd, given the
24017 program to run in that initrd.
24019 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24020 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24021 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24022 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24023 upon booting. All the derivations referenced by @var{exp} are
24024 automatically copied to the initrd.
24027 @node Bootloader Configuration
24028 @section Bootloader Configuration
24031 @cindex boot loader
24033 The operating system supports multiple bootloaders. The bootloader is
24034 configured using @code{bootloader-configuration} declaration. All the
24035 fields of this structure are bootloader agnostic except for one field,
24036 @code{bootloader} that indicates the bootloader to be configured and
24039 Some of the bootloaders do not honor every field of
24040 @code{bootloader-configuration}. For instance, the extlinux
24041 bootloader does not support themes and thus ignores the @code{theme}
24044 @deftp {Data Type} bootloader-configuration
24045 The type of a bootloader configuration declaration.
24049 @item @code{bootloader}
24050 @cindex EFI, bootloader
24051 @cindex UEFI, bootloader
24052 @cindex BIOS, bootloader
24053 The bootloader to use, as a @code{bootloader} object. For now
24054 @code{grub-bootloader}, @code{grub-efi-bootloader},
24055 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24057 @vindex grub-efi-bootloader
24058 @code{grub-efi-bootloader} allows to boot on modern systems using the
24059 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24060 use if the installation image contains a @file{/sys/firmware/efi} directory
24061 when you boot it on your system.
24063 @vindex grub-bootloader
24064 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24065 in ``legacy'' BIOS mode.
24067 @cindex ARM, bootloaders
24068 @cindex AArch64, bootloaders
24069 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24070 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24071 of bootloaders for a wide range of ARM and AArch64 systems, using the
24072 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24074 @item @code{target}
24075 This is a string denoting the target onto which to install the
24078 The interpretation depends on the bootloader in question. For
24079 @code{grub-bootloader}, for example, it should be a device name understood by
24080 the bootloader @command{installer} command, such as @code{/dev/sda} or
24081 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24082 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24083 system, usually @file{/boot/efi}.
24085 @item @code{menu-entries} (default: @code{()})
24086 A possibly empty list of @code{menu-entry} objects (see below), denoting
24087 entries to appear in the bootloader menu, in addition to the current
24088 system entry and the entry pointing to previous system generations.
24090 @item @code{default-entry} (default: @code{0})
24091 The index of the default boot menu entry. Index 0 is for the entry of the
24094 @item @code{timeout} (default: @code{5})
24095 The number of seconds to wait for keyboard input before booting. Set to
24096 0 to boot immediately, and to -1 to wait indefinitely.
24098 @cindex keyboard layout, for the bootloader
24099 @item @code{keyboard-layout} (default: @code{#f})
24100 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24101 layout, usually US@tie{}English (``qwerty'').
24103 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24107 This option is currently ignored by bootloaders other than @code{grub} and
24111 @item @code{theme} (default: @var{#f})
24112 The bootloader theme object describing the theme to use. If no theme
24113 is provided, some bootloaders might use a default theme, that's true
24116 @item @code{terminal-outputs} (default: @code{'gfxterm})
24117 The output terminals used for the bootloader boot menu, as a list of
24118 symbols. GRUB accepts the values: @code{console}, @code{serial},
24119 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24120 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24121 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24122 configuration,,, grub,GNU GRUB manual}).
24124 @item @code{terminal-inputs} (default: @code{'()})
24125 The input terminals used for the bootloader boot menu, as a list of
24126 symbols. For GRUB, the default is the native platform terminal as
24127 determined at run-time. GRUB accepts the values: @code{console},
24128 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24129 @code{usb_keyboard}. This field corresponds to the GRUB variable
24130 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24133 @item @code{serial-unit} (default: @code{#f})
24134 The serial unit used by the bootloader, as an integer from 0 to 3.
24135 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24136 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24138 @item @code{serial-speed} (default: @code{#f})
24139 The speed of the serial interface, as an integer. For GRUB, the
24140 default value is chosen at run-time; currently GRUB chooses
24141 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24148 Should you want to list additional boot menu entries @i{via} the
24149 @code{menu-entries} field above, you will need to create them with the
24150 @code{menu-entry} form. For example, imagine you want to be able to
24151 boot another distro (hard to imagine!), you can define a menu entry
24156 (label "The Other Distro")
24157 (linux "/boot/old/vmlinux-2.6.32")
24158 (linux-arguments '("root=/dev/sda2"))
24159 (initrd "/boot/old/initrd"))
24164 @deftp {Data Type} menu-entry
24165 The type of an entry in the bootloader menu.
24170 The label to show in the menu---e.g., @code{"GNU"}.
24173 The Linux kernel image to boot, for example:
24176 (file-append linux-libre "/bzImage")
24179 For GRUB, it is also possible to specify a device explicitly in the
24180 file path using GRUB's device naming convention (@pxref{Naming
24181 convention,,, grub, GNU GRUB manual}), for example:
24184 "(hd0,msdos1)/boot/vmlinuz"
24187 If the device is specified explicitly as above, then the @code{device}
24188 field is ignored entirely.
24190 @item @code{linux-arguments} (default: @code{()})
24191 The list of extra Linux kernel command-line arguments---e.g.,
24192 @code{("console=ttyS0")}.
24194 @item @code{initrd}
24195 A G-Expression or string denoting the file name of the initial RAM disk
24196 to use (@pxref{G-Expressions}).
24197 @item @code{device} (default: @code{#f})
24198 The device where the kernel and initrd are to be found---i.e., for GRUB,
24199 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24201 This may be a file system label (a string), a file system UUID (a
24202 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24203 the bootloader will search the device containing the file specified by
24204 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24205 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24210 @c FIXME: Write documentation once it's stable.
24211 For now only GRUB has theme support. GRUB themes are created using
24212 the @code{grub-theme} form, which is not documented yet.
24214 @defvr {Scheme Variable} %default-theme
24215 This is the default GRUB theme used by the operating system if no
24216 @code{theme} field is specified in @code{bootloader-configuration}
24219 It comes with a fancy background image displaying the GNU and Guix
24224 @node Invoking guix system
24225 @section Invoking @code{guix system}
24227 Once you have written an operating system declaration as seen in the
24228 previous section, it can be @dfn{instantiated} using the @command{guix
24229 system} command. The synopsis is:
24232 guix system @var{options}@dots{} @var{action} @var{file}
24235 @var{file} must be the name of a file containing an
24236 @code{operating-system} declaration. @var{action} specifies how the
24237 operating system is instantiated. Currently the following values are
24242 Display available service type definitions that match the given regular
24243 expressions, sorted by relevance:
24246 $ guix system search console font
24247 name: console-fonts
24248 location: gnu/services/base.scm:729:2
24249 extends: shepherd-root
24250 description: Install the given fonts on the specified ttys (fonts are
24251 + per virtual console on GNU/Linux). The value of this service is a list
24252 + of tty/font pairs like:
24254 + '(("tty1" . "LatGrkCyr-8x16"))
24258 location: gnu/services/base.scm:1048:2
24259 extends: shepherd-root
24260 description: Provide console login using the `mingetty' program.
24264 location: gnu/services/base.scm:775:2
24266 description: Provide a console log-in service as specified by its
24267 + configuration value, a `login-configuration' object.
24273 As for @command{guix package --search}, the result is written in
24274 @code{recutils} format, which makes it easy to filter the output
24275 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24278 Build the operating system described in @var{file}, activate it, and
24279 switch to it@footnote{This action (and the related actions
24280 @code{switch-generation} and @code{roll-back}) are usable only on
24281 systems already running Guix System.}.
24283 This effects all the configuration specified in @var{file}: user
24284 accounts, system services, global package list, setuid programs, etc.
24285 The command starts system services specified in @var{file} that are not
24286 currently running; if a service is currently running this command will
24287 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24288 @code{herd stop X} or @code{herd restart X}).
24290 This command creates a new generation whose number is one greater than
24291 the current generation (as reported by @command{guix system
24292 list-generations}). If that generation already exists, it will be
24293 overwritten. This behavior mirrors that of @command{guix package}
24294 (@pxref{Invoking guix package}).
24296 It also adds a bootloader menu entry for the new OS configuration,
24297 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24298 entries for older configurations to a submenu, allowing you to choose
24299 an older system generation at boot time should you need it.
24302 @c The paragraph below refers to the problem discussed at
24303 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24304 It is highly recommended to run @command{guix pull} once before you run
24305 @command{guix system reconfigure} for the first time (@pxref{Invoking
24306 guix pull}). Failing to do that you would see an older version of Guix
24307 once @command{reconfigure} has completed.
24310 @item switch-generation
24311 @cindex generations
24312 Switch to an existing system generation. This action atomically
24313 switches the system profile to the specified system generation. It
24314 also rearranges the system's existing bootloader menu entries. It
24315 makes the menu entry for the specified system generation the default,
24316 and it moves the entries for the other generatiors to a submenu, if
24317 supported by the bootloader being used. The next time the system
24318 boots, it will use the specified system generation.
24320 The bootloader itself is not being reinstalled when using this
24321 command. Thus, the installed bootloader is used with an updated
24322 configuration file.
24324 The target generation can be specified explicitly by its generation
24325 number. For example, the following invocation would switch to system
24329 guix system switch-generation 7
24332 The target generation can also be specified relative to the current
24333 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24334 ``3 generations ahead of the current generation,'' and @code{-1} means
24335 ``1 generation prior to the current generation.'' When specifying a
24336 negative value such as @code{-1}, you must precede it with @code{--} to
24337 prevent it from being parsed as an option. For example:
24340 guix system switch-generation -- -1
24343 Currently, the effect of invoking this action is @emph{only} to switch
24344 the system profile to an existing generation and rearrange the
24345 bootloader menu entries. To actually start using the target system
24346 generation, you must reboot after running this action. In the future,
24347 it will be updated to do the same things as @command{reconfigure},
24348 like activating and deactivating services.
24350 This action will fail if the specified generation does not exist.
24353 @cindex rolling back
24354 Switch to the preceding system generation. The next time the system
24355 boots, it will use the preceding system generation. This is the inverse
24356 of @command{reconfigure}, and it is exactly the same as invoking
24357 @command{switch-generation} with an argument of @code{-1}.
24359 Currently, as with @command{switch-generation}, you must reboot after
24360 running this action to actually start using the preceding system
24363 @item delete-generations
24364 @cindex deleting system generations
24365 @cindex saving space
24366 Delete system generations, making them candidates for garbage collection
24367 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24370 This works in the same way as @command{guix package --delete-generations}
24371 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24372 arguments, all system generations but the current one are deleted:
24375 guix system delete-generations
24378 You can also select the generations you want to delete. The example below
24379 deletes all the system generations that are more than two month old:
24382 guix system delete-generations 2m
24385 Running this command automatically reinstalls the bootloader with an updated
24386 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24387 longer lists the generations that have been deleted.
24390 Build the derivation of the operating system, which includes all the
24391 configuration files and programs needed to boot and run the system.
24392 This action does not actually install anything.
24395 Populate the given directory with all the files necessary to run the
24396 operating system specified in @var{file}. This is useful for first-time
24397 installations of Guix System. For instance:
24400 guix system init my-os-config.scm /mnt
24403 copies to @file{/mnt} all the store items required by the configuration
24404 specified in @file{my-os-config.scm}. This includes configuration
24405 files, packages, and so on. It also creates other essential files
24406 needed for the system to operate correctly---e.g., the @file{/etc},
24407 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24409 This command also installs bootloader on the target specified in
24410 @file{my-os-config}, unless the @option{--no-bootloader} option was
24414 @cindex virtual machine
24416 @anchor{guix system vm}
24417 Build a virtual machine that contains the operating system declared in
24418 @var{file}, and return a script to run that virtual machine (VM).
24421 The @code{vm} action and others below
24422 can use KVM support in the Linux-libre kernel. Specifically, if the
24423 machine has hardware virtualization support, the corresponding
24424 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24425 must exist and be readable and writable by the user and by the
24426 build users of the daemon (@pxref{Build Environment Setup}).
24429 Arguments given to the script are passed to QEMU as in the example
24430 below, which enables networking and requests 1@tie{}GiB of RAM for the
24434 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24437 The VM shares its store with the host system.
24439 Additional file systems can be shared between the host and the VM using
24440 the @code{--share} and @code{--expose} command-line options: the former
24441 specifies a directory to be shared with write access, while the latter
24442 provides read-only access to the shared directory.
24444 The example below creates a VM in which the user's home directory is
24445 accessible read-only, and where the @file{/exchange} directory is a
24446 read-write mapping of @file{$HOME/tmp} on the host:
24449 guix system vm my-config.scm \
24450 --expose=$HOME --share=$HOME/tmp=/exchange
24453 On GNU/Linux, the default is to boot directly to the kernel; this has
24454 the advantage of requiring only a very tiny root disk image since the
24455 store of the host can then be mounted.
24457 The @code{--full-boot} option forces a complete boot sequence, starting
24458 with the bootloader. This requires more disk space since a root image
24459 containing at least the kernel, initrd, and bootloader data files must
24460 be created. The @code{--image-size} option can be used to specify the
24463 @cindex System images, creation in various formats
24464 @cindex Creating system images in various formats
24467 @itemx docker-image
24468 Return a virtual machine, disk image, or Docker image of the operating
24469 system declared in @var{file} that stands alone. By default,
24470 @command{guix system} estimates the size of the image needed to store
24471 the system, but you can use the @option{--image-size} option to specify
24472 a value. Docker images are built to contain exactly what they need, so
24473 the @option{--image-size} option is ignored in the case of
24474 @code{docker-image}.
24476 You can specify the root file system type by using the
24477 @option{--file-system-type} option. It defaults to @code{ext4}.
24479 When using @code{vm-image}, the returned image is in qcow2 format, which
24480 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24481 for more information on how to run the image in a virtual machine.
24483 When using @code{disk-image}, a raw disk image is produced; it can be
24484 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24485 the device corresponding to a USB stick, one can copy the image to it
24486 using the following command:
24489 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24492 When using @code{docker-image}, a Docker image is produced. Guix builds
24493 the image from scratch, not from a pre-existing Docker base image. As a
24494 result, it contains @emph{exactly} what you define in the operating
24495 system configuration file. You can then load the image and launch a
24496 Docker container using commands like the following:
24499 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24500 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24501 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24502 $image_id /var/guix/profiles/system/boot
24505 This command starts a new Docker container from the specified image. It
24506 will boot the Guix system in the usual manner, which means it will
24507 start any services you have defined in the operating system
24508 configuration. Depending on what you run in the Docker container, it
24509 may be necessary to give the container additional permissions. For
24510 example, if you intend to build software using Guix inside of the Docker
24511 container, you may need to pass the @option{--privileged} option to
24515 Return a script to run the operating system declared in @var{file}
24516 within a container. Containers are a set of lightweight isolation
24517 mechanisms provided by the kernel Linux-libre. Containers are
24518 substantially less resource-demanding than full virtual machines since
24519 the kernel, shared objects, and other resources can be shared with the
24520 host system; this also means they provide thinner isolation.
24522 Currently, the script must be run as root in order to support more than
24523 a single user and group. The container shares its store with the host
24526 As with the @code{vm} action (@pxref{guix system vm}), additional file
24527 systems to be shared between the host and container can be specified
24528 using the @option{--share} and @option{--expose} options:
24531 guix system container my-config.scm \
24532 --expose=$HOME --share=$HOME/tmp=/exchange
24536 This option requires Linux-libre 3.19 or newer.
24541 @var{options} can contain any of the common build options (@pxref{Common
24542 Build Options}). In addition, @var{options} can contain one of the
24546 @item --expression=@var{expr}
24547 @itemx -e @var{expr}
24548 Consider the operating-system @var{expr} evaluates to.
24549 This is an alternative to specifying a file which evaluates to an
24551 This is used to generate the Guix system installer @pxref{Building the
24552 Installation Image}).
24554 @item --system=@var{system}
24555 @itemx -s @var{system}
24556 Attempt to build for @var{system} instead of the host system type.
24557 This works as per @command{guix build} (@pxref{Invoking guix build}).
24561 Return the derivation file name of the given operating system without
24564 @item --file-system-type=@var{type}
24565 @itemx -t @var{type}
24566 For the @code{disk-image} action, create a file system of the given
24567 @var{type} on the image.
24569 When this option is omitted, @command{guix system} uses @code{ext4}.
24571 @cindex ISO-9660 format
24572 @cindex CD image format
24573 @cindex DVD image format
24574 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24575 for burning on CDs and DVDs.
24577 @item --image-size=@var{size}
24578 For the @code{vm-image} and @code{disk-image} actions, create an image
24579 of the given @var{size}. @var{size} may be a number of bytes, or it may
24580 include a unit as a suffix (@pxref{Block size, size specifications,,
24581 coreutils, GNU Coreutils}).
24583 When this option is omitted, @command{guix system} computes an estimate
24584 of the image size as a function of the size of the system declared in
24587 @item --root=@var{file}
24588 @itemx -r @var{file}
24589 Make @var{file} a symlink to the result, and register it as a garbage
24592 @item --skip-checks
24593 Skip pre-installation safety checks.
24595 By default, @command{guix system init} and @command{guix system
24596 reconfigure} perform safety checks: they make sure the file systems that
24597 appear in the @code{operating-system} declaration actually exist
24598 (@pxref{File Systems}), and that any Linux kernel modules that may be
24599 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24600 RAM Disk}). Passing this option skips these tests altogether.
24603 @cindex on-error strategy
24604 @cindex error strategy
24605 @item --on-error=@var{strategy}
24606 Apply @var{strategy} when an error occurs when reading @var{file}.
24607 @var{strategy} may be one of the following:
24610 @item nothing-special
24611 Report the error concisely and exit. This is the default strategy.
24614 Likewise, but also display a backtrace.
24617 Report the error and enter Guile's debugger. From there, you can run
24618 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24619 display local variable values, and more generally inspect the state of the
24620 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24621 a list of available debugging commands.
24625 Once you have built, configured, re-configured, and re-re-configured
24626 your Guix installation, you may find it useful to list the operating
24627 system generations available on disk---and that you can choose from the
24628 bootloader boot menu:
24632 @item list-generations
24633 List a summary of each generation of the operating system available on
24634 disk, in a human-readable way. This is similar to the
24635 @option{--list-generations} option of @command{guix package}
24636 (@pxref{Invoking guix package}).
24638 Optionally, one can specify a pattern, with the same syntax that is used
24639 in @command{guix package --list-generations}, to restrict the list of
24640 generations displayed. For instance, the following command displays
24641 generations that are up to 10 days old:
24644 $ guix system list-generations 10d
24649 The @command{guix system} command has even more to offer! The following
24650 sub-commands allow you to visualize how your system services relate to
24653 @anchor{system-extension-graph}
24656 @item extension-graph
24657 Emit in Dot/Graphviz format to standard output the @dfn{service
24658 extension graph} of the operating system defined in @var{file}
24659 (@pxref{Service Composition}, for more information on service
24665 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24668 produces a PDF file showing the extension relations among services.
24670 @anchor{system-shepherd-graph}
24671 @item shepherd-graph
24672 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24673 graph} of shepherd services of the operating system defined in
24674 @var{file}. @xref{Shepherd Services}, for more information and for an
24679 @node Running Guix in a VM
24680 @section Running Guix in a Virtual Machine
24682 @cindex virtual machine
24683 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
24685 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
24686 This image is a compressed image in QCOW format. You will first need to
24687 decompress with @command{xz -d}, and then you can pass it to an emulator such
24688 as QEMU (see below for details).
24690 This image boots the Xfce graphical environment and it contains some
24691 commonly-used tools. You can install more software in the image by running
24692 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
24693 also reconfigure the system based on its initial configuration file available
24694 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
24696 Instead of using this pre-built image, one can also build their own virtual
24697 machine image using @command{guix system vm-image} (@pxref{Invoking guix
24698 system}). The returned image is in qcow2 format, which the
24699 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
24702 If you built your own image, you must copy it out of the store
24703 (@pxref{The Store}) and give yourself permission to write to the copy
24704 before you can use it. When invoking QEMU, you must choose a system
24705 emulator that is suitable for your hardware platform. Here is a minimal
24706 QEMU invocation that will boot the result of @command{guix system
24707 vm-image} on x86_64 hardware:
24710 $ qemu-system-x86_64 \
24711 -net user -net nic,model=virtio \
24712 -enable-kvm -m 512 \
24713 -device virtio-blk,drive=myhd \
24714 -drive if=none,file=/tmp/qemu-image,id=myhd
24717 Here is what each of these options means:
24720 @item qemu-system-x86_64
24721 This specifies the hardware platform to emulate. This should match the
24725 Enable the unprivileged user-mode network stack. The guest OS can
24726 access the host but not vice versa. This is the simplest way to get the
24729 @item -net nic,model=virtio
24730 You must create a network interface of a given model. If you do not
24731 create a NIC, the boot will fail. Assuming your hardware platform is
24732 x86_64, you can get a list of available NIC models by running
24733 @command{qemu-system-x86_64 -net nic,model=help}.
24736 If your system has hardware virtualization extensions, enabling the
24737 virtual machine support (KVM) of the Linux kernel will make things run
24740 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
24742 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24743 which may be insufficient for some operations.
24745 @item -device virtio-blk,drive=myhd
24746 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
24747 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
24748 better performance than if it were emulating a complete disk drive. See the
24749 QEMU and KVM documentation for more info.
24751 @item -drive if=none,file=/tmp/qemu-image,id=myhd
24752 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
24753 the ``myhd'' drive.
24756 The default @command{run-vm.sh} script that is returned by an invocation of
24757 @command{guix system vm} does not add a @command{-net user} flag by default.
24758 To get network access from within the vm add the @code{(dhcp-client-service)}
24759 to your system definition and start the VM using
24760 @command{`guix system vm config.scm` -net user}. An important caveat of using
24761 @command{-net user} for networking is that @command{ping} will not work, because
24762 it uses the ICMP protocol. You'll have to use a different command to check for
24763 network connectivity, for example @command{guix download}.
24765 @subsection Connecting Through SSH
24769 To enable SSH inside a VM you need to add an SSH server like
24770 @code{openssh-service-type} to your VM (@pxref{Networking Services,
24771 @code{openssh-service-type}}). In addition you need to forward the SSH port,
24772 22 by default, to the host. You can do this with
24775 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24778 To connect to the VM you can run
24781 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24784 The @command{-p} tells @command{ssh} the port you want to connect to.
24785 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24786 every time you modify your @command{config.scm} file and the
24787 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24788 connection to an unknown host every time you connect.
24790 @subsection Using @command{virt-viewer} with Spice
24792 As an alternative to the default @command{qemu} graphical client you can
24793 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24794 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24795 @command{qemu}. See previous section for further information on how to do this.
24797 Spice also allows you to do some nice stuff like share your clipboard with your
24798 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24801 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24802 -chardev spicevmc,name=vdagent,id=vdagent
24803 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24804 name=com.redhat.spice.0
24807 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24809 @node Defining Services
24810 @section Defining Services
24812 The previous sections show the available services and how one can combine
24813 them in an @code{operating-system} declaration. But how do we define
24814 them in the first place? And what is a service anyway?
24817 * Service Composition:: The model for composing services.
24818 * Service Types and Services:: Types and services.
24819 * Service Reference:: API reference.
24820 * Shepherd Services:: A particular type of service.
24823 @node Service Composition
24824 @subsection Service Composition
24828 Here we define a @dfn{service} as, broadly, something that extends the
24829 functionality of the operating system. Often a service is a process---a
24830 @dfn{daemon}---started when the system boots: a secure shell server, a
24831 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24832 whose execution can be triggered by another daemon---e.g., an FTP server
24833 started by @command{inetd} or a D-Bus service activated by
24834 @command{dbus-daemon}. Occasionally, a service does not map to a
24835 daemon. For instance, the ``account'' service collects user accounts
24836 and makes sure they exist when the system runs; the ``udev'' service
24837 collects device management rules and makes them available to the eudev
24838 daemon; the @file{/etc} service populates the @file{/etc} directory
24841 @cindex service extensions
24842 Guix system services are connected by @dfn{extensions}. For instance, the
24843 secure shell service @emph{extends} the Shepherd---the
24844 initialization system, running as PID@tie{}1---by giving it the command
24845 lines to start and stop the secure shell daemon (@pxref{Networking
24846 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24847 service by passing it its @file{.service} specification, and extends the
24848 udev service by passing it device management rules (@pxref{Desktop
24849 Services, @code{upower-service}}); the Guix daemon service extends the
24850 Shepherd by passing it the command lines to start and stop the daemon,
24851 and extends the account service by passing it a list of required build
24852 user accounts (@pxref{Base Services}).
24854 All in all, services and their ``extends'' relations form a directed
24855 acyclic graph (DAG). If we represent services as boxes and extensions
24856 as arrows, a typical system might provide something like this:
24858 @image{images/service-graph,,5in,Typical service extension graph.}
24860 @cindex system service
24861 At the bottom, we see the @dfn{system service}, which produces the
24862 directory containing everything to run and boot the system, as returned
24863 by the @command{guix system build} command. @xref{Service Reference},
24864 to learn about the other service types shown here.
24865 @xref{system-extension-graph, the @command{guix system extension-graph}
24866 command}, for information on how to generate this representation for a
24867 particular operating system definition.
24869 @cindex service types
24870 Technically, developers can define @dfn{service types} to express these
24871 relations. There can be any number of services of a given type on the
24872 system---for instance, a system running two instances of the GNU secure
24873 shell server (lsh) has two instances of @code{lsh-service-type}, with
24874 different parameters.
24876 The following section describes the programming interface for service
24877 types and services.
24879 @node Service Types and Services
24880 @subsection Service Types and Services
24882 A @dfn{service type} is a node in the DAG described above. Let us start
24883 with a simple example, the service type for the Guix build daemon
24884 (@pxref{Invoking guix-daemon}):
24887 (define guix-service-type
24891 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24892 (service-extension account-service-type guix-accounts)
24893 (service-extension activation-service-type guix-activation)))
24894 (default-value (guix-configuration))))
24898 It defines three things:
24902 A name, whose sole purpose is to make inspection and debugging easier.
24905 A list of @dfn{service extensions}, where each extension designates the
24906 target service type and a procedure that, given the parameters of the
24907 service, returns a list of objects to extend the service of that type.
24909 Every service type has at least one service extension. The only
24910 exception is the @dfn{boot service type}, which is the ultimate service.
24913 Optionally, a default value for instances of this type.
24916 In this example, @code{guix-service-type} extends three services:
24919 @item shepherd-root-service-type
24920 The @code{guix-shepherd-service} procedure defines how the Shepherd
24921 service is extended. Namely, it returns a @code{<shepherd-service>}
24922 object that defines how @command{guix-daemon} is started and stopped
24923 (@pxref{Shepherd Services}).
24925 @item account-service-type
24926 This extension for this service is computed by @code{guix-accounts},
24927 which returns a list of @code{user-group} and @code{user-account}
24928 objects representing the build user accounts (@pxref{Invoking
24931 @item activation-service-type
24932 Here @code{guix-activation} is a procedure that returns a gexp, which is
24933 a code snippet to run at ``activation time''---e.g., when the service is
24937 A service of this type is instantiated like this:
24940 (service guix-service-type
24941 (guix-configuration
24943 (use-substitutes? #f)))
24946 The second argument to the @code{service} form is a value representing
24947 the parameters of this specific service instance.
24948 @xref{guix-configuration-type, @code{guix-configuration}}, for
24949 information about the @code{guix-configuration} data type. When the
24950 value is omitted, the default value specified by
24951 @code{guix-service-type} is used:
24954 (service guix-service-type)
24957 @code{guix-service-type} is quite simple because it extends other
24958 services but is not extensible itself.
24960 @c @subsubsubsection Extensible Service Types
24962 The service type for an @emph{extensible} service looks like this:
24965 (define udev-service-type
24966 (service-type (name 'udev)
24968 (list (service-extension shepherd-root-service-type
24969 udev-shepherd-service)))
24971 (compose concatenate) ;concatenate the list of rules
24972 (extend (lambda (config rules)
24974 (($ <udev-configuration> udev initial-rules)
24975 (udev-configuration
24976 (udev udev) ;the udev package to use
24977 (rules (append initial-rules rules)))))))))
24980 This is the service type for the
24981 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24982 management daemon}. Compared to the previous example, in addition to an
24983 extension of @code{shepherd-root-service-type}, we see two new fields:
24987 This is the procedure to @dfn{compose} the list of extensions to
24988 services of this type.
24990 Services can extend the udev service by passing it lists of rules; we
24991 compose those extensions simply by concatenating them.
24994 This procedure defines how the value of the service is @dfn{extended} with
24995 the composition of the extensions.
24997 Udev extensions are composed into a list of rules, but the udev service
24998 value is itself a @code{<udev-configuration>} record. So here, we
24999 extend that record by appending the list of rules it contains to the
25000 list of contributed rules.
25003 This is a string giving an overview of the service type. The string can
25004 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25005 @command{guix system search} command searches these strings and displays
25006 them (@pxref{Invoking guix system}).
25009 There can be only one instance of an extensible service type such as
25010 @code{udev-service-type}. If there were more, the
25011 @code{service-extension} specifications would be ambiguous.
25013 Still here? The next section provides a reference of the programming
25014 interface for services.
25016 @node Service Reference
25017 @subsection Service Reference
25019 We have seen an overview of service types (@pxref{Service Types and
25020 Services}). This section provides a reference on how to manipulate
25021 services and service types. This interface is provided by the
25022 @code{(gnu services)} module.
25024 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25025 Return a new service of @var{type}, a @code{<service-type>} object (see
25026 below.) @var{value} can be any object; it represents the parameters of
25027 this particular service instance.
25029 When @var{value} is omitted, the default value specified by @var{type}
25030 is used; if @var{type} does not specify a default value, an error is
25033 For instance, this:
25036 (service openssh-service-type)
25040 is equivalent to this:
25043 (service openssh-service-type
25044 (openssh-configuration))
25047 In both cases the result is an instance of @code{openssh-service-type}
25048 with the default configuration.
25051 @deffn {Scheme Procedure} service? @var{obj}
25052 Return true if @var{obj} is a service.
25055 @deffn {Scheme Procedure} service-kind @var{service}
25056 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25059 @deffn {Scheme Procedure} service-value @var{service}
25060 Return the value associated with @var{service}. It represents its
25064 Here is an example of how a service is created and manipulated:
25068 (service nginx-service-type
25069 (nginx-configuration
25071 (log-directory log-directory)
25072 (run-directory run-directory)
25073 (file config-file))))
25078 (eq? (service-kind s) nginx-service-type)
25082 The @code{modify-services} form provides a handy way to change the
25083 parameters of some of the services of a list such as
25084 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25085 evaluates to a list of services. Of course, you could always use
25086 standard list combinators such as @code{map} and @code{fold} to do that
25087 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25088 @code{modify-services} simply provides a more concise form for this
25091 @deffn {Scheme Syntax} modify-services @var{services} @
25092 (@var{type} @var{variable} => @var{body}) @dots{}
25094 Modify the services listed in @var{services} according to the given
25095 clauses. Each clause has the form:
25098 (@var{type} @var{variable} => @var{body})
25101 where @var{type} is a service type---e.g.,
25102 @code{guix-service-type}---and @var{variable} is an identifier that is
25103 bound within the @var{body} to the service parameters---e.g., a
25104 @code{guix-configuration} instance---of the original service of that
25107 The @var{body} should evaluate to the new service parameters, which will
25108 be used to configure the new service. This new service will replace the
25109 original in the resulting list. Because a service's service parameters
25110 are created using @code{define-record-type*}, you can write a succinct
25111 @var{body} that evaluates to the new service parameters by using the
25112 @code{inherit} feature that @code{define-record-type*} provides.
25114 @xref{Using the Configuration System}, for example usage.
25118 Next comes the programming interface for service types. This is
25119 something you want to know when writing new service definitions, but not
25120 necessarily when simply looking for ways to customize your
25121 @code{operating-system} declaration.
25123 @deftp {Data Type} service-type
25124 @cindex service type
25125 This is the representation of a @dfn{service type} (@pxref{Service Types
25130 This is a symbol, used only to simplify inspection and debugging.
25132 @item @code{extensions}
25133 A non-empty list of @code{<service-extension>} objects (see below).
25135 @item @code{compose} (default: @code{#f})
25136 If this is @code{#f}, then the service type denotes services that cannot
25137 be extended---i.e., services that do not receive ``values'' from other
25140 Otherwise, it must be a one-argument procedure. The procedure is called
25141 by @code{fold-services} and is passed a list of values collected from
25142 extensions. It may return any single value.
25144 @item @code{extend} (default: @code{#f})
25145 If this is @code{#f}, services of this type cannot be extended.
25147 Otherwise, it must be a two-argument procedure: @code{fold-services}
25148 calls it, passing it the initial value of the service as the first
25149 argument and the result of applying @code{compose} to the extension
25150 values as the second argument. It must return a value that is a valid
25151 parameter value for the service instance.
25154 @xref{Service Types and Services}, for examples.
25157 @deffn {Scheme Procedure} service-extension @var{target-type} @
25159 Return a new extension for services of type @var{target-type}.
25160 @var{compute} must be a one-argument procedure: @code{fold-services}
25161 calls it, passing it the value associated with the service that provides
25162 the extension; it must return a valid value for the target service.
25165 @deffn {Scheme Procedure} service-extension? @var{obj}
25166 Return true if @var{obj} is a service extension.
25169 Occasionally, you might want to simply extend an existing service. This
25170 involves creating a new service type and specifying the extension of
25171 interest, which can be verbose; the @code{simple-service} procedure
25172 provides a shorthand for this.
25174 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25175 Return a service that extends @var{target} with @var{value}. This works
25176 by creating a singleton service type @var{name}, of which the returned
25177 service is an instance.
25179 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25183 (simple-service 'my-mcron-job mcron-service-type
25184 #~(job '(next-hour (3)) "guix gc -F 2G"))
25188 At the core of the service abstraction lies the @code{fold-services}
25189 procedure, which is responsible for ``compiling'' a list of services
25190 down to a single directory that contains everything needed to boot and
25191 run the system---the directory shown by the @command{guix system build}
25192 command (@pxref{Invoking guix system}). In essence, it propagates
25193 service extensions down the service graph, updating each node parameters
25194 on the way, until it reaches the root node.
25196 @deffn {Scheme Procedure} fold-services @var{services} @
25197 [#:target-type @var{system-service-type}]
25198 Fold @var{services} by propagating their extensions down to the root of
25199 type @var{target-type}; return the root service adjusted accordingly.
25202 Lastly, the @code{(gnu services)} module also defines several essential
25203 service types, some of which are listed below.
25205 @defvr {Scheme Variable} system-service-type
25206 This is the root of the service graph. It produces the system directory
25207 as returned by the @command{guix system build} command.
25210 @defvr {Scheme Variable} boot-service-type
25211 The type of the ``boot service'', which produces the @dfn{boot script}.
25212 The boot script is what the initial RAM disk runs when booting.
25215 @defvr {Scheme Variable} etc-service-type
25216 The type of the @file{/etc} service. This service is used to create
25217 files under @file{/etc} and can be extended by
25218 passing it name/file tuples such as:
25221 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25224 In this example, the effect would be to add an @file{/etc/issue} file
25225 pointing to the given file.
25228 @defvr {Scheme Variable} setuid-program-service-type
25229 Type for the ``setuid-program service''. This service collects lists of
25230 executable file names, passed as gexps, and adds them to the set of
25231 setuid-root programs on the system (@pxref{Setuid Programs}).
25234 @defvr {Scheme Variable} profile-service-type
25235 Type of the service that populates the @dfn{system profile}---i.e., the
25236 programs under @file{/run/current-system/profile}. Other services can
25237 extend it by passing it lists of packages to add to the system profile.
25241 @node Shepherd Services
25242 @subsection Shepherd Services
25244 @cindex shepherd services
25246 @cindex init system
25247 The @code{(gnu services shepherd)} module provides a way to define
25248 services managed by the GNU@tie{}Shepherd, which is the
25249 initialization system---the first process that is started when the
25250 system boots, also known as PID@tie{}1
25251 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25253 Services in the Shepherd can depend on each other. For instance, the
25254 SSH daemon may need to be started after the syslog daemon has been
25255 started, which in turn can only happen once all the file systems have
25256 been mounted. The simple operating system defined earlier (@pxref{Using
25257 the Configuration System}) results in a service graph like this:
25259 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25261 You can actually generate such a graph for any operating system
25262 definition using the @command{guix system shepherd-graph} command
25263 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25265 The @code{%shepherd-root-service} is a service object representing
25266 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25267 by passing it lists of @code{<shepherd-service>} objects.
25269 @deftp {Data Type} shepherd-service
25270 The data type representing a service managed by the Shepherd.
25273 @item @code{provision}
25274 This is a list of symbols denoting what the service provides.
25276 These are the names that may be passed to @command{herd start},
25277 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25278 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25279 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25281 @item @code{requirements} (default: @code{'()})
25282 List of symbols denoting the Shepherd services this one depends on.
25284 @cindex one-shot services, for the Shepherd
25285 @item @code{one-shot?} (default: @code{#f})
25286 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25287 after their @code{start} action has completed. @xref{Slots of services,,,
25288 shepherd, The GNU Shepherd Manual}, for more info.
25290 @item @code{respawn?} (default: @code{#t})
25291 Whether to restart the service when it stops, for instance when the
25292 underlying process dies.
25295 @itemx @code{stop} (default: @code{#~(const #f)})
25296 The @code{start} and @code{stop} fields refer to the Shepherd's
25297 facilities to start and stop processes (@pxref{Service De- and
25298 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25299 G-expressions that get expanded in the Shepherd configuration file
25300 (@pxref{G-Expressions}).
25302 @item @code{actions} (default: @code{'()})
25303 @cindex actions, of Shepherd services
25304 This is a list of @code{shepherd-action} objects (see below) defining
25305 @dfn{actions} supported by the service, in addition to the standard
25306 @code{start} and @code{stop} actions. Actions listed here become available as
25307 @command{herd} sub-commands:
25310 herd @var{action} @var{service} [@var{arguments}@dots{}]
25313 @item @code{documentation}
25314 A documentation string, as shown when running:
25317 herd doc @var{service-name}
25320 where @var{service-name} is one of the symbols in @code{provision}
25321 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25323 @item @code{modules} (default: @code{%default-modules})
25324 This is the list of modules that must be in scope when @code{start} and
25325 @code{stop} are evaluated.
25330 @deftp {Data Type} shepherd-action
25331 This is the data type that defines additional actions implemented by a
25332 Shepherd service (see above).
25336 Symbol naming the action.
25338 @item documentation
25339 This is a documentation string for the action. It can be viewed by running:
25342 herd doc @var{service} action @var{action}
25346 This should be a gexp that evaluates to a procedure of at least one argument,
25347 which is the ``running value'' of the service (@pxref{Slots of services,,,
25348 shepherd, The GNU Shepherd Manual}).
25351 The following example defines an action called @code{say-hello} that kindly
25357 (documentation "Say hi!")
25358 (procedure #~(lambda (running . args)
25359 (format #t "Hello, friend! arguments: ~s\n"
25364 Assuming this action is added to the @code{example} service, then you can do:
25367 # herd say-hello example
25368 Hello, friend! arguments: ()
25369 # herd say-hello example a b c
25370 Hello, friend! arguments: ("a" "b" "c")
25373 This, as you can see, is a fairly sophisticated way to say hello.
25374 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25378 @defvr {Scheme Variable} shepherd-root-service-type
25379 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25381 This is the service type that extensions target when they want to create
25382 shepherd services (@pxref{Service Types and Services}, for an example).
25383 Each extension must pass a list of @code{<shepherd-service>}.
25386 @defvr {Scheme Variable} %shepherd-root-service
25387 This service represents PID@tie{}1.
25391 @node Documentation
25392 @chapter Documentation
25394 @cindex documentation, searching for
25395 @cindex searching for documentation
25396 @cindex Info, documentation format
25398 @cindex manual pages
25399 In most cases packages installed with Guix come with documentation.
25400 There are two main documentation formats: ``Info'', a browseable
25401 hypertext format used for GNU software, and ``manual pages'' (or ``man
25402 pages''), the linear documentation format traditionally found on Unix.
25403 Info manuals are accessed with the @command{info} command or with Emacs,
25404 and man pages are accessed using @command{man}.
25406 You can look for documentation of software installed on your system by
25407 keyword. For example, the following command searches for information
25408 about ``TLS'' in Info manuals:
25412 "(emacs)Network Security" -- STARTTLS
25413 "(emacs)Network Security" -- TLS
25414 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25415 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25420 The command below searches for the same keyword in man pages:
25424 SSL (7) - OpenSSL SSL/TLS library
25425 certtool (1) - GnuTLS certificate tool
25429 These searches are purely local to your computer so you have the
25430 guarantee that documentation you find corresponds to what you have
25431 actually installed, you can access it off-line, and your privacy is
25434 Once you have these results, you can view the relevant documentation by
25438 $ info "(gnutls)Core TLS API"
25448 Info manuals contain sections and indices as well as hyperlinks like
25449 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25450 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25451 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25452 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25453 Introduction}, for an introduction to Info navigation.
25455 @node Installing Debugging Files
25456 @chapter Installing Debugging Files
25458 @cindex debugging files
25459 Program binaries, as produced by the GCC compilers for instance, are
25460 typically written in the ELF format, with a section containing
25461 @dfn{debugging information}. Debugging information is what allows the
25462 debugger, GDB, to map binary code to source code; it is required to
25463 debug a compiled program in good conditions.
25465 The problem with debugging information is that is takes up a fair amount
25466 of disk space. For example, debugging information for the GNU C Library
25467 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25468 debugging info of all the installed programs is usually not an option.
25469 Yet, space savings should not come at the cost of an impediment to
25470 debugging---especially in the GNU system, which should make it easier
25471 for users to exert their computing freedom (@pxref{GNU Distribution}).
25473 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25474 mechanism that allows users to get the best of both worlds: debugging
25475 information can be stripped from the binaries and stored in separate
25476 files. GDB is then able to load debugging information from those files,
25477 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25480 The GNU distribution takes advantage of this by storing debugging
25481 information in the @code{lib/debug} sub-directory of a separate package
25482 output unimaginatively called @code{debug} (@pxref{Packages with
25483 Multiple Outputs}). Users can choose to install the @code{debug} output
25484 of a package when they need it. For instance, the following command
25485 installs the debugging information for the GNU C Library and for GNU
25489 guix install glibc:debug guile:debug
25492 GDB must then be told to look for debug files in the user's profile, by
25493 setting the @code{debug-file-directory} variable (consider setting it
25494 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25498 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25501 From there on, GDB will pick up debugging information from the
25502 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25504 In addition, you will most likely want GDB to be able to show the source
25505 code being debugged. To do that, you will have to unpack the source
25506 code of the package of interest (obtained with @code{guix build
25507 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25508 directory using the @code{directory} command (@pxref{Source Path,
25509 @code{directory},, gdb, Debugging with GDB}).
25511 @c XXX: keep me up-to-date
25512 The @code{debug} output mechanism in Guix is implemented by the
25513 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25514 opt-in---debugging information is available only for the packages
25515 with definitions explicitly declaring a @code{debug} output. This may be
25516 changed to opt-out in the future if our build farm servers can handle
25517 the load. To check whether a package has a @code{debug} output, use
25518 @command{guix package --list-available} (@pxref{Invoking guix package}).
25521 @node Security Updates
25522 @chapter Security Updates
25524 @cindex security updates
25525 @cindex security vulnerabilities
25526 Occasionally, important security vulnerabilities are discovered in software
25527 packages and must be patched. Guix developers try hard to keep track of
25528 known vulnerabilities and to apply fixes as soon as possible in the
25529 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25530 containing only security updates.) The @command{guix lint} tool helps
25531 developers find out about vulnerable versions of software packages in the
25536 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25537 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25538 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25542 @xref{Invoking guix lint}, for more information.
25545 As of version @value{VERSION}, the feature described below is considered
25549 Guix follows a functional
25550 package management discipline (@pxref{Introduction}), which implies
25551 that, when a package is changed, @emph{every package that depends on it}
25552 must be rebuilt. This can significantly slow down the deployment of
25553 fixes in core packages such as libc or Bash, since basically the whole
25554 distribution would need to be rebuilt. Using pre-built binaries helps
25555 (@pxref{Substitutes}), but deployment may still take more time than
25559 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25560 for fast deployment of critical updates without the costs associated
25561 with a whole-distribution rebuild. The idea is to rebuild only the
25562 package that needs to be patched, and then to ``graft'' it onto packages
25563 explicitly installed by the user and that were previously referring to
25564 the original package. The cost of grafting is typically very low, and
25565 order of magnitudes lower than a full rebuild of the dependency chain.
25567 @cindex replacements of packages, for grafts
25568 For instance, suppose a security update needs to be applied to Bash.
25569 Guix developers will provide a package definition for the ``fixed''
25570 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
25571 Packages}). Then, the original package definition is augmented with a
25572 @code{replacement} field pointing to the package containing the bug fix:
25579 (replacement bash-fixed)))
25582 From there on, any package depending directly or indirectly on Bash---as
25583 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25584 gc})---that is installed is automatically ``rewritten'' to refer to
25585 @code{bash-fixed} instead of @code{bash}. This grafting process takes
25586 time proportional to the size of the package, usually less than a
25587 minute for an ``average'' package on a recent machine. Grafting is
25588 recursive: when an indirect dependency requires grafting, then grafting
25589 ``propagates'' up to the package that the user is installing.
25591 Currently, the length of the name and version of the graft and that of
25592 the package it replaces (@code{bash-fixed} and @code{bash} in the example
25593 above) must be equal. This restriction mostly comes from the fact that
25594 grafting works by patching files, including binary files, directly.
25595 Other restrictions may apply: for instance, when adding a graft to a
25596 package providing a shared library, the original shared library and its
25597 replacement must have the same @code{SONAME} and be binary-compatible.
25599 The @option{--no-grafts} command-line option allows you to forcefully
25600 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25604 guix build bash --no-grafts
25608 returns the store file name of the original Bash, whereas:
25615 returns the store file name of the ``fixed'', replacement Bash. This
25616 allows you to distinguish between the two variants of Bash.
25618 To verify which Bash your whole profile refers to, you can run
25619 (@pxref{Invoking guix gc}):
25622 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25626 @dots{} and compare the store file names that you get with those above.
25627 Likewise for a complete Guix system generation:
25630 guix gc -R `guix system build my-config.scm` | grep bash
25633 Lastly, to check which Bash running processes are using, you can use the
25634 @command{lsof} command:
25637 lsof | grep /gnu/store/.*bash
25641 @node Bootstrapping
25642 @chapter Bootstrapping
25644 @c Adapted from the ELS 2013 paper.
25646 @cindex bootstrapping
25648 Bootstrapping in our context refers to how the distribution gets built
25649 ``from nothing''. Remember that the build environment of a derivation
25650 contains nothing but its declared inputs (@pxref{Introduction}). So
25651 there's an obvious chicken-and-egg problem: how does the first package
25652 get built? How does the first compiler get compiled? Note that this is
25653 a question of interest only to the curious hacker, not to the regular
25654 user, so you can shamelessly skip this section if you consider yourself
25655 a ``regular user''.
25657 @cindex bootstrap binaries
25658 The GNU system is primarily made of C code, with libc at its core. The
25659 GNU build system itself assumes the availability of a Bourne shell and
25660 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25661 `grep'. Furthermore, build programs---programs that run
25662 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25663 (@pxref{Derivations}). Consequently, to be able to build anything at
25664 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25665 Binutils, libc, and the other packages mentioned above---the
25666 @dfn{bootstrap binaries}.
25668 These bootstrap binaries are ``taken for granted'', though we can also
25669 re-create them if needed (more on that later).
25671 @unnumberedsec Preparing to Use the Bootstrap Binaries
25673 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25674 @c large image, it's hard to scroll. Oh well.
25675 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25677 The figure above shows the very beginning of the dependency graph of the
25678 distribution, corresponding to the package definitions of the @code{(gnu
25679 packages bootstrap)} module. A similar figure can be generated with
25680 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25683 guix graph -t derivation \
25684 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25688 At this level of detail, things are
25689 slightly complex. First, Guile itself consists of an ELF executable,
25690 along with many source and compiled Scheme files that are dynamically
25691 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25692 tarball shown in this graph. This tarball is part of Guix's ``source''
25693 distribution, and gets inserted into the store with @code{add-to-store}
25694 (@pxref{The Store}).
25696 But how do we write a derivation that unpacks this tarball and adds it
25697 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25698 derivation---the first one that gets built---uses @code{bash} as its
25699 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25700 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25701 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25702 the Guix source distribution, whose sole purpose is to allow the Guile
25703 tarball to be unpacked.
25705 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25706 Guile that can be used to run subsequent build programs. Its first task
25707 is to download tarballs containing the other pre-built binaries---this
25708 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25709 @code{ftp-client.scm} are used for this purpose. The
25710 @code{module-import.drv} derivations import those modules in a directory
25711 in the store, using the original layout. The
25712 @code{module-import-compiled.drv} derivations compile those modules, and
25713 write them in an output directory with the right layout. This
25714 corresponds to the @code{#:modules} argument of
25715 @code{build-expression->derivation} (@pxref{Derivations}).
25717 Finally, the various tarballs are unpacked by the
25718 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25719 etc., at which point we have a working C tool chain.
25722 @unnumberedsec Building the Build Tools
25724 Bootstrapping is complete when we have a full tool chain that does not
25725 depend on the pre-built bootstrap tools discussed above. This
25726 no-dependency requirement is verified by checking whether the files of
25727 the final tool chain contain references to the @file{/gnu/store}
25728 directories of the bootstrap inputs. The process that leads to this
25729 ``final'' tool chain is described by the package definitions found in
25730 the @code{(gnu packages commencement)} module.
25732 The @command{guix graph} command allows us to ``zoom out'' compared to
25733 the graph above, by looking at the level of package objects instead of
25734 individual derivations---remember that a package may translate to
25735 several derivations, typically one derivation to download its source,
25736 one to build the Guile modules it needs, and one to actually build the
25737 package from source. The command:
25740 guix graph -t bag \
25741 -e '(@@@@ (gnu packages commencement)
25742 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25746 produces the dependency graph leading to the ``final'' C
25747 library@footnote{You may notice the @code{glibc-intermediate} label,
25748 suggesting that it is not @emph{quite} final, but as a good
25749 approximation, we will consider it final.}, depicted below.
25751 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25753 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25754 The first tool that gets built with the bootstrap binaries is
25755 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25756 for all the following packages. From there Findutils and Diffutils get
25759 Then come the first-stage Binutils and GCC, built as pseudo cross
25760 tools---i.e., with @code{--target} equal to @code{--host}. They are
25761 used to build libc. Thanks to this cross-build trick, this libc is
25762 guaranteed not to hold any reference to the initial tool chain.
25764 From there the final Binutils and GCC (not shown above) are built.
25766 from the final Binutils, and links programs against the just-built libc.
25767 This tool chain is used to build the other packages used by Guix and by
25768 the GNU Build System: Guile, Bash, Coreutils, etc.
25770 And voilà! At this point we have the complete set of build tools that
25771 the GNU Build System expects. These are in the @code{%final-inputs}
25772 variable of the @code{(gnu packages commencement)} module, and are
25773 implicitly used by any package that uses @code{gnu-build-system}
25774 (@pxref{Build Systems, @code{gnu-build-system}}).
25777 @unnumberedsec Building the Bootstrap Binaries
25779 @cindex bootstrap binaries
25780 Because the final tool chain does not depend on the bootstrap binaries,
25781 those rarely need to be updated. Nevertheless, it is useful to have an
25782 automated way to produce them, should an update occur, and this is what
25783 the @code{(gnu packages make-bootstrap)} module provides.
25785 The following command builds the tarballs containing the bootstrap
25786 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25787 of Coreutils and other basic command-line tools):
25790 guix build bootstrap-tarballs
25793 The generated tarballs are those that should be referred to in the
25794 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25797 Still here? Then perhaps by now you've started to wonder: when do we
25798 reach a fixed point? That is an interesting question! The answer is
25799 unknown, but if you would like to investigate further (and have
25800 significant computational and storage resources to do so), then let us
25803 @unnumberedsec Reducing the Set of Bootstrap Binaries
25805 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25806 of binary code! Why is that a problem? It's a problem because these
25807 big chunks of binary code are practically non-auditable, which makes it
25808 hard to establish what source code produced them. Every unauditable
25809 binary also leaves us vulnerable to compiler backdoors as described by
25810 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25812 This is mitigated by the fact that our bootstrap binaries were generated
25813 from an earlier Guix revision. Nevertheless it lacks the level of
25814 transparency that we get in the rest of the package dependency graph,
25815 where Guix always gives us a source-to-binary mapping. Thus, our goal
25816 is to reduce the set of bootstrap binaries to the bare minimum.
25818 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25819 on-going projects to do that. One of these is about replacing the
25820 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25821 of increasing complexity, which could be built from source starting from
25822 a simple and auditable assembler. Your help is welcome!
25826 @chapter Porting to a New Platform
25828 As discussed above, the GNU distribution is self-contained, and
25829 self-containment is achieved by relying on pre-built ``bootstrap
25830 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25831 operating system kernel, CPU architecture, and application binary
25832 interface (ABI). Thus, to port the distribution to a platform that is
25833 not yet supported, one must build those bootstrap binaries, and update
25834 the @code{(gnu packages bootstrap)} module to use them on that platform.
25836 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25837 When everything goes well, and assuming the GNU tool chain supports the
25838 target platform, this can be as simple as running a command like this
25842 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25845 For this to work, the @code{glibc-dynamic-linker} procedure in
25846 @code{(gnu packages bootstrap)} must be augmented to return the right
25847 file name for libc's dynamic linker on that platform; likewise,
25848 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25849 taught about the new platform.
25851 Once these are built, the @code{(gnu packages bootstrap)} module needs
25852 to be updated to refer to these binaries on the target platform. That
25853 is, the hashes and URLs of the bootstrap tarballs for the new platform
25854 must be added alongside those of the currently supported platforms. The
25855 bootstrap Guile tarball is treated specially: it is expected to be
25856 available locally, and @file{gnu/local.mk} has rules to download it for
25857 the supported architectures; a rule for the new platform must be added
25860 In practice, there may be some complications. First, it may be that the
25861 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25862 above) is not recognized by all the GNU tools. Typically, glibc
25863 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25864 configure flag (see @code{gcc.scm} for examples of how to handle this).
25865 Second, some of the required packages could fail to build for that
25866 platform. Lastly, the generated binaries could be broken for some
25869 @c *********************************************************************
25870 @include contributing.texi
25872 @c *********************************************************************
25873 @node Acknowledgments
25874 @chapter Acknowledgments
25876 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
25877 which was designed and
25878 implemented by Eelco Dolstra, with contributions from other people (see
25879 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25880 management, and promoted unprecedented features, such as transactional
25881 package upgrades and rollbacks, per-user profiles, and referentially
25882 transparent build processes. Without this work, Guix would not exist.
25884 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25885 an inspiration for Guix.
25887 GNU@tie{}Guix itself is a collective work with contributions from a
25888 number of people. See the @file{AUTHORS} file in Guix for more
25889 information on these fine people. The @file{THANKS} file lists people
25890 who have helped by reporting bugs, taking care of the infrastructure,
25891 providing artwork and themes, making suggestions, and more---thank you!
25894 @c *********************************************************************
25895 @node GNU Free Documentation License
25896 @appendix GNU Free Documentation License
25897 @cindex license, GNU Free Documentation License
25898 @include fdl-1.3.texi
25900 @c *********************************************************************
25901 @node Concept Index
25902 @unnumbered Concept Index
25905 @node Programming Index
25906 @unnumbered Programming Index
25907 @syncodeindex tp fn
25908 @syncodeindex vr fn
25913 @c Local Variables:
25914 @c ispell-local-dictionary: "american";